Image display device and video wall having same

Abstract

An image display device and a video wall including the same are disclosed. The image display device includes: a panel including a plurality of light emitting diodes; a driving controller to output a data signals and output a scan signal during each of a plurality of subframe periods, wherein in a first mode, the driving controller is configured to sequentially output a first scan signal to only some scan lines during some subframe periods among the plurality of subframe periods, and to sequentially output a second scan signal to only other scan lines during other subframe periods. Accordingly, it is possible to prevent deterioration of image quality while reducing flicker.

Description

[Technical Field]

[0001] The present disclosure relates to an image display device and a video wall including the same, and more particularly to an image display device capable of preventing deterioration of image quality while reducing flicker, and a video wall including the same.[Background Art]

[0002] An image display device is a device with a display that displays images.

[0003] Meanwhile, various types of displays are used in the image display device, including a liquid crystal display panel, a light emitting diode panel, etc.

[0004] Meanwhile, for a light emitting diode panel-based image display device, an active matrix driving scheme or a passive-matrix driving scheme is used in order to drive the light emitting diode panel.

[0005] When driving the light emitting diode panel-based image display device based on the passive-matrix driving scheme, light emitting diodes are made to emit light or not by using a plurality of subframes.

[0006] However, if no light is emitted for a considerable length of time during a plurality of subframes, flicker occurs when an image is output.

[0007] In order to reduce the flicker, there is a method of increasing the frame rate. However, as the frame rate increases, the pulse width of a scan signal decreases, such that the scan signal is unstable, causing a problem in that image quality is significantly deteriorated when an image is displayed.[Disclosure of Invention][Technical Problem]

[0008] It is an object of the present disclosure to provide an image display device capable of preventing deterioration of image quality while reducing flicker, and a video wall including the same.

[0009] It is another object of the present disclosure to provide an image display device capable of preventing deterioration of image quality while reducing flicker by changing a scan driving method for each mode, and a video wall including the same.

[0010] It is yet another object of the present disclosure to provide an image display device capable of ensuring stable color expression by outputting a data signal corresponding to a light emitting diode, and a video wall including the same.[Technical Solution]

[0011] In accordance with an aspect of the present disclosure, the above and other objects can be accomplished by providing an image display device including: a panel including a plurality of light emitting diodes; a driving controller configured to output a data signal to the plurality of light emitting diodes, and to output a scan signal to the plurality of light emitting diodes during each of a plurality of subframe periods, wherein in a first mode, the driving controller is configured to sequentially output a first scan signal to only some scan lines during some subframe periods among the plurality of subframe periods, and to sequentially output a second scan signal to only other scan lines during other subframe periods among the plurality of subframe periods.

[0012] Meanwhile, in the first mode, the driving controller can be configured to sequentially output the first scan signal to only odd-numbered scan lines during some subframe periods among the plurality of subframe periods, and to sequentially output the second scan signal to only even-numbered scan lines during other subframe periods among the plurality of subframe periods.

[0013] Meanwhile, in the first mode, the driving controller can be configured to sequentially output the first scan signal to only odd-numbered scan lines during a first subframe period among the plurality of subframe periods, and to sequentially output the second scan signal to only even-numbered scan lines during a second subframe period among the plurality of subframe periods.

[0014] Meanwhile, in the first mode, the driving controller can be configured to set a dead time period after ends of even-numbered subframe periods among the plurality of subframe periods, and to control odd-numbered subframe periods to be performed after the dead time period.

[0015] Meanwhile, in a second mode, the driving controller can be configured to sequentially output a third scan signal to a plurality of scan lines during the plurality of subframe periods.

[0016] Meanwhile, the driving controller can be configured to control a pulse width of the third scan signal to be at a first level in the second mode, and to control pulse widths of the first scan signal and the second scan signal to be at the first level in the first mode.

[0017] Meanwhile, the driving controller can be configured to control a number of the plurality of subframe periods in the second mode to be smaller than a number of the plurality of subframe periods in the first mode.

[0018] Meanwhile, the driving controller can be configured to control a frame rate in the first mode to be equal to a frame rate in the second mode.

[0019] Meanwhile, in response to a gray level of a frame, including a plurality of subframes, being less than or equal to a predetermined level, the driving controller can be configured to perform the first mode.

[0020] Meanwhile, in response to a gray level of a frame, including the plurality of subframes, exceeding the predetermined level, the driving controller can be configured to perform the second mode.

[0021] Meanwhile, the driving controller can be configured to sequentially output a scan signal to only some scan lines during each of the plurality of subframe periods in the first mode, and to sequentially output a scan signal to all the scan lines during each of the plurality of subframe periods in the second mode.

[0022] Meanwhile, the driving controller can be configured to alternately output a scan signal during each of the plurality of subframe periods in the first mode, and to sequentially output a scan signal to all the scan lines during each of the plurality of subframe periods in the second mode.

[0023] Meanwhile, the plurality of light emitting diodes can include a red light emitting diode, a green light emitting diode, and a blue light emitting diode, wherein the driving controller is configured to control a level of a data signal supplied to the red light emitting diode to be less than a level of a data signal supplied to the green light emitting diode or the blue light emitting diode.

[0024] The image display device according to an embodiment of the present disclosure can further include a signal processing device configured to output an image signal to the display.

[0025] In accordance with another aspect of the present disclosure, the above and other objects can be accomplished by providing an image display device including: a panel including a plurality of light emitting diodes; a driving controller configured to output a data signal to the plurality of light emitting diodes, and to output a scan signal to the plurality of light emitting diodes during each of a plurality of subframe periods, wherein the driving controller is configured to sequentially output a scan signal to only some scan lines during each of the plurality of subframe periods in a first mode, and to sequentially output a scan signal to all the scan lines during each of the plurality of subframe periods in a second mode.

[0026] Meanwhile, the driving controller can be configured to alternately output the scan signal during each of the plurality of subframe periods in the first mode, and to sequentially output the scan signal to all the scan lines during each of the plurality of subframe periods in the second mode.

[0027] Meanwhile, in the first mode, the driving controller can be configured to sequentially output a first scan signal to only some scan lines during some subframe periods among the plurality of subframe periods and to sequentially output a second scan signal to only other scan lines during other subframe periods among the plurality of subframe periods.

[0028] Meanwhile, in the first mode, the driving controller can be configured to sequentially output the first scan signal to only odd-numbered scan lines during some subframe periods among the plurality of subframe periods and to sequentially output the second scan signal to only even-numbered scan lines during other subframe periods among the plurality of subframe periods.

[0029] In accordance with yet another aspect of the present disclosure, the above and other objects can be accomplished by providing a video wall including a plurality of image display devices, wherein the image display device includes: a panel including a plurality of light emitting diodes; a driving controller configured to output a data signal to the plurality of light emitting diodes, and to output a scan signal to the plurality of light emitting diodes during each of a plurality of subframe periods, wherein in a first mode, the driving controller is configured to sequentially output a first scan signal to only some scan lines during some subframe periods among the plurality of subframe periods, and to sequentially output a second scan signal to only other scan lines during other subframe periods among the plurality of subframe periods.

[0030] In accordance with yet another aspect of the present disclosure, the above and other objects can be accomplished by providing a video wall including a plurality of image display devices, wherein the image display device includes: a panel including a plurality of light emitting diodes; a driving controller configured to output a data signal to the plurality of light emitting diodes, and to output a scan signal to the plurality of light emitting diodes during each of a plurality of subframe periods, wherein the driving controller is configured to sequentially output a scan signal to only some scan lines during each of the plurality of subframe periods in a first mode, and to sequentially output a scan signal to all the scan lines during each of the plurality of subframe periods in a second mode.[Advantageous Effects]

[0031] An image display device according to an embodiment of the present disclosure includes: a panel including a plurality of light emitting diodes; a driving controller configured to output a data signal to the plurality of light emitting diodes, and to output a scan signal to the plurality of light emitting diodes during each of a plurality of subframe periods, wherein in a first mode, the driving controller is configured to sequentially output a first scan signal to only some scan lines during some subframe periods among the plurality of subframe periods, and to sequentially output a second scan signal to only other scan lines during other subframe periods among the plurality of subframe periods. Accordingly, it is possible to prevent deterioration of image quality while reducing flicker. Particularly, it is possible to prevent deterioration of image quality while reducing flicker despite an increase in frame rate.

[0032] Meanwhile, in the first mode, the driving controller can be configured to sequentially output the first scan signal to only odd-numbered scan lines during some subframe periods among the plurality of subframe periods, and to sequentially output the second scan signal to only even-numbered scan lines during other subframe periods among the plurality of subframe periods. Accordingly, it is possible to prevent deterioration of image quality while reducing flicker.

[0033] Meanwhile, in the first mode, the driving controller can be configured to sequentially output the first scan signal to only odd-numbered scan lines during a first subframe period among the plurality of subframe periods, and to sequentially output the second scan signal to only even-numbered scan lines during a second subframe period among the plurality of subframe periods. Accordingly, it is possible to prevent deterioration of image quality while reducing flicker.

[0034] Meanwhile, in the first mode, the driving controller can be configured to set a dead time period after ends of even-numbered subframe periods among the plurality of subframe periods, and to control odd-numbered subframe periods to be performed after the dead time period. Accordingly, it is possible to prevent deterioration of image quality while reducing flicker.

[0035] Meanwhile, in a second mode, the driving controller can be configured to sequentially output a third scan signal to a plurality of scan lines during the plurality of subframe periods. Accordingly, it is possible to prevent deterioration of image quality while reducing flicker by changing a scan driving method for each mode.

[0036] Meanwhile, the driving controller can be configured to control a pulse width of the third scan signal to be at a first level in the second mode, and to control pulse widths of the first scan signal and the second scan signal to be at the first level in the first mode. Accordingly, it is possible to prevent deterioration of image quality while reducing flicker by changing a scan driving method for each mode.

[0037] Meanwhile, the driving controller can be configured to control a number of the plurality of subframe periods in the second mode to be smaller than a number of the plurality of subframe periods in the first mode. Accordingly, it is possible to prevent deterioration of image quality while reducing flicker by changing a scan driving method for each mode.

[0038] Meanwhile, the driving controller can be configured to control a frame rate in the first mode to be equal to a frame rate in the second mode. Accordingly, it is possible to prevent deterioration of image quality while reducing flicker by changing a scan driving method for each mode.

[0039] Meanwhile, in response to a gray level of a frame, including a plurality of subframes, being less than or equal to a predetermined level, the driving controller can be configured to perform the first mode. Accordingly, it is possible to prevent deterioration of image quality while reducing flicker when a gray level is low.

[0040] Meanwhile, in response to a gray level of a frame, including the plurality of subframes, exceeding the predetermined level, the driving controller can be configured to perform the second mode. Accordingly, it is possible to prevent deterioration of image quality while reducing flicker by classifying the modes according to the gray level and changing a scan driving method for each mode.

[0041] Meanwhile, the driving controller can be configured to sequentially output a scan signal to only some scan lines during each of the plurality of subframe periods in the first mode, and to sequentially output a scan signal to all the scan lines during each of the plurality of subframe periods in the second mode. Accordingly, it is possible to prevent deterioration of image quality while reducing flicker by changing a scan driving method for each mode.

[0042] Meanwhile, the driving controller can be configured to alternately output a scan signal during each of the plurality of subframe periods in the first mode, and to sequentially output a scan signal to all the scan lines during each of the plurality of subframe periods in the second mode. Accordingly, it is possible to prevent deterioration of image quality while reducing flicker.

[0043] Meanwhile, the plurality of light emitting diodes can include a red light emitting diode, a green light emitting diode, and a blue light emitting diode, wherein the driving controller is configured to control a level of a data signal supplied to the red light emitting diode to be less than a level of a data signal supplied to the green light emitting diode or the blue light emitting diode. Accordingly, a data signal corresponding to a light emitting diode can be output, and furthermore uniform colors can be achieved.

[0044] The image display device according to an embodiment of the present disclosure can further include a signal processing device configured to output an image signal to the display. Accordingly, a signal-processed image can be displayed.

[0045] An image display device according to another embodiment of the present disclosure includes: a panel including a plurality of light emitting diodes; a driving controller configured to output a data signal to the plurality of light emitting diodes, and to output a scan signal to the plurality of light emitting diodes during each of a plurality of subframe periods, wherein the driving controller is configured to sequentially output a scan signal to only some scan lines during each of the plurality of subframe periods in a first mode, and to sequentially output a scan signal to all the scan lines during each of the plurality of subframe periods in a second mode. Accordingly, it is possible to prevent deterioration of image quality while reducing flicker by changing a scan driving method for each mode.

[0046] Meanwhile, the driving controller can be configured to alternately output the scan signal during each of the plurality of subframe periods in the first mode, and to sequentially output the scan signal to all the scan lines during each of the plurality of subframe periods in the second mode. Accordingly, it is possible to prevent deterioration of image quality while reducing flicker by changing a scan driving method for each mode.

[0047] Meanwhile, in the first mode, the driving controller can be configured to sequentially output a first scan signal to only some scan lines during some subframe periods among the plurality of subframe periods and to sequentially output a second scan signal to only other scan lines during other subframe periods among the plurality of subframe periods. Accordingly, it is possible to prevent deterioration of image quality while reducing flicker.

[0048] Meanwhile, in the first mode, the driving controller can be configured to sequentially output the first scan signal to only odd-numbered scan lines during some subframe periods among the plurality of subframe periods and to sequentially output the second scan signal to only even-numbered scan lines during other subframe periods among the plurality of subframe periods. Accordingly, it is possible to prevent deterioration of image quality while reducing flicker.

[0049] A video wall according to an embodiment of the present disclosure includes a plurality of image display devices, wherein the image display device includes: a panel including a plurality of light emitting diodes; a driving controller configured to output a data signal to the plurality of light emitting diodes, and to output a scan signal to the plurality of light emitting diodes during each of a plurality of subframe periods, wherein in a first mode, the driving controller is configured to sequentially output a first scan signal to only some scan lines during some subframe periods among the plurality of subframe periods, and to sequentially output a second scan signal to only other scan lines during other subframe periods among the plurality of subframe periods. Accordingly, it is possible to prevent deterioration of image quality while reducing flicker.

[0050] A video wall according to another embodiment of the present disclosure includes a plurality of image display devices, wherein the image display device includes: a panel including a plurality of light emitting diodes; a driving controller configured to output a data signal to the plurality of light emitting diodes, and to output a scan signal to the plurality of light emitting diodes during each of a plurality of subframe periods, wherein the driving controller is configured to sequentially output a scan signal to only some scan lines during each of the plurality of subframe periods in a first mode, and to sequentially output a scan signal to all the scan lines during each of the plurality of subframe periods in a second mode. Accordingly, it is possible to prevent deterioration of image quality while reducing flicker by changing a scan driving method for each mode.[Description of Drawings]

[0051] FIG. 1 is a diagram illustrating a video wall according to an embodiment of the present disclosure; FIG. 2 is an exemplary internal block diagram of the video wall of FIG. 1; FIG. 3 is an exemplary internal block diagram of a signal processing device of FIG. 2; FIG. 4 is an internal block diagram of a display of FIG. 2; FIGS. 5A to 5C are diagrams referred to in the description of a light emitting diode panel of FIG. 4; FIG. 6 is a diagram illustrating an example of the light emitting diode panel of FIG. 4; FIGS. 7A to 7E are diagrams referred to in the description of the operation of an image display device related to the present disclosure; FIG. 8 is a flowchart illustrating a method of operating an image display device according to an embodiment of the present disclosure; and FIGS. 9 to 11B are diagrams referred to in the description of FIG. 8. [Best Mode for Carrying Out the Invention]

[0052] Hereinafter, the present disclosure will be described in detail with reference to the accompanying drawings.

[0053] The suffixes "module" and "unit" in elements used in description below are given only in consideration of ease in preparation of the specification and do not have specific meanings or functions. Therefore, the suffixes "module" and "unit" can be used interchangeably.

[0054] FIG. 1 is a diagram illustrating a video wall according to an embodiment of the present disclosure.

[0055] Referring to the drawing, a video wall 10 according to an embodiment of the present disclosure can include a plurality of image display devices 100a to 100d.

[0056] The video wall 10 according to an embodiment of the present disclosure can receive images from a set-top box (not shown), a server (not shown), an internal memory, or the like.

[0057] For example, the video wall 10 can receive an image signal from the set-top box (not shown) through an HDMI terminal.

[0058] In another example, the video wall 10 can receive an image signal from the server (not shown) through a network terminal.

[0059] Meanwhile, the video wall 10 can be installed inside or outside a building.

[0060] For example, the video wall 10 can be provided in public places such as vehicles, bus terminals, railroad stations and airports, in order to provide information such as advertisements, news and notices. In addition, the display device can also be provided near display windows of department stores, shopping malls or markets, for advertisements of specific products.

[0061] In another example, the video wall 10 can be installed on a wall surface in a house.

[0062] The video wall 10 can include a plurality of displays 180a to 180d arranged contiguously.

[0063] Meanwhile, the plurality of displays 180a to 180d can be implemented with any one of various panels. For example, the plurality of displays 180a to 180d can be any one of a liquid crystal display (LCD) panel, an organic light emitting diode (OLED) panel, an inorganic light emitting diode (LED) panel, and the like.

[0064] The following description will be made based on an example in which the plurality of displays 180a to 180d include the inorganic light emitting diode (LED) panel.

[0065] Meanwhile, the inorganic light emitting diode (LED) panel includes light emitting diodes, and is advantageous in that it has a fast response speed and can reproduce colors very well.

[0066] Meanwhile, the plurality of displays 180a to 180d can include a plurality of panels 210a to 210d and bezels Ba to Bd surrounding the panels 210a to 210d, respectively.

[0067] In the drawing, it is illustrated that the video wall 10 includes a plurality of image display devices 100a to 100d including respective displays 180a to 180d.

[0068] Alternatively, for image display of the video wall 10, signal processing devices 170 to 170d provided respectively in the plurality of image display devices 100a to 100d can be used.

[0069] For example, images distributed by the signal processing device 170 can be input into the signal processing devices 170 to 170d provided respectively in the plurality of image display devices 100a to 100d, and images whose image signals are processed by the respective signal processing devices 170 to 170d can be input into the respective displays 180a to 180d, and the respective displays 180a to 180d can display the images.

[0070] Accordingly, a viewer 50 can view the images displayed through the video wall 10 as illustrated in the drawing. Particularly, the viewer can view the images displayed through the plurality of displays 180a to 180d.

[0071] In another example, the video wall 10 can include one signal processing device for commonly controlling the plurality of image display devices 100a to 100d. Accordingly, the common signal processing device can perform signal processing on the displayed image. The processed images can be input to the displays 180a to 180d and the respective displays 180a to 180d can display the images.

[0072] Meanwhile, in the case in which the plurality of displays 180a to 180d include an inorganic light emitting diode panel including light emitting diodes, and the light emitting diodes emit light or not by using a plurality of subframes based on a passive-matrix scheme, flicker can occur when an image is output.

[0073] Particularly, if no light is emitted for a considerable length of time during a plurality of subframes, severe flicker can occur.

[0074] In this regard, the present disclosure adopts a method in which a data signal based on pulse width modulation is output to light emitting diodes at low gray levels, and a data signal based on pulse width modulation is output to the light emitting diodes at gray levels other than the low gray levels. Accordingly, it is possible to prevent deterioration of image quality while reducing flicker, which will be described in detail with reference to FIG. 8 and subsequent figures.

[0075] FIG. 2 is an exemplary internal block diagram of the video wall of FIG. 1.

[0076] Referring to the drawing, the video wall 10 can include a first to fourth image display devices 100a to 100d.

[0077] For convenience of explanation, it is illustrated in the drawing that second to fourth image display devices 100b to 100d include second to fourth displays 180b to 180d, respectively, and second to fourth signal processing devices 170b to 170d, respectively, but can include an external device interface, a network interface, a memory, an image divider, a power supply, an audio output device, etc., unlike the drawing.

[0078] Meanwhile, a first image display device 100a can include an external device interface 130, a network interface 135, a memory 140, a user input interface 150, a signal processing device 170, a signal processing device 170, a first display 180a, a power supply 190, an audio output device 185, and the like.

[0079] The external device interface 130 can serve to transmit or receive data to or from an external device (not shown) connected thereto. To this end, the external device interface 130 can include an A / V input / output (I / O) device (not shown) or a data input / output module (not shown).

[0080] For example, the external device interface 130 can include an HDMI port, an RGB port, a component port, a USB port, a micro SD port, etc.

[0081] The network interface 135 serves as an interface between the image display device 100 and a wired / wireless network such as the Internet. For example, the network interface 135 can receive content or data provided by an Internet or content provider or a network operator over a network.

[0082] The memory 140 can store various programs necessary for the signal processing device 170 to process and control signals, and can also store processed video, audio and data signals.

[0083] Further, the memory 140 can temporarily store a video, audio and / or data signal received from the external device interface 130.

[0084] Meanwhile, the plurality of displays 180a to 180d can be contiguously arranged, can include various display panels such as LCDs, OLEDs, PDPs, etc., and can display predetermined images through the display panels.

[0085] The user input interface 150 transmits a signal input by a user to the signal processing device 170 or transmits a signal received from the signal processing device 170 to the user.

[0086] To this end, the user input interface 150 can include a local key including a power key, a touch panel for inputting user information, etc.

[0087] The signal processing device 170 can divide an input image stored in the memory 140 or an input image received from an external device through the external device interface 130 or the network interface 135 into a plurality of images, for displaying the input image through the plurality of displays 180a to 180d.

[0088] For example, the signal processing device 170 can crop the input image into a plurality of images and scale the images.

[0089] Particularly, the signal processing device 170 can perform cropping and scaling in consideration of the resolution and size of the plurality of displays 180a to 180d.

[0090] Meanwhile, the signal processing device 170 can perform overall control of the video wall 10, and, more particularly, control operation of the units of the video wall 10.

[0091] Meanwhile, the signal processing device 170 can distribute images and send the distributed images to the plurality of signal processing devices 170 to 170d.

[0092] Meanwhile, at least one signal processing device can be provided in order to control the plurality of displays 180a to 180d.

[0093] Meanwhile, in order to control the plurality of displays 180a to 180d, the plurality of signal processing devices 170 to 170d corresponding to the number of the plurality of displays 180a to 180d are illustrated in the drawing.

[0094] The plurality of signal processing devices 170 to 170d can perform a control operation for image display through the plurality of displays 180a to 180d.

[0095] The plurality of signal processing devices 170 to 170d can process an input image signal and send the processed image signal to the plurality of displays 180a to 180d, respectively.

[0096] That is, each of the plurality of signal processing devices 170 to 170d can control the plurality of displays 180a to 180d to output a predetermined image. More specifically, RGB signals corresponding to a video image to be displayed can be output through the plurality of displays 180a to 180d. Thus, the plurality of displays 180a to 180d can display respective images.

[0097] The power supply 190 can receive external or internal power and supply power necessary for operation of the components.

[0098] The power supply 190 supplies power throughout the image display device 100 and, more particularly, supplies power to the plurality of signal processing devices 170 to 170d implemented in the form of a system on chip (SOC), the plurality of displays 180a to 180d for displaying a video, and the audio output device 185 for outputting audio.

[0099] A temperature sensor (not shown) can detect the temperature of the video wall 10.

[0100] The temperature detected by the temperature sensor (not shown) can be input to at least one of the plurality of signal processing devices 170 to 170d, and at least one of the plurality of signal processing devices 170 to 170d can control the operation of a fan driver (not shown) in order to reduce internal heat based on the detected temperature.

[0101] Meanwhile, the image display device 100A according to an embodiment of the present disclosure can include an image receiver 105, a memory 140, a user input interface 150, a sensor part (not shown), a signal processing device 170, a display 180, and an audio output device 185.

[0102] The image receiver 105 can include a tuner 110, a demodulator 120, a network interface 135, and an external device interface 130.

[0103] Meanwhile, unlike the drawing, the image receiver 105 can include only the tuner 110, the demodulator 120, and the external device interface 130. That is, the network interface 135 can not be included.

[0104] The tuner 110 selects an RF broadcast signal corresponding to a channel selected by a user or all prestored channels among radio frequency (RF) broadcast signals received through an antenna (not shown). In addition, the selected RF broadcast signal is converted into an intermediate frequency signal, a baseband image, or an audio signal.

[0105] For example, if the selected RF broadcast signal is a digital broadcast signal, it is converted into a digital IF signal (DIF). If the selected RF broadcast signal is an analog broadcast signal, it is converted into an analog baseband image or audio signal (CVBS / SIF). That is, the tuner 110 can process a digital broadcast signal or an analog broadcast signal. The analog baseband image or audio signal (CVBS / SIF) output from the tuner 110 can be directly input to the signal processing device 170.

[0106] Meanwhile, the tuner 110 can include a plurality of tuners for receiving broadcast signals of a plurality of channels. Alternatively, a single tuner that simultaneously receives broadcast signals of a plurality of channels is also available.

[0107] The demodulator 120 receives the converted digital IF signal DIF from the tuner 110 and performs a demodulation operation.

[0108] The demodulator 120 can perform demodulation and channel decoding and then output a stream signal TS. In this case, the stream signal can be a demultiplexed signal of an image signal, an audio signal, or a data signal.

[0109] The stream signal output from the demodulator 120 can be input to the signal processing device 170. The signal processing device 170 performs demultiplexing, image / audio signal processing, and the like, and then outputs an image to the display 180 and outputs audio to the audio output device 185.

[0110] The external device interface 130 can transmit or receive data with a connected external apparatus (not shown), e.g., a set-top box 50. To this end, the external device interface 130 can include an A / V input and output unit (not shown).

[0111] The external device interface 130 can be connected by wire or wirelessly to an external device such as a digital versatile disk (DVD), a Blu ray, a game equipment, a camera, a camcorder, a computer (note book), and a set-top box, and can perform an input / output operation with an external device.

[0112] The A / V input and output unit can receive image and audio signals from an external device. Meanwhile, a wireless communication unit (not shown) can perform short-range wireless communication with other electronic devices.

[0113] Through the wireless communication unit (not shown), the external device interface 130 can exchange data with an adjacent mobile terminal 600. Particularly, in a mirroring mode, the external device interface 130 can receive device information, executed application information, application image, and the like from the mobile terminal 600.

[0114] The network interface 135 provides an interface for connecting the image display device 100 to a wired / wireless network including the Internet network. For example, the network interface 135 can receive, via the network, content or data provided by the Internet, a content provider, or a network operator.

[0115] Meanwhile, the network interface 135 can include a wireless communication unit (not shown).

[0116] The memory 140 can store a program for each signal processing and control in the controller 170, and can store a signal-processed image, audio, or data signal.

[0117] In addition, the memory 140 can serve to temporarily store image, audio, or data signal input to the external device interface 130. In addition, the memory 140 can store information on a certain broadcast channel through a channel memory function such as a channel map.

[0118] Although FIG. 2 illustrates that the memory 140 is provided separately from the signal processing device 170, the scope of the present invention is not limited thereto. The memory 140 can be included in the signal processing device 170.

[0119] The user input interface 150 transmits a signal input by the user to the controller 170 or transmits a signal from the controller 170 to the user.

[0120] For example, it can transmit / receive a user input signal such as power on / off, channel selection, screen setting, etc., from a remote controller 200, can transfer a user input signal input from a local key (not shown) such as a power key, a channel key, a volume key, a set value, etc., to the signal processing device 170, can transfer a user input signal input from a sensor device (not shown) for sensing a user's gesture to the signal processing device 170, or can transmit a signal from the signal processing device 170 to the sensor device (not shown).

[0121] The signal processing device 170 can demultiplex the input stream through the tuner 110, the demodulator 120, the network interface 135, or the external device interface 130, or can process the demultiplexed signals to generate and output a signal for image or audio output.

[0122] For example, the controller 170 receives a broadcast signal received by the image receiver 105 or an HDMI signal, and perform signal processing based on the received broadcast signal or the HDMI signal to thereby output a signal-processed image signal.

[0123] The image signal processed by the signal processing device 170 is input to the display 180, and can be displayed as an image corresponding to the image signal. In addition, the image signal processed by the signal processing device 170 can be input to the external output device through the external device interface 130.

[0124] The audio signal processed by the signal processing device 170 can be output to the audio output device 185 as an audio signal. In addition, audio signal processed by the signal processing device 170 can be input to the external output device through the external device interface 130.

[0125] Although not illustrated in FIG. 2, the signal processing device 170 can include a demultiplexer, an image processor, and the like. That is, the signal processing device 170 can perform various signal processing operations, and thus can be implemented in the form of a system on chip (SOC), which will be described later with reference to FIG. 3.

[0126] In addition, the signal processing device 170 can control the overall operation of the image display device 100. For example, the signal processing device 170 can control the tuner 110 to control the tuning of the RF broadcast corresponding to the channel selected by the user or the previously stored channel.

[0127] In addition, the signal processing device 170 can control the image display device 100 according to a user command input through the user input interface 150 or an internal program.

[0128] Meanwhile, the signal processing device 170 can control the display 180 to display an image. In this case, the image displayed on the display 180 can be a still image or a moving image, and can be a 2D image or a 3D image.

[0129] Meanwhile, the signal processing device 170 can display a certain object in an image displayed on the display 180. For example, the object can be at least one of a connected web screen (newspaper, magazine, etc.), an electronic program guide (EPG), various menus, a widget, an icon, a still image, a moving image, and a text.

[0130] Meanwhile, the signal processing device 170 can recognize the position of the user based on the image photographed by a photographing device (not shown). For example, the distance (z-axis coordinate) between a user and the image display device 100 can be determined. In addition, the x-axis coordinate and the y-axis coordinate in the display 180 corresponding to a user position can be determined.

[0131] The display 180 generates a driving signal by converting an image signal, a data signal, an OSD signal, a control signal processed by the signal processing device 170, an image signal, a data signal, a control signal, and the like received from the external device interface 130.

[0132] Meanwhile, the display 180 can be configured as a touch screen and used as an input device in addition to an output device.

[0133] The audio output device 185 receives a signal processed by the signal processing device 170 and outputs it as an audio.

[0134] The photographing device (not shown) photographs a user. The photographing device (not shown) can be implemented by a single camera, but is not limited thereto and can be implemented by a plurality of cameras. Image information photographed by the photographing device (not shown) can be input to the signal processing device 170.

[0135] The signal processing device 170 can sense a gesture of the user based on each of the images photographed by the photographing device (not shown), the signals detected from the sensor device (not shown), or a combination thereof.

[0136] The power supply 190 supplies corresponding power throughout the image display device 100. Particularly, the power can be supplied to the signal processing device 170 which can be implemented in the form of a system on chip (SOC), the display 180 for displaying an image, and the audio output device 185 for outputting an audio.

[0137] Specifically, the power supply 190 can include a converter for converting AC power into DC power, and a DC / DC converter for converting the level of the DC power.

[0138] The remote controller 200 transmits the user input to the user input interface 150. To this end, the remote controller 200 can use Bluetooth, a radio frequency (RF) communication, an infrared (IR) communication, an Ultra Wideband (UWB), ZigBee, or the like. In addition, the remote controller 200 can receive the image, audio, or data signal output from the user input interface 150, and display it on the remote controller 200 or output it as an audio.

[0139] Meanwhile, the image display device 100 can be a fixed or mobile digital broadcasting receiver capable of receiving digital broadcasting.

[0140] Meanwhile, the block diagram of the image display device 100 shown in FIG. 3 is a block diagram for an embodiment of the present disclosure. Each component of the block diagram can be integrated, added, or omitted according to a specification of the image display device 100 actually implemented. That is, two or more components can be combined into a single component as needed, or a single component can be divided into two or more components. The function performed in each block is described for the purpose of illustrating embodiments of the present disclosure, and specific operation and apparatus do not limit the scope of the present disclosure.

[0141] FIG. 3 is an exemplary internal block diagram of a signal processing device of FIG. 2.

[0142] Referring to the drawing, the signal processing device 170 according to an embodiment of the present invention can include a demultiplexer 310, an image processor 320, a processor 330, and an audio processor 370. In addition, the signal processing device 170 can further include a data processor (not shown).

[0143] The demultiplexer 310 demultiplexes the input stream. For example, when an MPEG-2 TS is input, it can be demultiplexed into image, audio, and data signal, respectively. Here, the stream signal input to the demultiplexer 310 can be a stream signal output from the tuner 110, the demodulator 120, or the external device interface 130.

[0144] The image processor 320 can perform signal processing on an input image. For example, the image processor 320 can perform image processing on an image signal demultiplexed by the demultiplexer 310.

[0145] To this end, the image processor 320 can include an image decoder 325, a scaler 335, an image quality processor 635, an image encoder (not shown), an OSD processor 340, a frame rate converter 350, a formatter 360, etc.

[0146] The image decoder 325 decodes a demultiplexed image signal, and the scaler 335 performs scaling so that the resolution of the decoded image signal can be output from the display 180.

[0147] The image decoder 325 can include a decoder of various standards. For example, a 3D image decoder for MPEG-2, H.264 decoder, a color image, and a depth image, and a decoder for a plurality of view image can be provided.

[0148] The scaler 335 can scale an input image signal decoded by the image decoder 325 or the like.

[0149] For example, if the size or resolution of an input image signal is small, the scaler 335 can upscale the input image signal, and if the size or resolution of the input image signal is great, the scaler 335 can downscale the input image signal.

[0150] The image quality processor 635 can perform image quality processing on an input image signal decoded by the image decoder 325 or the like.

[0151] For example, the image quality processor 625 can perform noise reduction processing on an input image signal, extend a resolution of high gray level of the input image signal, perform image resolution enhancement, perform high dynamic range (HDR)-based signal processing, change a video frame rate, perform image quality processing appropriate for properties of a panel, especially a light emitting diode panel, etc.

[0152] The OSD processor 340 generates an OSD signal according to a user input or by itself. For example, based on a user input signal, the OSD processor 340 can generate a signal for displaying various information as a graphic or a text on the screen of the display 180. The generated OSD signal can include various data such as a user interface screen of the image display device 100, various menu screens, a widget, and an icon. In addition, the generated OSD signal can include a 2D object or a 3D object.

[0153] In addition, the OSD processor 340 can generate a pointer that can be displayed on the display, based on a pointing signal input from the remote controller 200. In particular, such a pointer can be generated by a pointing controller, and the OSD processor 240 can include the pointing controller (not shown). Obviously, the pointing controller (not shown) can be provided separately from the OSD processor 240.

[0154] The Frame Rate Converter (FRC) 350 can convert a frame rate of the input image. The frame rate converter 350 can output the image as it is without separate frame rate conversion.

[0155] Meanwhile, the formatter 360 can change a format of an input image signal into a format suitable for displaying the image signal on a display and output the image signal in the changed format.

[0156] In particular, the formatter 360 can change a format of an image signal to correspond to a display panel.

[0157] The processor 330 can control the overall operation of the image display device 100 or the signal processing device 170.

[0158] For example, the processor 330 can control the tuner 110 to control the tuning of an RF broadcast corresponding to a channel selected by a user or a previously stored channel.

[0159] In addition, the processor 330 can control the image display device 100 according to a user command input through the user input interface 150 or an internal program.

[0160] In addition, the processor 330 can control data transmission to the network interface 135 or to the external device interface 130.

[0161] In addition, the processor 330 can control the operation of the demultiplexer 310, the image processor 320, and the like in the signal processing device 170.

[0162] Meanwhile, the audio processor 370 in the signal processing device 170 can perform the audio processing of the demultiplexed audio signal. To this end, the audio processor 370 can include various decoders.

[0163] In addition, the audio processor 370 in the signal processing device 170 can process a base, a treble, a volume control, and the like.

[0164] The data processor (not shown) in the signal processing device 170 can perform data processing of the demultiplexed data signal. For example, when the demultiplexed data signal is a coded data signal, it can be decoded. The encoded data signal can be electronic program guide information including broadcast information such as a start time and an end time of a broadcast program broadcasted on each channel.

[0165] Meanwhile, the block diagram of the signal processing device 170 shown in FIG. 4 is a block diagram for an embodiment of the present disclosure. Each component of the block diagram can be integrated, added, or omitted according to a specification of the signal processing device 170 actually implemented.

[0166] In particular, the frame rate converter 350 and the formatter 360 can be provided separately in addition to the image processor 320.

[0167] FIG. 4 is an internal block diagram of a display of FIG. 2.

[0168] Referring to the drawing, the light emitting diode panel-based display 180 can include a light emitting diode panel 210, a first interface 230, a second interface 231, a timing controller 232, a gate driver 234, a data driver 236, a memory 240, a power supply 290, and the like.

[0169] The display 180 receives an image signal Vd, a first DC power V1, and a second DC power V2, and can display a predetermined image based on the image signal Vd.

[0170] Meanwhile, the first interface 230 in the display 180 can receive the image signal Vd and the first DC power V1 from the signal processing device 170.

[0171] Here, the first DC power V1 can be used for the operation of the power supply 290 and the timing controller 232 in the display 180.

[0172] Next, the second interface 231 can receive a second DC power V2 from an external power supply 190. Meanwhile, the second DC power V2 can be input to the data driver 236 in the display 180.

[0173] The timing controller 232 can output a data driving signal Sda and a gate driving signal Sga, based on the image signal Vd.

[0174] For example, when the first interface 230 converts the input image signal Vd and outputs the converted image signal va1, the timing controller 232 can output the data driving signal Sda and the gate driving signal Sga based on the converted image signal va1.

[0175] The timing controller 232 can further receive a control signal, a vertical synchronization signal Vsync, etc., in addition to the video signal Vd from the signal processing device 170.

[0176] In addition to the video signal Vd, based on a control signal, a vertical synchronization signal Vsync, and the like, the timing controller 232 generates a gate driving signal Sga for the operation of the gate driver 234, and a data driving signal Sda for the operation of the data driver 236.

[0177] In this case, when the panel 210 includes a RGB subpixel, the data driving signal Sda can be a data driving signal for driving of RGB subpixel.

[0178] Meanwhile, the timing controller 232 can further output a control signal Cs to the gate driver 234.

[0179] The gate driver 234 and the data driver 236 supply a scan signal and a data signal to the light emitting diode panel 210 through a gate line GL and a data line DL, respectively, according to the gate driving signal Sga and the data driving signal Sda from the timing controller 232. Accordingly, the light emitting diode panel 210 displays a predetermined image.

[0180] Meanwhile, the light emitting diode panel 210 can include a light emitting layer. In order to display an image, a plurality of gate lines GL and data lines DL can be disposed in a matrix form in each pixel corresponding to the light emitting layer.

[0181] Meanwhile, the gate line GL can be called a scan line since a scan signal is input through it.

[0182] Meanwhile, the data driver 236 can output a data signal to the light emitting diode panel 210 based on a second DC power V2 from the second interface 231.

[0183] The power supply 290 can supply various powers to the gate driver 234, the data driver 236, the timing controller 232, and the like.

[0184] Meanwhile, in the drawing, the timing controller 232, the gate driver 234, and the data driver 236 can be implemented as a single integrated circuit IC.

[0185] Accordingly, the timing controller 232, the gate driver 234, and the data driver 236 can be referred to as a driving controller 285.

[0186] FIGS. 5A to 5C are diagrams referred to in the description of a light emitting diode panel of FIG. 4

[0187] First, FIG. 5A is a diagram illustrating a pixel in the light emitting diode panel 210.

[0188] Referring to the drawing, the light emitting diode panel 210 can include a plurality of scan lines Scan 1 to Scan n and a plurality of data lines R1, G1, and B1 to Rm, Gm, and Bm intersecting the scan lines.

[0189] Meanwhile, a pixel (subpixel) is defined in an intersecting area of the scan line and the data line in the light emitting diode panel 210. In the drawing, a pixel including sub-pixels SR1, SG1, and SB1 of RGB is shown.

[0190] Meanwhile, a red light emitting diode, a green light emitting diode, and a blue light emitting diode are disposed in the subpixels SR1, SG1, and SB1 of RGB.

[0191] FIG. 5B illustrates a circuit of any one sub-pixel in the pixel of the light emitting diode panel of FIG. 5A.

[0192] Referring to the drawing, a light emitting sub pixel circuit (CRTm) can be of a passive type, and can include only a light emitting diode LED without a separate switching element.

[0193] As illustrated in the drawing, an anode of the light emitting diode LED can be connected to a data line through which a data signal Vdata is input, and a cathode of the light emitting diode LED can be connected to a scan line through which a scan signal Vscan is input.

[0194] Meanwhile, the light emitting diode can emit light or not using a plurality of subframes based on a passive-matrix scheme.

[0195] FIG. 5C is a diagram illustrating an example of a scan signal and data signals.

[0196] Referring to the drawing, a scan signal Vscan applied to each of a red light emitting diode, a green light emitting diode, and a blue light emitting diode maintains LVb level and then drops to LVa level at a scan timing.

[0197] In this case, the width of the scan signal Vscan can be set to Wa.

[0198] Meanwhile, the red light emitting diode can have higher luminance efficiency than the green light emitting diode and the blue light emitting diode because of the device characteristics.

[0199] In response thereto, the driving controller 285 can be configured to control the level of a data signal supplied to the red light emitting diode to be less than the level of a data signal supplied to the green light emitting diode or the blue light emitting diode.

[0200] In (b) of FIG. 5C, a data signal Vdata is illustrated which maintains LVd level and rises to LVc level in response to a scan timing of the scan signal Vscan.

[0201] In (c) of FIG. 5C, a data signal Vdatam is illustrated which maintains LVd level and rises to LVe level which is higher than LVc level in response to a scan timing of the scan signal Vscan.

[0202] The data signal Vdata of LVc level can be applied to the red light emitting diode, and the data signal Vdatam of LVe level which is higher than LVc level can be applied to the green light emitting diode or the blue light emitting diode.

[0203] Accordingly, a data signal corresponding to a light emitting diode can be output, and furthermore uniform colors can be achieved.

[0204] Meanwhile, the data signal Vdatda in (b) of FIG. 5C or the data signal Vdatam in (c) of FIG. 5C is a data signal based on pulse width modulations, and the luminance of the light emitting diodes changes with variations in duty corresponding to pulse width.

[0205] FIG. 6 is a diagram illustrating an example of the light emitting diode panel of FIG. 4.

[0206] Referring to the drawing, the light emitting diode panel 210 can include a plurality of data lines and a plurality of scan lines.

[0207] In FIG. 6, four data lines Data 1 to Data 4 and four scan lines Scan 1 to Scan 4 are illustrated as an example of the light emitting diode panel 210 for convenience of explanation.

[0208] FIGS. 7A to 7E are diagrams referred to in the description of the operation of an image display device related to the present disclosure.

[0209] First, FIGS. 7A and 7B illustrate a driving waveform when a frame rate is a first frame rate.

[0210] FIG. 7A illustrates an example of data signals and scan signals applied when a frame has a first gray level, during a plurality of subframe periods within a frame period.

[0211] Referring to the drawing, a plurality of subframe periods Subframes 1 and 2 and a dead time period DT can be included within a frame period Frame 1.

[0212] For convenience of explanation, two subframe periods Subframes 1 and 2 within the frame period Frame 1 are illustrated in the drawing, but can be variously modified.

[0213] In (a) of FIG. 7A, it is illustrated that data signals Vdata 1 to 4 are respectively applied to the four data lines illustrated in FIG. 6 during a first subframe period Subframe 1 which is one of the plurality of subframe periods Subframes 1 and 2.

[0214] In the drawing, data signals Vdata 1 to 4 each having four pulses or voltages Vx are respectively applied to four data lines during the first subframe period Subframe 1.

[0215] In this case, the pulse width of the data signals Vdata 1 to 4 can be Wx.

[0216] In (b) of FIG. 7A, it is illustrated that scan signals Vscan 1 to 4 are sequentially applied to four scan lines during the first subframe period Subframe 1.

[0217] Accordingly, sixteen light emitting diodes emit light during the first subframe period Subframe 1 in a first emission mode 712, as illustrated in (c) of FIG. 7A.

[0218] In (a) of FIG. 7A, it is illustrated that data signals Vdata 1 to 4 are respectively applied to the four data lines illustrated in FIG. 6 during a second subframe period Subframe 2.

[0219] In the drawing, data signals Vdata 1 to 4 each having one pulse or voltage Vx are respectively applied to four data lines during the second subframe period Subframe 2.

[0220] In (b) of FIG. 7A, it is illustrated that scan signals Vscan 1 to 4 are sequentially applied to four scan lines during the second subframe period Subframe 2.

[0221] Accordingly, four light emitting diodes in a diagonal direction emit light during the second subframe period Subframe 2 in a second emission mode 714, as illustrated in (c) of FIG. 7A.

[0222] In (a) of FIG. 7A, it is illustrated that the data signals are not applied to the four data lines illustrated in FIG. 6 during the dead time period DT.

[0223] In (b) of FIG. 7A, it is illustrated that the scan signals are not applied to the four scan lines during the dead time period DT.

[0224] Accordingly, all of the sixteen light emitting diodes are turned off and emit no light during the dead time period DT in a non-emission mode 716, as illustrated in (c) of FIG. 7A.

[0225] FIG. 7B illustrates a flicker phenomenon resulting from a scan signal.

[0226] Referring to the drawing, (a) of FIG. 7B illustrates a scan waveform applied to four scan lines corresponding to (b) of FIG. 7A.

[0227] As illustrated in the drawing, scan signals Vscan 1 to 4 are sequentially applied to four scan lines during the first subframe period Subframe 1, scan signals Vscan 1 to 4 are sequentially applied to four scan lines during the second subframe period Subframe 2, and scan signals Vscan 1 to 4 are not applied to four scan lines during the dead time period DT.

[0228] In (b) of FIG. 7B, an area Arb where flicker occurs is included in a displayed image 710.

[0229] Meanwhile, the dead time period DT is disposed between frame periods, and as the dead time period DT increases, a non-emission period during which the light emitting diodes emit no light increases, thereby leading to a more severe flicker phenomenon. In order to reduce the flicker, there is a method of increasing the frame rate.

[0230] FIG. 7C is a diagram explaining the case in which a frame rate is a second frame rate higher than the first frame rate of FIGS. 7A and 7B.

[0231] Specifically, FIG. 7C illustrates an example of data signals and scan signals applied when a frame has a second gray level which is less than the first gray level, during a plurality of subframe periods within a frame period.

[0232] Referring to the drawing, a plurality of subframe periods Subframes 1 to 4 and dead time periods DTa and DTb can be included within a frame period Frame 1.

[0233] In the drawing, a first dead time period DTa is disposed after first and second subframe periods Subframes 1 and 2, and a second dead time period DTb is disposed after third and fourth subframe periods Subframes 3 and 4.

[0234] In this case, the first and second dead time periods DTa and DTb can be less than the dead time period DTb of FIG. 7A. Further, a sum of the first and second dead time periods DTa and DTb can be less than the dead time period DTb of FIG. 7A.

[0235] Meanwhile, for convenience of explanation, four subframe periods Subframes 1 to 4 and two dead time periods DTa and DTb within the frame period Frame 1 are illustrated in the drawing, but can be variously modified.

[0236] In (a) of FIG. 7C, it is illustrated that data signals Vdata 1 to 4 each having four pulses or voltages Vx are respectively applied to the four data lines illustrated in FIG. 6, during the plurality of subframe periods Subframes 1 to 4.

[0237] In this case, the pulse width of the data signals Vdata 1 to 4 can be Wy smaller than Wx, as the frame rate increases compared to FIG. A.

[0238] In (a) of FIG. 7C, it is illustrated that the data signals are not applied to the four data lines illustrated in FIG. 6 during the dead time periods DTa and DTb.

[0239] In (b) of FIG. 7C, it is illustrated that scan signals Vscan 1 to 4 are sequentially applied to the four scan lines illustrated in FIG. 6, during the plurality of subframe periods Subframes 1 to 4.

[0240] Meanwhile, (b) of FIG. 7C illustrates that the scan signals are not applied to the four scan lines during the dead time periods DTa and DTb.

[0241] Accordingly, four light emitting diodes in a diagonal direction emit light during the plurality of subframe periods Subframes 1 to 4 in the second emission mode 714, as illustrated in (c)d of FIG. 7A.

[0242] Meanwhile, the scan signals and the data signals based on the second frame rate of FIG. 7C show that as the frame rate increases compared to FIG. 7A, a non-emission period is reduced.

[0243] Further, the dead time periods DTa and DTb are distributed, such that a non-emission period is reduced compared to FIG. 7A.

[0244] FIG. 7D is a diagram illustrating actual waveforms of the data signal and the scan signal of FIGS. 7A and 7B.

[0245] Referring to the drawing, (a) of FIG. 7D illustrates a data signal Vdatax of FIG. 7A and an actual data waveform Vdrx applied to a data line, and (b) of FIG. 7D illustrates a scan signal Vscanx of FIG. 7A and an actual scan waveform Vsrx applied to a scan line.

[0246] The pulse width of the data signal Vdatax and the scan signal Vscanx in FIG. 7A can be Wx.

[0247] In (c) of FIG. 7D, a data signal Vdatay of FIG. 7C and an actual data waveform Vdry applied to a data line are illustrated, and (d) of FIG. 7D illustrates a scan signal Vscany of FIG. 7C and an actual scan waveform Vsry applied to a scan line.

[0248] The pulse width of the data signal Vdatay and the scan signal Vscany in FIG. 7C can be Wx smaller than Wx.

[0249] In comparison of the actual scan waveform Vsrx applied to the scan line in (b) of FIG. 7D with the actual scan waveform Vsry applied to the scan line in (d) of FIG. 7D, the actual scan waveform Vsry applied to the scan line in (d) of FIG. 7D is distorted more.

[0250] This is because the frame rate is the second frame rate higher than the first frame rate, and as the frame rate increases, the actual scan waveform is distorted more.

[0251] FIG. 7E is a diagram illustrating an actual scan waveform Vsrz corresponding to (b) of FIG. 7C.

[0252] Referring to the drawing, it is illustrated that the scan waveform Vsrz is applied sequentially to the four scan lines illustrated in FIG. 6, during the plurality of subframe periods Subframes 1 to 4.

[0253] Meanwhile, (b) of FIG. 7C illustrates that the scan waveform Vsrz is not applied to each of the four scan lines during the dead time periods DTa and DTb.

[0254] In comparison of an ideal scan signal in (b) of FIG. 7D with the actual scan waveform Vsrz, a pulse area of the actual scan waveform Vsrz is approximately 50% of a pulse area of the ideal scan signal, such that luminous efficiency in the actual light emitting diode can be approximately 50% or less. That is, the luminous efficiency decreases, resulting in a significant deterioration of image quality, as in a certain area 767 of an image 765 in (b) of FIG. 7E.

[0255] This phenomenon becomes severe as the frame rate increases, such that as the frame rate increases, the decrease in luminous efficiency results in a significant deterioration of image quality.

[0256] Accordingly, the present disclosure proposes a method of preventing deterioration of image quality despite an increase in the frame rate, which will be described below with reference to FIG. 8 and subsequent figures.

[0257] FIG. 8 is a flowchart illustrating a method of operating an image display device according to an embodiment of the present disclosure.

[0258] Referring to the drawing, a driving controller 285 in an image display device 100 according to an embodiment of the present disclosure determines whether a first mode is performed (S810), and if so, controls scan signals to be alternately driven (S815).

[0259] Meanwhile, in response to the first mode not being performed in operation 810 (S810), the driving controller 285 in the image display device 100 according to an embodiment of the present disclosure controls scan signals to be sequentially driven in a second mode (S820).

[0260] The first mode can correspond to the case in which a frame has a gray level less than or equal to a predetermined level.

[0261] For example, if a frame has a gray level that is less than or equal to a predetermined level, the driving controller 285 can determine that the gray level is low and can control scan signals to be alternately driven in order to reduce flicker.

[0262] In another example, if a frame has a gray level that exceeds the predetermined level, the driving controller 285 can control low scan signals to be alternately driven.

[0263] Meanwhile, if a total gray level range is 256 gray levels, the driving controller 285 can set a predetermined gray level to 64 gray levels.

[0264] Specifically, if a frame has 30 gray levels, the driving controller 285 can perform the first mode to control the scan signals to be alternately driven.

[0265] Meanwhile, if a frame has 2000 gray levels, the driving controller 285 can perform a second mode to control the scan signals to be sequentially driven.

[0266] Meanwhile, in the first mode, the driving controller 285 sequentially outputs a first scan signal Sca to only some scan lines during some subframe periods among a plurality of subframe periods, and sequentially outputs a second scan signal Scb to only other scan lines during other subframe periods. Accordingly, it is possible to prevent deterioration of image quality while reducing flicker. Particularly, it is possible to prevent deterioration of image quality while reducing flicker, despite an increase in the frame rate.

[0267] Meanwhile, in the first mode, the driving controller 285 can sequentially output the first scan signal Sca to only odd-numbered scan lines during some subframe periods among the plurality of subframe periods, and can sequentially output the second scan signal Scb to only even-numbered scan lines during other subframe periods among the plurality of subframe periods. Accordingly, it is possible to prevent deterioration of image quality while reducing flicker.

[0268] Meanwhile, in the first mode, the driving controller 285 can sequentially output the first scan signal Sca to only the odd-numbered scan lines during a first subframe period among the plurality of subframe periods, and can sequentially output the second scan signal Scb to only the even-numbered scan lines during a second subframe period among the plurality of subframe periods. Accordingly, it is possible to prevent deterioration of image quality while reducing flicker.

[0269] FIGS. 9 to 11B are diagrams referred to in the description of FIG. 8.

[0270] FIG. 9A is a diagram illustrating an example of the first mode and the second mode.

[0271] Referring to the drawing, (a) of FIG. 9A illustrates a scan signal SCc in a second mode, and (b) of FIG. 9A illustrates scan signals SCa and SCb in a first mode.

[0272] In the second mode, the driving controller 285 can sequentially output a third scan signal Scc to a plurality of scan lines during a plurality of subframe periods SF1 to SF4, as illustrated (a) of FIG. 9A.

[0273] Meanwhile, in the first mode, the driving controller 285 can sequentially output the first scan signal Sca only to some scan lines during some subframe periods SF1, SF3, SF5, and SF7 among a plurality of subframe periods SF1 to SF8, and can sequentially output the second scan signal Scb to only other scan lines during other subframe periods SF2, SF4, SF6, and SF8 among the plurality of subframe periods SF1 to SF8.

[0274] Specifically, in the first mode, the driving controller 285 can sequentially output the first scan signal Sca to only the odd-numbered scan lines during some subframe periods SF1, SF3, SF5, and SF7 among a plurality of subframe periods SF1 to SF8, and can sequentially output the second scan signal Scb to only the even-numbered scan lines during other subframe periods SF2, SF4, SF6, and SF8 among the plurality of subframe periods SF1 to SF8.

[0275] For example, in the first mode, the driving controller 285 can sequentially output the first scan signal Sca to only the odd-numbered scan lines during the first subframe period SF1 among the plurality of subframe periods SF1 to SF8, and can sequentially output the second scan signal Scb to only the even-numbered scan lines during the second subframe period SF2 among the plurality of subframe periods SF1 to SF8.

[0276] In the drawing, it is illustrated that the first scan signal Sca is output to a first scan line during a first period of the first subframe period SF1, and the first scan signal Sca is output to a third scan line during a second period after the first period.

[0277] Meanwhile, in the drawing, it is illustrated that the second scan signal Scb is output to a second scan line during a third period of the second subframe period SF2, and the second scan signal Scb is output to a fourth scan line during a fourth period after the third period.

[0278] In comparison of the second mode of (a) of FIG. 9A with the first mode of (b) of FIG. 9A, the second mode can correspond to a sequential scan mode, and the first mode can correspond to an alternate scan mode.

[0279] In the alternate scan mode as the first mode, the scan signals are not applied to all the scan lines in one subfield, but applied to only some scan lines, thus having an advantage in that it is not required to shorten a pulse width of the scan signal even when the frame rate increases.

[0280] For example, the scan signal has a pulse width of wy in the case of a second frame rate as illustrated in (b) of FIG. 7C, but in (b) of FIG. 9A, the scan signal can have a pulse width of Wm which is greater than Wy, in the case of the same second frame rate.

[0281] Specifically, the pulse width of the scan signal in (b) of FIG. 9A can be approximately twice the pulse width Wy.

[0282] That is, in the alternate scan mode as the first mode, even when the frame rate increases twice, alternate scanning is performed by dividing the scan signals in half, such that the pulse width of the scan signals is not shortened but remains the same.

[0283] Accordingly, it is possible to prevent deterioration of image quality despite an increase in the frame rate. As a result, it is possible to prevent deterioration of image quality while reducing flicker.

[0284] Meanwhile, the driving controller 285 can control a pulse width of the third scan signal Scc to be at a first level Wam in the second mode, and can control the pulse widths of the first scan signal Sca and the second scan signal Scb to be at the same first level Wam in the first mode. Accordingly, it is possible to prevent deterioration of image quality while reducing flicker by changing a scan driving method for each mode.

[0285] Meanwhile, unlike the drawing, the pulse width of the scan signal Scc, which is at the first level Wam, can be greater than the pulse widths of the first scan signal Sca and the second scan signal Scb.

[0286] FIG. 9A illustrates an example in which the number of subframes within a frame in the second mode is four, and the number of subframes within a frame in the first mode is eight, which is greater than the number in the first mode.

[0287] Meanwhile, the driving controller 285 can control the number of the plurality of subframes in the second mode to be smaller than the number of the plurality of subframes in the first mode.

[0288] As described above, it is possible to prevent deterioration of image quality while reducing flicker by changing a scan driving method for each mode.

[0289] Meanwhile, the driving controller 285 can control the frame rate in the first mode to be equal to the frame rate in the second mode.

[0290] The frame rate in the second mode of (a) of FIG. 9A can be a second frame rate, and the frame rate in the first mode of (b) of FIG. 9A can be the same second frame rate. Accordingly, it is possible to prevent deterioration of image quality while reducing flicker by changing a scan driving method for each mode.

[0291] Meanwhile, the driving controller 285 can control the frame rate in the first mode to be different from the frame rate in the second mode.

[0292] For example, the driving controller 285 can control the frame rate in the second mode of (a) of FIG. 9A to be the second frame rate, and can control the frame rate in the first mode of (b) of FIG. 9A to be a third frame rate greater than the second frame rate. Accordingly, it is possible to prevent deterioration of image quality while reducing flicker by changing a scan driving method for each mode.

[0293] Meanwhile, even when the frame rate in the first mode is different from the frame rate in the second mode, the driving controller 285 can control the scan signals to have the same pulse width. Accordingly, it is possible to prevent deterioration of image quality while reducing flicker.

[0294] Meanwhile, in response to a gray level of a frame, including a plurality of subframes, being less than or equal to a predetermined level, the driving controller 285 can perform the first mode.

[0295] Meanwhile, in response to a gray level of a frame, including a plurality of subframes, exceeding the predetermined level, the driving controller 285 can perform the second mode.

[0296] Accordingly, it is possible to prevent deterioration of image quality while reducing flicker by classifying the modes according to the gray level and changing a scan driving method for each mode.

[0297] Meanwhile, the driving controller 285 can sequentially output the scan signals to only some scan lines during each of the plurality of subframe periods SF1 to SF8 in the first mode, and can sequentially output the scan signals to all the scan lines during each of the plurality of subframe periods SF1 to SF4 in the second mode. Accordingly, it is possible to prevent deterioration of image quality while reducing flicker by changing a scan driving method for each mode.

[0298] Meanwhile, the driving controller 285 can alternately output the scan signals during each of the plurality of subframe periods SF1 to SF8 in the first mode, and can sequentially output the scan signals to all the scan lines during each of the plurality of subframe periods SF1 to SF4 in the second mode.

[0299] FIG. 9B is a diagram illustrating another example of a first mode and a second mode.

[0300] Referring to the drawing, the first mode and the second mode of FIG. 9B can be similar to the first mode and the second mode of FIG. 9A, with a difference being that a dead time period is set.

[0301] Meanwhile, in the first mode, the driving controller 285 can set a dead time period after the ends of even-numbered subframe periods among the plurality of subframe periods, and can control odd-numbered subframe periods to be performed after the dead time period.

[0302] Meanwhile, in the second mode, the driving controller 285 can set a dead time period after the ends of the even-numbered subframe periods among the plurality of subframe periods, and can control the odd-numbered subframe periods to be performed after the dead time period.

[0303] In (a) of FIG. 9B, it is illustrated that the plurality of subframe periods SF1 to SF4 and dead time periods DTa and DTb are included within a frame period Frame 1.

[0304] Specifically, it is illustrated that a first dead time period DTa is disposed after first and second subframe periods SF1 and SF2, and a second dead time period DTb is disposed after third and fourth subframe periods SF3 and SF4.

[0305] In this case, the first and second dead time periods DTa and DTb can be less than the dead time period DTb of FIG. 7A. Further, a sum of the first and second dead time periods DTa and DTb can be less than the dead time period DTb of FIG. 7A.

[0306] In (b) of FIG. 9B, it is illustrated that the plurality of subframe periods SF1 to SF8 and dead time periods DT1 to DT4 are included within a frame period Frame 1 in the first mode.

[0307] Specifically, it is illustrated that a first dead time period DT1 is disposed after first and second subframe periods SF1 and SF2, a second dead time period DT2 is disposed after third and fourth subframe periods SF3 and SF4, a third dead time period DT3 is disposed after fifth and sixth subframe periods SF5 and SF6, and a fourth dead time period DT4 is disposed after seventh and eighth subframe periods SF7 and SF8.

[0308] In this case, each of the first to fourth dead time periods DT1 to DT4 can be less than each of the first and second dead time periods DTa and DTb in (a) of FIG. 9A. Further, a sum of the first to fourth dead time periods DT1 to DT4 can be less than a sum of the first and second dead time periods DTa and DTb in (a) of FIG. 9A. Accordingly, it is possible to prevent deterioration of image quality while reducing flicker in the second mode.

[0309] FIGS. 10A and 10B are diagrams referred to in the description of a second mode.

[0310] FIG. 10A is a diagram illustrating an example of data signals and scan signals in the second mode.

[0311] Referring to the drawing, a plurality of subframe periods SF1 to SF4 and dead time periods DTa and DTb are included within a frame.

[0312] FIG. 10A(a) illustrates an example of data signals during the plurality of subframe periods SF1 to SF4 within the frame.

[0313] In the drawing, it is illustrated that data signals Vdata 1 to 4 each having four pulses or voltages are respectively applied to four data lines during a first subframe period SF1, and data signals Vdata 1 to 4 each having one pulse or voltage are respectively applied to four data lines during second to fourth subframe periods SF2 to SF4.

[0314] FIG. 10A(b) illustrates an example of scan signals that are sequentially output during a plurality of subframe periods SF1 to SF4 within a frame.

[0315] FIG. 10B illustrates an emission mode in the second mode of FIG. 10A.

[0316] Referring to the drawing, (a) of FIG. 10B illustrates an example in which sixteen light emitting diodes emit light during the first subframe period SF1 in the first emission mode 712, and four light emitting diodes in a diagonal direction emit light during the second to fourth subframe periods SF1 to SF4 in the second emission mode 714.

[0317] The second mode is performed when a gray level of the frame exceeds a predetermined gray level, thereby ensuring stable image quality as shown in an image 1015 of (b) of FIG. 10B.

[0318] FIGS. 11A and 11B are diagrams referred to in the description of a first mode.

[0319] FIG. 11A is a diagram illustrating an example of data signals and scan signals in the first mode.

[0320] Referring to the drawing, a plurality of subframe periods SF1 to SF4 and first and second dead time periods DTa and DTb can be included within a frame.

[0321] FIG. 11A(a) illustrates an example of data signals during the plurality of subframe periods SF1 to SF4 within the frame.

[0322] In the drawing, it is illustrated that data signals Vdata 1 to 4 each having one pulse or voltage are respectively applied to odd-numbered data lines among four data lines during a first subframe period SF1 and a second subframe period SF3, and data signals Vdata 1 to 4 each having one pulse or voltage are respectively applied to even-numbered data lines during the second subframe period SF2 and the fourth subframe period SF4.

[0323] FIG. 11A(b) illustrates an example of scan signals that are alternately output during a plurality of subframe periods SF1 to SF4 within a frame.

[0324] In the drawing, it is illustrated that a first scan signal SCa is applied to the odd-numbered data lines among four data lines during the first subframe period SF1 and the second subframe period SF3, and a second scan signal SCb is respectively applied to the even-numbered data lines during the second subframe period SF2 and the fourth subframe period SF4.

[0325] FIG. 11B is a diagram illustrating an example of a light emitting mode in the first mode of FIG. 11A.

[0326] Referring to the drawing, (a) of FIG. 11B illustrates an example in which two light emitting diodes in a diagonal direction emit light during the first subframe period SF1 and the second subframe period SF3, and two light emitting diodes in a diagonal direction emit light during the second subframe period SF2 and the fourth subframe period SF4.

[0327] The first mode is performed when a gray level of the frame is less than or equal to a predetermined gray level, thereby ensuring stable image quality as shown in an image 1025 in (b) of FIG. 11B.

[0328] While the present disclosure has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that the present disclosure is not limited to those exemplary embodiments and various changes in form and details can be made therein without departing from the scope and spirit of the invention as defined by the appended claims and should not be individually understood from the technical spirit or prospect of the present disclosure.

Claims

1. An image display device comprising: a panel including a plurality of light emitting diodes; a driving controller configured to output a data signal to the plurality of light emitting diodes, and to output a scan signal to the plurality of light emitting diodes during each of a plurality of subframe periods, wherein in a first mode, the driving controller is configured to sequentially output a first scan signal to only some scan lines during some subframe periods among the plurality of subframe periods, and to sequentially output a second scan signal to only other scan lines during other subframe periods among the plurality of subframe periods.

2. The image display device of claim 1, wherein in the first mode, the driving controller is configured to sequentially output the first scan signal to only odd-numbered scan lines during some subframe periods among the plurality of subframe periods, and to sequentially output the second scan signal to only even-numbered scan lines during other subframe periods among the plurality of subframe periods.

3. The image display device of claim 1, wherein in the first mode, the driving controller is configured to sequentially output the first scan signal to only odd-numbered scan lines during a first subframe period among the plurality of subframe periods, and to sequentially output the second scan signal to only even-numbered scan lines during a second subframe period among the plurality of subframe periods.

4. The image display device of claim 3, wherein in the first mode, the driving controller is configured to set a dead time period after ends of even-numbered subframe periods among the plurality of subframe periods, and to control odd-numbered subframe periods to be performed after the dead time period.

5. The image display device of claim 1, wherein in a second mode, the driving controller is configured to sequentially output a third scan signal to a plurality of scan lines during the plurality of subframe periods.

6. The image display device of claim 5, wherein the driving controller is configured to control a pulse width of the third scan signal to be at a first level in the second mode, and to control pulse widths of the first scan signal and the second scan signal to be at the first level in the first mode.

7. The image display device of claim 5, wherein the driving controller is configured to control a number of the plurality of subframe periods in the second mode to be smaller than a number of the plurality of subframe periods in the first mode.

8. The image display device of claim 5, wherein the driving controller is configured to control a frame rate in the first mode to be equal to a frame rate in the second mode.

9. The image display device of claim 1, wherein in response to a gray level of a frame, including a plurality of subframes, being less than or equal to a predetermined level, the driving controller is configured to perform the first mode.

10. The image display device of claim 5, wherein in response to a gray level of a frame, including the plurality of subframes, exceeding the predetermined level, the driving controller is configured to perform the second mode.

11. The image display device of claim 1, wherein the driving controller is configured to sequentially output a scan signal to only some scan lines during each of the plurality of subframe periods in the first mode, and to sequentially output a scan signal to all the scan lines during each of the plurality of subframe periods in the second mode.

12. The image display device of claim 1, wherein the driving controller is configured to alternately output a scan signal during each of the plurality of subframe periods in the first mode, and to sequentially output a scan signal to all the scan lines during each of the plurality of subframe periods in the second mode.

13. The image display device of claim 1, wherein the plurality of light emitting diodes comprise a red light emitting diode, a green light emitting diode, and a blue light emitting diode, wherein the driving controller is configured to control a level of a data signal supplied to the red light emitting diode to be less than a level of a data signal supplied to the green light emitting diode or the blue light emitting diode.

14. The image display device of claim 1, further comprising a signal processing device configured to output an image signal to the display.

15. An image display device comprising: a panel including a plurality of light emitting diodes; a driving controller configured to output a data signal to the plurality of light emitting diodes, and to output a scan signal to the plurality of light emitting diodes during each of a plurality of subframe periods, wherein the driving controller is configured to sequentially output a scan signal to only some scan lines during each of the plurality of subframe periods in a first mode, and to sequentially output a scan signal to all the scan lines during each of the plurality of subframe periods in a second mode.

16. The image display device of claim 15, wherein the driving controller is configured to alternately output the scan signal during each of the plurality of subframe periods in the first mode, and to sequentially output the scan signal to all the scan lines during each of the plurality of subframe periods in the second mode.

17. The image display device of claim 15, wherein in the first mode, the driving controller is configured to sequentially output a first scan signal to only some scan lines during some subframe periods among the plurality of subframe periods and to sequentially output a second scan signal to only other scan lines during other subframe periods among the plurality of subframe periods.

18. The image display device of claim 15, wherein in the first mode, the driving controller is configured to sequentially output the first scan signal to only odd-numbered scan lines during some subframe periods among the plurality of subframe periods and to sequentially output the second scan signal to only even-numbered scan lines during other subframe periods among the plurality of subframe periods.

19. A video wall comprising a plurality of image display devices, wherein the image display device comprises the image display device of any one of claims 1 to 18.

Images