Image display device and video wall including same

Abstract

The present disclosure relates to an image display device and a video wall including same. The image display device according to one embodiment of the present disclosure comprises: a panel including a plurality of light-emitting diodes; and a driving control unit for outputting, to the plurality of light-emitting diodes, a scan signal for each of a plurality of sub-frame periods of time, and outputting a data signal for image display, wherein a signal processing device performs, if the input grayscale of a first pixel is less than a reference grayscale, a first grayscale compensation mode of decreasing the input grayscale of the first pixel, and performs, if the input grayscale of a second pixel with an increase amount lower than the luminance of the first pixel is less than the reference grayscale, a second grayscale compensation mode of increasing the input grayscale of the second pixel so as to control that the increased input grayscale of the second pixel exceeds the reference grayscale. Therefore, luminance uniformity between pixels can be maintained.

Description

Video display device and video wall equipped with the same

[0001] The present disclosure relates to a video display device and a video wall having the same, and more particularly, to a video display device capable of maintaining brightness uniformity between pixels and a video wall having the same.

[0002] A video display device is a device that has a display and displays images.

[0003] Meanwhile, various types of displays are used in video display devices, such as liquid crystal display panels and light-emitting diode panels.

[0004] Meanwhile, in the case of configuring a video display device based on a light-emitting diode panel, an active matrix driving method or a passive matrix driving method is used to drive the light-emitting diode panel.

[0005] When driving a display device based on a light-emitting diode panel based on a passive matrix driving method, a plurality of sub-frames are used to cause the light-emitting diode to emit light or not emit light.

[0006] Meanwhile, depending on the gradation of the video signal, a corresponding data signal is applied during a plurality of sub-frame periods, causing the light-emitting diode to emit light.

[0007] Meanwhile, when using multiple driving drivers to drive multiple light-emitting diodes, there is a problem that brightness uniformity is not maintained depending on the input grayscale.

[0008] Additionally, there is a problem that the luminance is not uniform between adjacent pixels, which breaks the luminance uniformity and further causes flicker.

[0009] The problem of the present disclosure is to provide a video display device capable of maintaining luminance uniformity between pixels and a video wall having the same.

[0010] Another object of the present disclosure is to provide a video display device capable of reducing flicker while maintaining brightness uniformity according to input gradation, and a video wall having the same.

[0011] According to one embodiment of the present disclosure for achieving the above-described problem, an image display device includes a panel having a plurality of light-emitting diodes, and a driving control unit for outputting a scan signal for each of a plurality of sub-frame periods to the plurality of light-emitting diodes and outputting a data signal for image display, and a signal processing device for performing a first grayscale compensation mode for reducing the input grayscale of the first pixel when the input grayscale of the first pixel is less than a reference grayscale, and for performing a second grayscale compensation mode for controlling the input grayscale of the second pixel to increase so that the increased input grayscale of the second pixel exceeds the reference grayscale when the input grayscale of the second pixel having an increase amount that is lower in luminance than the first pixel is less than the reference grayscale.

[0012] Meanwhile, when performing the first grayscale compensation mode, the signal processing device can decrease the input grayscale of the first pixel when the first pixel is lower than the reference grayscale, and increase the input grayscale of the second pixel when the second pixel is lower than the reference grayscale.

[0013] Meanwhile, the signal processing device can control the size of the increase in the input grayscale of the second pixel in the second grayscale compensation mode to be greater than the size of the decrease in the input grayscale of the first pixel in the first grayscale compensation mode.

[0014] Meanwhile, the signal processing device can increase the input grayscale of the second pixel to a second level that exceeds the reference grayscale when the input grayscale of the second pixel is a first level that is less than the reference grayscale.

[0015] Meanwhile, the signal processing device can reduce the input grayscale of the first pixel to a third level that is less than the reference grayscale when the input grayscale of the first pixel is a first level that is less than the reference grayscale.

[0016] Meanwhile, the signal processing device can perform a third grayscale compensation mode that reduces the input grayscale of the first pixel when the input grayscale of the first pixel exceeds the reference grayscale, thereby controlling the input grayscale of the first pixel to be less than the reference grayscale.

[0017] Meanwhile, the signal processing device can reduce the input grayscale of the first pixel to a fifth level that is less than the reference grayscale when the input grayscale of the first pixel is a fourth level that is greater than the reference grayscale.

[0018] Meanwhile, the signal processing device can increase the input grayscale of the second pixel to a sixth level exceeding the reference grayscale when the input grayscale of the second pixel is a fourth level exceeding the reference grayscale.

[0019] Meanwhile, the signal processing device can perform a fourth grayscale compensation mode that increases the input grayscale of the second pixel when the second pixel exceeds the reference grayscale.

[0020] Meanwhile, when performing the fourth grayscale compensation mode, the signal processing device can reduce the input grayscale of the first pixel when the first pixel exceeds the reference grayscale, and control the reduced input grayscale of the first pixel to exceed the reference grayscale.

[0021] Meanwhile, the signal processing device can control the size of the increase in the input grayscale of the second pixel in the fourth grayscale compensation mode to be greater than the size of the decrease in the input grayscale of the first pixel when performing the fourth grayscale compensation mode.

[0022] Meanwhile, the signal processing device can set the grayscale to which grayscale is allocated in each of a plurality of sub-frame periods as a reference grayscale.

[0023] Meanwhile, the signal processing device can control the first grayscale compensation mode to be performed based on the gain of the first pixel or the gain of the second pixel.

[0024] Meanwhile, the signal processing device can control the second grayscale compensation mode to be performed based on the gain of the first pixel or the gain of the second pixel, and the ratio of low grayscale below the reference level and high grayscale above the reference level.

[0025] Meanwhile, the signal processing device can control the third grayscale compensation mode to be performed based on the gain of the first pixel or the gain of the second pixel, and the ratio of low grayscale below the reference level and high grayscale above the reference level.

[0026] Meanwhile, the signal processing device can control the fourth grayscale compensation mode to be performed based on the gain of the first pixel or the gain of the second pixel, and the ratio of low grayscale below the reference level and high grayscale above the reference level.

[0027] According to another embodiment of the present disclosure, an image display device includes a panel having a plurality of light-emitting diodes, and a driving control unit that outputs a scan signal for each of a plurality of sub-frame periods to the plurality of light-emitting diodes and outputs a data signal for image display, and a signal processing device controls the input grayscale of a pixel to increase when the input grayscale of a predetermined pixel is less than a reference grayscale so that the input grayscale of the increased pixel exceeds the reference grayscale.

[0028] Meanwhile, the signal processing device can control the input grayscale of the second pixel to be reduced when the input grayscale of the second pixel exceeds the reference grayscale, so that the reduced input grayscale of the second pixel becomes less than the reference grayscale.

[0029] According to another embodiment of the present disclosure, an image display device includes a panel having a plurality of light-emitting diodes, and a driving control unit that outputs a scan signal for each of a plurality of sub-frame periods to the plurality of light-emitting diodes and outputs a data signal for image display, and a signal processing device that, when an input grayscale of a predetermined pixel exceeds a reference grayscale, reduces the input grayscale of the pixel so that the input grayscale of the reduced pixel becomes less than the reference grayscale.

[0030] According to one embodiment of the present disclosure, a display device includes a panel having a plurality of light-emitting diodes, and a driving control unit that outputs a scan signal for each of a plurality of sub-frame periods to the plurality of light-emitting diodes and outputs a data signal for displaying an image, and a signal processing device that, when an input grayscale of a first pixel is less than a reference grayscale, performs a first grayscale compensation mode that reduces the input grayscale of the first pixel, and, when an input grayscale of a second pixel having an increase amount that is lower in luminance than the first pixel is less than the reference grayscale, performs a second grayscale compensation mode that increases the input grayscale of the second pixel so that the increased input grayscale of the second pixel exceeds the reference grayscale. Accordingly, it is possible to maintain luminance uniformity between pixels. In particular, it is possible to reduce flicker while maintaining luminance uniformity according to the input grayscale.

[0031] Meanwhile, when performing the first grayscale compensation mode, the signal processing device can decrease the input grayscale of the first pixel when the first pixel is below the reference grayscale, and increase the input grayscale of the second pixel when the second pixel is below the reference grayscale. Accordingly, it is possible to maintain luminance uniformity between pixels.

[0032] Meanwhile, the signal processing device can control the size of the increase in the input grayscale of the second pixel in the second grayscale compensation mode to be greater than the size of the decrease in the input grayscale of the first pixel in the first grayscale compensation mode. Accordingly, it is possible to maintain luminance uniformity between pixels.

[0033] Meanwhile, the signal processing device can increase the input grayscale of the second pixel to a second level exceeding the reference grayscale when the input grayscale of the second pixel is a first level lower than the reference grayscale. Accordingly, it is possible to maintain luminance uniformity between pixels.

[0034] Meanwhile, the signal processing device can reduce the input grayscale of the first pixel to a third level that is lower than the reference grayscale when the input grayscale of the first pixel is a first level that is lower than the reference grayscale. Accordingly, it is possible to maintain luminance uniformity between pixels.

[0035] Meanwhile, the signal processing device may perform a third grayscale compensation mode in which, when the input grayscale of the first pixel exceeds the reference grayscale, the input grayscale of the first pixel is reduced so that the input grayscale of the first pixel that is reduced becomes less than the reference grayscale. Accordingly, it is possible to maintain luminance uniformity between pixels.

[0036] Meanwhile, the signal processing device can reduce the input grayscale of the first pixel to a fifth level that is lower than the reference grayscale when the input grayscale of the first pixel is a fourth level that exceeds the reference grayscale. Accordingly, it is possible to maintain luminance uniformity between pixels.

[0037] Meanwhile, the signal processing device can increase the input grayscale of the second pixel to a sixth level exceeding the reference grayscale when the input grayscale of the second pixel is at a fourth level exceeding the reference grayscale. Accordingly, it is possible to maintain luminance uniformity between pixels.

[0038] Meanwhile, the signal processing device can perform a fourth grayscale compensation mode that increases the input grayscale of the second pixel when the second pixel exceeds the reference grayscale. Accordingly, luminance uniformity between pixels can be maintained.

[0039] Meanwhile, when performing the fourth grayscale compensation mode, the signal processing device can reduce the input grayscale of the first pixel if the first pixel exceeds the reference grayscale, and control the reduced input grayscale of the first pixel to exceed the reference grayscale. Accordingly, it is possible to maintain luminance uniformity between pixels.

[0040] Meanwhile, the signal processing device can control the size of the increase in the input grayscale of the second pixel in the fourth grayscale compensation mode to be greater than the size of the decrease in the input grayscale of the first pixel when performing the fourth grayscale compensation mode. Accordingly, it is possible to maintain luminance uniformity between pixels.

[0041] Meanwhile, the signal processing device can set the grayscale to which grayscale is allocated in each of multiple sub-frame periods as a reference grayscale. Accordingly, luminance uniformity between pixels can be maintained.

[0042] Meanwhile, the signal processing device can control the first grayscale compensation mode to be performed based on the gain of the first pixel or the gain of the second pixel. Accordingly, luminance uniformity between pixels can be maintained.

[0043] Meanwhile, the signal processing device can control the second grayscale compensation mode to be performed based on the gain of the first pixel or the gain of the second pixel, and the ratio of low grayscale values ​​below a reference level and high grayscale values ​​above the reference level. Accordingly, it is possible to maintain luminance uniformity between pixels.

[0044] Meanwhile, the signal processing device can control the third grayscale compensation mode to be performed based on the gain of the first pixel or the gain of the second pixel, and the ratio of low grayscale values ​​below a reference level and high grayscale values ​​above a reference level. Accordingly, it is possible to maintain luminance uniformity between pixels.

[0045] Meanwhile, the signal processing device can control the fourth grayscale compensation mode to be performed based on the gain of the first pixel or the gain of the second pixel, and the ratio of low grayscale values ​​below a reference level and high grayscale values ​​above a reference level. Accordingly, it is possible to maintain luminance uniformity between pixels.

[0046] According to another embodiment of the present disclosure, a display device includes a panel having a plurality of light-emitting diodes, and a driving control unit that outputs a scan signal for each of a plurality of sub-frame periods to the plurality of light-emitting diodes and outputs a data signal for displaying an image, and a signal processing device controls, when an input grayscale of a predetermined pixel is less than a reference grayscale, to increase the input grayscale of the pixel so that the input grayscale of the increased pixel exceeds the reference grayscale. Accordingly, it is possible to maintain luminance uniformity between pixels. In particular, it is possible to reduce flicker while maintaining luminance uniformity according to the input grayscale.

[0047] Meanwhile, the signal processing device can control the input grayscale of the second pixel to be reduced when the input grayscale of the second pixel exceeds the reference grayscale, so that the reduced input grayscale of the second pixel becomes less than the reference grayscale.

[0048] According to another embodiment of the present disclosure, an image display device includes a panel having a plurality of light-emitting diodes, and a driving control unit that outputs a scan signal for each of a plurality of sub-frame periods to the plurality of light-emitting diodes and outputs a data signal for image display, and a signal processing device that, when an input grayscale of a predetermined pixel exceeds a reference grayscale, reduces the input grayscale of the pixel so that the input grayscale of the reduced pixel becomes less than the reference grayscale. Accordingly, it is possible to maintain luminance uniformity between pixels. In particular, it is possible to reduce flicker while maintaining luminance uniformity according to the input grayscale.

[0049] FIG. 1 is a diagram illustrating a video wall according to one embodiment of the present disclosure.

[0050] Figure 2 is an example of an internal block diagram of the video wall of Figure 1.

[0051] Figure 3 is an example of an internal block diagram of the signal processing device of Figure 2.

[0052] Figure 4 is an internal block diagram of the display of Figure 2.

[0053] FIGS. 5A to 5C are drawings for reference in the description of the light-emitting panel of FIG. 4.

[0054] Fig. 6 is a drawing illustrating an example of the light-emitting panel of Fig. 4.

[0055] FIGS. 7A to 8C are drawings for reference in explaining the operation of a video display device related to the present disclosure.

[0056] FIGS. 9A to 9C are drawings for reference in explaining the operation of a video display device according to an embodiment of the present disclosure.

[0057] FIGS. 10A and 10B are drawings for reference in explaining the operation of a video display device related to the present disclosure.

[0058] FIG. 11 is a diagram showing the operation of a video display device according to one embodiment of the present disclosure.

[0059] Figures 12 to 14 are drawings referred to in the description of Figure 11.

[0060] Hereinafter, the present disclosure will be described in more detail with reference to the drawings.

[0061] The suffixes "module" and "part" used in the following description are given solely for the convenience of writing this specification and do not impart any particularly significant meaning or role to the components themselves. Therefore, the terms "module" and "part" may be used interchangeably.

[0062] FIG. 1 is a diagram illustrating a video wall according to one embodiment of the present disclosure.

[0063] Referring to the drawing, a video wall (10) according to one embodiment of the present disclosure may include a plurality of image display devices (100a to 100d).

[0064] A video wall (10) according to one embodiment of the present disclosure can receive images from a set-top box (not shown), a server (not shown), or an internal memory.

[0065] For example, the video wall (10) can receive a video signal from a set-top box (not shown) through an HDMI terminal.

[0066] As another example, the video wall (10) can receive a video signal from a server (not shown) through a network terminal.

[0067] Meanwhile, the video wall (10) can be installed inside or outside the building.

[0068] For example, a video wall (10) can be installed in public facilities such as vehicles, terminals, train stations, and airports to provide information such as advertisements, news, and notices. Furthermore, it can be placed around show windows in stores such as department stores, shopping malls, and large marts to advertise specific products.

[0069] As another example, the video wall (10) can be installed and placed on a wall inside a house.

[0070] Such a video wall (10) may be equipped with a plurality of displays (180a to 180d) that are arranged adjacently.

[0071] Meanwhile, the plurality of displays (180a to 180d) may be implemented using any one of various panels. For example, the plurality of displays (180a to 180d) may be any one of a liquid crystal display panel (LCD panel), an organic light-emitting diode (OLED) panel, an inorganic light-emitting panel (LED panel), etc.

[0072] In this disclosure, a plurality of displays (180a to 180d) are described with a focus on having inorganic light-emitting panels (LED panels).

[0073] Meanwhile, the inorganic light-emitting panel (LED panel) contains light-emitting diodes and has the advantages of excellent response speed and color reproduction.

[0074] Meanwhile, a plurality of displays (180a to 180d) may be provided with a plurality of panels (210a to 210d) and bezels (Ba to Bd) surrounding the panels (210a to 210d).

[0075] In the drawing, the video wall (10) is exemplified as having a plurality of video display devices (100a to 100d) each having a display (180a to 180d).

[0076] Alternatively, for displaying images on a video wall (10), a signal processing device (170 to 170d) provided in each of a plurality of image display devices (100a to 100d) may be used.

[0077] For example, an image distributed from a signal processing device (170) is input to a signal processing device (170 to 170d) provided in each of a plurality of image display devices (100a to 100d), and an image signal processed in each of the signal processing devices (170 to 170d) is input to each display (180a to 180d), and each display (180a to 180d) can display the corresponding image.

[0078] Accordingly, the viewer (50) can view the image displayed on the video wall (10), as shown in the drawing. In particular, the viewer can view the image displayed on multiple displays (180a to 180d).

[0079] As another example, the video wall (10) may include a single signal processing device that commonly controls multiple image display devices (100a to 100d). Accordingly, the common signal processing device can perform signal processing on the displayed image. Then, the image signal-processed image is input to each display (180a to 180d), and each display (180a to 180d) can display the corresponding image.

[0080] Meanwhile, when a plurality of displays (180a to 180d) are driven based on a passive matrix method, inorganic light-emitting panels including light-emitting diodes, the light-emitting diodes are made to emit light or not emit light by using a plurality of sub-frames.

[0081] However, when driving multiple light-emitting diodes, the brightness uniformity may be broken depending on the input grayscale.

[0082] Additionally, there is a problem that the luminance is not uniform between adjacent pixels, which breaks the luminance uniformity and further causes flicker.

[0083] Accordingly, in this disclosure, a method for maintaining luminance uniformity between pixels is adopted. This is described in detail with reference to FIG. 11 and below.

[0084] Figure 2 is an example of an internal block diagram of the video wall of Figure 1.

[0085] Referring to the drawing, the video wall (10) may be equipped with first to fourth video display devices (100a to 100d).

[0086] In the drawing, for convenience, the second to fourth image display devices (100b to 100d) are illustrated as having second to fourth displays (180b to 180d) and second to fourth signal processing devices (170b to 170d), respectively; however, alternatively, they may be provided with an external device interface unit, a network interface unit, a memory, an image distribution unit, a power supply unit, an audio output unit, etc.

[0087] Meanwhile, the first image display device (100a) may be equipped with an external device interface unit (130), a network interface unit (135), a memory (140), a user input interface unit (150), a signal processing device (170), a signal processing device (170), a first display (180a), a power supply unit (190), an audio output unit (185), etc.

[0088] The external device interface unit (130) can transmit and receive data with a connected external device (not shown). To this end, the external device interface unit (130) may include an A / V input / output unit (not shown) or a data input / output unit (not shown).

[0089] For example, the external device interface unit (130) may include an HDMI terminal, an RGB terminal, a component terminal, a USB terminal, a micro SD terminal, etc.

[0090] The network interface unit (135) provides an interface for connecting the video display device (100) to a wired / wireless network, including the Internet. For example, the network interface unit (135) can transmit and receive content or data provided by the Internet, a content provider, or a network operator via a network.

[0091] The memory (140) may store a program for each signal processing and control within the signal processing device (170), and may also store a signal-processed image, voice, or data signal.

[0092] Additionally, the memory (140) may also perform a function for temporary storage of image, voice, or data signals input to the external device interface unit (130).

[0093] Meanwhile, multiple displays (180a to 180d) can be arranged adjacent to each other and can be equipped with various display panels such as LCD, OLED, PDP, etc., and can display a predetermined image through the display panels.

[0094] The user input interface unit (150) transmits a signal input by the user to the signal processing device (170) or transmits a signal from the signal processing device (170) to the user.

[0095] To this end, the user input interface unit (150) may be equipped with a local key including a power key, a touch panel for inputting user information, etc.

[0096] The signal processing device (170) can distribute an input image stored in a memory (140), an input image received from an external device through an external device interface unit (130), or a network interface unit (135) into a plurality of images for display on a plurality of displays (180a to 180d).

[0097] For example, the signal processing device (170) can crop an input image into multiple images and perform scaling.

[0098] In particular, the signal processing device (170) can perform cropping, scaling, etc., taking into account the resolution, size, etc. of the plurality of displays (180a to 180d).

[0099] Meanwhile, the signal processing device (170) may perform overall control operations of the video wall (10). Specifically, it may control the operations of each unit within the video wall (10).

[0100] Meanwhile, the signal processing device (170) can distribute the image and transmit the distributed image to a plurality of signal processing devices (170 to 170d).

[0101] Meanwhile, at least one signal processing device may be provided to control multiple displays (180a to 180d).

[0102] Meanwhile, in the drawing, a plurality of signal processing devices (170 to 170d) corresponding to the number of the plurality of displays (180a to 180d) are illustrated to control the plurality of displays (180a to 180d).

[0103] A plurality of signal processing devices (170 to 170d) can perform control operations for displaying images on a plurality of displays (180a to 180d).

[0104] A plurality of signal processing devices (170 to 170d) can perform signal processing on an input image and transmit the processed image signal to a plurality of displays (180a to 180d).

[0105] 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. Specifically, R, G, and B signals corresponding to the video image to be displayed can be output to the plurality of displays (180a to 180d). Accordingly, the plurality of displays (180a to 180d) can display each image.

[0106] The power supply unit (190) can supply power required for the operation of each component by receiving external power or internal power.

[0107] The power supply unit (190) supplies power to the entire image display device (100). In particular, it can supply power to a plurality of signal processing devices (170 to 170d) that can be implemented in the form of a system on chip (SOC), a plurality of displays (180a to 180d) for image display, and an audio output unit (185) for audio output.

[0108] The temperature sensing unit (not shown) can sense the temperature of the video wall (10).

[0109] The temperature detected by the temperature detection unit (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 the fan driving unit (not shown) to reduce internal heat based on the detected temperature.

[0110] Meanwhile, an image display device (100A) according to an embodiment of the present disclosure may include an image receiving unit (105), a memory (140), a user input interface unit (150), a sensor unit (not shown), a signal processing unit (170), a display (180), and an audio output unit (185).

[0111] The video receiving unit (105) may include a tuner unit (110), a demodulation unit (120), a network interface unit (130), and an external device interface unit (130).

[0112] Meanwhile, unlike the drawing, the video receiving unit (105) may include only a tuner unit (110), a demodulator unit (120), and an external device interface unit (130). That is, it may not include a network interface unit (130).

[0113] The tuner unit (110) selects an RF broadcast signal corresponding to a channel selected by the user or all pre-stored channels among RF (Radio Frequency) broadcast signals received through an antenna (not shown). In addition, it converts the selected RF broadcast signal into an intermediate frequency signal or a baseband video or audio signal.

[0114] For example, if the selected RF broadcast signal is a digital broadcast signal, it is converted into a digital IF signal (DIF), and if it is an analog broadcast signal, it is converted into an analog baseband video or audio signal (CVBS / SIF). That is, the tuner unit (110) can process a digital broadcast signal or an analog broadcast signal. The analog baseband video or audio signal (CVBS / SIF) output from the tuner unit (110) can be directly input to the signal processing device (170).

[0115] Meanwhile, the tuner unit (110) may be equipped with multiple tuners to receive broadcast signals of multiple channels. Alternatively, a single tuner that simultaneously receives broadcast signals of multiple channels is also possible.

[0116] The demodulation unit (120) receives the digital IF signal (DIF) converted from the tuner unit (110) and performs a demodulation operation.

[0117] The demodulator (120) can output a stream signal (TS) after performing demodulation and channel decoding. At this time, the stream signal may be a signal in which a video signal, an audio signal, or a data signal is multiplexed.

[0118] 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, etc., and then outputs an image to the display (180) and outputs an audio to the audio output device (185).

[0119] The external device interface unit (130) can transmit or receive data to or from a connected external device (not shown), for example, a set-top box (50). To this end, the external device interface unit (130) may include an A / V input / output unit (not shown).

[0120] The external device interface unit (130) can be connected to external devices such as a DVD (Digital Versatile Disk), Blu-ray, game device, camera, camcorder, computer (laptop), set-top box, etc., via wired / wireless connection, and can also perform input / output operations with the external devices.

[0121] The A / V input / output unit can receive video and audio signals from an external device. Meanwhile, the wireless communication unit (not shown) can perform short-range wireless communication with other electronic devices.

[0122] Through this wireless communication unit (not shown), the external device interface unit (130) can exchange data with an adjacent mobile terminal (600). In particular, the external device interface unit (130) can receive device information, running application information, application images, etc. from the mobile terminal (600) in mirroring mode.

[0123] The network interface unit (135) provides an interface for connecting the video display device (100) to a wired / wireless network, including the Internet. For example, the network interface unit (135) can receive content or data provided by the Internet, a content provider, or a network operator via a network.

[0124] Meanwhile, the network interface unit (135) may include a wireless communication unit (not shown).

[0125] The memory (140) may store a program for each signal processing and control within the signal processing device (170), and may also store a signal-processed image, voice, or data signal.

[0126] In addition, the memory (140) may also perform a function for temporary storage of video, audio, or data signals input to the external device interface unit (130). In addition, the memory (140) may store information about a specific broadcast channel through a channel memory function such as a channel map.

[0127] Although the memory (140) of FIG. 2 illustrates an embodiment in which the memory (140) is provided separately from the signal processing device (170), the scope of the present disclosure is not limited thereto. The memory (140) may be included within the signal processing device (170).

[0128] The user input interface unit (150) transmits a signal input by the user to the signal processing device (170) or transmits a signal from the signal processing device (170) to the user.

[0129] For example, a user input signal such as power on / off, channel selection, screen setting, etc. may be transmitted / received from a remote control device (200), a user input signal input from a local key (not shown) such as a power key, a channel key, a volume key, a setting value, etc. may be transmitted to a signal processing device (170), a user input signal input from a sensor unit (not shown) that senses a user's gesture may be transmitted to the signal processing device (170), or a signal from the signal processing device (170) may be transmitted to a sensor unit (not shown).

[0130] The signal processing device (170) can demultiplex an input stream or process demultiplexed signals through a tuner unit (110), a demodulator unit (120), a network interface unit (135), or an external device interface unit (130) to generate and output a signal for video or audio output.

[0131] For example, the signal processing device (170) can receive a broadcast signal or an HDMI signal received from the image receiving unit (105), perform signal processing based on the received broadcast signal or HDMI signal, and output a signal-processed image signal.

[0132] An image signal processed by a signal processing device (170) may be input to a display (180) and displayed as an image corresponding to the image signal. In addition, an image signal processed by a signal processing device (170) may be input to an external output device through an external device interface unit (130).

[0133] The voice signal processed in the signal processing device (170) can be output as sound to the audio output unit (185). In addition, the voice signal processed in the signal processing device (170) can be input to an external output device through the external device interface unit (130).

[0134] Although not illustrated in FIG. 2, the signal processing device (170) may include a demultiplexing unit, an image processing unit, etc. That is, the signal processing device (170) may perform various signal processing operations and, accordingly, may be implemented in the form of a system on chip (SOC). This will be described later with reference to FIG. 3.

[0135] In addition, the signal processing device (170) can control the overall operation within the video display device (100). For example, the signal processing device (170) can control the tuner unit (110) to select (tune) an RF broadcast corresponding to a channel selected by a user or a pre-stored channel.

[0136] In addition, the signal processing device (170) can control the image display device (100) by a user command or internal program input through the user input interface unit (150).

[0137] Meanwhile, the signal processing device (170) can 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 moving image, and may be a 2D image or a 3D image.

[0138] Meanwhile, the signal processing device (170) can cause a predetermined object to be displayed within 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 EPG (Electronic Program Guide), various menus, widgets, icons, still images, videos, and text.

[0139] Meanwhile, the signal processing device (170) can recognize the user's location based on an image captured from a camera (not shown). For example, the distance (z-axis coordinate) between the user and the image display device (100) can be determined. In addition, the x-axis coordinate and y-axis coordinate within the display (180) corresponding to the user's location can be determined.

[0140] The display (180) generates a driving signal by converting a video signal, data signal, OSD signal, control signal, etc. processed by the signal processing device (170) or a video signal, data signal, control signal, etc. received from the external device interface unit (130).

[0141] Meanwhile, the display (180) is configured as a touch screen and can be used as an input device in addition to an output device.

[0142] The audio output unit (185) receives a signal processed by the signal processing device (170) and outputs it as voice.

[0143] A camera unit (not shown) photographs a user. The camera unit (not shown) may be implemented with a single camera, but is not limited thereto, and may also be implemented with multiple cameras. Image information captured by the camera unit (not shown) may be input to a signal processing device (170).

[0144] The signal processing device (170) can detect the user's gesture based on an image captured from a shooting unit (not shown) or a signal detected from a sensor unit (not shown), or a combination thereof.

[0145] The power supply unit (190) supplies power to the entire image display device (100). In particular, the power supply unit (190) can supply power to a signal processing device (170) that can be implemented in the form of a system on chip (SOC), a display (180) for image display, and an audio output unit (185) for audio output.

[0146] Specifically, the power supply unit (190) may be equipped with a converter that converts AC power into DC power and a dc / dc converter that converts the level of the DC power.

[0147] The remote control device (200) transmits user input to the user input interface unit (150). To this end, the remote control device (200) may use Bluetooth, RF (Radio Frequency) communication, IR (Infrared) communication, UWB (Ultra Wideband), ZigBee, etc. In addition, the remote control device (200) may receive video, audio, or data signals output from the user input interface unit (150) and display or output the same as audio on the remote control device (200).

[0148] Meanwhile, the above-described video display device (100) may be a digital broadcast receiver capable of receiving fixed or mobile digital broadcasts.

[0149] Meanwhile, the block diagram of the image display device (100) illustrated in FIG. 3 is a block diagram for one embodiment of the present disclosure. Each component of the block diagram may be integrated, added, or omitted depending on the specifications of the image display device (100) actually implemented. That is, two or more components may be combined into one component, or one component may be subdivided into two or more components, as needed. In addition, the functions performed by each block are intended to explain the embodiment of the present disclosure, and the specific operations or devices thereof do not limit the scope of the present disclosure.

[0150] Figure 3 is an example of an internal block diagram of the signal processing device of Figure 2.

[0151] Referring to the drawings, a signal processing device (170) according to an embodiment of the present disclosure may include a demultiplexing unit (310), an image processing unit (320), a processor (330), and an audio processing unit (370). In addition, a data processing unit (not shown) may be further included.

[0152] The demultiplexer (310) demultiplexes the input stream. For example, when MPEG-2 TS is input, it can be demultiplexed to separate it into video, audio, and data signals, respectively. Here, the stream signal input to the demultiplexer (310) may be a stream signal output from the tuner (110), the demodulator (120), or the external device interface (130).

[0153] The image processing unit (320) can perform signal processing on an input image. For example, the image processing unit (320) can perform image processing on an image signal demultiplexed from the demultiplexing unit (310).

[0154] To this end, the image processing unit (320) may include an image decoder (325), a scaler (335), an image quality processing unit (635), an image encoder (not shown), an OSD processing unit (340), a frame image rate conversion unit (350), and a formatter (360).

[0155] The video decoder (325) decodes the demultiplexed video signal, and the scaler (335) scales the resolution of the decoded video signal so that it can be output on the display (180).

[0156] The video decoder (325) can be equipped with decoders of various standards. For example, it can be equipped with an MPEG-2, H.264 decoder, a 3D video decoder for color images and depth images, a decoder for multi-view images, etc.

[0157] The scaler (335) can scale an input video signal that has been decoded by a video decoder (325), etc.

[0158] For example, the scaler (335) can upscale when the size or resolution of the input image signal is small, and downscale when the size or resolution of the input image signal is large.

[0159] The image quality processing unit (635) can perform image quality processing on an input image signal for which image decoding has been completed in the image decoder (325), etc.

[0160] For example, the image quality processing unit (635) may perform noise removal processing of an input image signal, expand the resolution of the gradation of an input image signal, perform image resolution enhancement, perform signal processing based on high dynamic range (HDR), vary the frame image rate, or perform image quality processing corresponding to panel characteristics, particularly a light-emitting panel.

[0161] The OSD processing unit (340) generates an OSD signal based on user input or on its own. For example, based on a user input signal, a signal for displaying various information in the form of graphics or text on the screen of the display (180) may be generated. The generated OSD signal may include various data such as the user interface screen of the image display device (100), various menu screens, widgets, and icons. In addition, the generated OSD signal may include a 2D object or a 3D object.

[0162] In addition, the OSD processing unit (340) can generate a pointer that can be displayed on the display based on a pointing signal input from the remote control device (200). In particular, such a pointer can be generated by the pointing control unit, and the OSD processing unit (240) can include such a pointing control unit (not shown). Of course, the pointing control unit (not shown) can also be provided separately rather than being included within the OSD processing unit (240).

[0163] The frame rate converter (FRC) (350) can convert the frame rate of an input video. Meanwhile, the frame rate converter (350) can also output the video as is without a separate frame rate conversion.

[0164] Meanwhile, the formatter (360) can change the format of an input video signal into a video signal for display on a display and output it.

[0165] In particular, the formatter (360) can change the format of the video signal to correspond to the display panel.

[0166] The processor (330) can control the overall operation within the image display device (100) or the signal processing device (170).

[0167] For example, the processor (330) can control the tuner (110) to select (tuning) an RF broadcast corresponding to a channel selected by the user or a pre-stored channel.

[0168] In addition, the processor (330) can control the image display device (100) by a user command or internal program input through the user input interface unit (150).

[0169] Additionally, the processor (330) can perform data transmission control with the network interface unit (135) or the external device interface unit (130).

[0170] Additionally, the processor (330) can control the operation of the demultiplexing unit (310), the image processing unit (320), etc., within the signal processing device (170).

[0171] Meanwhile, the audio processing unit (370) within the signal processing device (170) can perform audio processing of the demultiplexed audio signal. To this end, the audio processing unit (370) can be equipped with various decoders.

[0172] Additionally, the audio processing unit (370) within the signal processing device (170) can process bass, treble, volume control, etc.

[0173] A data processing unit (not shown) within a signal processing device (170) can perform data processing on a demultiplexed data signal. For example, if the demultiplexed data signal is an encoded data signal, it can be decoded. The encoded data signal may be electronic program guide information (EPG) information that includes broadcast information such as the start time and end time of a broadcast program broadcast on each channel.

[0174] Meanwhile, the block diagram of the signal processing device (170) illustrated in FIG. 4 is a block diagram for one embodiment of the present disclosure. Each component of the block diagram may be integrated, added, or omitted depending on the specifications of the signal processing device (170) actually implemented.

[0175] In particular, the frame image rate conversion unit (350) and the formatter (360) may be provided separately from the image processing unit (320).

[0176] Figure 4 is an internal block diagram of the display of Figure 2.

[0177] Referring to the drawing, a display (180) based on a light-emitting panel may include a light-emitting panel (210), a first interface unit (230), a second interface unit (231), a timing controller (232), a gate driver unit (234), a data driver unit (236), a memory (240), a power supply unit (290), etc.

[0178] The display (180) receives a video signal (Vd), a first DC power source (V1), and a second DC power source (V2), and can display a predetermined image based on the video signal (Vd).

[0179] Meanwhile, the first interface unit (230) within the display (180) can receive a video signal (Vd) and a first DC power source (V1) from the signal processing device (170).

[0180] Here, the first DC power supply (V1) can be used for the operation of the power supply (290) and the timing controller (232) within the display (180).

[0181] Next, the second interface unit (231) can receive a second DC power supply (V2) from an external power supply unit (190). Meanwhile, the second DC power supply (V2) can be input to a data drive unit (236) within the display (180).

[0182] The timing controller (232) can output a data driving signal (Sda) and a gate driving signal (Sga) based on a video signal (Vd).

[0183] For example, when the first interface unit (230) converts an input image signal (Vd) and outputs a converted image signal (va1), the timing controller (232) can output a data driving signal (Sda) and a gate driving signal (Sga) based on the converted image signal (va1).

[0184] The timing controller (232) can receive, in addition to the video signal (Vd) from the signal processing device (170), a control signal, a vertical synchronization signal (Vsync), etc.

[0185] In addition, the timing controller (232) can output a gate drive signal (Sga) for the operation of the gate drive unit (234) and a data drive signal (Sda) for the operation of the data drive unit (236) based on a control signal, a vertical synchronization signal (Vsync), etc., in addition to a video signal (Vd).

[0186] The data driving signal (Sda) at this time may be a data driving signal for driving RGB subpixels when the panel (210) has RGB subpixels.

[0187] Meanwhile, the timing controller (232) can further output a control signal (Cs) to the gate driver (234).

[0188] The gate driving unit (234) and the data driving unit (236) supply scan signals and data signals to the light-emitting panel (210) through the gate line (GL) and the data line (DL), respectively, in accordance with the gate driving signal (Sga) and the data driving signal (Sda) from the timing controller (232). Accordingly, the light-emitting panel (210) displays a predetermined image.

[0189] Meanwhile, the light-emitting panel (210) may include a light-emitting layer, and in order to display an image, a plurality of gate lines (GL) and data lines (DL) may be arranged in a matrix form to cross each pixel corresponding to the light-emitting layer.

[0190] Meanwhile, the gate line (GL) may also be called a scan line because a scan signal is input.

[0191] Meanwhile, the data driving unit (236) can output a data signal to the light-emitting panel (210) based on the second direct current power supply (V2) from the second interface unit (231).

[0192] The power supply unit (290) can supply various power sources to the gate driver unit (234), the data driver unit (236), the timing controller (232), etc.

[0193] Meanwhile, the timing controller (232), gate driver (234), and data driver (236) in the drawing can be implemented as a single integrated circuit (IC).

[0194] Accordingly, the timing controller (232), gate driver (234), and data driver (236) may be named a drive control unit (285).

[0195] Meanwhile, the drive control unit (285) may include a buffer (238) that stores frame data.

[0196] In particular, the timing controller (232) in the drive control unit (285) can output a gate drive signal and a data drive signal based on frame data stored in the buffer (238).

[0197] FIGS. 5A to 5C are drawings for reference in the description of the light-emitting panel of FIG. 4.

[0198] First, FIG. 5a is a drawing showing pixels within a light-emitting panel (210).

[0199] Referring to the drawing, the light-emitting panel (210) may have a plurality of scan lines (Scan 1 to Scan n) and a plurality of data lines (R1, G1, B1 to Rm, Gm, Bm) intersecting therewith.

[0200] Meanwhile, a pixel (subpixel) is defined in the intersection area of ​​the scan line and the data line within the light-emitting panel (210). In the drawing, a pixel (Pixel) having RGB subpixels (SR1, SG1, SB1) is illustrated.

[0201] Meanwhile, red light-emitting diodes, green light-emitting diodes, and blue light-emitting diodes are placed in each of the RGB subpixels (SR1, SG1, SB1).

[0202] FIG. 5b illustrates the circuit of one subpixel within a pixel of the light-emitting panel of FIG. 5a.

[0203] Referring to the drawing, the light-emitting sub-pixel circuit (CRTm) may be of a passive type and may only include a light-emitting diode (LED) without a separate switching element.

[0204] As shown in the drawing, the anode of the light emitting diode (LED) is connected to a data line, so that a data signal (Vdata) can be input, and the cathode of the light emitting diode (LED) is connected to a scan line, so that a scan signal (Vscan) can be input.

[0205] Meanwhile, light-emitting diodes can emit light or not, based on multiple sub-frames based on a passive matrix method.

[0206] Figure 5c is a diagram showing examples of scan signals and data signals.

[0207] Referring to the drawing, the scan signal (Vscan) applied to each of the red light-emitting diode, green light-emitting diode, and blue light-emitting diode maintains the LVb level and then drops to the LVa level at the scan timing.

[0208] At this time, the width of the scan signal (Vscan) can be set to Wa.

[0209] Meanwhile, red light-emitting diodes may have higher luminous efficiency than green light-emitting diodes and blue light-emitting diodes due to their device characteristics.

[0210] In response to this, the driving control unit (285) can control the level of the data signal supplied to the red light-emitting diode to be lower than the level of the data signal supplied to the green light-emitting diode or the blue light-emitting diode.

[0211] Figure 5c (b) illustrates a data signal (Vdata) that maintains the level of LVd and then rises to the level of LVc in response to the scan timing of the scan signal (Vscan).

[0212] (c) of Fig. 5c illustrates a data signal (Vdatam) that maintains the level of LVd and then rises to the LVe level, which is higher than the LVc level, in response to the scan timing of the scan signal (Vscan).

[0213] A data signal (Vdata) of LVc level can be applied to a red light-emitting diode, and a data signal (Vdatam) of LVe level higher than the LVc level is preferably applied to a green light-emitting diode or a blue light-emitting diode.

[0214] Accordingly, it is possible to output a data signal corresponding to the light-emitting diode, and further perform uniform color implementation.

[0215] Meanwhile, the data signal (Vdata) of (b) of Fig. 5c or the data signal (Vdatam) of (c) of Fig. 5c is a data signal based on pulse width variation, and the brightness of the light-emitting diode is varied by variation of the duty corresponding to the pulse width.

[0216] Fig. 6 is a drawing illustrating an example of the light-emitting panel of Fig. 4.

[0217] Referring to the drawing, the light-emitting panel (210) may have a plurality of data lines and a plurality of scan lines.

[0218] In Fig. 6, as an example of a light-emitting panel (210), for convenience of explanation, four data lines (Data 1 to Data 4) and four scan lines (Scan 1 to Scan 4) are illustrated.

[0219] FIGS. 7A to 8C are drawings for reference in explaining the operation of a video display device related to the present disclosure.

[0220] FIG. 7a illustrates an example of a data signal applied corresponding to a case where the frame grayscale is the first grayscale during a plurality of sub-frame periods within a frame period.

[0221] Referring to the drawing, a plurality of sub-frame periods (Subframe 1 to 3) may be provided within a frame period (Frame 1).

[0222] For convenience of explanation, the drawing illustrates three subframe periods (Subframe 1 to 3) within a frame period (Frame 1), but various variations are possible.

[0223] (a) of FIG. 7a illustrates that data signals (Vdata 1 to 4) are applied to each of the four data lines illustrated in FIG. 6 during the first subframe (Subframe 1) period among multiple subframe periods (Subframe 1 to 3).

[0224] In the drawing, during the first subframe (Subframe 1) period, data signals (Vdata 1 to 4) each having four pulses or voltages (Vx) on four data lines are illustrated.

[0225] At this time, the pulse width of the data signal (Vdata 1~4) can be Wx.

[0226] Figure 7a (b) illustrates that during the first subframe (Subframe 1), scan signals (Vscan 1 to 4) are sequentially applied to each of the four scan lines.

[0227] Accordingly, during the first subframe (Subframe 1) period, 16 light-emitting diodes emit light, as shown in (c) of Fig. 7a.

[0228] Figure 7a (a) illustrates that during the second subframe (Subframe 2) period, data signals (Vdata 1 to 4) are applied to each of the four data lines illustrated in Figure 6.

[0229] In the drawing, during the second subframe (Subframe 2) period, data signals (Vdata 1 to 4) each having one pulse or voltage (Vx) on four data lines are illustrated.

[0230] Figure 7a (b) illustrates that during the second subframe (Subframe 2) period, scan signals (Vscan 1 to 4) are sequentially applied to each of the four scan lines.

[0231] Accordingly, during the second subframe (Subframe 2) period, four light-emitting diodes in the diagonal direction emit light, as shown in (c) of Fig. 7a.

[0232] Figure 7a (a) illustrates that during the third subframe (Subframe 3) period, data signals (Vdata 1 to 4) are applied to each of the four data lines illustrated in Figure 6.

[0233] In the drawing, during the third subframe (Subframe 3) period, data signals (Vdata 1 to 4) each having one pulse or voltage (Vx) on four data lines are illustrated.

[0234] Figure 7a (b) illustrates that during the third subframe (Subframe 3), scan signals (Vscan 1 to 4) are sequentially applied to each of the four scan lines.

[0235] Accordingly, during the third subframe (Subframe 3), four light-emitting diodes in the diagonal direction emit light, as shown in (c) of Fig. 7a.

[0236] FIG. 7b illustrates an example of a data signal applied in response to a case where the frame grayscale is a second grayscale lower than the first grayscale during a plurality of sub-frame periods within a frame period.

[0237] (a) of FIG. 7b illustrates that data signals (Vdata 1 to 4) are applied to each of the four data lines illustrated in FIG. 6 during the first subframe (Subframe 1) period among multiple subframe periods (Subframe 1 to 3).

[0238] In the drawing, during the first subframe (Subframe 1) period, data signals (Vdata 1 to 4) each having four pulses or voltages (Vx) on four data lines are illustrated.

[0239] At this time, the pulse width of the data signal (Vdata 1~4) can be Wx.

[0240] (b) of Fig. 7b illustrates that scan signals (Vscan 1 to 4) are sequentially applied to each of four scan lines during a period of multiple subframes (Subframe 1 to 3).

[0241] Accordingly, during the first subframe (Subframe 1) period, 16 light-emitting diodes emit light, as shown in (c) of Fig. 7b.

[0242] Meanwhile, (a) of FIG. 7b illustrates that during the second subframe (Subframe 2) period among multiple subframe periods (Subframe 1 to 3), data signals (Vdata 1 to 4) each having one pulse or voltage (Vx) are applied to the four data lines illustrated in FIG. 6, and during the third subframe (Subframe 3) period, no pulse or voltage (Vx) is applied.

[0243] Accordingly, during the second subframe (Subframe 2) period, four light-emitting diodes in the diagonal direction, as shown in (c) of Fig. 7b, emit light, and during the third subframe (Subframe 3) period, all 16 light-emitting diodes are turned off and do not emit light.

[0244] As shown in Fig. 7b, if multiple light-emitting diodes are turned off and do not emit light during some period of multiple subframes (Subframes 1 to 3), a flicker phenomenon may occur.

[0245] FIG. 7c illustrates an example of a data signal applied in response to a case where the frame grayscale is a third grayscale lower than the second grayscale during a plurality of sub-frame periods within a frame period.

[0246] (a) of FIG. 7c illustrates that during the first subframe (Subframe 1) period among multiple subframes (Subframes 1 to 3), data signals (Vdata 1 to 4) each having one pulse or voltage (Vx) are applied to the four data lines illustrated in FIG. 6, and during the second subframe (Subframe 2) period and the third subframe (Subframe 3) period, no pulse or voltage (Vx) is applied.

[0247] Figure 7c (b) illustrates that scan signals (Vscan 1 to 4) are sequentially applied to each of four scan lines during a period of multiple subframes (Subframe 1 to 3).

[0248] Accordingly, during the first subframe (Subframe 1) period, four light-emitting diodes in the diagonal direction, as shown in (c) of Fig. 7c, emit light, and during the second subframe (Subframe 2) period and the third subframe (Subframe 3) period, all 16 light-emitting diodes are turned off and do not emit light.

[0249] As shown in Fig. 7c, when multiple light-emitting diodes are turned off and do not emit light during some period of multiple subframes (Subframes 1 to 3), a flicker phenomenon may occur.

[0250] In particular, in the case of Fig. 7c, the diode non-emission period becomes longer than in Fig. 7b, so the possibility of flicker occurrence increases.

[0251] FIG. 8a illustrates an example of a subframe driving method related to the present disclosure.

[0252] Referring to the drawing, the input grayscale can be varied in steps from 1 to 39.

[0253] In order to express the input grayscale, according to the driving method of the passive matrix, a data signal is output during a plurality of sub-frame periods.

[0254] The driving control unit (285) can output a first data signal (D1x) including an offset signal (OFx) and a first weighted signal (W1x) during the first subframe period (Subframe 1) when the input gray level is 1.

[0255] Meanwhile, the offset signal (OFx) may include multiple step-up signals (Rx) and multiple sustain signals (Sx).

[0256] At this time, the plurality of step-up signals (Rx) may include seven step-up signals that increase stepwise, and the plurality of sustain signals (Sx) may include seven basic weighted signals (Ux) of a certain level.

[0257] Meanwhile, the first weighted signal (W1x) may include one basic weighted signal (Ux).

[0258] That is, the first data signal (D1x) may include seven step-up signals that increase stepwise and eight basic weighted signals (Ux).

[0259] Meanwhile, the driving control unit (285) can output a second data signal (D2x) including an offset signal (OFx) and a second weighted signal (W2x) during the first subframe period (Subframe 1) when the input gray level is 2.

[0260] That is, the second data signal (D2x) may include one more basic weighted signal (Ux) than the first data signal (D1x).

[0261] Meanwhile, the driving control unit (285) can output a second data signal (D12x) including an offset signal (OFx) and a 12th weighted signal (W12x) during the first subframe period (Subframe 1) when the input gray level is 12.

[0262] The 12th weighted signal (W12x) at this time may include 12 basic weighted signals (Ux).

[0263] Meanwhile, the driving control unit (285) can output a data signal (D13xa) including an offset signal (OFx) and a 12th weighting signal (W12x) during the first subframe period (Subframe 1) when the input grayscale is 13, and can output a data signal (D13xb) including an offset signal (OFx) and one basic weighting signal (Ux) during the second subframe period (Subframe 2).

[0264] Comparing the case where the input grayscale is 12 and the case where it is 13, a data signal (D13xb) including an offset signal (OFx) and one basic weighting signal (Ux) is output more.

[0265] Meanwhile, the driving control unit (285) can output a data signal (D24xa) including an offset signal (OFx) and a 12th weighted signal (W12x) during the first subframe period (Subframe 1) when the input grayscale is 24, and can output a data signal (D24xb) including an offset signal (OFx) and a 12th weighted signal (W12x) during the second subframe period (Subframe 2).

[0266] Meanwhile, the driving control unit (285) can output a data signal (D25xa) including an offset signal (OFx) and a twelfth weighted signal (W12x) during a first sub-frame period (Subframe 1), output a data signal (D25xb) including an offset signal (OFx) and a twelfth weighted signal (W12x) during a second sub-frame period (Subframe 2), and output a data signal (D25xc) including an offset signal (OFx) and one basic weighted signal (Ux) during a third sub-frame period (Subframe 3).

[0267] Comparing the case where the input grayscale is 24 and the case where it is 25, an additional data signal (D25xc) including an offset signal (OFx) and one basic weighting signal (Ux) is output.

[0268] Meanwhile, the driving control unit (285) can output a data signal (D36xa) including an offset signal (OFx) and a 12th weighted signal (W12x) during a first sub-frame period (Subframe 1), a data signal (D36xb) including an offset signal (OFx) and a 12th weighted signal (W12x) during a second sub-frame period (Subframe 2), and a data signal (D36xc) including an offset signal (OFx) and a 12th weighted signal (W12x) during a third sub-frame period (Subframe 3), when the input grayscale is 36.

[0269] Meanwhile, the driving control unit (285) can output, when the input grayscale is 37, a data signal (D37xa) including an offset signal (OFx) and a twelfth weighted signal (W12x) during a first sub-frame period (Subframe 1), a data signal (D37xb) including an offset signal (OFx) and a twelfth weighted signal (W12x) during a second sub-frame period (Subframe 2), a data signal (D37xc) including an offset signal (OFx) and a twelfth weighted signal (W12x) during a third sub-frame period (Subframe 3), and a data signal (D37xd) including an offset signal (OFx) and one basic weighted signal (Ux) during a fourth sub-frame period (Subframe 4).

[0270] Comparing the case where the input grayscale is 36 and the case where it is 37, a data signal (D37xd) including an offset signal (OFx) and one basic weighting signal (Ux) is output more.

[0271] According to the method of FIG. 8a, as the number of subframes increases, an offset signal (OFx) and one basic weight signal (Ux) of data signals are additionally applied.

[0272] For example, when the luminance by the offset signal (OFx) is approximately 0.5 nits and the luminance by one basic weighting signal (Ux) is 0.04 nits, each time the number of subframes changes, a change of 0.54 nits occurs, not a change of 0.04 nits. Accordingly, there is a problem that the linearity of the luminance according to the grayscale is significantly broken.

[0273] FIG. 8b illustrates another example of a subframe driving method related to the present disclosure.

[0274] Referring to the drawing, the input grayscale can be varied in steps from 1 to 39.

[0275] In order to express the input grayscale, according to the driving method of the passive matrix, a data signal is output during a plurality of sub-frame periods.

[0276] The driving control unit (285) can output a first data signal (D1y) including an offset signal (OFy) and a first weighted signal (W1y) during the first subframe period (Subframe 1) when the input gray level is 1.

[0277] Meanwhile, the offset signal (OFy) may include multiple step-up signals (Ry) and multiple sustain signals (Sy).

[0278] At this time, the plurality of step-up signals (Ry) may include seven step-up signals that increase stepwise, and the plurality of sustain signals (Sy) may include seven basic weighted signals (Uy) of a certain level.

[0279] Meanwhile, the first weighted signal (W1y) may include one basic weighted signal (Uy).

[0280] That is, the first data signal (D1y) may include seven step-up signals that increase stepwise and eight basic weighted signals (Uy).

[0281] Meanwhile, the driving control unit (285) can output a second data signal (D2y) including an offset signal (OFy) and a second weighted signal (W2y) during the first subframe period (Subframe 1) when the input gray level is 2.

[0282] That is, the second data signal (D2y) may include one more basic weighted signal (Uy) than the first data signal (D1y).

[0283] Meanwhile, the driving control unit (285) can output a 23rd data signal (D23y) including an offset signal (OFy) and a 23rd weighted signal (W23y) during the first subframe period (Subframe 1) when the input gray level is 23.

[0284] The 23rd weighted signal (W12y) at this time may include 23 basic weighted signals (Uy).

[0285] Meanwhile, the driving control unit (285) can output a data signal (D24ya) including an offset signal (OFy) and a 12th weighted signal (W12y) during the first sub-frame period (Subframe 1) when the input gray level is 24, and can output a data signal (D24xb) including an offset signal (OFy) and a 12th weighted signal (W12y) during the second sub-frame period (Subframe 2).

[0286] At this time, the 12th weighted signal (W12y) may include 12 basic weighted signals (Uy).

[0287] Comparing the case where the input gray level is 23 and 24, an offset signal (OFy) and one more basic weighting signal (Uy) are output.

[0288] Meanwhile, the driving control unit (285) can output a data signal (D25ya) including an offset signal (OFy) and a 13th weighted signal (W12y) during the first sub-frame period (Subframe 1) when the input grayscale is 25, and can output a data signal (D25yb) including an offset signal (OFy) and a 12th weighted signal (W12y) during the second sub-frame period (Subframe 2).

[0289] Meanwhile, the driving control unit (285) can output a data signal (D35ya) including an offset signal (OFy) and an 18th weighted signal (W18y) during the first sub-frame period (Subframe 1) when the input grayscale is 35, and can output a data signal (D35yb) including an offset signal (OFy) and a 17th weighted signal (W17y) during the second sub-frame period (Subframe 2).

[0290] At this time, the 18th weighted signal (W18y) may include 18 basic weighted signals (Uy), and the 17th weighted signal (W17y) may include 17 basic weighted signals (Uy).

[0291] Meanwhile, the driving control unit (285) can output a data signal (D36ya) including an offset signal (OFy) and a twelfth weighted signal (W18y) during a first sub-frame period (Subframe 1), output a data signal (D35yb) including an offset signal (OFy) and a twelfth weighted signal (W12y) during a second sub-frame period (Subframe 2), and output a data signal (D36yc) including an offset signal (OFy) and a twelfth weighted signal (W12y) during a third sub-frame period (Subframe 3).

[0292] Comparing the cases where the input grayscale is 35 and 36, an offset signal (OFy) and one more basic weighting signal (Uy) are output.

[0293] According to the method of FIG. 8b, as the number of subframes increases, an offset signal (OFy) and one data signal equal to the basic weighting signal (Uy) are additionally applied.

[0294] For example, when the luminance by the offset signal (OFy) is approximately 0.5 nits and the luminance by one basic weighting signal (Uy) is 0.04 nits, each time the number of subframes changes, a change of 0.54 nits occurs, not a change of 0.04 nits. Accordingly, there is a problem in which the linearity of the luminance according to the grayscale is significantly broken.

[0295] FIGS. 9A to 9C are drawings for reference in explaining the operation of a video display device according to an embodiment of the present disclosure.

[0296] FIG. 9a is a diagram showing the operation of an image display device according to one embodiment of the present disclosure.

[0297] Referring to the drawings, FIG. 9a illustrates an example of a sub-frame driving method of a video display device according to one embodiment of the present disclosure.

[0298] Referring to the drawing, the input grayscale can be varied in steps from 1 to 39.

[0299] In order to express the input grayscale, according to the driving method of the passive matrix, a data signal is output during a plurality of sub-frame periods.

[0300] According to one embodiment of the present disclosure, a driving control unit (285) outputs a first data signal (D1) including an offset signal (OF) and a first weighted signal (W1) during a first sub-frame period (Subframe 1) when the input grayscale is 1.

[0301] Meanwhile, the offset signal (OF) may include multiple step-up signals (R) and multiple sustain signals (S).

[0302] At this time, the plurality of step-up signals (R) may include seven step-up signals that increase stepwise, and the plurality of sustain signals (S) may include eight basic weighted signals (U) of a certain level.

[0303] Meanwhile, the first weighted signal (W1) may include one basic weighted signal (U).

[0304] That is, the first data signal (D1) may include seven step-up signals that increase stepwise and nine basic weighted signals (U).

[0305] Meanwhile, the luminance of the offset signal (OF) may be approximately 0.5 nits, and the luminance of the basic weighting signal (U) may be approximately 0.04 nits. Accordingly, when the input grayscale is 1, the luminance by the first data signal (D1) may be approximately 0.54 nits.

[0306] Meanwhile, the driving control unit (285) can output a second data signal (D2) including an offset signal (OF) and a second weighted signal (W2) during the first subframe period (Subframe 1) when the input gray level is 2.

[0307] That is, the second data signal (D2) may include one more basic weighted signal (U) than the first data signal (D1).

[0308] Therefore, when the input grayscale is 2, the luminance by the second data signal (D2) can be approximately 0.58 nits, which is 0.54+0.04.

[0309] Meanwhile, the driving control unit (285) can output a 12th data signal (D12) including an offset signal (OF) and a 12th weighted signal (W12) during the first subframe period (Subframe 1) when the input gray level is 12.

[0310] The 12th weighted signal (W12) at this time may include 12 basic weighted signals (U).

[0311] That is, when the input grayscale is 12, the luminance by the 12th data signal (D12) can be approximately 0.98 nits, as 0.5+0.04*12.

[0312] Meanwhile, the driving control unit (285) can output a data signal (D13a) including only an offset signal (OF) during the first subframe period (Subframe 1) when the input grayscale is 13, and can output a data signal (D13b) including only an offset signal (OF) during the second subframe period (Subframe 2).

[0313] When comparing the case where the input grayscale is 13 with the case where the input grayscale is 12, the number of offset signals (OF) increases by 1 to 2, but 12 basic weighting signals (U) are omitted.

[0314] That is, when the input grayscale is 13, the luminance by the 13th data signal (D13) including the data signal (D13a) during the first subframe period (Subframe 1) and the data signal (D13b) during the second subframe period (Subframe 2) can be approximately 1.0 nit, as 0.5+0.5.

[0315] That is, when the input grayscale is 13, the luminance increases by approximately 0.02 nits compared to when the input grayscale is 12.

[0316] Meanwhile, the driving control unit (285) can output a data signal (D14a) including an offset signal (OF) and a first weighted signal (W1) during the first subframe period (Subframe 1) when the input gray level is 14, and can output a data signal (D14b) including only the offset signal (OF) during the second subframe period (Subframe 2).

[0317] Meanwhile, if the input grayscale is 14, the luminance by the 14th data signal (D14) can be approximately 1.04 nits, as 2*0.5+0.04.

[0318] Meanwhile, the driving control unit (285) can output a data signal (D15a) including an offset signal (OF) and a first weighted signal (W1) during a first sub-frame period (Subframe 1) when the input grayscale is 15, and can output a data signal (D15b) including an offset signal (OF) and a first weighted signal (W1) during a second sub-frame period (Subframe 2).

[0319] Meanwhile, the first weighted signal (W1) may include one basic weighted signal (U).

[0320] Meanwhile, if the input grayscale is 12, the luminance by the 12th data signal (D12) can be approximately 1.08 nits, as 2*0.5+0.04*2.

[0321] Meanwhile, the driving control unit (285) can output a data signal (D25a) including an offset signal (OF) and a sixth weighted signal (W6) during the first subframe period (Subframe 1) when the input grayscale is 25, and can output a data signal (D25b) including an offset signal (OF) and a sixth weighted signal (W6) during the second subframe period (Subframe 2).

[0322] The sixth weighted signal (W6) at this time may include six basic weighted signals (U).

[0323] Meanwhile, when the input grayscale is 25, the luminance by the 25th data signal (D25) can be approximately 1.48 nits, as 2*0.5+0.04*12.

[0324] Meanwhile, the driving control unit (285) can output a data signal (D26a) including only an offset signal (OF) during a first sub-frame period (Subframe 1), output a data signal (D26b) including only an offset signal (OF) during a second sub-frame period (Subframe 2), and output a data signal (D26c) including only an offset signal (OF) during a third sub-frame period (Subframe 3) when the input grayscale is 26.

[0325] When comparing the case where the input grayscale is 26 with the case where the input grayscale is 25, the number of offset signals (OF) increases by 1 to 3, but 12 basic weighting signals (U) are omitted.

[0326] That is, when the input grayscale is 26, the luminance by the 26th data signal (D26) including the data signal (D26a) during the first subframe period (Subframe 1), the data signal (D26b) during the second subframe period (Subframe 2), and the data signal (D26c) during the third subframe period (Subframe 3) can be approximately 1.5 nits, as 0.5+0.5+0.5.

[0327] That is, when the input grayscale is 26, the luminance increases by approximately 0.02 nits compared to when the input grayscale is 25.

[0328] Meanwhile, the driving control unit (285) can output a data signal (D38a) including an offset signal (OF) and a fourth weighted signal (W4) during a first sub-frame period (Subframe 1), output a data signal (D38b) including an offset signal (OF) and a fourth weighted signal (W4) during a second sub-frame period (Subframe 2), and output a data signal (D38c) including an offset signal (OF) and a fourth weighted signal (W4) during a third sub-frame period (Subframe 3).

[0329] The fourth weighted signal (W4) at this time may include four basic weighted signals (U).

[0330] Meanwhile, if the input grayscale is 38, the luminance by the 38th data signal (D38) can be approximately 1.98 nits, as 3*0.5+0.04*12.

[0331] Meanwhile, the driving control unit (285) can output a data signal (D39a) including only an offset signal (OF) during a first sub-frame period (Subframe 1) when the input grayscale is 39, a data signal (D39b) including only an offset signal (OF) during a second sub-frame period (Subframe 2), a data signal (D39c) including only an offset signal (OF) during a third sub-frame period (Subframe 3), and a data signal (D39d) including only an offset signal (OF) during a fourth sub-frame period (Subframe 4).

[0332] When comparing the case where the input grayscale is 39 with the case where the input grayscale is 38, the number of offset signals (OF) increases by 1 to 4, but 12 basic weighting signals (U) are omitted.

[0333] That is, when the input grayscale is 39, the luminance by the 39th data signal (D39) including the data signal (D39a) during the first subframe period (Subframe 1), the data signal (D39b) during the second subframe period (Subframe 2), the data signal (D39c) during the third subframe period (Subframe 3), and the data signal (D39d) during the fourth subframe period (Subframe 4) can be approximately 2.0 nits, as 0.5+0.5+0.5+0.5.

[0334] That is, when the input grayscale is 39, the luminance increases by approximately 0.02 nits compared to when the input grayscale is 38.

[0335] According to a method such as Fig. 9a, the basic weighting signal (U) is increased by one at a time until a total of 12 basic weighting signals (U) are reached, and then the number of sub-frame periods is increased, while the addition of the basic weighting signal is omitted and only the offset signal is applied. Accordingly, the linearity of the luminance according to the grayscale can be maintained. In particular, flicker can be reduced while maintaining the linearity of the luminance at low grayscale.

[0336] According to one embodiment of the present disclosure, a driving control unit (285) in a video display device (100) outputs a first data signal (Dn) when an input grayscale is n, outputs a second data signal (Dn+1) whose luminance at a first level is increased compared to that of the first data signal (Dn) when the input grayscale is n+1, and outputs a third data signal whose luminance at a second level, which is lower than the first level, is increased when the input grayscale is n+2 and an increase in the number of sub-frame periods is required. Accordingly, linearity of luminance according to grayscale can be maintained.

[0337] Meanwhile, the driving control unit (285) outputs a second data signal (Dn+1) having an offset signal (OF) and n+1 basic weighting signals (U) during the first sub-frame period (Subframe 1) when the input grayscale is n+1, and when the input grayscale is n+2 and an increase in the number of sub-frame periods is required, the driving control unit (285) outputs a fourth data signal including an offset signal (OF) during the first sub-frame period (Subframe 1), and outputs a fourth data signal including an offset signal (OF) during the second sub-frame period (Subframe 2) after the first sub-frame period (Subframe 1).

[0338] For example, in the case where n is 11 in the n input grayscale, in order to express the input grayscale 11, the driving control unit (285) outputs an 11th data signal including one offset signal (OF) and 11 basic weighting signals (U), and the luminance by the 11th data signal at this time can be approximately 0.94 nits, as 0.5+0.04*11.

[0339] Meanwhile, in the n+1 input grayscale, when n is 11, in order to express the input grayscale 12, the driving control unit (285) outputs a 12th data signal including one offset signal (OF) and 12 basic weighting signals (U), and the luminance by the 12th data signal at this time can be approximately 0.98 nits, as 0.5+0.04*12.

[0340] Meanwhile, in the n+2 input grayscale, when n is 11, in order to express input grayscale 13, the driving control unit (285) outputs a 13th data signal including only the offset signal (OF) during the first subframe period (Subframe 1) and including only the offset signal (OF) during the second subframe period (Subframe 2).

[0341] The luminance by the 13th data signal at this time can be approximately 1.0 nit, as 2*0.5.

[0342] Meanwhile, the driving control unit (285) can output a data signal including an offset signal (OF) and one basic weighting signal (U) during the first sub-frame period (Subframe 1) when the input grayscale is n+3, and can output a data signal including only the offset signal (OF) during the second sub-frame period (Subframe 2) following the first sub-frame period (Subframe 1).

[0343] For example, in the case of n+3 input grayscales, when n is 11, to express input grayscale 14, the driving control unit (285) outputs a 14th data signal including an offset signal (OF) and one basic weighting signal (U) during the first subframe period (Subframe 1), and including only the offset signal (OF) during the second subframe period (Subframe 2).

[0344] The luminance by the 14th data signal at this time can be approximately 1.04 nits, as 2*0.5+0.04.

[0345] Meanwhile, the offset signal (OF) includes a plurality of step-up signals (R) and a plurality of sustain signals (S), and when the input gray level is n+1, the number of basic weighting signals (U) may be greater than the number of the plurality of sustain signals (S).

[0346] For example, in the n+1 input grayscale, when n is 11, to express input grayscale 12, the driving control unit (285) outputs a 12th data signal including an offset signal (OF) and 12 basic weighting signals (U) during the first subframe period (Subframe 1).

[0347] At this time, since the 12th data signal includes a sustain signal (S) corresponding to 9 basic weighted signals (U) and 12 basic weighted signals (U), the number of basic weighted signals (U) may be greater than the number of multiple sustain signals (S).

[0348] Meanwhile, the offset signal (OF) includes a plurality of step-up signals (R) and a plurality of sustain signals (S), and the number of sustain signals (S) may be greater than the number of step-up signals (R).

[0349] That is, the offset signal (OF) can include seven step-up signals and nine basic weighted signals (U), and accordingly, the number of sustain signals (S) can be greater than the number of step-up signals (R).

[0350] Meanwhile, the driving control unit (285) can control the light-emitting diode to emit light only during the first sub-frame period (Subframe 1) when the input grayscale is n+1 or less.

[0351] For example, when n is 11 or less, that is, when the input grayscale is 12 or less, the driving control unit (285) can control the light-emitting diode to emit light only during the first sub-frame period (Subframe 1).

[0352] Meanwhile, the driving control unit (285) can output a sixth data signal having an offset signal (OF) and a number of basic weighting signals (U) during the first subframe period (Subframe 1) when the input grayscale is m, and can output a sixth data signal having an offset signal (OF) and a number of basic weighting signals (U) during the second subframe period (Subframe 2).

[0353] Meanwhile, the driving control unit (285) can output a fourth data signal including an offset signal (OF) during the first subframe period (Subframe 1), the second subframe period (Subframe 2), and the third subframe period following the second subframe period (Subframe 2), when the input grayscale is m+1 and an increase in the number of subframe periods is required.

[0354] At this time, m can be 25 and a can be 6.

[0355] That is, the driving control unit (285) can output a data signal having an offset signal (OF) and six basic weighting signals (U) during the first subframe period (Subframe 1) when the input grayscale is m=25, and can output a data signal having an offset signal (OF) and six basic weighting signals (U) during the second subframe period (Subframe 2).

[0356] Meanwhile, the driving control unit (285) can output a data signal including only an offset signal (OF) during the first subframe period (Subframe 1), the second subframe period (Subframe 2), and the third subframe period following the second subframe period (Subframe 2), when the input grayscale is m+1=26 and an increase in the number of subframe periods is required. Accordingly, linearity of luminance according to grayscale can be maintained.

[0357] Meanwhile, the driving control unit (285) can output a data signal including an offset signal (OF) and one basic weighting signal (U) during the first sub-frame period (Subframe 1) when the input grayscale is m+2=27, and can output a data signal including only the offset signal (OF) during the second sub-frame period (Subframe 2) and the third sub-frame period. Accordingly, linearity of luminance according to grayscale can be maintained.

[0358] Meanwhile, the offset signal (OF) includes a plurality of step-up signals (R) and a plurality of sustain signals (S), and when the input gray level is m=25, the number of a=6 basic weighted signals (U) may be less than the number of a plurality of sustain signals (S).

[0359] Meanwhile, the driving control unit (285) can output a data signal that increases the luminance of the second level, which is less than the first level, when the input gradation is n+2 and an increase in the number of sub-frame periods is required. Accordingly, linearity of luminance according to gradation can be maintained.

[0360] For example, the driving control unit (285) can output a data signal in which the brightness of the second level, which is less than the first level, increases when n is 11, the input signal is 13 which is n+2, and an increase in the number of sub-frame periods is required.

[0361] The first level at this time may be 0.04 nits, and the second level may be 0.02 nits.

[0362] Meanwhile, the driving control unit (285) can control the luminance level of the data signal to linearly and sequentially increase when the input grayscale increases sequentially. Accordingly, linearity of luminance according to grayscale can be maintained.

[0363] Meanwhile, the driving control unit (285) according to another embodiment of the present disclosure outputs a data signal including an offset signal (OF) and a weighting signal during a first number of sub-frame periods, and when an increase in the number of sub-frames is required, outputs a data signal including only the offset signal (OF) during a second number of sub-frame periods. Accordingly, linearity of luminance according to grayscale can be maintained.

[0364] In Fig. 9a, when the input grayscale is 12, a data signal having an offset signal (OF) and a weighting signal is output during one sub-frame period, and when the input grayscale is 13, a data signal having only an offset signal (OF) is output during two sub-frame periods.

[0365] Meanwhile, in Fig. 9a, when the input grayscale is 25, a data signal having an offset signal (OF) and a weighting signal is output for two sub-frame periods, and when the input grayscale is 26, a data signal having only an offset signal (OF) is output for three sub-frame periods.

[0366] Meanwhile, in Fig. 9a, when the input grayscale is 38, a data signal having an offset signal (OF) and a weighting signal is output for three sub-frame periods, and when the input grayscale is 39, a data signal having only an offset signal (OF) is output for four sub-frame periods.

[0367] Figures 9b to 9c are drawings referenced in the description of Figure 9a.

[0368] FIG. 9b illustrates a luminance curve (SLx) versus input grayscale according to the driving method of FIG. 8a or FIG. 8b, and a luminance curve (SLxa) versus input grayscale according to the driving method of FIG. 9a.

[0369] Referring to the drawings, according to an embodiment of the present disclosure, the luminance curve (SLxa) versus input grayscale can sequentially increase the luminance level of the data signal linearly across all grayscales.

[0370] That is, according to the embodiment of the present disclosure, the driving control unit (285) can control the luminance level of the data signal to sequentially increase linearly when the input gray level sequentially increases.

[0371] Meanwhile, according to the luminance curve (SLx) versus input grayscale according to the driving method of Fig. 8a or Fig. 8b, when the input grayscale is between 500 and 1000, a section in which the luminance increase amount varies occurs. Accordingly, according to the luminance curve (SLx) versus input grayscale according to the driving method of Fig. 8a or Fig. 8b, linearity of luminance according to grayscale cannot be maintained.

[0372] Figure 9c is an enlarged view of the luminance curve (SLx) versus input grayscale of Figure 9b and the low grayscale area (Ara) of the luminance curve (SLxa) versus input grayscale.

[0373] Referring to the drawing, when the input grayscale is 200 or less, the linearity of the luminance according to the grayscale is broken in the luminance curve (SLx) according to the driving method of Fig. 8a or Fig. 8b.

[0374] Meanwhile, according to the embodiment of the present disclosure, in the luminance curve (SLxa) versus input grayscale, linearity of luminance according to grayscale is maintained even when the input grayscale is 200 or less.

[0375] Accordingly, according to the luminance curve (SLxa) versus input grayscale according to the embodiment of the present disclosure, flicker can be reduced while maintaining linearity of luminance at low grayscale.

[0376] FIGS. 10A and 10B are drawings for reference in explaining the operation of a video display device related to the present disclosure.

[0377] Figure 10a is a diagram showing an example of the brightness of a light-emitting diode compared to the input grayscale of an image signal input to a driving control unit.

[0378] Referring to the drawing, the horizontal axis may represent the input grayscale of the image signal input to the driving control unit, and the vertical axis may represent the brightness of the light-emitting diode.

[0379] GRxm in the drawing can represent the brightness of the actual light-emitting diode compared to the input gray level.

[0380] Meanwhile, if the input grayscale of the video signal is Prxa, calibration measurement can be performed.

[0381] Meanwhile, when the input grayscale of the video signal is Prxb, the input grayscale can be allocated to each of the multiple sub-frame periods. That is, when the input grayscale is Prxb, for the first time, the input grayscale can be allocated to each of the multiple sub-frame periods.

[0382] When the luminance of the light-emitting diode at the input grayscale of Prxa is Lx1, the signal processing device (170) or the driving control unit (285) can calculate the increase in luminance compared to the input grayscale, such as a graph such as GRxa.

[0383] Meanwhile, when the luminance of the light-emitting diode at the input grayscale of Prxa is Lx2, the signal processing device (170) or the driving control unit (285) can calculate the increase in luminance compared to the input grayscale, such as a graph such as GRxb.

[0384] When the signal processing device (170) or the driving control unit (285) causes the light-emitting diode to emit light based on a graph such as GRxa or GRxb, as shown in the drawing, a significant difference is shown between the actual luminance of the light-emitting diode and GRxm compared to the input grayscale.

[0385] For example, the graph of GRxa has a problem in that the luminance of the light-emitting diode is lowered across the entire grayscale range compared to the input grayscale, compared to GRxm. Furthermore, when the input grayscale is around Prxb, there is a problem in that the luminance uniformity is significantly broken.

[0386] Meanwhile, the graph of GRxb, compared to GRxm, has a problem in that it lacks low-tonal expression and has a problem in that the expression of mid-tonal or high-tonal expression is increased. Furthermore, when the input tonal is near Prxb, there is a problem in that the luminance uniformity is significantly broken.

[0387] Figure 10b is a diagram showing another example of the brightness of a light-emitting diode compared to the input grayscale of an image signal input to a driving control unit.

[0388] Referring to the drawing, the horizontal axis may represent the input grayscale of the image signal input to the driving control unit, and the vertical axis may represent the brightness of the light-emitting diode.

[0389] GRyn in the drawing can represent the brightness of the actual light-emitting diode compared to the input grayscale of the first pixel (PTy1).

[0390] GRyc in the drawing can represent the brightness of the actual light-emitting diode compared to the input grayscale of the second pixel (PTy2).

[0391] Meanwhile, if the input grayscale of the video signal is Prya, calibration measurement can be performed.

[0392] Meanwhile, when the input grayscale of the video signal is Pryb, the input grayscale can be allocated to each of the multiple sub-frame periods. That is, when the input grayscale is Pryb, for the first time, the input grayscale can be allocated to each of the multiple sub-frame periods.

[0393] Meanwhile, if the input grayscale of the image signal is Pryb, calibration measurement can be performed. That is, unlike Fig. 10a, two calibration measurements can be performed.

[0394] When the luminance of the light-emitting diode in the input grayscale of Prya is Ly1, the signal processing device (170) or the driving control unit (285) can calculate the increase in luminance compared to the input grayscale, such as a graph such as GRya.

[0395] Meanwhile, when the luminance of the light-emitting diode in the input grayscale of Prya is Ly2, the signal processing device (170) or the driving control unit (285) can calculate the increase in luminance compared to the input grayscale, such as a graph such as GRyb.

[0396] When the signal processing device (170) or the driving control unit (285) causes the light-emitting diode to emit light based on a graph such as GRya or GRyb, a significant difference is shown between the actual luminance of the light-emitting diode, GRyn, and the input grayscale, as shown in the drawing.

[0397] For example, the graph of GRya has a problem in that the luminance of the light-emitting diode is lowered across the entire grayscale range compared to the input grayscale, compared to GRyn or GRyv. Furthermore, when the input grayscale is near Pryb, there is a problem in that the luminance uniformity is significantly broken.

[0398] Meanwhile, GRyb's graph, compared to GRyn, lacks low-level expression and suffers from the problem of increased mid-level or high-level expression. Furthermore, when the input level is near Pryb, there is a problem of significantly broken luminance uniformity.

[0399] Meanwhile, as in Fig. 10b, when performing two calibration measurements, if the input grayscale is Pryb, there is a disadvantage in that it is not easy to measure brightness, etc. because it is a low grayscale.

[0400] FIG. 10c is an example of an internal block diagram of a signal processing device related to the operation of FIG. 10a or FIG. 10b.

[0401] Referring to the drawing, a signal processing device (170x) related to the present invention may include a pixel gain calculation unit (1014), a pulse length calculation unit (1016), and a synthesis unit (1020).

[0402] The pixel gain calculation unit (1014) can calculate the slope of a graph such as GRxa or GRxb of FIG. 10a.

[0403] Meanwhile, the slope of a graph such as GRya or GRyb in Fig. 10b can be calculated.

[0404] That is, the pixel gain calculation unit (1014) can calculate the increase in brightness of the light-emitting diode compared to the input grayscale.

[0405] The pulse length calculation unit (1016) can calculate the pulse width length of the data signal output from the driving control unit (285) according to the input grayscale.

[0406] Meanwhile, the pulse length calculation unit (1016) can calculate the pulse width length of a PWM pulse when the data signal is a pulse width modulation (PWM)-based signal.

[0407] Next, the synthesis unit (1020) can output an image signal (SGX) according to the input grayscale based on the output of the pixel gain calculation unit (1014) and the output of the pulse length calculation unit (1016). At this time, the image signal (SGX) can be input to the driving control unit (285).

[0408] Meanwhile, according to the driving method of Fig. 10c, there is a problem that the uniformity of the luminance of the light-emitting diode compared to the input grayscale is broken, as in the description of Fig. 10a or Fig. 10b, and in particular, when the input grayscale is near Prcb or Pryb, there is a problem that the luminance uniformity is significantly broken.

[0409] FIG. 11 is a diagram showing the operation of a video display device according to one embodiment of the present disclosure.

[0410] Referring to the drawing, a signal processing device (170) in an image display device (100) according to one embodiment of the present disclosure can calculate pixel gain (S1110).

[0411] For example, a signal processing device (170) according to one embodiment of the present disclosure can calculate pixel gain based on an image signal.

[0412] Specifically, the signal processing device (170) can calculate the increase in brightness of the light-emitting diode compared to the input grayscale.

[0413] And, the signal processing device (170) can calculate the pixel gain, which is the ratio of the increase in brightness of the light-emitting diode and the reference increase.

[0414] Next, the signal processing device (170) can calculate the gray scale ratio (S1120).

[0415] For example, the signal processing device (170) can calculate the ratio (R) of low grayscale below the reference level and high grayscale above the reference level.

[0416] Specifically, the signal processing device (170) can calculate the ratio (R) of low grayscale that is below the reference level to high grayscale that is above the reference level.

[0417] Next, the signal processing device (170) can calculate the pulse length of the data signal (S1130).

[0418] For example, the signal processing device (170) can calculate the pulse width length of a PWM pulse when the data signal is a pulse width modulation (PWM)-based signal.

[0419] Next, the signal processing device (170) can perform case classification for multiple grayscale compensation modes based on pixel gain, grayscale ratio, and pulse width length (S1135).

[0420] Meanwhile, the signal processing device (170) can select one of a plurality of grayscale compensation modes based on the input grayscale and the input grayscale to be converted.

[0421] For example, the signal processing device (170) can determine whether the input grayscale and the input grayscale to be converted are both less than the reference grayscale (Cbnd) in the first case (S1142), and if so, can perform the first grayscale compensation mode (S1152).

[0422] As another example, the signal processing device (170) can determine whether the input grayscale is less than the reference grayscale (Cbnd) and the input grayscale to be converted is the second case in which the input grayscale is greater than the reference grayscale (Cbnd) (S1144), and if so, can perform the second grayscale compensation mode (S1154).

[0423] As another example, the signal processing device (170) determines whether the input grayscale is greater than the reference grayscale (Cbnd) and the input grayscale to be converted is less than the reference grayscale (Cbnd), which is the third case (S1146), and if so, can perform the third grayscale compensation mode (S1156).

[0424] As another example, the signal processing device (170) can determine whether the input grayscale and the input grayscale to be converted are both in the fourth case exceeding the reference grayscale (Cbnd) (S1148), and if so, can perform the fourth grayscale compensation mode (S1158).

[0425] Accordingly, it is possible to maintain luminance uniformity between pixels. In particular, flicker can be reduced while maintaining luminance uniformity according to the input grayscale.

[0426] Figures 12 to 14 are drawings referred to in the description of Figure 11.

[0427] First, FIG. 12 is an example of an internal block diagram of a signal processing device according to one embodiment of the present disclosure.

[0428] Referring to the drawing, a signal processing device (170) according to one embodiment of the present disclosure may include a pixel gain calculation unit (1212), a grayscale ratio calculation unit (1214), a pulse length calculation unit (1216), a case classification view (1218), a case selection unit (1220), a grayscale compensation unit (1230), and an output unit (1235).

[0429] The pixel gain calculation unit (1212) can calculate the slope of the GRa graph of the first pixel (pixel1) of FIG. 13 or the slope of the GRb graph of the second pixel (pixel2).

[0430] For example, the pixel gain calculation unit (1212) can calculate the increase in brightness of the light-emitting diode compared to the input grayscale exceeding the reference grayscale (Cbnd) of the first pixel (pixel1).

[0431] Meanwhile, the pixel gain calculation unit (1212) can calculate the increase in brightness of the light-emitting diode compared to the input grayscale below the reference grayscale (Cbnd) of the first pixel (pixel1).

[0432] The pixel gain calculation unit (1212) can calculate the pixel gain, which is the ratio of the increase in brightness of the light-emitting diode to the reference increase, as shown in the following mathematical expression 1.

[0433] [Mathematical Formula 1]

[0434] g=At / A=Bt / B

[0435] Here, g represents pixel gain, At represents a reference luminance increase amount below the reference grayscale (Cbnd), A represents a luminance increase amount below the reference grayscale (Cbnd), Bt represents a reference luminance increase amount exceeding the reference grayscale (Cbnd), and B may represent a luminance increase amount exceeding the reference grayscale (Cbnd).

[0436] As another example, the pixel gain calculation unit (1212) can calculate the increase in brightness of the light-emitting diode compared to the input grayscale exceeding the reference grayscale (Cbnd) of the second pixel (pixel2).

[0437] Meanwhile, the pixel gain calculation unit (1212) can calculate the increase in brightness of the light-emitting diode compared to the input grayscale below the reference grayscale (Cbnd) of the second pixel (pixel2).

[0438] Meanwhile, the gradation ratio calculation unit (1214) can calculate the gradation ratio (R), which is the ratio of the input gradations of the image signal exceeding the reference gradation (Cbnd) and the ratio of the input gradations below the reference gradation (Cbnd).

[0439] Specifically, the grayscale ratio calculation unit (1214) can calculate the ratio (R) of low grayscale levels that are below the reference level to high grayscale levels that are above the reference grayscale (Cbnd) among the input grayscale levels of the image signal, as shown in the following mathematical expression 2.

[0440] [Equation 2]

[0441] R= A / B

[0442] Next, the pulse length calculation unit (1216) can calculate the pulse width length of the data signal output from the driving control unit (285) according to the input grayscale.

[0443] Meanwhile, the pulse length calculation unit (1216) can calculate the pulse width length of a PWM pulse when the data signal is a pulse width modulation (PWM)-based signal.

[0444] The case classification view (1218) can perform case classification for multiple grayscale compensation modes based on pixel gain, grayscale ratio, and pulse width length, such as the case classification (S1135) of FIG. 11.

[0445] Next, the case selection unit (1220) can select one of a plurality of gradation compensation modes based on the input gradation and the input gradation to be converted.

[0446] For example, the case selection unit (1220) can select the first grayscale compensation mode in the first case where both the input grayscale and the input grayscale to be converted are less than the reference grayscale (Cbnd).

[0447] As another example, the case selection unit (1220) may select the second grayscale compensation mode in the second case where the input grayscale is less than the reference grayscale (Cbnd) and the input grayscale to be converted is greater than the reference grayscale (Cbnd).

[0448] As another example, the case selection unit (1220) can select the third grayscale compensation mode when the input grayscale exceeds the reference grayscale (Cbnd) and the input grayscale to be converted is the third case that is less than the reference grayscale (Cbnd).

[0449] As another example, the case selection unit (1220) can select the fourth grayscale compensation mode when the input grayscale and the input grayscale to be converted are both in the fourth case, exceeding the reference grayscale (Cbnd).

[0450] Next, the gradation compensation unit (1230) can perform the gradation compensation mode according to the gradation compensation mode selected in the case selection unit (1220).

[0451] For example, the first tone compensation unit (1232) within the tone compensation unit (1230) can perform the first tone compensation mode according to the selected first tone compensation mode.

[0452] As another example, the second tone compensation unit (1234) within the tone compensation unit (1230) can perform the second tone compensation mode according to the selected second tone compensation mode.

[0453] As another example, the third tone compensation unit (1236) within the tone compensation unit (1230) can perform the third tone compensation mode according to the selected third tone compensation mode.

[0454] As another example, the fourth tone compensation unit (1238) within the tone compensation unit (1230) can perform the fourth tone compensation mode according to the selected fourth tone compensation mode.

[0455] Meanwhile, the output unit (1235) can output a signal that has been compensated for in the tone compensation unit (1230).

[0456] Specifically, the output unit (1235) can output an image signal including a tone compensated by the tone compensation unit (1230) to the driving control unit (285), etc.

[0457] Accordingly, it is possible to maintain luminance uniformity between pixels. In particular, flicker can be reduced while maintaining luminance uniformity according to the input grayscale.

[0458] Fig. 13 is a drawing referred to in the description of Fig. 11 or Fig. 12.

[0459] Referring to the drawings, FIG. 13 is a diagram showing an example of the brightness of a light-emitting diode compared to the input grayscale of an image signal input to a driving control unit according to an embodiment of the present disclosure.

[0460] Referring to the drawing, the horizontal axis may represent the input grayscale of the image signal input to the driving control unit, and the vertical axis may represent the brightness of the light-emitting diode.

[0461] GRa in the drawing can represent the brightness of the actual light-emitting diode compared to the input grayscale of the first pixel (pixel1).

[0462] GRb in the drawing can represent the brightness of the actual light-emitting diode compared to the input grayscale of the second pixel (pixel2).

[0463] GRr in the drawing can represent the target luminance of the light-emitting diode compared to the input gray level.

[0464] Meanwhile, if the input grayscale of the video signal is Xcal, calibration measurement can be performed.

[0465] Meanwhile, the signal processing device (170) can allocate input grayscale to each of a plurality of sub-frame periods when the input grayscale of the image signal is the reference grayscale (Cbnd).

[0466] That is, the signal processing device (170) can, for the first time, allocate the input grayscale to each of a plurality of sub-frame periods when the input grayscale is the reference grayscale (Cbnd).

[0467] Meanwhile, the signal processing device (170) can set the grayscale to which grayscale is allocated in each of multiple sub-frame periods as the reference grayscale (Cbnd). Accordingly, uniformity of luminance between pixels can be maintained.

[0468] Meanwhile, the signal processing device (170) can calculate the increase in luminance compared to the input grayscale, such as a graph like GRa, when the luminance of the light-emitting diode of the first pixel (pixel1) in the input grayscale of Xcal is La.

[0469] Meanwhile, the signal processing device (170) can calculate the increase in brightness compared to the input grayscale, such as a graph like GRb, when the brightness of the light-emitting diode of the second pixel (pixel2) in the input grayscale of Xcal is Lb.

[0470] Meanwhile, the signal processing device (170) can calculate a reference increase amount of luminance compared to the input grayscale, such as a graph such as GRr, based on the luminance of the light-emitting diode of the first pixel (pixel1) and the luminance of the light-emitting diode of the second pixel (pixel2) in the input grayscale of Xcal.

[0471] Meanwhile, a signal processing device (170) according to an embodiment of the present disclosure performs a first grayscale compensation mode for reducing the input grayscale of the first pixel (pixel1) when the input grayscale of the first pixel (pixel1) is less than the reference grayscale (Cbnd), and performs a second grayscale compensation mode for controlling the input grayscale of the second pixel (pixel2) to increase the input grayscale of the second pixel (pixel2) so that the increased input grayscale of the second pixel (pixel2) exceeds the reference grayscale (Cbnd) when the input grayscale of the second pixel (pixel2) having an increase amount that is lower in luminance than the first pixel (pixel1) is less than the reference grayscale (Cbnd).

[0472] Meanwhile, the signal processing device (170) performs the first grayscale compensation mode when the input grayscale and the input grayscale to be converted are both less than the reference grayscale (Cbnd).

[0473] Meanwhile, the signal processing device (170) can control the first grayscale compensation mode to be performed based on the gain (g) of the first pixel (pixel1) or the gain (g) of the second pixel (pixel2), as in the following mathematical expression 3.

[0474] [Equation 3]

[0475] Xnew=At / A*Xorg=g*Xorg

[0476] Here, Xnew represents the input grayscale, Xorg represents the input grayscale to be converted, g represents the pixel gain, At represents the reference luminance increase amount below the reference grayscale (Cbnd), and A can represent the luminance increase amount below the reference grayscale (Cbnd).

[0477] In the drawing, when the first grayscale compensation mode of the first pixel (pixel1) is performed, the input grayscale of Xorg1 is reduced and converted to the input grayscale of xnew1.

[0478] That is, as shown in the drawing, the signal processing device (170) can reduce the input grayscale of the first pixel (pixel1) when the first grayscale compensation mode is performed and the first pixel (pixel1) is lower than the reference grayscale (Cbnd).

[0479] Meanwhile, the drawing illustrates that when the first grayscale compensation mode of the second pixel (pixel2) is performed, the input grayscale of Xorg1 increases and is converted to the input grayscale of xa.

[0480] That is, as shown in the drawing, when performing the first grayscale compensation mode, the signal processing device (170) can increase the input grayscale of the second pixel (pixel2) when the second pixel (pixel2) is lower than the reference grayscale (Cbnd). Accordingly, it is possible to maintain luminance uniformity between pixels.

[0481] Meanwhile, the signal processing device (170) can perform the second grayscale compensation mode in the second case where the input grayscale is less than the reference grayscale (Cbnd) and the input grayscale to be converted is greater than the reference grayscale (Cbnd).

[0482] Meanwhile, the signal processing device (170) can control the second grayscale compensation mode to be performed based on the gain (g) of the first pixel (pixel1) or the gain (g) of the second pixel (pixel2), and the ratio (R) of the low grayscale below the reference level and the high grayscale above the reference level, as in the following mathematical expression 4.

[0483] [Equation 4]

[0484] Xnew=At / B*Xorg+Cbnd-A / B*Cbnd

[0485] =A / B*At / A*Xorg+Cbnd-A / B*Cbnd

[0486] =R*g*Xorg+Cbnd-R*Cbnd

[0487] Here, Xnew represents the input grayscale, Xorg represents the input grayscale to be converted, B represents the amount of luminance increase exceeding the reference grayscale (Cbnd), and Cbnd can represent the reference grayscale.

[0488] In the drawing, when the second grayscale compensation mode of the first pixel (pixel1) is performed, the input grayscale of Xorg2 is increased and converted to the input grayscale of xnew2 that exceeds the reference grayscale (Cbnd).

[0489] That is, as shown in the drawing, the signal processing device (170) can increase the input grayscale of the second pixel (pixel2) to a second level (Xnew2) exceeding the reference grayscale (Cbnd) according to the second grayscale compensation mode when the input grayscale of the second pixel (pixel2) is a first level (Xorg2) that is less than the reference grayscale (Cbnd). Accordingly, it is possible to maintain luminance uniformity between pixels.

[0490] Meanwhile, the signal processing device (170) can control the size of the increase in the input grayscale of the second pixel (pixel2) in the second grayscale compensation mode to be greater than the size of the decrease in the input grayscale of the first pixel (pixel1) in the first grayscale compensation mode (Xorg1-Xnew1). Accordingly, it is possible to maintain uniformity of luminance between pixels.

[0491] Meanwhile, the signal processing device (170) can reduce the input grayscale of the first pixel (pixel1) to a third level (Xb) that is less than the reference grayscale (Cbnd) according to the first grayscale compensation mode when the input grayscale of the first pixel (pixel1) is a first level (Xorg2) that is less than the reference grayscale (Cbnd). Accordingly, it is possible to maintain luminance uniformity between pixels.

[0492] Meanwhile, the signal processing device (170) can perform the third grayscale compensation mode when the input grayscale exceeds the reference grayscale (Cbnd) and the input grayscale to be converted is less than the reference grayscale (Cbnd).

[0493] For example, the signal processing device (170) may perform a third grayscale compensation mode that reduces the input grayscale of the first pixel (pixel1) when the input grayscale of the first pixel (pixel1) exceeds the reference grayscale (Cbnd) so that the input grayscale of the first pixel (pixel1) that is reduced becomes less than the reference grayscale (Cbnd).

[0494] Meanwhile, the signal processing device (170) can control the third grayscale compensation mode to be performed based on the gain (g) of the first pixel (pixel1) or the gain (g) of the second pixel (pixel2), and the ratio (R) of the low grayscale below the reference level and the high grayscale above the reference level, as in the following mathematical expression 5.

[0495] [Equation 5]

[0496] Xnew=Bt / A*Xorg-Bt / A&Cbnd+At / A*Cbnd

[0497] =B / A*Bt / B*Xorg- B / A*Bt / B*Cbnd+At / A*Cbnd

[0498] =1 / R*g*Xorg-1 / R*g*Cbnd+g*Cbnd

[0499] Here, Xnew represents the input grayscale, Xorg represents the input grayscale to be converted, B represents the amount of luminance increase exceeding the reference grayscale (Cbnd), and g can represent pixel gain.

[0500] In the drawing, when the third grayscale compensation mode of the first pixel (pixel1) is performed, the input grayscale of Xorg3 is reduced and converted to the input grayscale of xnew3 that is less than the reference grayscale (Cbnd).

[0501] That is, as shown in the drawing, when the input grayscale of the first pixel (pixel1) is the fourth level (Xorg3) that exceeds the reference grayscale (Cbnd), the signal processing device (170) can reduce the input grayscale of the first pixel (pixel1) to the fifth level (Xnew3) that is less than the reference grayscale (Cbnd). Accordingly, it is possible to maintain luminance uniformity between pixels.

[0502] Meanwhile, the signal processing device (170) can increase the input grayscale of the second pixel (pixel2) to a sixth level (Xc) that exceeds the reference grayscale (Cbnd) when the input grayscale of the second pixel (pixel2) is a fourth level (Xorg3) that exceeds the reference grayscale (Cbnd).

[0503] Meanwhile, the signal processing device (170) can perform the fourth grayscale compensation mode when both the input grayscale and the input grayscale to be converted exceed the reference grayscale (Cbnd).

[0504] For example, the signal processing device (170) can perform a fourth grayscale compensation mode that increases the input grayscale of the second pixel (pixel2) when the second pixel (pixel2) exceeds the reference grayscale (Cbnd).

[0505] Meanwhile, the signal processing device (170) can control the fourth grayscale compensation mode to be performed based on the gain (g) of the first pixel (pixel1) or the gain (g) of the second pixel (pixel2), and the ratio (R) of the low grayscale below the reference level and the high grayscale above the reference level, as in the following mathematical expression 6.

[0506] [Equation 6]

[0507] Xnew=Bt / B*Xorg-Bt / B*bnd+At / B*Cbnd-A / B*Cbnd

[0508] =Bt / B*Xorg-Bt / B*Cbnd+A / B*At / A*Cbnd-A / B*Cbnd

[0509] =g*Xorg-g*Cbnd+R*g*Cbnd-R*Cbnd

[0510] Here, Xnew represents the input grayscale, Xorg represents the input grayscale to be converted, B represents the amount of luminance increase exceeding the reference grayscale (Cbnd), and g can represent pixel gain.

[0511] In the drawing, when the fourth grayscale compensation mode of the second pixel (pixel2) is performed, the input grayscale of Xorg4 is increased and converted to the input grayscale of xnew4 that exceeds the reference grayscale (Cbnd).

[0512] That is, as shown in the drawing, when the input grayscale of the second pixel (pixel2) is Xorg4, which is greater than the reference grayscale (Cbnd), the signal processing device (170) can increase the input grayscale of the second pixel (pixel2) to Xnew4, which is greater than the reference grayscale (Cbnd). Accordingly, it is possible to maintain luminance uniformity between pixels.

[0513] Meanwhile, when performing the fourth grayscale compensation mode, the signal processing device (170) can reduce the input grayscale of the first pixel (pixel1) when the first pixel (pixel1) exceeds the reference grayscale (Cbnd), and control the reduced input grayscale (Xd) of the first pixel (pixel1) to exceed the reference grayscale (Cbnd). Accordingly, it is possible to maintain luminance uniformity between pixels.

[0514] Meanwhile, the signal processing device (170) can control the size (Xnew4-Xorg4) of the increase in the input grayscale of the second pixel (pixel2) in the fourth grayscale compensation mode to be greater than the size (Xorg-Xd) of the decrease in the input grayscale of the first pixel (pixel1) when performing the fourth grayscale compensation mode. Accordingly, it is possible to maintain uniformity of brightness between pixels.

[0515] Meanwhile, a signal processing device (170) according to another embodiment of the present disclosure increases the input grayscale of the pixel (pixel2) when the input grayscale of a predetermined pixel (pixel2) is less than the reference grayscale (Cbnd), and controls the increased input grayscale of the pixel (pixel2) to exceed the reference grayscale (Cbnd). Accordingly, it is possible to maintain luminance uniformity between pixels. In particular, it is possible to reduce flicker while maintaining luminance uniformity according to the input grayscale.

[0516] At this time, the signal processing device (170) can control the input grayscale of the second pixel (pixel1) to be reduced so that the input grayscale of the second pixel (pixel1) that is reduced becomes less than the reference grayscale (Cbnd) when the input grayscale of the second pixel (pixel1) exceeds the reference grayscale (Cbnd).

[0517] A signal processing device (170) according to another embodiment of the present disclosure reduces the input grayscale of a pixel (pixel1) when the input grayscale exceeds the reference grayscale (Cbnd), thereby controlling the input grayscale of the pixel (pixel1) to be reduced so that the input grayscale becomes less than the reference grayscale (Cbnd). Accordingly, it is possible to maintain luminance uniformity between pixels. In particular, it is possible to reduce flicker while maintaining luminance uniformity according to the input grayscale.

[0518] FIG. 14 is a drawing showing an example of a tone allocation method according to an embodiment of the present disclosure.

[0519] Referring to the drawing, when the plurality of sub-frames are four sub-frames, the signal processing device (170) can allocate input grayscale as shown in the drawing.

[0520] For example, the signal processing device (170) can assign the input grayscale only to the first sub-frame, such as DIC1, in the case of the first grayscale.

[0521] Meanwhile, the signal processing device (170) can, in the case of the second grayscale, allocate input grayscale only to the first subframe and the second subframe, such as DIC2.

[0522] Meanwhile, the signal processing device (170) can, in the case of the third grayscale, assign input grayscales only to the first subframe, the second subframe, and the third subframe, such as DIC3.

[0523] Meanwhile, the signal processing device (170) can assign input grayscales to each of the first to fourth sub-frames, such as DIC4, in the case of the fourth grayscale.

[0524] Accordingly, the signal processing device (170) can set the above-described reference grayscale (Cbnd) to the fourth grayscale.

[0525] Meanwhile, the signal processing device (170) can, in the case of the fifth grayscale, allocate input grayscales to the first to fourth sub-frames, such as DIC5, and then allocate additional grayscales to the first sub-frame.

[0526] Meanwhile, the signal processing device (170), in the case of the 6th grayscale, can allocate input grayscales to the first to fourth sub-frames, such as DIC6, and then allocate additional grayscales to the first and second sub-frames. Accordingly, flicker can be reduced while maintaining luminance uniformity according to the input grayscale.

[0527] Although the preferred embodiments of the present disclosure have been illustrated and described above, the present disclosure is not limited to the specific embodiments described above, and various modifications may be made by a person skilled in the art to which the present invention pertains without departing from the gist of the present disclosure as claimed in the claims, and such modifications should not be understood individually from the technical idea or prospect of the present disclosure.

Claims

1. A panel having a plurality of light-emitting diodes; A signal processing device that outputs a video signal; A driving control unit is included, based on the image signal, for outputting a scan signal to the plurality of light-emitting diodes for each of a plurality of sub-frame periods and outputting a data signal for image display; The above signal processing device, When the input grayscale of the first pixel is less than the reference grayscale, the first grayscale compensation mode is performed to reduce the input grayscale of the first pixel, A display device that performs a second tone compensation mode for controlling the input tone of the second pixel to exceed the reference tone by increasing the input tone of the second pixel when the input tone of the second pixel having an increase amount that is lower in luminance than the first pixel is less than the reference tone.

2. In paragraph 1, The above signal processing device, When performing the above first tone compensation mode, If the first pixel is less than the reference grayscale, the input grayscale of the first pixel is reduced, An image display device that increases the input grayscale of the second pixel when the second pixel is lower than the reference grayscale.

3. In paragraph 1, The above signal processing device, An image display device that controls the size of the increase in the input grayscale of the second pixel in the second grayscale compensation mode to be greater than the size of the decrease in the input grayscale of the first pixel in the first grayscale compensation mode.

4. In paragraph 1, The above signal processing device, An image display device that increases the input grayscale of the second pixel to a second level that exceeds the reference grayscale when the input grayscale of the second pixel is a first level that is less than the reference grayscale.

5. In paragraph 4, The above signal processing device, An image display device, wherein, when the input grayscale of the first pixel is the first level that is less than the reference grayscale, the input grayscale of the first pixel is reduced to a third level that is less than the reference grayscale.

6. In paragraph 1, The above signal processing device, A display device that performs a third grayscale compensation mode for controlling the input grayscale of the first pixel to be reduced so that the input grayscale of the first pixel, which is reduced, becomes less than the reference grayscale when the input grayscale of the first pixel exceeds the reference grayscale.

7. In paragraph 6, The above signal processing device, An image display device that reduces the input grayscale of the first pixel to a fifth level that is less than the reference grayscale when the input grayscale of the first pixel is a fourth level that exceeds the reference grayscale.

8. In paragraph 7, The above signal processing device, An image display device that increases the input grayscale of the second pixel to a sixth level exceeding the reference grayscale when the input grayscale of the second pixel is the fourth level exceeding the reference grayscale.

9. In paragraph 1, The above signal processing device, An image display device that performs a fourth tone compensation mode that increases the input tone of the second pixel when the second pixel exceeds the reference tone.

10. In paragraph 9, The above signal processing device, When performing the above 4th tone compensation mode, An image display device, wherein when the first pixel exceeds the reference grayscale, the input grayscale of the first pixel is reduced, and the reduced input grayscale of the first pixel is controlled to exceed the reference grayscale.

11. In paragraph 9, The above signal processing device, An image display device, wherein, when performing the fourth tone compensation mode, the size of the increase in the input tone of the second pixel in the fourth tone compensation mode is controlled to be greater than the size of the decrease in the input tone of the first pixel.

12. In paragraph 1, The above signal processing device, A display device in which the grayscale to which each of the plurality of sub-frame periods is allocated is set as the reference grayscale.

13. In paragraph 1, The above signal processing device, An image display device that controls the first grayscale compensation mode to be performed based on the gain of the first pixel or the gain of the second pixel.

14. In paragraph 1, The above signal processing device, An image display device that controls the second grayscale compensation mode to be performed based on the gain of the first pixel or the gain of the second pixel, and the ratio of low grayscale below the reference level and high grayscale above the reference level.

15. In paragraph 6, The above signal processing device, An image display device that controls the third grayscale compensation mode to be performed based on the gain of the first pixel or the gain of the second pixel, and the ratio of low grayscale below the reference level and high grayscale above the reference level.

16. In paragraph 9, The above signal processing device, An image display device that controls the fourth grayscale compensation mode to be performed based on the gain of the first pixel or the gain of the second pixel, and the ratio of low grayscale below the reference level and high grayscale above the reference level.

17. A panel having a plurality of light-emitting diodes; A signal processing device that outputs a video signal; A driving control unit is included, based on the image signal, for outputting a scan signal to the plurality of light-emitting diodes for each of a plurality of sub-frame periods and outputting a data signal for image display; The above signal processing device, An image display device that increases the input grayscale of a pixel when the input grayscale of a given pixel is lower than the reference grayscale, and controls the increased input grayscale of the pixel so that it exceeds the reference grayscale.

18. In paragraph 17, The above signal processing device, An image display device that controls the input grayscale of the second pixel to be reduced when the input grayscale of the second pixel exceeds the reference grayscale so that the reduced input grayscale of the second pixel becomes less than the reference grayscale.

19. A panel having a plurality of light-emitting diodes; A signal processing device that outputs a video signal; A driving control unit is included, based on the image signal, for outputting a scan signal to the plurality of light-emitting diodes for each of a plurality of sub-frame periods and outputting a data signal for image display; The above signal processing device, An image display device that reduces the input grayscale of a pixel when the input grayscale of a given pixel exceeds a reference grayscale, thereby controlling the input grayscale of the pixel to be reduced so that the input grayscale of the pixel becomes less than the reference grayscale.

20. Including multiple video display devices; The above video display device, A video wall comprising a video display device according to any one of claims 1 to 19.

Images