Image display device and control method therefor

Abstract

The present invention is for preventing side effects of a viewing angle compensation algorithm while widening the viewing angle of a display by selectively applying the viewing angle compensation algorithm, and may provide an image display device comprising: a display unit; a storage unit for storing the viewing angle compensation algorithm; and a control unit for displaying content on the display unit, and determining whether to apply the viewing angle compensation algorithm according to attributes of the content being displayed.

Description

Video display device and its control method

[0001] The present disclosure relates to an image display device for outputting an image by applying a viewing angle compensation algorithm and a control method thereof.

[0002] A video display device is a device that has the function of receiving and processing digital images and displaying them, such as a digital TV and monitor.

[0003] The display unit of a video display device may include, for example, an LCD (Liquid Crystal Display). An LCD is a display that outputs a screen by controlling the arrangement of liquid crystals. Depending on the arrangement of the liquid crystals, LCDs can be classified into TN (Twisted Nematic) displays, VA (Vertical Alignment) displays, and IPS (In-Plane Switching) displays.

[0004] In TN displays, the liquid crystal molecules are arranged horizontally. While TN displays offer the advantages of fast response times and low power consumption, they also have the disadvantages of narrow viewing angles and poor color reproduction.

[0005] In VA displays, the liquid crystal molecules are aligned vertically and rotate vertically when voltage is applied. VA displays offer higher contrast ratios, wider viewing angles, and better color reproducibility than TN displays, but they also have slower response times than TN displays.

[0006] In IPS displays, liquid crystal molecules are arranged vertically and rotate horizontally when voltage is applied. While IPS displays offer the advantages of wide viewing angles and high color reproducibility, they also have the disadvantages of slow response times and high power consumption.

[0007] Among the three types of LCDs, when comparing VA displays and IPS displays, which have relatively good color reproducibility, VA displays are advantageous in terms of production cost, while IPS displays are disadvantageous in terms of viewing angle.

[0008] To further increase the market share of VA displays, various solutions need to be studied to solve the viewing angle problem of VA displays.

[0009] The present disclosure is proposed to solve the aforementioned problems, and aims to provide an image display device and a control method thereof that can prevent side effects of a viewing angle compensation algorithm while widening the viewing angle of a display by selectively applying a viewing angle compensation algorithm.

[0010] In order to achieve the above purpose, according to one aspect of the present disclosure, an image display device can be provided that includes a display unit, a storage unit that stores a viewing angle compensation algorithm, and a control unit that displays content on the display unit and determines whether to apply the viewing angle compensation algorithm based on the properties of the displayed content.

[0011] The above control unit can control to turn off the viewing angle compensation algorithm when the property of the content is text, and to turn on the viewing angle compensation algorithm when the property of the content is non-text.

[0012] The control unit can control to display a multi-screen including a first split screen and a second split screen on the display unit, to display first content of a text attribute on the first split screen, and to display second content of a non-text attribute on the second split screen.

[0013] The above control unit can determine whether to apply the viewing angle compensation algorithm depending on the size of the first split screen.

[0014] The control unit can control to turn off the viewing angle compensation algorithm when the size of the first split screen is greater than or equal to a preset threshold size, and to turn on the viewing angle compensation algorithm when the size of the first split screen is less than the threshold size.

[0015] The above video display device may further include a camera for detecting the user.

[0016] The above control unit can determine whether to keep the field of view compensation algorithm turned off depending on whether a user is detected in the frontal area of ​​the first split screen when the size of the first split screen is greater than or equal to a preset threshold size.

[0017] The control unit can control the viewing angle compensation algorithm to be turned off when a user is detected in the front area of ​​the first split screen, and to be turned on when a user is not detected in the front area of ​​the first split screen.

[0018] The control unit may set an area within a predetermined angle of view radiating from a center point of the display unit as a front area of ​​the image display device, calculate a horizontal distance between the center point of the first split screen and the center point of the display unit, and control to set the front area of ​​the first split screen by moving the front area of ​​the image display device toward the center point of the first split screen by the horizontal distance.

[0019] The above display unit may include a VA (Vertical Alignment) display.

[0020] The above viewing angle compensation algorithm may include a first LUT (Look Up Table) and a second LUT for grayscale and brightness.

[0021] The control unit can control, when the viewing angle compensation algorithm is turned on, to apply a first LUT for implementing bright luminance to a first pixel area of ​​the VA display and to apply a second LUT for implementing dark luminance to a second pixel area of ​​the VA display.

[0022] In addition, in order to achieve the above purpose, according to one aspect of the present disclosure, a method for controlling a video display device can be provided, including a step of displaying content on a display unit, and a step of determining whether to apply a viewing angle compensation algorithm according to the properties of the displayed content.

[0023] The effects of the video display device and its control method according to the present disclosure are described as follows.

[0024] According to at least one of the embodiments of the present disclosure, there is an advantage in that the viewing angle of the display can be widened while preventing side effects of the viewing angle compensation algorithm by selectively applying the viewing angle compensation algorithm.

[0025] Figure 1 is a schematic block diagram of a video display device related to the present disclosure.

[0026] Figure 2 is an example explaining the viewing angle of a VA display and an IPS display.

[0027] Figure 3 is an example of EOTF according to LUT.

[0028] Figure 4 is an example of side effects according to the field of view compensation algorithm.

[0029] FIG. 5 is a flowchart of the operation of a field of view compensation algorithm according to one aspect of the present disclosure.

[0030] FIG. 6 illustrates an example of a screen displayed on a video display device according to one aspect of the present disclosure.

[0031] Figure 7 is an example of a multi-screen related to the present disclosure.

[0032] Figure 8 is a flowchart of the operation of a field of view compensation algorithm according to one aspect of the present disclosure.

[0033] FIG. 9 illustrates an example of a screen displayed on a video display device according to one aspect of the present disclosure.

[0034] Fig. 10 is a flowchart of the operation of a field of view compensation algorithm according to one aspect of the present disclosure.

[0035] FIG. 11 and FIG. 12 illustrate examples of screens displayed on a video display device according to one aspect of the present disclosure.

[0036] Hereinafter, embodiments disclosed in this specification will be described in detail with reference to the attached drawings. Regardless of the drawing numbers, identical or similar components will be given the same reference numbers and redundant descriptions thereof will be omitted. The suffixes "module" and "part" used for components in the following description are assigned or used interchangeably only for the convenience of writing the specification, and do not in themselves have distinct meanings or roles. In addition, when describing the embodiments disclosed in this specification, if it is determined that a specific description of a related known technology may obscure the gist of the embodiments disclosed in this specification, a detailed description thereof will be omitted. In addition, the attached drawings are only intended to facilitate easy understanding of the embodiments disclosed in this specification, and the technical ideas disclosed in this specification are not limited by the attached drawings, and should be understood to include all modifications, equivalents, and substitutes included in the spirit and technical scope of the present disclosure.

[0037] The suffixes "module" and "part" used for components in the following description are given simply for the convenience of writing this specification, and "module" and "part" may be used interchangeably.

[0038] Additionally, these components may be implemented as separate individual hardware modules, or as two or more hardware modules, or as two or more components may be implemented as one hardware module, and in some cases, they may also be implemented as software.

[0039] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the attached drawings and the contents described in the attached drawings, but the present disclosure is not limited or restricted by the embodiments.

[0040] The terms used in this specification have been selected from widely used and commonly accepted terms, taking into account the functions of the present disclosure. However, these terms may vary depending on the intentions or practices of those skilled in the art, the emergence of new technologies, etc. Furthermore, in certain cases, terms may be arbitrarily selected by the applicant, in which case their meanings will be described in the relevant description of the invention. Therefore, it is to be noted that the terms used in this specification should be interpreted based on their substantive meaning and the overall content of this specification, rather than simply their names.

[0041] Figure 1 is a schematic block diagram of a video display device related to the present disclosure. The video display device may be a display device capable of video output, including a display panel. For example, the video display device may include a computer monitor, a TV, a projector, a smartphone, a laptop, or a digital signage device.

[0042] Referring to FIG. 1, an image display device (100) according to an embodiment of the present disclosure may include a broadcast receiving unit (105), an external device interface unit (135), a storage unit (140), a user input interface unit (150), a control unit (170), a display unit (180), an audio output unit (185), a power supply unit (190), and a photographing unit (not shown). If the image display device (100) is a computer monitor, it may not include at least one of the broadcast receiving unit (105), the audio output unit (183), and the photographing unit.

[0043] The broadcast receiving unit (105) may include a tuner (110), a demodulator (120), and a network interface unit (130). Of course, if necessary, it may be designed to include a tuner (110) and a demodulator (120) but not a network interface unit (130), and conversely, it may be designed to include a network interface unit (130) but not a tuner (110) and a demodulator (120).

[0044] The tuner (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. In addition, it converts the selected RF broadcast signal into an intermediate frequency signal or a baseband video or audio signal.

[0045] 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 (110) can process both digital broadcast signals and analog broadcast signals. The analog baseband video or audio signal (CVBS / SIF) output from the tuner (110) can be directly input to the control unit (170).

[0046] Additionally, the tuner (110) can receive RF broadcast signals of a single carrier according to the ATSC (Advanced Television System Committee) method or RF broadcast signals of multiple carriers according to the DVB (Digital Video Broadcasting) method.

[0047] Meanwhile, the tuner (110) can sequentially select RF broadcast signals of all broadcast channels stored through a channel memory function among RF broadcast signals received through an antenna and convert them into intermediate frequency signals or baseband video or audio signals.

[0048] The demodulation unit (120) receives a digital IF signal (DIF) converted by the tuner (110) and performs a demodulation operation.

[0049] For example, if the digital IF signal output from the tuner (110) is in ATSC format, the demodulation unit (120) performs, for example, 8-VSB (8-Vestigal Side Band) demodulation. In addition, the demodulation unit (120) may also perform channel decoding. To this end, the demodulation unit (120) may be equipped with a Trellis Decoder, a De-interleaver, a Reed-Solomon Decoder, etc., and may perform Trellis decoding, deinterleaving, and Reed-Solomon decoding.

[0050] For example, if the digital IF signal output from the tuner (110) is in the DVB format, the demodulation unit (120) performs, for example, COFDMA (Coded Orthogonal Frequency Division Modulation) demodulation. In addition, the demodulation unit (120) may also perform channel decoding. To this end, the demodulation unit (120) may be equipped with a convolution decoder, a deinterleaver, a Reed-Solomon decoder, and the like, and may perform convolution decoding, deinterleaving, and Reed-Solomon decoding.

[0051] 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. For example, the stream signal may be an MPEG-2 TS (Transport Stream) in which a video signal in the MPEG-2 standard and an audio signal in the Dolby AC-3 standard are multiplexed. Specifically, the MPEG-2 TS may include a 4-byte header and a 184-byte payload.

[0052] Meanwhile, the above-described demodulation unit (120) can be provided separately according to the ATSC method and the DVB method. That is, it can be provided as an ATSC demodulation unit and a DVB demodulation unit.

[0053] The stream signal output from the demodulation unit (120) can be input to the control unit (170). The control unit (170) performs demultiplexing, image / audio signal processing, etc., and then outputs the image to the display unit (180) and outputs the audio to the audio output unit (185).

[0054] The external device interface unit (135) can connect an external device and a video display device (100). To this end, the external device interface unit (135) may include an A / V input / output unit (not shown) or a wireless communication unit (not shown).

[0055] The external device interface unit (135) can be connected to external devices such as a DVD (Digital Versatile Disk), Blu-ray, game device, camera, camcorder, computer (laptop), etc., via wired / wireless connection. The external device interface unit (135) transmits a video, audio, or data signal input from the outside through the connected external device to the control unit (170) of the video display device (100). In addition, the video, audio, or data signal processed by the control unit (170) can be output to the connected external device. For this purpose, the external device interface unit (135) may include an A / V input / output unit (not shown) or a wireless communication unit (not shown).

[0056] The A / V input / output section may include a USB terminal, a CVBS (Composite Video Banking Sync) terminal, a component terminal, an S-video terminal (analog), a DVI (Digital Visual Interface) terminal, an HDMI (High Definition Multimedia Interface) terminal, an RGB terminal, a D-SUB terminal, etc., so as to input video and audio signals from an external device to the video display device (100).

[0057] The wireless communication unit can perform short-range wireless communication with other electronic devices. The video display device (100) can be connected to a network with other electronic devices according to communication standards such as Bluetooth, RFID (Radio Frequency Identification), IrDA (Infrared Data Association), UWB (Ultra Wideband), ZigBee, and DLNA (Digital Living Network Alliance), for example.

[0058] In addition, the external device interface unit (135) can be connected to various set-top boxes through at least one of the various terminals described above, and can perform input / output operations with the set-top box.

[0059] Meanwhile, the external device interface unit (135) can receive an application or a list of applications in an adjacent external device and transmit it to the control unit (170) or storage unit (140).

[0060] The network interface unit (130) provides an interface for connecting the video display device (100) to a wired / wireless network including the Internet. The network interface unit (130) may be equipped with, for example, an Ethernet terminal for connection to a wired network, and may use, for example, WLAN (Wireless LAN) (Wi-Fi), Wibro (Wireless broadband), Wimax (World Interoperability for Microwave Access), HSDPA (High Speed ​​Downlink Packet Access) communication standards for connection to a wireless network.

[0061] The network interface unit (130) can transmit or receive data to or from other users or other electronic devices via the connected network or another network linked to the connected network. In particular, it can transmit some content data stored in the video display device (100) to a selected user or electronic device among other users or other electronic devices pre-registered in the video display device (100).

[0062] Meanwhile, the network interface unit (130) can access a predetermined web page via the connected network or another network linked to the connected network. That is, it can access a predetermined web page via the network and transmit or receive data with the corresponding server. In addition, it can receive content or data provided by a content provider or network operator. That is, it can receive content such as movies, advertisements, games, VOD, broadcast signals, and other related information provided by a content provider or network provider via the network. In addition, it can receive firmware update information and update files provided by the network operator. In addition, it can transmit data to the Internet or to a content provider or network operator.

[0063] In addition, the network interface unit (130) can select and receive a desired application from among applications open to the public through the network.

[0064] According to an embodiment, the network interface unit (130) may, when a game application is executed on a video display device, transmit or receive predetermined data with a user terminal connected to the video display device through a network. In addition, the network interface unit may transmit or receive predetermined data with a server that stores game scores.

[0065] The storage unit (140) may store programs for each signal processing and control within the control unit (170), and may also store signal-processed images, voices, or data signals.

[0066] In addition, the storage unit (140) may perform a function for temporary storage of video, audio, or data signals input from the external device interface unit (135) or the network interface unit (130). In addition, the storage unit (140) may store information regarding a specific broadcast channel through a channel memory function.

[0067] Additionally, the storage unit (140) can store an application or a list of applications input from the external device interface unit (135) or the network interface unit (130).

[0068] Additionally, according to an embodiment, the storage unit (140) can store unique information and game play information of a user terminal used as a game controller when providing a game application on a video display device.

[0069] The storage unit (140) may include at least one type of storage medium, for example, a flash memory type, a hard disk type, a multimedia card micro type, a card type memory (for example, an SD or XD memory, etc.), RAM, or ROM (for example, an EEPROM). The video display device (100) may play content files (video files, still image files, music files, document files, application files, etc.) stored in the storage unit (140) and provide them to the user.

[0070] Although FIG. 1 illustrates an embodiment in which the storage unit (140) is provided separately from the control unit (170), the scope of the present disclosure is not limited thereto. The storage unit (140) may also be included within the control unit (170).

[0071] The user input interface unit (150) transmits a signal input by the user to the control unit (170) or transmits a signal from the control unit (170) to the user.

[0072] For example, the user input interface unit (150) may receive and process control signals such as power on / off, channel selection, and screen setting from the remote control device (200) according to various communication methods such as RF (Radio Frequency) communication method and infrared (IR) communication method, or may process control signals from the control unit (170) to be transmitted to the remote control device (200).

[0073] Additionally, for example, the user input interface unit (150) can transmit a control signal input from a local key (not shown) such as a power key, channel key, volume key, or setting key to the control unit (170).

[0074] In addition, for example, the user input interface unit (150) may transmit a control signal input from a sensing unit (not shown) that senses a user's gesture to the control unit (170), or transmit a signal from the control unit (170) to the sensing unit (not shown). Here, the sensing unit (not shown) may include a touch sensor, a voice sensor, a position sensor, a motion sensor, etc.

[0075] The control unit (170) can demultiplex an input stream or process demultiplexed signals through a tuner (110), a demodulator (120), or an external device interface unit (135) to generate and output a signal for video or audio output.

[0076] The image signal processed by the control unit (170) can be input to the display unit (180) and displayed as an image corresponding to the image signal. In addition, the image signal processed by the control unit (170) can be input to an external output device through the external device interface unit (135).

[0077] The voice signal processed in the control unit (170) can be output as audio to the audio output unit (185). In addition, the voice signal processed in the control unit (170) can be input to an external output device through the external device interface unit (135).

[0078] Although not shown in FIG. 1, the control unit (170) may include a demultiplexing unit, an image processing unit, etc.

[0079] In addition, the control unit (170) can control the overall operation within the video display device (100). For example, the control unit (170) can control the tuner (110) to select (tune) an RF broadcast corresponding to a channel selected by a user or a pre-stored channel.

[0080] In addition, the control unit (170) can control the video display device (100) by a user command or internal program input through the user input interface unit (150). In particular, it can connect to a network and enable the user to download a desired application or application list into the video display device (100).

[0081] For example, the control unit (170) controls the tuner (110) to input a signal of a selected channel according to a predetermined channel selection command received through the user input interface unit (150). Then, the control unit processes the video, audio, or data signal of the selected channel. The control unit (170) enables the channel information selected by the user to be output through the display unit (180) or the audio output unit (185) together with the processed video or audio signal.

[0082] As another example, the control unit (170) allows a video signal or audio signal from an external device, for example, a camera or camcorder, input through the external device interface unit (135) to be output through the display unit (180) or the audio output unit (185) in accordance with an external device video playback command received through the user input interface unit (150).

[0083] Meanwhile, the control unit (170) can control the display unit (180) to display an image. For example, the control unit (170) can control the display unit (180) to display a broadcast image input through the tuner (110), an external input image input through the external device interface unit (135), an image input through the network interface unit, or an image stored in the storage unit (140). At this time, the image displayed on the display unit (180) can be a still image or a moving image, and can be a 2D image or a 3D image.

[0084] Additionally, the control unit (170) can control content playback. The content may be content stored within the video display device (100), received broadcast content, or externally input content. The content may be at least one of broadcast video, externally input video, audio files, still images, connected web screens, and document files.

[0085] Meanwhile, in relation to the embodiment of the present disclosure, the control unit (170) can control the display unit (180) to display the home screen according to an input for moving to the home screen.

[0086] The home screen may include a plurality of card objects classified by content source. The card objects may include at least one of a card object representing a thumbnail list of broadcast channels, a card object representing a broadcast guide list, a card object representing a broadcast reservation list or recording list, and a card object representing a media list within the video display device or within a device connected to the video display device. In addition, the home screen may further include at least one of a card object representing a list of connected external devices and a card object representing a list related to calls.

[0087] Additionally, the home screen may further include an application menu having at least one executable application item.

[0088] Meanwhile, when there is a card object movement input, the control unit (170) can control the card object to be moved and displayed, or a card object not displayed on the display unit (180) to be moved and displayed on the display unit (180).

[0089] Meanwhile, the control unit (170) can control the display unit (180) to display an image corresponding to a card object when a certain card object is selected from among multiple card objects in the home screen.

[0090] Meanwhile, the control unit (170) can control to display an object indicating the received broadcast image and information related to the broadcast image within a card object displaying the broadcast image. In addition, the size of the broadcast image can be controlled to be fixed by a lock setting.

[0091] Meanwhile, the control unit (170) can control to display a setup object for at least one of video settings, audio settings, screen settings, reservation settings, pointer settings of a remote control device, and network settings within the home screen.

[0092] Meanwhile, the control unit (170) may also control to display objects for login, help, or exit items in one area of ​​the home screen.

[0093] Meanwhile, the control unit (170) can control an area of ​​the home screen to display an object indicating the number of total card objects or the number of card objects displayed on the display unit (180) among the total card objects.

[0094] Meanwhile, the control unit (170) can control the display unit (180) to display the card object in full screen mode when a card object name within a given card object is selected among the card objects displayed on the display unit (180).

[0095] Meanwhile, when an incoming call is received within a connected external device or video display device, the control unit (170) can control to focus and display a call-related card object among a plurality of card objects, or to move and display a call-related card object within the display unit (180).

[0096] Meanwhile, when entering the application view item, the control unit (170) can control to display an application or a list of applications that can be downloaded from within the video display device (100) or from an external network.

[0097] The control unit (170) can control the installation and execution of applications downloaded from an external network, along with various user interfaces. Furthermore, it can control the display unit (180) to display images related to the running applications, based on the user's selection.

[0098] Meanwhile, although not shown in the drawing, it is also possible to further include a channel browsing processing unit that generates a thumbnail image corresponding to a channel signal or external input signal.

[0099] The channel browsing processing unit can receive a stream signal (TS) output from the demodulation unit (120) or a stream signal output from the external device interface unit (135), extract an image from the input stream signal, and generate a thumbnail image. The generated thumbnail image can be input to the control unit (170) as is or after being encoded. In addition, the generated thumbnail image can also be encoded in a stream form and input to the control unit (170). The control unit (170) can display a thumbnail list including a plurality of thumbnail images on the display unit (180) using the input thumbnail images. Meanwhile, the thumbnail images in the thumbnail list can be updated sequentially or simultaneously. Accordingly, the user can easily understand the contents of a plurality of broadcast channels.

[0100] The display unit (180) converts the image signal, data signal, OSD signal processed by the control unit (170) or the image signal, data signal, etc. received from the external device interface unit (135) into R, G, and B signals to generate a driving signal.

[0101] The display unit (180) may be a PDP, LCD, OLED, flexible display, 3D display, etc.

[0102] Meanwhile, the display unit (180) is configured as a touch screen and can be used as an input device in addition to an output device.

[0103] The audio output unit (185) receives a signal processed by the control unit (170), for example, a stereo signal, a 3.1 channel signal, or a 5.1 channel signal, and outputs it as audio. The audio output unit (185) can be implemented as various types of speakers.

[0104] Meanwhile, in order to detect a user's gesture, a sensing unit (not shown) including at least one of a touch sensor, a voice sensor, a position sensor, and a motion sensor, as described above, may be further provided in the image display device (100). A signal detected by the sensing unit (not shown) may be transmitted to the control unit (170) via the user input interface unit (150).

[0105] Meanwhile, a camera unit (not shown) for filming a user may be further provided. Image information captured by the camera unit (not shown) may be input to the control unit (170).

[0106] The control unit (170) may detect the user's gesture by using an image captured from a shooting unit (not shown) or a signal detected from a sensing unit (not shown), individually or in combination.

[0107] The power supply unit (190) supplies power to the entire video display device (100).

[0108] In particular, power can be supplied to a control unit (170) that can be implemented in the form of a system on chip (SOC), a display unit (180) for displaying images, and an audio output unit (185) for audio output.

[0109] For this purpose, the power supply unit (190) may be equipped with a converter (not shown) that converts AC power into DC power. Meanwhile, for example, when the display unit (180) is implemented as a liquid crystal panel equipped with a plurality of backlight lamps, an inverter (not shown) capable of PWM operation may be further equipped for brightness variable or dimming operation.

[0110] 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, infrared (IR) communication, UWB (Ultra Wideband), ZigBee, etc.

[0111] In addition, the remote control device (200) can receive video, voice or data signals output from the user input interface unit (150) and display them on the remote control device (200) or output voice or vibration.

[0112] The above-described video display device (100) may be a digital broadcast receiver capable of receiving at least one of digital broadcasting in the ATSC format (8-VSB format), digital broadcasting in the DVB-T format (COFDM format), and digital broadcasting in the ISDB-T format (BST-OFDM format) as a fixed type.

[0113] Meanwhile, the block diagram of the image display device (100) illustrated in FIG. 1 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.

[0114] The display unit (180) of the above video display device (100) may include, for example, an LCD (Liquid Crystal Display). An LCD is a display that outputs a screen by controlling the arrangement of liquid crystals. Depending on the arrangement of the liquid crystals, LCDs can be classified into TN (Twisted Nematic) displays, VA (Vertical Alignment) displays, and IPS (In-Plane Switching) displays.

[0115] In TN displays, the liquid crystal molecules are arranged horizontally. While TN displays offer the advantages of fast response times and low power consumption, they also have the disadvantages of narrow viewing angles and poor color reproduction.

[0116] In VA displays, the liquid crystal molecules are aligned vertically and rotate vertically when voltage is applied. VA displays offer higher contrast ratios, wider viewing angles, and better color reproducibility than TN displays, but they also have slower response times than TN displays.

[0117] In IPS displays, liquid crystal molecules are arranged vertically and rotate horizontally when voltage is applied. While IPS displays offer the advantages of wide viewing angles and high color reproducibility, they also have the disadvantages of slow response times and high power consumption.

[0118] Among the three types of LCDs, VA displays and IPS displays, which have relatively good color reproducibility, will be further explained with reference to Fig. 2. Fig. 2 is an example explaining the viewing angles of VA displays and IPS displays.

[0119] When comparing VA displays to IPS displays, VA displays have an advantage in terms of production costs. However, they are disadvantaged in terms of viewing angle.

[0120] To be more specific, as shown in Figure 2, both VA and IPS displays perform well when viewed from the front. However, when viewed from the side, VA displays exhibit more pronounced color fading than IPS displays. In other words, VA displays have narrower viewing angles than IPS displays.

[0121] In order to further increase the market share of VA displays, various methods are being studied to solve the viewing angle problem of VA displays, and a representative example of these is the View Angle Compensation (VAC) algorithm.

[0122] The viewing angle compensation algorithm uses multiple Look Up Tables (LUTs) for tonal and brightness. Each LUT can configure a corresponding Electro-Optical Transfer Function (EOTF). The EOTF is a function that defines the mutual conversion relationship between the electrical information of an HDR image and the optical brightness information when it is output. The use of LUTs will be described with reference to Fig. 3. Fig. 3 is an example of an EOTF according to an LUT.

[0123] (3-1) of Fig. 3 is an example in which a single LUT is applied to the image display device (100) when the viewing angle compensation algorithm is turned off. A single EOTF according to a single LUT is applied to an entire group of pixels.

[0124] (3-2) of FIG. 3 is an example in which multiple LUTs are applied in the image display device (100) when the viewing angle compensation algorithm is turned on. One pixel group is divided into multiple pixel areas (A1, A2), and different EOTFs according to different LUTs are applied to each pixel area. That is, by applying the second EOTF (L) according to the second LUT to the second pixel area (A2), a darker luminance is implemented in the second pixel area (A2), thereby improving the viewing angle, while by applying the first EOTF (H) according to the first LUT to the first pixel area (A1), a brighter luminance is implemented in the first pixel area (A1), thereby compensating for the dark luminance of the second pixel area (A2).

[0125] The viewing angle compensation algorithm according to the above plurality of LUTs may be stored in the storage unit (140).

[0126] However, when a viewing angle compensation algorithm is applied to a VA display, side effects may occur, which will be explained with reference to Fig. 4. Fig. 4 is an example of side effects according to the viewing angle compensation algorithm.

[0127] As illustrated in FIG. 4, when a viewing angle compensation algorithm is applied, dark pixel areas may appear intermittently when viewing the screen closely, making the screen appear unnatural. In particular, when the viewing angle compensation algorithm is applied while displaying content with a specific pattern, such as text, the specific pattern may appear broken or its border may appear discontinuous, like a sawtooth shape. In addition to the text, the specific pattern may include a square pattern, a diamond pattern, a zigzag pattern, and the like.

[0128] Such side effects may cause a decrease in screen visibility.

[0129] Therefore, if a viewing angle compensation algorithm is selectively operated depending on what content is displayed (e.g., depending on the properties of the displayed content) in a video display device equipped with an LCD display such as a VA display, the above-mentioned side effect can be minimized and the deterioration of screen visibility can be prevented. This will be further described with reference to FIGS. 5 and 6. FIG. 5 is an operation flowchart of a viewing angle compensation algorithm according to one aspect of the present disclosure. FIG. 6 illustrates an example of a screen displayed in a video display device according to one aspect of the present disclosure.

[0130] The control unit (170) of the video display device (100) can control multimedia content to be played and displayed on the display unit (180) [S501]. The multimedia content may be received from the outside by the video display device (100) through at least one of the network interface unit (130) and the external device interface unit (135) or may be stored in the storage unit (140).

[0131] The control unit (170) can determine the properties of the displayed content [S503]. The content may be text-based (or pattern-based) content, such as a web page, or image-based content, such as a landscape or a person. Hereinafter, text-based content will be said to have text properties, while content without text or with negligible text will be said to have non-text properties.

[0132] The control unit (170) may determine the properties of the displayed content based on the external source from which the displayed content is provided. Alternatively, the control unit (170) may determine the properties of the displayed content based on metadata of the displayed content. Alternatively, the control unit (170) may determine the properties of the displayed content based on screen analysis of the displayed content (e.g., boundary analysis of objects within the screen).

[0133] As shown in (6-1) of Fig. 6, if the property of the content is text, the control unit (170) can turn off the viewing angle compensation algorithm [S505, S507].

[0134] However, if the property of the content is non-text as shown in (6-2) of Fig. 6, the control unit (170) can turn on the viewing angle compensation algorithm [S509, S511].

[0135] Meanwhile, the video display device (100) may implement a multi-screen comprising multiple split screens, and content with different properties may be displayed on each split screen. This will be further described with reference to FIG. 7. FIG. 7 is an example of a multi-screen related to the present disclosure.

[0136] As illustrated in (7-1) and (7-2) of FIG. 7, the video display device (100) can display a multi-screen (200) including two or more independent split screens (200A, 200B) on the display unit (180). The two or more split screens (20 0A, 200B) may have the same size or different sizes.

[0137] Alternatively, as illustrated in (7-3) of FIG. 7, the video display device (100) may display a multi-screen (200) in which one split screen (200B) is included within another split screen (200A).

[0138] Each split screen can display content with different properties. In this case, the operation of the viewing angle compensation algorithm will be described with reference to FIGS. 8 and 9. FIG. 8 is a flowchart illustrating the operation of the viewing angle compensation algorithm according to one aspect of the present disclosure. FIG. 9 illustrates an example of a screen displayed on a video display device according to one aspect of the present disclosure.

[0139] The control unit (170) of the above video display device (100) can display a multi-screen (200) on the display unit (180) [S801]. The multi-screen (200) can include two or more split screens including a first split screen (200A) and a second split screen (200B).

[0140] The control unit (170) can display first content having text properties on the first split screen (200A) and second content having non-text properties on the second split screen (200B) [S803]. Each of the first content and the second content may be received from the outside by the video display device (100) through at least one of the network interface unit (130) and the external device interface unit (135) or may be stored in the storage unit (140). As described above, the control unit (170) can identify the properties of each content.

[0141] The above control unit (170) can determine the size of the first split screen (200A) on which the first content of the text attribute is displayed.

[0142] When the size of the first split screen (200A) as shown in (9-1) of Fig. 9 is greater than or equal to a preset threshold size, the control unit (170) can turn off the viewing angle compensation algorithm [S805, S807].

[0143] However, if the size of the first split screen (200A) as shown in (9-2) of Fig. 9 is less than the critical size, the control unit (170) can turn on the viewing angle compensation algorithm [S811, S813].

[0144] Meanwhile, when the first content of the text attribute is displayed on the first split screen (200A) and the second content of the non-text attribute is displayed on the second split screen (200B), even if the size of the first split screen (200A) is greater than the threshold size, it is possible to further determine whether the viewing angle compensation algorithm is turned on based on the position of the user (or viewer) detected in front of the image display device (100). This will be further described with reference to FIGS. 10 to 12. FIG. 10 is an operation flowchart of the viewing angle compensation algorithm according to one aspect of the present disclosure. FIGS. 11 and 12 illustrate examples of screens displayed on the image display device according to one aspect of the present disclosure.

[0145] When the size of the first split screen (200A) is greater than or equal to a preset threshold size, the control unit (170) can detect a user in front of the image display device (100) using a camera (or human body detection sensor) (121) provided in the image display device (100) [S1001]. The camera (121) may be a built-in camera of the image display device (100) or an external camera connected via the external device interface unit (135). The camera (121) may be placed at the central upper portion of the image display device (100).

[0146] As shown in (11-1) of FIG. 11, when the user is detected within the front area of ​​the first split screen (200A) where the first content of the text attribute is displayed, the control unit (170) can keep the viewing angle compensation algorithm turned off [S1003, 1005].

[0147] However, as shown in (11-2) of FIG. 11, if the user is detected outside the front area (i.e., in the side area) of the first split screen (200A) where the first content of the text attribute is displayed, the control unit (170) can turn on the viewing angle compensation algorithm [S1007, 1009].

[0148] That is, as shown in (11-1) and (11-2) of FIG. 11, when the position of the first split screen (200A) on which the first content is displayed is changed, the frontal area of ​​the first split screen (200A) also changes, so even if the user is detected at substantially the same position, the viewing angle compensation algorithm may be turned on or off depending on the position of the first split screen (200A).

[0149] Hereinafter, with reference to FIG. 12, the settings of the front area of ​​the first split screen (200A) will be examined in more detail.

[0150] As illustrated in FIG. 12, the control unit (170) can set an area within a predetermined angle of view radiating from the center point (C1) of the image display device (100) (i.e., the display unit (180)) within the maximum angle of view range of the camera (121) as the front area (R1) of the image display device (100).

[0151] The above control unit (170) can calculate the horizontal distance (Lx) between the center point (C2) of the first split screen (200A) on which the first content is displayed and the center point (C1) of the video display device (100).

[0152] In addition, the control unit (170) can set the front area (R2) of the first split screen (200A) by moving the front area (R2) of the video display device toward the center point (C2) of the first split screen (200A) by the horizontal separation distance (Lx).

[0153] The above-described present disclosure can be implemented as computer-readable code on a program-recorded medium. The computer-readable medium includes all types of recording devices that store data that can be read by a computer system. Examples of computer-readable media include hard disk drives (HDDs), solid-state disks (SSDs), silicon disk drives (SDDs), ROMs, RAMs, CD-ROMs, magnetic tapes, floppy disks, optical data storage devices, etc., and also includes media implemented in the form of carrier waves (e.g., transmission via the Internet). In addition, the computer may include a control unit (170) of a video display device and a control unit (not shown) of a remote control device. Therefore, the above detailed description should not be construed as limiting in all respects, but should be considered as illustrative. The scope of the present disclosure should be determined by a reasonable interpretation of the appended claims, and all changes within the equivalent scope of the present disclosure are intended to be included within the scope of the present disclosure.

Claims

1. Display section; A storage unit that stores the field of view compensation algorithm; Display content on the above display section, A display device including a control unit that determines whether to apply the viewing angle compensation algorithm according to the properties of the displayed content.

2. In paragraph 1, the control unit, If the property of the above content is text, turn off the field of view compensation algorithm, A display device characterized in that it controls to turn on the viewing angle compensation algorithm when the property of the above content is non-text.

3. In paragraph 1, the control unit, A multi-screen including a first split screen and a second split screen is displayed on the display unit, A display device characterized by controlling a first content having a text attribute to be displayed on a first split screen and a second content having a non-text attribute to be displayed on a second split screen.

4. In the third paragraph, the control unit, A display device characterized by controlling whether to apply the viewing angle compensation algorithm according to the size of the first split screen.

5. In paragraph 4, the control unit, If the size of the first split screen is greater than a preset threshold size, the above field of view compensation algorithm is turned off, A display device characterized in that the viewing angle compensation algorithm is turned on when the size of the first split screen is less than the threshold size.

6. In paragraph 5, A display device further comprising a camera for detecting a user.

7. In paragraph 6, the control unit, A display device characterized in that it controls whether to keep the viewing angle compensation algorithm turned off depending on whether a user is detected in the frontal area of ​​the first split screen when the size of the first split screen is greater than a preset threshold size.

8. In paragraph 7, the control unit, If a user is detected in the frontal area of ​​the first split screen, the field of view compensation algorithm is kept turned off, A display device characterized in that the viewing angle compensation algorithm is turned on when a user is not detected in the frontal area of ​​the first split screen.

9. In paragraph 8, the control unit, The area within a predetermined angle of view radiating from the center point of the above display section is set as the front area of ​​the image display device, Calculate the horizontal distance between the center point of the first split screen and the center point of the display unit, A video display device characterized in that the front area of ​​the video display device is controlled to set the front area of ​​the first split screen by moving the front area of ​​the video display device toward the center point of the first split screen by the horizontal distance.

10. In paragraph 1, The above display unit is a video display device characterized by including a VA (Vertical Alignment) display.

11. In Article 10, An image display device, characterized in that the above viewing angle compensation algorithm includes a first LUT (Look Up Table) and a second LUT regarding gradation and brightness.

12. In the 11th paragraph, the control unit, An image display device characterized in that, when the above viewing angle compensation algorithm is turned on, a first LUT for implementing bright brightness is applied to a first pixel area of ​​the VA display, and a second LUT for implementing dark brightness is applied to a second pixel area of ​​the VA display.

13. A step of displaying content on the display unit; and A method for controlling a video display device, comprising: a step of determining whether to apply a viewing angle compensation algorithm according to the properties of the displayed content.

14. In paragraph 13, A step of turning off the viewing angle compensation algorithm when the property of the above content is text; and A method for controlling a video display device, characterized by comprising: a step of turning on the viewing angle compensation algorithm when the property of the content is non-text.

15. In paragraph 13, A step of displaying a multi-screen including a first split screen and a second split screen on the display unit; and A method for controlling a video display device, comprising: a step of displaying first content of a text attribute on a first split screen, and displaying second content of a non-text attribute on a second split screen.

16. In paragraph 15, A method for controlling an image display device, characterized by comprising: a step of determining whether to apply the viewing angle compensation algorithm according to the size of the first split screen.

17. In paragraph 16, A step of controlling the viewing angle compensation algorithm to be turned off when the size of the first split screen is greater than or equal to a preset threshold size; and A method for controlling an image display device, characterized by comprising the step of turning on the viewing angle compensation algorithm when the size of the first split screen is less than the threshold size.

18. In paragraph 17, A method for controlling a video display device, comprising: a step of determining whether to keep the viewing angle compensation algorithm turned off depending on whether a user is detected in the frontal area of ​​the first split screen when the size of the first split screen is greater than or equal to a preset threshold size; 19. In paragraph 18, A step of keeping the field of view compensation algorithm turned off when a user is detected in the frontal area of ​​the first split screen; and A method for controlling a video display device, characterized by comprising the step of turning on the viewing angle compensation algorithm when a user is not detected in the frontal area of ​​the first split screen.

20. In paragraph 19, A step of setting an area within a predetermined angle of view radiating from the center point of the display unit as the front area of ​​the image display device; A step of calculating a horizontal distance between the center point of the first split screen and the center point of the display unit; and A method for controlling a video display device, characterized by comprising: a step of setting a front area of ​​a first split screen by moving the front area of ​​the video display device toward the center point of the first split screen by the horizontal distance;

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