Sink device and operating method thereof

Abstract

A sink device according to an embodiment of the present disclosure may comprise: a memory for storing extended display identification data (EDID); an external device interface for receiving a signal from a source device through a high-definition multimedia interface (HDMI) standard; and a controller, which transmits first EDID to the source device, receives a first video signal from the source device in response to the transmission of the first EDID, determines whether the resolution format of the received first video signal is a valid resolution format, acquires a pixel clock frequency on the basis of the first video signal if it is determined that the resolution format of the first video signal is not the valid resolution format, and determines to update the first EDID according to whether the acquired pixel clock frequency is within a tolerance range.

Description

Sync device and method of operation thereof

[0001] The present disclosure relates to a sink device, and more particularly, to a sink device that receives a signal from a source device via the HDMI standard.

[0002] HDMI (High-Definition Multimedia Interface) is an uncompressed digital video / audio interface standard. A sink device, such as a display device, receives video / audio signals from a source device via the HDMI standard.

[0003] The source device transmits video to the sink device at one of the resolutions supported by the sink device. For example, when the source device transmits video with a resolution of 3840x2160 to the sink device, the video may be input to the sink device at a different resolution, such as 3845x2160, depending on a problem with the equipment output (a problem with the chip in the source device or a problem with the software).

[0004] When the sink device receives a video signal with a different resolution, it treats the video as being in an invalid format and outputs a notification (No-signal notification) indicating that no external input signal is being received.

[0005] If the sink device determines that there is an abnormality in the output of the source device, it can output a UI (User Interface) indicating that it is invalid without taking any separate action because it determines that there is an abnormality in the equipment.

[0006] However, conventional sync devices treat video resolution as invalid and do not display the screen even when the pixel clock frequency is within the tolerance range. This means that even when the screen can be displayed sufficiently, the video is not displayed, which can cause inconvenience to the user while watching the video.

[0007] The purpose of the present disclosure may be to improve equipment compatibility issues that may occur in devices using the HDMI specification.

[0008] An object of the present disclosure may be to provide a sink device capable of outputting video normally even if the resolution of the video received from the source device is different.

[0009] An object of the present disclosure may be to provide a sink device that can output video normally by operating backup extended display identification data (EDID) even if the resolution of the video received from the source device is different.

[0010] According to an embodiment of the present disclosure, a sink device may include a memory that stores extended display identification data (EDID); an external device interface that receives a signal from a source device through a High-Definition Multimedia Interface (HDMI) standard; and a controller that transmits a first EDID to the source device, receives a first video signal from the source device in response to transmission of the first EDID, determines whether a resolution format of the received first video signal is a valid resolution format, and, if it is determined that the resolution format of the first video signal is not a valid resolution format, obtains a pixel clock frequency based on the first video signal, and determines an update of the first EDID depending on whether the obtained pixel clock frequency is within an allowable error range.

[0011] A method of operating a sink device communicating with a source device via a High-Definition Multimedia Interface (HDMI) standard according to an embodiment of the present disclosure may include the steps of: transmitting a first EDID (Extended Display Identification Data) to the source device; receiving a first video signal from the source device in response to the transmission of the first EDID; determining whether a resolution format of the received first video signal is a valid resolution format; obtaining a pixel clock frequency based on the first video signal when the resolution format of the first video signal is determined not to be a valid resolution format; and determining an update of the first EDID depending on whether the obtained pixel clock frequency is within an allowable error range.

[0012] A sink device according to an embodiment of the present disclosure can output a video signal normally even if the resolution format of a video signal received from a source device is incorrect, provided that the pixel clock frequency is within a tolerable error range. In other words, even if some of the resolution information output from the source device is incorrect, the video can be output normally.

[0013] According to an embodiment of the present disclosure, even if the resolution format of a video signal received from a source device is not a valid format, an updated EDID can be transmitted to the source device. Accordingly, the sink device can receive a video signal with a valid resolution format from the source device and automatically output normal video. Furthermore, video restoration can be performed automatically without any additional user action, providing an enhanced user experience.

[0014] Figure 1 is a block diagram illustrating the configuration of a display device according to one embodiment of the present invention.

[0015] FIG. 2 is a drawing illustrating the configuration of an HDMI system according to an embodiment of the present disclosure.

[0016] FIG. 3 is a flowchart illustrating an operation method of a sink device according to an embodiment of the present disclosure.

[0017] FIG. 4a is a block diagram illustrating the configuration of a sink device according to one embodiment of the present disclosure.

[0018] FIG. 4b is a flowchart illustrating an operation method of an HDMI system according to an embodiment of the present disclosure.

[0019] FIG. 5 illustrates an example of a first EDID including VIC information according to one embodiment of the present disclosure.

[0020] FIG. 6 is a drawing illustrating an example of a mapping table according to one embodiment of the present disclosure.

[0021] FIG. 7 is a diagram illustrating an updated second EDID according to one embodiment of the present disclosure.

[0022] FIGS. 8A and 8B are drawings illustrating a pop-up window that guides input resolution settings according to an embodiment of the present disclosure.

[0023] Hereinafter, embodiments related to the present invention will be described in more detail with reference to the drawings. The suffixes "module" and "part" used in the following description for components are assigned or used interchangeably solely for the convenience of writing the specification, and do not in themselves have distinct meanings or roles.

[0024] A display device according to an embodiment of the present invention is, for example, an intelligent display device that adds computer-assisted functionality to its broadcast reception function. While faithfully performing the broadcast reception function, it can also be equipped with Internet functionality and other features, providing a more user-friendly interface, such as a manual input device, touch screen, or space remote control. Furthermore, with support for wired or wireless Internet functionality, it can connect to the Internet and a computer, enabling functions such as email, web browsing, banking, or gaming. A standardized, general-purpose operating system can be used for these various functions.

[0025] Accordingly, the display device described in the present invention can perform various user-friendly functions, for example, by allowing various applications to be freely added or deleted on a general-purpose operating system kernel. More specifically, the display device can be a network TV, HBB TV, smart TV, LED TV, OLED TV, etc., and in some cases, it can also be applied to smartphones.

[0026] FIG. 1 is a block diagram illustrating the configuration of a display device according to one embodiment of the present invention.

[0027] Referring to FIG. 1, the display device (100) may include a broadcast receiving unit (130), an external device interface (135), a memory (140), a user input interface (150), a controller (170), a wireless communication interface (173), a display (180), a speaker (185), and a power supply circuit (190).

[0028] The broadcast receiving unit (130) may include a tuner (131), a demodulator (132), and a network interface (133).

[0029] The tuner (131) can select a specific broadcast channel according to a channel selection command. The tuner (131) can receive a broadcast signal for the selected specific broadcast channel.

[0030] The demodulator (132) can separate the received broadcast signal into a video signal, an audio signal, and a data signal related to the broadcast program, and can restore the separated video signal, audio signal, and data signal into a form that can be output.

[0031] The external device interface (135) can receive an application or a list of applications within an adjacent external device and transmit it to the controller (170) or memory (140).

[0032] The external device interface (135) can provide a connection path between the display device (100) and the external device. The external device interface (135) can receive one or more of images and audio output from an external device connected wirelessly or wiredly to the display device (100) and transmit them to the controller (170). The external device interface (135) can include a plurality of external input terminals. The plurality of external input terminals can include an RGB terminal, one or more HDMI (High Definition Multimedia Interface) terminals, and a component terminal.

[0033] A video signal of an external device input through an external device interface (135) can be output through a display (180). A voice signal of an external device input through an external device interface (135) can be output through a speaker (185).

[0034] An external device that can be connected to the external device interface (135) may be any one of a set-top box, a Blu-ray player, a DVD player, a game console, a sound bar, a smartphone, a PC, a USB memory, and a home theater, but this is only an example.

[0035] The network interface (133) may provide an interface for connecting the display device (100) to a wired / wireless network including the Internet. The network interface (133) may 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.

[0036] Additionally, some content data stored in the display device (100) can be transmitted to a selected user or electronic device among other users or other electronic devices pre-registered in the display device (100).

[0037] The network interface (133) can access a predetermined web page through a connected network or another network linked to the connected network. That is, by accessing a predetermined web page through a network, data can be transmitted or received with the corresponding server.

[0038] In addition, the network interface (133) can receive content or data provided by a content provider or network operator. That is, the network interface (133) can receive content such as movies, advertisements, games, VOD, broadcast signals, etc. and information related thereto provided from a content provider or network provider via a network.

[0039] Additionally, the network interface (133) can receive firmware update information and update files provided by the network operator, and can transmit data to the Internet or content provider or network operator.

[0040] The network interface (133) can select and receive a desired application from among applications open to the public via a network.

[0041] The memory (140) stores a program for each signal processing and control within the controller (170), and can store signal-processed image, voice, or data signals.

[0042] In addition, the memory (140) may perform a function for temporary storage of video, audio, or data signals input from an external device interface (135) or a network interface (133), and may store information about a specific image through a channel memory function.

[0043] The memory (140) can store an application or a list of applications input from an external device interface (135) or a network interface (133).

[0044] The display device (100) can play content files (video files, still image files, music files, document files, application files, etc.) stored in the memory (140) and provide them to the user.

[0045] The user input interface (150) can transmit a signal input by the user to the controller (170) or transmit a signal from the controller (170) to the user. For example, the user input interface (150) can receive and process control signals such as power on / off, channel selection, and screen setting from a remote control device according to various communication methods such as Bluetooth, Ultra Wideband (WB), ZigBee, Radio Frequency (RF) communication, or infrared (IR) communication, or process control signals from the controller (170) to be transmitted to the remote control device.

[0046] In addition, the user input interface (150) can transmit control signals input from local keys (not shown) such as a power key, channel key, volume key, and setting value to the controller (170).

[0047] An image signal processed by the controller (170) can be input to the display (180) and displayed as an image corresponding to the image signal. In addition, an image signal processed by the controller (170) can be input to an external output device through an external device interface (135).

[0048] The voice signal processed by the controller (170) can be output as audio to the speaker (185). In addition, the voice signal processed by the controller (170) can be input to an external output device through the external device interface (135).

[0049] In addition, the controller (170) can control the overall operation within the display device (100).

[0050] In addition, the controller (170) can control the display device (100) by a user command or internal program input through the user input interface (150), and can connect to a network to enable the user to download a desired application or application list into the display device (100).

[0051] The controller (170) enables the user-selected channel information, etc. to be output through a display (180) or speaker (185) together with processed video or audio signals.

[0052] In addition, the controller (170) allows a video signal or audio signal from an external device, for example, a camera or camcorder, input through the external device interface (135) to be output through the display (180) or speaker (185) in accordance with an external device video playback command received through the user input interface (150).

[0053] Meanwhile, the controller (170) can control the display (180) to display an image, for example, a broadcast image input through a tuner (131), an external input image input through an external device interface (135), an image input through a network interface, or an image stored in a memory (140) can be controlled to be displayed on the display (180). In this case, the image displayed on the display (180) can be a still image or a moving image, and can be a 2D image or a 3D image.

[0054] In addition, the controller (170) can control the playback of content stored in the display device (100), received broadcast content, or external input content input from outside, and the content can be in various forms such as broadcast video, external input video, audio file, still image, connected web screen, and document file.

[0055] The wireless communication interface (173) can communicate with an external device through wired or wireless communication. The wireless communication interface (173) can perform short-range communication with the external device. To this end, the wireless communication interface (173) can support short-range communication using at least one of Bluetooth, RFID (Radio Frequency Identification), Infrared Data Association (IrDA), UWB (Ultra Wideband), ZigBee, NFC (Near Field Communication), Wi-Fi (Wireless-Fidelity), Wi-Fi Direct, and Wireless USB (Wireless Universal Serial Bus) technologies. This wireless communication interface (173) can support wireless communication between the display device (100) and a wireless communication system, between the display device (100) and another display device (100), or between the display device (100) and a network in which the display device (100, or an external server) is located via a short-range wireless communication network (Wireless Area Network). The short-range wireless communication network can be a short-range wireless personal area network (Wireless Personal Area Network).

[0056] Here, the other display device (100) may be a wearable device (e.g., a smartwatch, smart glasses, a head-mounted display (HMD)) or a mobile terminal such as a smart phone that can exchange data with (or be linked to) the display device (100) according to the present invention. The wireless communication interface (173) may detect (or recognize) a wearable device capable of communication around the display device (100).

[0057] Furthermore, if the detected wearable device is a device certified to communicate with the display device (100) according to the present invention, the controller (170) can transmit at least a portion of the data processed in the display device (100) to the wearable device via the wireless communication interface (173). Accordingly, a user of the wearable device can utilize the data processed in the display device (100) via the wearable device.

[0058] The display (180) can generate a driving signal by converting a video signal, data signal, OSD signal processed by the controller (170) or a video signal, data signal, etc. received from an external device interface (135) into R, G, and B signals, respectively.

[0059] Meanwhile, since the display device (100) illustrated in FIG. 1 is merely an embodiment of the present invention, some of the illustrated components may be integrated, added, or omitted depending on the specifications of the display device (100) actually implemented.

[0060] That is, two or more components may be combined into a single component, or a single component may be subdivided into two or more components, as needed. Furthermore, the functions performed by each block are intended to illustrate embodiments of the present invention, and their specific operations or devices do not limit the scope of the present invention.

[0061] According to another embodiment of the present invention, the display device (100) may receive and play back an image through a network interface (133) or an external device interface (135) without having a tuner (131) and a demodulator (132), unlike that shown in FIG. 1.

[0062] For example, the display device (100) may be implemented separately as an image processing device, such as a set-top box, for receiving broadcast signals or contents according to various network services, and a content playback device for playing contents input from the image processing device.

[0063] In this case, the operating method of the display device according to the embodiment of the present invention described below may be performed by any one of the display device (100) described with reference to FIG. 1, as well as an image processing device such as the separated set-top box, or a content playback device having a display (180) and a speaker (185).

[0064] FIG. 2 is a drawing illustrating the configuration of an HDMI system according to an embodiment of the present disclosure.

[0065] An HDMI system (2) may include a source device (10) and a sink device (20).

[0066] The source device (10) can transmit a signal to the sink device (20) through the HDMI (High Definition Multimedia Interface) standard. Specifically, the source device (10) can transmit an output signal to the sink device (20) under the FRL (Fixed Rate Link) mode through the HDMI 2.1 standard.

[0067] The sink device (20) can output a signal received from the source device (10).

[0068] The display device (100) of Fig. 1 is an example of a sink device (20). The sink device (20) may include all components of the display device (100).

[0069] The source device (10) can be connected to the sink device (20) via an HDMI cable.

[0070] The source device (10) may be an external device such as a set-top box, game console, laptop, or smartphone.

[0071] The sink device (20) may be an electronic device such as a display device (100), a smart pad, a smartphone, or a PC.

[0072] The source device (10) may be a device that supports the HDMI 2.1 standard. The source device (10) may be connected through the external device interface (135) of the sink device (20).

[0073] When the source device (10) is connected to the sink device (20) via HDMI, the source device (10) can supply 5V of power to the sink device (20) via a display data channel (DDC). When the 5V power received from the source device (10) is supplied to the EDID circuit of the sink device (20), the sink device (20) can switch the HPD (Hot Plug Detect) signal from low to high.

[0074] The sink device (20) can transmit a connection confirmation signal (high signal) to the source device (10) as the HPD signal changes from low to high.

[0075] When a high signal is received, the source device (10) can transmit a command to the sink device (20) through the DDC to request the EDID of the sink device (20).

[0076] The sink device (20) can transmit the EDID of the sink device (20) through the DDC according to the received command.

[0077] The source device (10) can output a video signal having a resolution, refresh rate, and color range that matches the EDID received from the sink device (20) to the sink device (20).

[0078] The sink device (20) can transmit a new EDID to the source device (10) instead of the existing EDID depending on the refresh rate supported by the source device (10).

[0079] Figure 3 is a drawing that describes the UI that is output when the sink device detects an abnormality in the video output received from the source device.

[0080] In Fig. 3, it is assumed that the sink device (20) is the display device (100) of Fig. 1.

[0081] The display device (100) receives a video signal of HDMI standard from a source device (10) through an external device interface (135).

[0082] When an abnormality in the output of a received video signal is detected, the display device (100) determines that an abnormality has occurred in the source device (10) and can display an Invalid format UI (300) on the display (180) without taking any separate action.

[0083] The display device (100) may determine that an output abnormality has been detected if the resolution obtained based on the received video signal is different from the set resolution of 3840x2160, such as 3845x2160.

[0084] If the display device (100) determines that an output abnormality has been detected, it can display an Invalid format UI (300) indicating that the video is in an invalid format on the display (180), as shown in FIG. 3.

[0085] However, even if the resolution of the video received from the source device (10) is somewhat off, if the pixel clock frequency is within the allowable error range, the user's video viewing will not be significantly affected even if the video is output to the sink device (20).

[0086] Therefore, even in these cases, it may be unreasonable to output Invalid format UI (300).

[0087] The purpose of the present disclosure is that a sink device (20) may output video normally even if the resolution of the video received from the source device (10) is partially off, if the pixel clock frequency is within an acceptable error range.

[0088] FIG. 4a is a block diagram illustrating the configuration of a sink device according to one embodiment of the present disclosure.

[0089] Referring to FIG. 4a, the sink device (20) may include an external device interface (135), memory (140), display (180), and controller (170).

[0090] The controller (170) can transmit a first EDID including multiple VIC (Video Identification Code) items to the source device (10) via the external device interface (135).

[0091] The controller (170) can receive a video signal from the source device (10) through the external device interface (135) in response to transmission of the first EDID.

[0092] The controller (170) can determine whether the resolution format of the video signal is a valid resolution format based on the received video signal.

[0093] If the controller (170) determines that the resolution format of the video signal is a valid resolution format, it can output the video signal with video information corresponding to the VIC index.

[0094] The controller (170) can obtain a pixel clock frequency based on the video signal when it is determined that the resolution format of the video signal is not a valid resolution format.

[0095] The controller (170) can determine whether the acquired pixel clock frequency is within an acceptable error range.

[0096] The controller (170) can output a video signal to the display (180) with video information corresponding to the VIC index if the acquired pixel clock frequency is within the allowable error range.

[0097] The controller (170) may delete a VIC entry corresponding to the VIC index in the first EDID if the acquired pixel clock frequency is not within the allowable error range.

[0098] The controller (170) can transmit the second EDID with the VIC item deleted from the first EDID to the source device (10) through the external device interface (135).

[0099] The controller (170) can receive a video signal including a VIC index from the source device (10) through the external device interface (135) in response to transmission of the second EDID.

[0100] FIG. 4b is a flowchart illustrating an operation method of an HDMI system according to an embodiment of the present disclosure.

[0101] Referring to FIG. 4b, the controller (170) of the sink device (20) can transmit a first EDID including multiple VIC (Video Identification Code) items to the source device (10) via the external device interface (135) (S401).

[0102] When the source device (10) is connected to the HDMI terminal provided in the external device interface (135) of the sink device (20), it can supply 5V of power to the sink device (20) through the Display Data Channel (DDC). When the 5V power received from the source device (10) is supplied to the EDID (Extended Display Identification Data) circuit of the sink device (20), the sink device (20) can switch the HPD (Hot Plug Detect) signal from low to high.

[0103] The sink device (20) can transmit a connection confirmation signal (high signal) to the source device (10) as the HPD signal changes from low to high.

[0104] When a high signal is received, the source device (10) can transmit a command to the sink device (20) through the DDC to request the EDID of the sink device (20).

[0105] The sink device (20) can transmit the first EDID of the sink device (20) through the DDC according to the received command.

[0106] EDID may include video information supported by the sink device (20). EDID may include multiple VIC entries. Each VIC entry may include a VIC index identifying the VIC entry, a resolution, and an output frequency (or frame rate).

[0107] FIG. 5 illustrates an example of a first EDID including VIC information according to one embodiment of the present disclosure.

[0108] The sink device (20) can transmit the first EDID (500) to the source device (10) in response to an EDID request from the source device (10).

[0109] The first EDID (500) may include a plurality of VIC entries (501 to 505). Each VIC entry may include information about the video supported by the sink device (20). Specifically, each VIC entry may include video quality indicators supported by the sink device (20).

[0110] Each of the plurality of VIC entries (501 to 505) may include a VIC index, a resolution, and an output frequency that identify the VIC entry. For example, the first VIC entry (501) may include a VIC index of 97, a resolution of 3840 x 2160, and an output frequency of 60 Hz.

[0111] The source device (10) can select a VIC item it supports from among a plurality of VIC items (501 to 505) and transmit a VIC index matching the selected VIC item to the sink device (20).

[0112] Again, Figure 4 is explained.

[0113] The controller (170) of the sink device (20) can receive a video signal from the source device (10) through the external device interface (135) in response to transmission of the first EDID (S403).

[0114] The controller (170) of the sink device (20) can receive a video signal containing video data from the source device (10). The video data can include pixel data for a plurality of pixels corresponding to the resolution. The pixel data can include RGB data to be applied to the pixels.

[0115] The source device (10) can select a VIC item corresponding to the video information it supports from among a plurality of VIC items. The source device (10) can transmit a VIC index that identifies the selected VIC item to the sink device (20).

[0116] The VIC index can be included in the video signal and transmitted to the sink device (20) or transmitted separately to the sink device (20).

[0117] For example, the source device (10) can select the first VIC item (501) among the plurality of VIC items (501 to 505) of FIG. 5 and transmit the VIC index 97 matching the first VIC item (501) to the sink device (20).

[0118] The controller (170) of the sink device (20) can determine whether the resolution format of the video signal is a valid resolution format based on the received video signal (S405).

[0119] The controller (170) can obtain a horizontal total value and a vertical total value based on the video signal. The horizontal total value may be the total number of horizontal pixels required to display one row of the screen, and the vertical total value may be the total number of vertical pixels required to display one column of the screen.

[0120] The horizontal total value may include a horizontal active value containing pixel data for pixels in the horizontal direction and a horizontal blank value corresponding to a blank area. The vertical total value may include a vertical active value containing pixel data for pixels in the vertical direction and a vertical blank value corresponding to a blank area.

[0121] The video signal may include pixel data for all pixels in the horizontal direction and pixel data for all pixels in the vertical direction. The controller (170) may calculate a horizontal active value and a vertical active value from the video signal.

[0122] The controller (170) can obtain the number of data for horizontal pixels included in the video signal as a horizontal active value, and can obtain the number of data for vertical pixels included in the video signal as a vertical active value.

[0123] The controller (170) can compare the acquired horizontal active value with a reference horizontal active value corresponding to the VIC index.

[0124] The controller (170) can compare the acquired vertical active value with a reference vertical active value corresponding to the VIC index.

[0125] The controller (170) can determine that the resolution format of the video signal is an invalid format if the acquired horizontal active value and the reference horizontal active value corresponding to the VIC index are different from each other.

[0126] The controller (170) can determine that the resolution format of the video signal is an invalid format if the acquired vertical active value and the reference vertical active value corresponding to the VIC index are different from each other.

[0127] The controller (170) can determine that the resolution format of the video signal is a valid format when the acquired horizontal active value and the reference horizontal active value corresponding to the VIC index are the same, and when the acquired vertical active value and the reference vertical active value corresponding to the VIC index are the same.

[0128] When the controller (170) receives 97 as the value of the VIC index from the source device (10), it can obtain a reference horizontal active value and a reference vertical active value from the first VIC item (501) corresponding to 97. Since the resolution of the first VIC item (501) is 3840 x 2160, the reference horizontal active value may be 3840, and the reference vertical active value may be 2160.

[0129] For example, assume that the sink device (20) receives a VIC index of 97 from the source device (10), and the horizontal active value calculated from the video signal received from the source device (10) is 3845 and the vertical active value is 2160. The controller (170) may determine that the video signal received from the source device (10) is not in a valid resolution format because the horizontal active value is not 3840, which matches the VIC index of 97.

[0130] If the controller (170) of the sink device (20) determines that the resolution format of the video signal is a valid resolution format, it can output the video signal with video information corresponding to the VIC index (S407).

[0131] For example, the controller (170) may receive a first VIC index value of 97, and if each of the calculated horizontal active value and the vertical active value is equal to a reference horizontal active value and a reference vertical active value that match the first VIC index value, the controller (170) may output a video signal with a resolution (3840 x 2160) and an output frequency (60 Hz) corresponding to the first VIC item (501). That is, the controller (170) may control the display (180) to output a video signal with a resolution (3840 x 2160) and an output frequency (60 Hz) corresponding to the first VIC item (501).

[0132] If the controller (170) of the sink device (20) determines that the resolution format of the video signal is not a valid resolution format, it can obtain the pixel clock frequency based on the video signal (S409).

[0133] For example, the controller (170) may determine that the resolution format of the video signal is not a valid resolution format if the calculated horizontal active value is different from the reference horizontal active value that matches the VIC index value transmitted by the source device (10).

[0134] As another example, the controller (170) may determine that the resolution format of the video signal is not a valid resolution format if the calculated horizontal active value differs by a certain percentage from the reference horizontal active value that matches the VIC index value transmitted by the source device (10).

[0135] The controller (170) can calculate the pixel clock frequency using the horizontal total value, the vertical total value, and the frame rate (or output frequency) for three video frames based on the video signal received from the source device (10).

[0136] The controller (170) can calculate the pixel clock frequency using the following [Mathematical Formula 1].

[0137] [Mathematical Formula 1]

[0138] Pixel Clock Frequency = Frame Rate * (Horizontal Total Value * Vertical Total Value)

[0139] The controller (170) can calculate the frame rate of the video signal using three frames received from the source device (10). The sink device (20) can calculate the output frequency of the video signal using three frames received from the source device (10). The sink device (20) can obtain the average of the first frame rate calculated through the first frame and the second frame among the first to third frames sequentially received and the second frame rate calculated through the second frame and the third frame as the frame rate of the video signal.

[0140] The controller (170) can calculate a horizontal total value and a vertical total value using the number of pixel data included in the video signal received from the source device (10).

[0141] The controller (170) of the sink device (20) can determine whether the acquired pixel clock frequency is within the allowable error range (S411).

[0142] The tolerance range may be the range required for stability and compatibility of the HMDI system (2).

[0143] The controller (170) can determine whether the acquired pixel clock frequency is within the allowable error range using the mapping table stored in the memory (140).

[0144] The mapping table may be a table that maps the tolerance range of pixel clock frequency to VIC index, horizontal total value, vertical total value, and frame rate.

[0145] The mapping table is described with reference to Fig. 6.

[0146] FIG. 6 is a drawing illustrating an example of a mapping table according to one embodiment of the present disclosure.

[0147] Referring to FIG. 6, the mapping table (600) may include a VIC index, a pixel frequency (PCLK), a horizontal total value (HTOTAL), a vertical total value (VTOTAL), a frame rate (or output frequency), a tolerance frequency range (Tolerance), and a tolerance range of pixel clock frequency (PCLK Tol).

[0148] The controller (170) can use the mapping table (600) to determine whether the pixel clock frequency obtained in step S409 is within the allowable error range of the pixel clock frequency matched to the VIC index value received from the source device (10).

[0149] For example, if the controller (170) receives a first VIC index value of 97 from the source device (10), it can determine whether the calculated pixel clock frequency is within an allowable error range of 487.5 to 579 (MHz) that matches the first VIC index value.

[0150] The controller (170) can determine that the video signal is in a valid resolution format if the calculated pixel clock frequency is within the tolerance range of 487.5 to 579 (MHz) matching the first VIC index value (97).

[0151] If the calculated pixel clock frequency is not within the tolerance range of 487.5 to 579 (MHz) matching the first VIC index value (97), the controller (170) can generate a new EDID for resolution re-setting and transmit the generated EDID to the source device (10).

[0152] Let's explain Figure 4 again.

[0153] The controller (170) of the sink device (20) can output a video signal with video information corresponding to the VIC index if the acquired pixel clock frequency is within the allowable error range (S413).

[0154] The controller (170) can normally output a video signal received from the source device (10) if the acquired pixel clock frequency is within the allowable error range. The controller (170) can output a video signal with a resolution and output frequency that match the VIC index value received from the source device (10).

[0155] Conventional sink devices did not output the screen by processing it as an invalid format even if the resolution format of the video signal received from the source device was slightly off, or even if the pixel clock frequency was within the allowable error range.

[0156] However, the sink device (20) according to the embodiment of the present disclosure can output the video signal normally even if the resolution format of the video signal received from the source device (10) is incorrect, provided that the pixel clock frequency is within the allowable error range. In other words, the video can be output normally even if some of the resolution information output from the source device (10) is incorrect.

[0157] The controller (170) of the sink device (20) can delete the VIC entry corresponding to the VIC index in the first EDID if the acquired pixel clock frequency is not within the allowable error range (S415).

[0158] For example, the controller (170) may delete the first VIC entry (501) from the first EDID (500) if the calculated pixel clock frequency is not within the tolerance range of 487.5 to 579 (MHz) matching the first VIC index value (97) received from the source device (10). The controller (170) may delete the first VIC entry (501) from the first EDID (500) to generate a new second EDID.

[0159] The controller (170) can generate a second EDID by deleting the first VIC item (501) and transmit the generated second EDID to the source device (10).

[0160] FIG. 7 is a diagram illustrating an updated second EDID according to one embodiment of the present disclosure.

[0161] FIG. 7 illustrates an updated second EDID (510) in which the first VIC item (501) is deleted from the first EDID (500) of FIG. 5.

[0162] Referring to FIG. 7, if the acquired pixel clock frequency is not within the allowable error range, the controller (170) can generate a second EDID (510) in which the first VIC entry (501) is deleted.

[0163] The second EDID (510) may include the second to sixth VIC items (502 to 506). The second EDID (510) may be data that induces the source device (10) to select more accurate video information.

[0164] Again, Figure 4 is explained.

[0165] The controller (170) of the sink device (20) can transmit the second EDID with the VIC item deleted from the first EDID to the source device (10) through the external device interface (135) (S417).

[0166] The controller (170) can transmit the second EDID to the source device (10) via HPD toggle.

[0167] The controller (170) may output a first notification that induces output settings of a different resolution before, after, or simultaneously with transmitting the second EDID to the source device (10). As another example, the controller (170) may output a second notification that induces abnormality checks of the input resolution before, after, or simultaneously with transmitting the second EDID to the source device (10).

[0168] The controller (170) can display the first notification or the second notification on the display (180).

[0169] In another embodiment, the controller (170) may display an Invalid format UI (300) on the display (180) indicating an invalid resolution format, such as FIG. 3, if the acquired pixel clock frequency is not within the acceptable error range.

[0170] FIGS. 8A and 8B are drawings illustrating a pop-up window that guides input resolution settings according to an embodiment of the present disclosure.

[0171] The controller (170) of the sink device (20) can display a first pop-up window (810) on the display (180) to induce the input resolution of the source device (10) to be set to a different resolution if the acquired pixel clock frequency is not within the allowable error range.

[0172] The controller (170) of the sink device (20) can display a second pop-up window (830) on the display (180) to induce an abnormality check of the input resolution of the source device (10) if the acquired pixel clock frequency is not within the allowable error range.

[0173] The controller (170) may display a first pop-up window (810) and a second pop-up window (830) simultaneously.

[0174] The user can be guided to set the input resolution of the source device (10) through the first pop-up window (810) or the second pop-up window (830).

[0175] In another embodiment, the controller (170) may display an Invalid format UI (300) on the display (180) indicating an invalid resolution format, such as FIG. 3, if the acquired pixel clock frequency is not within the acceptable error range.

[0176] Again, Figure 4 is explained.

[0177] The controller (170) of the sink device (20) can receive a video signal including a VIC index from the source device (10) through the external device interface (135) in response to transmission of the second EDID (S419).

[0178] For example, the controller (170) may receive a video signal including a second VIC index value (96) from the source device (10).

[0179] The controller (170) can output the received video signal with a resolution and output frequency matching the second VIC index value (96) if the received video signal is in a valid resolution format.

[0180] In this way, according to an embodiment of the present disclosure, even if the resolution format of the video signal received from the source device (10) is not a valid format, an updated EDID can be transmitted to the source device (10). Accordingly, the sink device (20) can receive a video signal having a valid resolution format from the source device (10) and automatically output a normal video.

[0181] Additionally, video recovery can be performed automatically without any additional action from the user, providing an improved user experience.

[0182] A sink device (20) according to an embodiment of the present disclosure may include a memory (140) storing Extended Display Identification Data (EDID), an external device interface (135) receiving a signal from a source device (10) through a High-Definition Multimedia Interface (HDMI) standard, and a controller (170) transmitting a first EDID (500) to the source device (10), receiving a first video signal from the source device (10) in response to the transmission of the first EDID (500), determining whether a resolution format of the received first video signal is a valid resolution format, and, if it is determined that the resolution format of the first video signal is not a valid resolution format, obtaining a pixel clock frequency based on the first video signal, and determining an update of the first EDID (500) depending on whether the obtained pixel clock frequency is within an allowable error range.

[0183] If the acquired pixel clock frequency is outside the allowable error range, the controller (170) can change the first EDID (500) to the second EDID (510) and transmit the changed second EDID (510) to the source device (10).

[0184] The first EDID (500) includes a plurality of VIC (Video identification Code) items, and the controller (170) receives a first VIC index value matching the first VIC item (501) from the source device (10) in response to transmission of the first EDID (500), and when the acquired pixel clock frequency is outside the tolerance range matching the received first VIC index value, the controller can generate a second EDID (510) from which the first VIC item (501) is deleted from the first EDID (500).

[0185] The memory (140) can store a mapping table (600) that maps a VIC index value, a horizontal total value, a vertical total value, a frame rate, and an allowable error range of the pixel clock frequency. The controller (170) can obtain the allowable error range matching the first VIC index value from the mapping table (600).

[0186] The controller (170) can obtain a horizontal total value, a vertical total value, and a frame rate for three frames based on the first video signal, and calculate the pixel clock frequency using the horizontal total value, the vertical total value, and the frame rate.

[0187] The above controller (170) can output a notification that induces output settings of a different resolution when the acquired pixel clock frequency is outside the above tolerance range.

[0188] The above controller (170) can output a notification that induces an abnormality check of the input resolution when the acquired pixel clock frequency is outside the above tolerance range.

[0189] The controller (170) receives a second video signal including a second VIC index value matching a second VIC item from the source device (10) in response to transmission of the second EDID (510), and when the resolution format of the second video signal is determined to be a valid resolution format, the controller (170) can output the second video signal with a resolution and output frequency matching the second VIC index value.

[0190] The controller (170) can output the video signal with a resolution and output frequency that match the VIC index value received from the source device (10) when the acquired pixel clock frequency is within the allowable error range.

[0191] The controller (170) can output the first video signal without updating the first EDID (500) when the acquired pixel clock frequency is within the allowable error range, and can change the first EDID (500) to the second EDID (510) and transmit the changed second EDID (510) to the source device, and output the received second video signal in response to the transmission of the second EDID (510) when the acquired pixel clock frequency is outside the allowable error range.

[0192] The resolutions of the first video signal and the second video signal may be the same, and the output frequencies may be different.

[0193] The controller (170) calculates a horizontal active value and a vertical active value from the first video signal, and if either the horizontal active value or the vertical active value is different from a reference horizontal active value or a reference vertical active value that matches a VIC index value included in the first video signal, it can determine that the resolution format of the first video signal is not a valid resolution format.

[0194] The controller (170) may determine that the resolution format of the first video signal is a valid resolution format when each of the horizontal active value and the vertical active value is equal to a reference horizontal active value and a reference vertical active value that match a VIC index value included in the first video signal.

[0195] The above controller (170) can output the first video signal with a resolution and output frequency matching the VIC index value.

[0196] An operating method of a sink device (20) communicating with a source device (10) through an HDMI (High-Definition Multimedia Interface) standard according to an embodiment of the present disclosure may include the steps of transmitting a first EDID (Extended Display Identification Data, 500) to the source device (10), receiving a first video signal from the source device (10) in response to the transmission of the first EDID (500), determining whether a resolution format of the received first video signal is a valid resolution format, obtaining a pixel clock frequency based on the first video signal when the resolution format of the first video signal is determined not to be a valid resolution format, and determining an update of the first EDID (500) depending on whether the obtained pixel clock frequency is within an allowable error range.

[0197] According to one embodiment of the present disclosure, the above-described method can be implemented as processor-readable code on a medium in which a program is recorded. Examples of processor-readable media include ROM, RAM, CD-ROM, magnetic tape, floppy disk, and optical data storage devices.

[0198] The display device described above is not limited to the configuration and method of the embodiments described above, and the embodiments may be configured by selectively combining all or part of each embodiment so that various modifications can be made.

Claims

1. In sink equipment, Memory that stores Extended Display Identification Data (EDID); An external device interface that receives signals from a source device through the HDMI (High-Definition Multimedia Interface) standard; and A controller that transmits a first EDID to the source device, receives a first video signal from the source device in response to the transmission of the first EDID, determines whether a resolution format of the received first video signal is a valid resolution format, and, if the resolution format of the first video signal is determined not to be a valid resolution format, obtains a pixel clock frequency based on the first video signal, and determines an update of the first EDID depending on whether the obtained pixel clock frequency is within an allowable error range. Sink device.

2. In paragraph 1, The above controller If the acquired pixel clock frequency is outside the tolerance range, the first EDID is changed to a second EDID, and the changed second EDID is transmitted to the source device. Sink device.

3. In paragraph 2, The above first EDID includes multiple VIC (Video identification Code) items, The above controller In response to the transmission of the first EDID, a first VIC index value matching the first VIC item is received from the source device, and if the acquired pixel clock frequency is outside the tolerance range matching the received first VIC index value, a second EDID is generated from the first EDID in which the first VIC item is deleted. Sink device.

4. In paragraph 3, Further comprising a memory storing a mapping table that maps the VIC index value, the horizontal total value, the vertical total value, the frame rate, and the tolerance range of the pixel clock frequency, The above controller Obtaining the tolerance range matching the first VIC index value from the mapping table Sink device.

5. In paragraph 1, The above controller Obtaining a horizontal total value, a vertical total value, and a frame rate for three frames based on the first video signal, Calculating the pixel clock frequency using the horizontal total value, the vertical total value, and the frame rate Sink device.

6. In paragraph 2, The above controller If the acquired pixel clock frequency is outside the above tolerance range, a notification is output to induce output settings of a different resolution. Sink device.

7. In paragraph 2, The above controller If the acquired pixel clock frequency is outside the above tolerance range, a notification is output to induce an abnormality check of the input resolution. Sink device.

8. In paragraph 3, The above controller In response to the transmission of the second EDID, a second video signal including a second VIC index value matching a second VIC item is received from the source device, and if the resolution format of the second video signal is determined to be a valid resolution format, the second video signal is output with a resolution and output frequency matching the second VIC index value. Sink device.

9. In paragraph 1, The above controller If the acquired pixel clock frequency is within the above tolerance range, the video signal is output with a resolution and output frequency matching the VIC index value received from the source device. Sink device.

10. In paragraph 1, The above controller If the acquired pixel clock frequency is within the tolerance range, output the first video signal without updating the first EDID, If the acquired pixel clock frequency is out of the allowable error range, the first EDID is changed to the second EDID, the changed second EDID is transmitted to the source device, and the second video signal is output in response to the transmission of the second EDID. Sink device.

11. In paragraph 10, The resolution of the first video signal and the second video signal are the same, and the output frequencies are different. Sink device.

12. In paragraph 1, The above controller Calculating a horizontal active value and a vertical active value from the first video signal, If either the horizontal active value or the vertical active value is different from the reference horizontal active value or the reference vertical active value that matches the VIC index value included in the first video signal, it is determined that the resolution format of the first video signal is not a valid resolution format. Sink device.

13. In paragraph 12, The above controller If each of the horizontal active value and the vertical active value is equal to a reference horizontal active value and a reference vertical active value that match the VIC index value included in the first video signal, it is determined that the resolution format of the first video signal is a valid resolution format. Sink device.

14. In paragraph 13, The above controller Outputting the first video signal with a resolution and output frequency matching the VIC index value. Sink device.

15. In the operation method of a sink device that communicates with a source device through the HDMI (High-Definition Multimedia Interface) standard, A step of transmitting a first EDID (Extended Display Identification Data) to the source device; A step of receiving a first video signal from the source device in response to transmission of the first EDID; A step of determining whether the resolution format of the received first video signal is a valid resolution format; If it is determined that the resolution format of the first video signal is not a valid resolution format, a step of obtaining a pixel clock frequency based on the first video signal; and A step of determining an update of the first EDID based on whether the acquired pixel clock frequency is within an acceptable error range. How the sink device works.

Images