KR20110001420A - Display device and controlling method thereof - Google Patents

Abstract

PURPOSE: A display device controlling method is provided to reduce the display pause time by reducing HDCP authentication process in change over of the input device. CONSTITUTION: If the change over of the input device is performed, a display device decides whether performing the HDCP(High-bandwidth Digital Content Protection) authentication process or not with reference to the memory(S5010,S5020). In case the HDCP authentication was not performed, the display device performs the HDCP authentication(S5030). The display device stores the HDCP authentication information in the memory(S5040). If the HDCP authentication is succeeded, the display device displays the input image of the authenticated input equipment to user(S5050).

Description

DISPLAY DEVICE AND CONTROLLING METHOD THEREOF}

The present invention relates to a display device and a control method thereof, and more particularly, to a display device and a control method for shortening the HDCP authentication procedure performed when switching the input of a plurality of digital input devices connected via HDMI.

Recently, DVD (Digital Versatile Disc) has become the main recording medium for recording and reproducing high quality video and audio signals, and the digital video display device capable of displaying high-quality video and the digital high-definition video of DVDs more clearly. Display high-definition digital TV is becoming widespread.

Therefore, an increasing number of DVD devices (e.g., DVD players, DVD recorders, etc.) and digital TVs that record or play video on DVDs are increasingly used. As a digital interface for data transmission between these devices, DVI ( Digital Visual Interface (HDD) or High Definition Multimedia Interface (HDMI) is used.

DVI (Digital Video / Visual Interactive) is a video compression / restoration processing technology that can reproduce video images stored as digital data and is a standard developed by the Digital Display Working Group (DDWG).

HDMI is a multimedia interface for transmitting uncompressed full digital audio / video signals on a single cable. HDMI is an interface between audio and video sources, set-top boxes and DVD players, and sink devices such as monitors and digital TVs. to provide. A device for transmitting audio and video signals to a sink device such as a digital TV using the digital interface of HDMI is also called a digital interface device. The digital interface device may include not only various DVD devices but also set-top boxes, VTRs, and game machines. .

Digital devices supporting DVI and HDMI provide high resolution digital audio and video, and support High-bandwidth Digital Content Protection (HDCP) for copy protection of content. Digital devices that support HDMI and DVI must undergo at least one HDCP certification, which takes time to recognize the user. In particular, when a plurality of digital devices are connected to the digital video display device, HDCP authentication is required for each switching of input sources, resulting in inconvenience on the user side and system inefficiency.

The present invention is to solve the problems of the prior art as described above is to shorten the HDCP authentication procedure when switching the input device when a plurality of input equipment is connected to the digital image display equipment.

In addition, the present invention is to shorten the HDCP authentication procedure when switching the input equipment to significantly reduce the display stop time when switching the input equipment from the user side to increase the user convenience, and to increase the system efficiency by not repeating unnecessary authentication procedures For that purpose.

According to an aspect of the present invention, there is provided a method of controlling a display device, the method including: performing high-bandwidth digital content protection (HDCP) authentication of an connected input device; Storing the HDCP authentication information generated as a result of the HDCP authentication in a memory for each connected input device; When input switching of the input device occurs, determining whether to output the video signal received from the input switch input device using the HDCP authentication information stored in the memory. The method may further include displaying an image received from the input-switched input device when the HDCP authentication result is successful, and performing the HDCP authentication again when the HDCP authentication result is failed.

Preferably, the input device is connected to the display device through HDMI (High Definition Multimedia Interface) or DVI (Digital Video / Visual Interactive).

Preferably, the HDCP authentication information, characterized in that it comprises HDCP authentication result information and input device identification information, characterized in that the HDCP authentication information is generated and stored as a flag.

Preferably, the HDCP authentication result information includes HDCP authentication success (PASS) or HDCP authentication failure (NG), and the input device distinguishing information includes at least one of a device name, a serial number and a port number of the input device. The input device distinguishing information may be generated by being received through an HDMI CEC (Consumer Electronics Control) line or an HDMI Display Data Channel (DDC) line.

The display device for performing the HDCP authentication according to the present invention, HDMI (High Definition Multimedia Interface) receiving unit for communicating with the input device, HDCP authentication unit for performing HDCP (High-bandwidth Digital Content Protection) authentication of the input device, the HDCP A memory for storing HDCP authentication information generated as a result of authentication, an image signal output unit for outputting an image received from the input device, and the input converted using the HDCP authentication information stored in the memory when an input change occurs. It includes a control unit for determining whether to output the video signal received from the equipment. The controller may display an image received from the input-switched input device when the HDCP authentication result is successful, and re-perform the HDCP authentication when the HDCP authentication result is an authentication failure.

Preferably, the input device is connected to the display device through HDMI (High Definition Multimedia Interface) or DVI (Digital Video / Visual Interactive).

Preferably, the HDCP authentication information includes HDCP authentication result information and input device discrimination information, and the HDCP authentication information is generated and stored as a flag.

Preferably, the HDCP authentication result information includes HDCP authentication success (PASS) or HDCP authentication failure (NG), and the input device distinguishing information includes at least one of a device name, a serial number and a port number of the input device. The input device distinguishing information is received and generated by the HDMI receiver through an HDMI Consumer Electronics Control (CEC) line and an HDMI Display Data Channel (DDC) line.

The present invention can shorten the HDCP authentication procedure when switching the input equipment to significantly shorten the display stop time when switching the input equipment from the user side can increase user convenience.

In addition, the present invention can increase system efficiency by unnecessarily using system resources by not repeating unnecessary authentication procedures.

In addition, the present invention can increase the output by reducing the production time to shorten the confirmation time when the next connection when the HDMI HDCP certification procedure only once when the HDMI input check in the manufacturing line in the production of display equipment.

Hereinafter, with reference to the accompanying drawings an embodiment of the present invention that can specifically realize the above object will be described. The configuration and operation of the present invention shown in the drawings and described by the drawings are described as at least one embodiment, and the technical spirit, configuration, and operation of the present invention are not limited by such embodiments.

The terms used in the present invention have been selected as widely used general terms as possible in consideration of the configuration and function of the present invention, but may vary according to the intention and custom of the person skilled in the art or the emergence of new technologies. In certain cases, there is also a term arbitrarily selected in this specification, in which case the meaning will be described in detail in the description of the invention. Therefore, it is to be understood that the terminology used in the present invention should be defined and understood based on the meaning of the term and the contents throughout the present specification, rather than simply the name of the term.

1 is a diagram illustrating a source device and a sink device connected by a digital interface cable according to an embodiment of the present invention.

In FIG. 1, a DVD player 1010 is shown as an example of source equipment, a digital TV 1020 is shown as an example of sink equipment, and an HDMI cable 1030 is shown as an example of a digital interface cable.

In addition to the DVD player, the source equipment may include various video signal output equipment such as a set top box, a cable receiver, a satellite broadcast receiver, and a personal computer. As a sink device, in addition to digital TV, various video display devices such as a monitor and a projector may be included. Digital interface cables may include DVI cables in addition to HDMI cables. For convenience of description below, the source device may be referred to as a display device and the sink device as an input device.

Recently, as multimedia contents are diversified, various multimedia equipments for playing and transmitting various multimedia contents have been developed together, and interface technologies for simple and lossless signal connection between them have been developed. The most representative multimedia interfaces are DVI and HDMI.

DVI (Digital Visual Interface) is a transmission standard established by a consortium formed by leading companies in the computer industry called DIGITAL DISPLAY WORKING GROUP to digitally connect monitors and PCs. The DVI standard has been widely applied to not only PCs and monitors but also commercial plasma displays and peripherals. Recently, HDMI standards, which are more suitable for high-definition multimedia environments, have been developed and commercialized.

HDMI (High Definition Multimedia Interface) is a high-speed multimedia interface that integrates and transmits uncompressed full digital audio and video signals, and is newly developed as a standard that replaces analog interfaces such as composite, S-video, and component video. It is mainly applied to DVD players, HDTVs, and set-top boxes.

The HDMI is processed by 5Gbps digital video and audio without any compression, so the circuit is simple, quality deterioration does not occur, and content protection by HDCP (High-bandwidth Digital Content Protection) is supported. It has the advantage of being easy to use with a single cable connection. In addition, it is compatible with DVI, which is mainly used in the computer industry, and its application is a multimedia interface that is being developed.

In the following description, a case where an HDMI cable is connected as a digital interface will be described as an example.

2 is a block diagram of an HDMI system including an HDMI source device 2010 and an HDMI sink device 2020 according to an embodiment of the present invention.

The HDMI interface includes three independent communication channels, such as Transition Minimized Differential Signaling (TMDS), Display Data Channel (DDC), and Consumer Electronics Control (CEC), which provide audio / video data, device information, and control commands. Can send and receive

The HDMI source equipment 2010 transmits the video signal and the audio signal included in the video signal to the HDMI sink device through the TMDS channel. The HDMI sink device 2020 receives a video signal and an audio signal transmitted through a TMDS channel, and stores its standard information in an EDIDROM. The TMDS channel supports data transmission below 5 Gbps and is responsible for transmitting and receiving video signals and audio signals.

The HDMI source device 2010 may query the detailed information stored in the EDIDROM of the HDMI sink device 2020 through the DDC channel and transmit the video signal and the audio signal optimized for the HDMI sink device 2020. The DDC channel is a data communication standard defined by the international standard organization VESA, and has a function of realizing an optimal screen by referring to the standard information of the HDMI source equipment (2010). In detail, the HDMI source device 2010 may know detailed information of the HDMI sink device 2020 through EDID (Extended Display Identification) outputted by the HDMI sink device 2020 through the DDC channel. The media data is converted according to the display environment of the HDMI sink device 2020 and output to the HDMI sink device 2020 through the TMDS channel. The EDID includes, for example, a producer ID indicating a manufacturing company, a model ID indicating a model name of a product, a supporting function of the display device, timing information, and the like.

HDCP (High-bandwidth Digital Content Protection system) is a copyright protection technology that prevents content from being copied illegally by encrypting a path for transmitting and receiving digital signals from a video playback device such as a PC to a display device such as a display. It is used to encrypt digital interfaces such as DVI and HDMI, and is managed by Digital Content Protection, LLC by a method developed by Intel.

In DVD or digital broadcasting, video data is protected by encryption technology, so it can't be reproduced by simply extracting the data and making it into a copy.However, when it is played on a PC and sent to the display, the password is released and becomes unprotected. It was concerned that pirate copying was made by extracting images from the transmission system. In other words, since the transmission between the PC and the display was performed by analog signals, only the degraded image such as a tape dubbed into a video deck could be obtained even if the signal was extracted and a copy was made. When the same digital signal is transmitted, the entire digital copy can be duplicated by subtracting the transmitted video data, and this path needs to be encrypted and protected. HDCP responds to this request and is standardized.

In HDCP, the content sending side authenticates the receiving side and shares the key used to encrypt the content by the public key encryption. This key is used to encrypt the outgoing video data to prevent data from being leaked during transmission. The protected content is not displayed unless both parties support HDCP, and transmission is rejected by authentication even if a fake receiver is used to extract data.

3 is a block diagram illustrating an embodiment of an HDCP encryption / decryption process.

24-bit RGB data is encrypted via XOR logic with 24-bit pseudo random data from the HDMI Cipher (3010) and then encoded in the TMDS Encoder (3020), and then TMDS link Send data to the display device via The display device decodes the data received through the TMDS link in the TMDS Decoder (3030) and then decodes the 24-bit pseudo-random data from the HDMI cipher (HDMI Cipher) 3040 and the data decrypted through the XOR logic operation. Display on the monitor.

HDCP authentication through such encryption / decryption takes time for the user to recognize. In particular, when one input device is connected to the display device, since the HDCP authentication process is performed only at the first connection, this authentication time may not cause a great inconvenience in use, but when a plurality of input devices are connected This may cause inconvenience to the user.

The HDCP encryption / decryption process for HDCP authentication shown in FIG. 3 is an embodiment, and the HDCP authentication procedure used in the present invention may be performed by a method other than the method shown in FIG.

4 is a diagram illustrating display equipment to which a plurality of input equipments are connected.

With the trend toward higher capacity and higher resolution display devices, the types and utilization of input devices that can use displays are increasing day by day. In FIG. 4, a digital TV 4010 is shown as an example of display equipment, and a camcorder 4020, a set top box 4030, and a home theater 4040 are input devices. The display device may include various display devices such as a projector and a monitor, in addition to the digital TV 401. In addition to the input devices shown in FIG. 4 as input devices connected to the display device, various digital devices such as a mobile phone, a PDA, a DVD player, and a computer may be used. Digital devices capable of transmitting an image may be included. In FIG. 4, the display device and the input device are illustrated as being connected via HDMI, but it is obvious that the description of the present invention may be applied even when the display device and the input device are connected via DVI.

In FIG. 4, all of the outputs of the camcorder 4020, the set-top box 4030, and the home theater 4040 may be simultaneously displayed on the digital TV 4010, but input switching between connected input devices may occur. That is, power on / off or input connection / disconnection of the input equipment or switching of the input equipment through menu manipulation in the digital TV 4010 occurs, and the output of the currently connected input equipment is displayed on the digital TV 4010 by switching. Can be. At this time, since the digital TV 4010 and the input devices are connected through HDMI, HDCP authentication is required to display an image transmitted from the input device in the digital TV 4010.

When the input equipment to the digital TV 4010 is switched, each time the input equipment is switched, the HDCP authentication procedure is performed. Therefore, even though the same input devices are connected and have already undergone the HDCP authentication process, the HDCP authentication process is performed again every time the input device is switched, and there is a problem in that an input delay occurs as long as the time required for HDCP authentication when the input device is switched.

5 is a flowchart illustrating a control method of display equipment performing HDCP authentication according to an embodiment of the present invention.

When a plurality of digital devices are connected to the display device, switching of the input device to the display device occurs due to power ON / OFF of the connected digital devices, connection / disconnection of the digital device input terminals, switching in the display device, etc. (S5010). . When the switching of the input device occurs, it is determined whether the input device has been HDCP authentication with reference to the memory (S5020).

In case of an input device for which HDCP authentication has not been performed, HDCP authentication is performed (S5030). The result of performing the HDCP authentication is PASS when the authentication is successful, and NG when the authentication is unsuccessful, and the display device stores the HDCP authentication information in the memory (S5040). The storage of the HDCP authentication information may include generating a flag related to HDCP authentication, and storing the flag in a memory to make a database. The flag including HDCP authentication information includes HDCP authentication result information (PASS, NG) and input device identification information (serial number, modem name, device name, port number, etc.), and the storage space (memory, EEPROM, HDCP certification results are stored in the database of digital devices stored in the EDIDROM and connected to the display device. In this case, the distinguishing information of the input equipment may be identified and stored using HDMI Consumer Electronics Control (CEC) and Display Data Channel (DDC) lines.

If the HDCP authentication result authentication is successful (PASS) The video input from the authentication device is successfully transmitted to the display means of the display equipment is displayed to the user (S5050). If HDCP authentication fails (NG), try HDCP authentication again, and do not display the image. In the case of HDCP authentication failure, in addition to the basic operation of not displaying an image, an additional operation such as outputting a message informing of HDCP authentication failure or notifying the user that content reproduction failed due to copyright authentication failed is possible.

In the case where the input device switching occurs (S5010), it is determined whether or not the device has performed HDCP authentication (S5020) by searching for the flags stored in the above process. When an input device change occurs, the input device distinguishing information stored in the memory is searched to determine whether the first input device is a device that has been subjected to the HDCP authentication procedure. At this time, if it is determined that the performing of the HDCP authentication is input switching to the stored device, the memory is searched to check the stored HDCP authentication result information (S5020). From the stored HDCP authentication result information, if the performed HDCP authentication result is PASS, the input image is immediately displayed without performing HDCP authentication again. From the stored HDCP authentication result information, if the performed HDCP authentication result is NG, HDCP authentication is performed again, and the above-described steps S5030 to S5050 are repeated.

FIG. 6 is a diagram illustrating display equipment for performing HDCP authentication according to an embodiment of the present invention.

In FIG. 6, the display device 6010 includes a controller 6050, a memory 6060, an HDMI receiver 6070, an HDCP authentication unit 6080, and an image signal output unit 6090. A plurality of input devices-input device 1 6020, input device 2 6030 and input device 3 6040-are connected to the display device 6010 via HDMI.

The HDMI receiver 6070 may communicate with input devices through HDMI. When power on / off of the input devices, connection / disconnection of the input devices, or switching of the input device through the control unit of the display device occurs, the HDMI receiver 6070 recognizes the converted input device and starts communication. In this case, the controller 6050 searches the memory 6060 to determine whether the input device currently communicating with the HDMI receiver 6070 is a device for which HDCP authentication has been performed, and when the input device is newly connected or switched, the HDCP authentication unit 6080. Perform HDCP authentication. When the HDCP authentication unit 6080 performs HDCP authentication, the result of the execution (authentication success (PASS), authentication failure (NG)) is stored in the memory 6060, and the image signal output unit 6090 outputs the image to the user. do.

At this time, the HDCP authentication information stored in the memory 6060 includes HDCP authentication result information performed by the HDCP authentication unit 6080 and input device discrimination information. The storage of the HDCP authentication information may include generating a flag related to HDCP authentication, and storing the flag in the memory 6060 to make a database. The flag including the HDCP authentication information includes HDCP authentication result information (PASS, NG) and information for identifying the input device (serial number, modem name, device name, port number, etc.), and display device memory 6060. The HDCP authentication results are stored in the database for the input devices connected to the display device. In this case, the distinguishing information of the input equipment may be received, identified, and stored through the HDMI receiver 6070 using an HDMI Consumer Electronics Control (CEC) line or a Display Data Channel (DDC) line.

If it is determined that the switched input device is a device for which HDCP authentication has been performed as a result of the memory 6060 search, the controller 6050 retrieves HDCP authentication result information, and bypasses the HDCP authentication unit 6080 when the HDCP authentication is successful. The video output unit 6090 immediately displays the video signal from the input device. If the HDCP authentication result has failed, the HDCP authentication unit 6080 performs HDCP authentication again.

7 is a diagram illustrating HDCP authentication information flags generated and stored through HDCP authentication according to an embodiment of the present invention.

As shown in Fig. 7, the HDCP authentication information flag to be stored has an input device distinguishing information field and an HDCP authentication result information field. In the embodiment of FIG. 7, the device name field, the serial number field, and the port number field are defined and stored as the input device distinguishing information. In addition, other fields including information for identifying the input device may be added. The flag may be generated using only one or more of the fields shown. The HDCP authentication result information field may store the HDCP authentication result by marking the PASS field when the authentication succeeds (PASS) and marking the NG field when the authentication fails (NG).

In addition to the HDCP authentication information flag of the type shown in FIG. 7, the HDCP authentication information may be generated and stored in any other form that may distinguish and recognize the input device and store and recognize the HDCP authentication result. It will be obvious.

When the equipment switching occurs, the control unit searches for the HDCP authentication information flag of FIG. 7 stored in the memory. The controller performs a method illustrated in FIG. 5 by first searching an input device distinguishing information field matched with the switched input device and searching for an HDCP authentication result for the device if there is matching input device distinguishing information.

The present invention can shorten the HDCP authentication procedure when switching the input equipment to significantly reduce the display stop time when switching the input equipment from the user side can solve the inconvenience that the user has to wait every time the input equipment switching.

In addition, the present invention can increase system efficiency by unnecessarily using system resources by not repeating unnecessary authentication procedures.

In addition, the present invention can increase the output by reducing the production time to shorten the confirmation time when the next connection when the HDMI HDCP certification procedure only once when the HDMI input check in the manufacturing line in the production of display equipment.

1 is a block diagram illustrating source equipment and sink equipment connected with a digital interface cable according to an embodiment of the present invention;

2 is a block diagram illustrating an HDMI system including an HDMI source device 2010 and an HDMI sink device 2020 according to an embodiment of the present invention;

3 is a block diagram illustrating one embodiment of an HDCP encryption / decryption process;

4 is a diagram illustrating a display device to which a plurality of input devices are connected;

5 is a flowchart illustrating a control method of display equipment performing HDCP authentication according to an embodiment of the present invention;

6 is a block diagram showing a display device for performing HDCP authentication according to an embodiment of the present invention;

7 is a diagram illustrating HDCP authentication information flags generated and stored through HDCP authentication according to an embodiment of the present invention.

Claims (14)

In the control method of the display equipment connected to the input device and the network, Performing high-bandwidth digital content protection (HDCP) authentication of the connected input device; Storing the HDCP authentication information generated as a result of the HDCP authentication in a memory for each connected input device; And determining whether to output an image signal received from the input-switched input device by using the HDCP authentication information stored in the memory when input switching of an input device occurs. Display equipment control method. The method of claim 1, And displaying the video received from the input-switched input device when the HDCP authentication result is successful, and re-executing the HDCP authentication when the HDCP authentication result is failed. Display equipment control method to carry out. The method of claim 1, And the input device is connected to the display device via HDMI (High Definition Multimedia Interface) or DVI (Digital Video / Visual Interactive). The method of claim 1, And the HDCP authentication information includes HDCP authentication result information and input device discrimination information. The method of claim 1, The HDCP authentication information is generated and stored as a flag, the display device control method for performing HDCP authentication. The method of claim 4, wherein The HDCP authentication result information includes HDCP authentication success (PASS) or HDCP authentication failure (NG), and the input device distinguishing information includes at least one of a device name, a serial number, and a port number of the input device. To control the display equipment to perform HDCP authentication. The method of claim 4, wherein The input device identification information, characterized in that the received via the HDMI CEC (Consumer Electronics Control) line, HDMI DDC (Display Data Channel) line, characterized in that the display equipment control method for performing HDCP. In the display equipment connected to the input device and the network, HDMI (High Definition Multimedia Interface) receiver for communicating with the input device, HDCP authentication unit for performing HDCP (High-bandwidth Digital Content Protection) authentication of the input device, A memory for storing HDCP authentication information generated as a result of the HDCP authentication; Image signal output unit for outputting the image received from the input device, And And a controller configured to determine whether to output an image signal received from the input switched input device by using the HDCP authentication information stored in the memory when the input change occurs. The method of claim 8, The controller may display an image received from the input-switched input device when the HDCP authentication result is successful, and perform the HDCP authentication again when the HDCP authentication result is failed. Performing display equipment. The method of claim 8, And the input device is connected to the display device via HDMI (High Definition Multimedia Interface) or DVI (Digital Video / Visual Interactive). The method of claim 8, And the HDCP authentication information includes HDCP authentication result information and input device discrimination information. The method of claim 8, And the HDCP authentication information is generated and stored as a flag. The method of claim 11, The HDCP authentication result information includes HDCP authentication success (PASS) or HDCP authentication failure (NG), and the input device distinguishing information includes at least one of a device name, a serial number, and a port number of the input device. Display equipment to perform HDCP certification. The method of claim 11, The input device distinguishing information is received and generated by the HDMI receiver through an HDMI Consumer Electronics Control (CEC) line and an HDMI Display Data Channel (DDC) line.

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