# US 12,184,589 B2 · Interface circuit and information processing system for detecting a connection state based on a notification received through a hot plug detect line > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,184,589 B2 - Document ID: US12184589B2 - Status: Granted - Kind: B2 - Application number: 18/339,383 - Filed: 2023-06-22 - Published: 2023-10-19 - Granted: 2024-12-31 - Earliest claimed: 2014-06-12 - Assignees: Sony Group Corporation - Applicants: Sony Group Corporation - Inventors: Kazuaki Toba; Gen Ichimura - Web page: https://patentgrep.com/patent/US12184589B2 ## CPC - H04L 5/02: Channels characterised by the type of signal - G09G 5/006: {Details of the interface to the display terminal (specific for a display terminal using a CRT G09G1/167; using a flat panel G09G3/2096; circuits for interfacing with colour displays G09G5/04)} - G09G 5/008: {Clock recovery} - H04L 5/22: using time-division multiplexing - H04L 9/0825: {using asymmetric-key encryption or public key infrastructure [PKI], e.g. key signature or public key certificates} - H04L 25/0272: {Arrangements for coupling to multiple lines, e.g. for differential transmission} - H04L 25/14: Channel dividing arrangements {, i.e. in which a single bit stream is divided between several baseband channels and reassembled at the receiver} - H04N 5/44: Receiver circuitry {for the reception of television signals according to analogue transmission standards} (H04N5/14 takes precedence) - H04N 21/436: Interfacing a local distribution network, e.g. communicating with another STB {or one or more peripheral devices} inside the home - H04N 21/43635: {HDMI} - G09G 2370/042: for monitor identification - G09G 2370/047: using display data channel standard [DDC] communication - G09G 2370/12: Use of DVI or HDMI protocol in interfaces along the display data pipeline - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - G09G: ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION (arrangements for transferring data between digital computers and displays G06F3/14; static indicating arrangements comprising an association of a number of separate sources or light control cells G09F9/00; static indicating arrangements comprising integral associations of a number of light sources H01J, H01K, H10H, H05B33/12; scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission, details thereof H04N1/00) - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract A signal is transmitted at a high speed in a direction opposite to a transmitting direction of a main large-capacity channel. A first transmitting unit transmits a first signal including a clock component to an external device through a transmission path as a differential signal. A second transmitting unit superimposes a second signal including a clock component on the transmission path as an in-phase signal to transmit to the external device. A state notifying unit communicates with the external device through a pair of differential transmission paths included in the transmission path and notifies the external device of a connection state of its own device by a DC bias potential of at least one of the pair of differential transmission paths. ## Claims ### Claim 1 An information processing apparatus, comprising: receiving circuitry configured to: receive a first signal by a differential signal from an external device through a pair of a utility line and a Hot Plug Detect (HPD) line of a High-Definition Multimedia Interface (HDMI) cable, wherein the first signal includes a first clock component and an audio signal; receive a second signal by an in-phase signal from the external device through the pair of the utility line and the HPD line, wherein the second signal includes a second clock component; and detect a connection state of the external device based on a notification received from the external device through the HPD line, and processing circuitry configured to process the first signal and the second signal. ### Claim 2 (depends on 1) The information processing apparatus according to claim 1, wherein the processing circuitry is further configured to request, based on activation of the information processing apparatus, activation of a transmitting function of the first signal of the external device. ### Claim 3 (depends on 2) The information processing apparatus according to claim 2, wherein the processing circuitry is configured to request the activation of the transmitting function of the external device by a command through a Consumer Electronics Control (CEC) line of the HDMI cable. ### Claim 4 (depends on 1) The information processing apparatus according to claim 1, further comprising an audio output terminal, wherein the processing circuitry is further configured to output audio data from the audio output terminal to a speaker. ### Claim 5 (depends on 4) The information processing apparatus according to claim 4, wherein the processing circuitry is further configured to: receive a signal from a remote control device; and control output of the audio data from the audio output terminal based on user operation. ### Claim 6 (depends on 1) The information processing apparatus according to claim 1, wherein the processing circuitry is further configured to obtain content data by at least one of a tuner, a network interface, or an HDMI terminal, and the content data corresponds to at least audio data. ### Claim 7 (depends on 6) The information processing apparatus according to claim 6, further comprising the tuner or the network interface, wherein the processing circuitry is further configured to receive the content data using the tuner or the network interface. ### Claim 8 (depends on 6) The information processing apparatus according to claim 6, wherein the processing circuitry is further configured to receive the content data from the external device using the HDMI terminal. ### Claim 9 (depends on 1) The information processing apparatus according to claim 1, wherein the processing circuitry is further configured to transmit content data including audio data and image data to the external device through a Transition Minimized Differential Signaling (TMDS) channel of the HDMI cable. ### Claim 10 (depends on 9) The information processing apparatus according to claim 9, wherein the audio data and the image data are baseband data. ### Claim 11 An information processing system, comprising: a first apparatus; and a second apparatus, wherein the first apparatus is configured to communicate with the second apparatus via a High-Definition Multimedia Interface (HDMI) cable, the first apparatus comprises: receiving circuitry configured to: receive a first signal by a differential signal from the second apparatus through a pair of a utility line and a Hot Plug Detect (HPD) line of the HDMI cable, wherein the first signal includes a first clock component and an audio signal; receive a second signal by an in-phase signal from the second apparatus through the pair of the utility line and the HPD line, wherein the second signal includes a second clock component; and receive a notification of a connection state of the second apparatus from the second apparatus through the HPD line, and processing circuitry configured to process the audio signal, and the second apparatus comprises: transmission circuitry configured to: transmit the first signal by the differential signal to the first apparatus through the pair of the utility line and the HPD line; transmit the second signal by the in-phase signal to the first apparatus through the pair of the utility line and the HPD line; and notify the first apparatus of the connection state of the second apparatus through the HPD line. ### Claim 12 (depends on 11) The information processing system according to claim 11, wherein the processing circuitry of the first apparatus is further configured to request, based on activation of the first apparatus, activation of a transmitting function of the first signal of the second apparatus. ### Claim 13 (depends on 12) The information processing system according to claim 12, wherein the processing circuitry of the first apparatus is further configured to request the activation of the transmitting function of the second apparatus by a command through a Consumer Electronics Control (CEC) line of the HDMI cable. ### Claim 14 (depends on 11) The information processing system according to claim 11, wherein the first apparatus further comprises an audio output terminal, and the processing circuitry of the first apparatus is further configured to output audio data from the audio output terminal to a speaker. ### Claim 15 (depends on 14) The information processing system according to claim 14, wherein the processing circuitry of the first apparatus is further configured to: receive a signal from a remote control device; and control output of the audio data from the audio output terminal based on user operation. ### Claim 16 (depends on 11) The information processing system according to claim 11, wherein the processing circuitry of the first apparatus is further configured to obtain content data by at least one of a tuner, a network interface, or an HDMI terminal, and the content data corresponds to at least audio data. ### Claim 17 (depends on 16) The information processing system according to claim 16, wherein the first apparatus further comprises the tuner or the network interface, and the processing circuitry is further configured to receive the content data using the tuner or the network interface. ### Claim 18 (depends on 16) The information processing system according to claim 16, wherein the processing circuitry of the first apparatus is further configured to receive the content data from the second apparatus using the HDMI terminal. ### Claim 19 (depends on 11) The information processing system according to claim 11, wherein the processing circuitry of the first apparatus is further configured to transmit content data including audio data and image data to the second apparatus through a Transition Minimized Differential Signaling (TMDS) channel of the HDMI cable. ### Claim 20 (depends on 19) The information processing system according to claim 19, wherein the audio data and the image data are baseband data.