JP5801458B2 - Transmission equipment - Google Patents

Description

  The technical field relates to power supply and receipt.

  In Patent Document 1, “a signal transmission unit that transmits a video signal to a receiving device via a cable using a plurality of channels and a differential signal, and request information for requesting power supply are transmitted via the cable. An information transmission unit that transmits to the reception device, and a power supply switching unit that supplies power supplied from the reception device via the cable to the internal circuit in accordance with transmission of the request information of the information transmission unit. "Transmission device characterized by comprising" (see Patent Document 1 [0017]) is disclosed.

  Furthermore, “the source device 110 transmits the power supply request information to the sink device 120 using the CEC line of the HDMI cable 130” (see Patent Document 1 [0100]), or “the source device 110 receives the source from the sink device 120A. It is disclosed that power is supplied to the device 110A via the reserved line of the HDMI cable 130 "(see Patent Document 1 [0220]).

  Patent Document 2 discloses that “function information is CEC (Consumer Electronics Control) via a CEC line that is a control line between a source device and a sink device connected by HDMI (R) (High-Definition Multimedia Interface). Data or CDC (Capability Discovery Channel) data is transmitted from the source device to the sink device or from the sink device to the source device "(see Patent Document 2 [0160]).

JP 2009-44706 A JP 2010-4510 A

  However, none of the cited references disclose the power supply to the relay device (cable, repeater device, etc.) installed between the sink device and the source device.

  In order to solve the above problems, for example, the configuration described in the claims is adopted.

  The present application includes a plurality of means for solving the above-described problems. For example, a system for transmitting a video signal from a source device to a sink device via a relay device, the sink device includes the relay device. Power is supplied to the relay device based on a request from the device.

  According to the above means, it is possible to supply power to the relay device installed between the sink device and the source device, improving usability for the user.

Block diagram showing an example of a transmission system Explanatory drawing showing an example of a message structure in a transmission system Table showing an example of a message in the transmission system Table showing examples of message arguments in a transmission system The figure which shows an example of transmission / reception of the message in a transmission system Block diagram showing an example of a cable The figure which shows an example of transmission / reception of the message in a transmission system Table showing examples of message arguments in a transmission system Table showing examples of message arguments in a transmission system Table showing examples of message arguments in a transmission system The figure which shows an example of transmission / reception of the message in a transmission system The figure which shows an example of transmission / reception of the message in a transmission system Block diagram showing an example of a cable Table showing an example of device information description Table showing examples of message arguments in a transmission system Block diagram showing an example of wireless transmission Table showing examples of message arguments in a transmission system

  Examples will be described below.

  FIG. 1 is a block diagram illustrating an example of a transmission system according to the present embodiment, in which a source device 11 is connected to a sink device 21 via a cable 32 and supplies power from the sink device to the source device. A video signal is supplied from the device to the sink device.

  The source device 11 is a video signal transmission device such as a disk player, a disk recorder, a semiconductor recorder, a broadcast receiver, a game machine, or a PC. A reproduction unit 111 and a video transmission unit 112 for reproducing a video signal from data obtained from a storage medium such as an optical disk, a magnetic recording disk, and a semiconductor memory, broadcasting, and a network, an extended display identification data (EDID) reading unit 113, a CEC (Consumer) Electronics Control (Communication Control) communication unit 114, voltage detection unit 115, DDC (Display Data Channel) + 5V supply unit 116, HPD (Hot Plug Detect) detection unit 117, control unit 118, and power supply circuit 119.

  The sink device 21 is a video signal receiving device including a display device such as a liquid crystal display, a plasma display, or an organic EL display. The sink device 21 includes a display unit 211, a video reception unit 212, an EDID storage unit 213, a CEC communication unit 214, a current limiting unit 215, an HPD output unit 216, a control unit 217, a power supply unit 218, and a power supply circuit 219. It should be noted that a tuner, a descrambler, a demultiplexer, a decoder, a recording function, and the like that process broadcast waves received by an antenna may be included, and video content may be played back by a single sink device.

  The cable 32 is a cable that connects between the connector portions 312 to 317 that are connector portions to the source device and the connector portions 332 to 337 that are sink devices, and is, for example, an HDMI (R) converter cable. An electrical / optical conversion unit 321, an optical / electrical conversion unit 322, an optical fiber 327, an EDID acquisition unit 323, a CEC communication unit 324, a control unit 325, and a power supply circuit 326 are included.

  An example of the structure of messages exchanged by the CEC communication units 114, 214, and 324 is shown in FIG. As described in Patent Document 2, a CDC message is defined as one of CEC messages. Following the Start Bit indicating the head of the message, a CEC Header describing the logical address of the message transmitting device and the logical address of the receiving device. Block, CEC Opcode Block indicating a CDC message, Initiator Physical Address indicating the physical address of the message transmitting device, CDC Opcode indicating the type of the CDC message, and CDC Parameter indicating the argument of the CDC message.

  Hereinafter, a CDC message will be described as an example. However, the present invention is not limited to the CDC message structure, and if the CDC Opcode is defined in the CEC Opcode, the CEC message can be used instead of the CDC message. Alternatively, a bidirectional communication message such as DDC (Display Data Channel) or HDMI Ethernet Channel used for EDID reading may be used.

  In an HDMI (R) system, a source device having an output terminal, a sink device having an input terminal, and a repeater device having both an output terminal and an input terminal generally have different physical addresses, but a cable generally has a physical address. Do not get. There are several possible methods for describing the initiator physical address in the CDC message issued by a cable that does not acquire a physical address.

  For example, it is conceivable to describe the physical address of the source device indicated in the EDID of the sink device in the initiator physical address of the CDC message transmitted by the cable. In addition, “FFFF” may be assigned to the initiator physical address as the physical address unknown, and information corresponding to the physical address of the source device may be described in the argument of the CDC message.

  The latter has a long communication time because the argument of the CDC message is long, but there is an advantage that the risk that the source device malfunctions is small because the cable uses a physical address different from that of the source device. In the following description of the embodiments, the former method will be used.

  FIG. 3 is a table showing an example of the CDC message. <CDC_Power_Request> is a message requesting that the source device supply the current indicated by the argument [Power_Source] to the sink device (and / or cable).

  <CDC_Power_Status> is a message notifying that the sink device starts supplying the current indicated by the argument [Power_Sink] to the source device (and / or cable). <CDC_Power_Notice> is a message in which the sink device notifies the source device (and / or cable) of the change in supply current to the current indicated by the argument [Power_Sink].

  <CDC_Power_Request_C> is a message for requesting current supply indicated by an argument (parameter) [Power_Cable] from the cable to the sink device. <CDC_Power_Notice_C> is a message for notifying that the power to the source device is stopped when the cable is supplying power to the source device from an independent power source other than the power supply from the sink.

  FIG. 3 shows a response message for responding to each message if the destination device supports the function of the present invention.

  Further, in FIG. 3, by changing the message name (that is, Opcode) for requesting power supply between the source device and the cable, even if a common physical address is used as the initiator physical address, it is possible to distinguish which message is issued. it can. This may be defined such that the message name is common and the source device and the cable can be distinguished by adding, for example, a device type as an argument.

  Further, the number of arguments may be changed, and for example, the source device may be distinguished from the required current of the source device by describing the current that can be supplied to the source device in addition to the required current of the cable.

  FIG. 4 is a table showing an example of message arguments. [Power_Source] indicates the necessity of power supply in 1 bit. [Power_Sink] is the [Input Port Number] of 4 bits for the power supply input terminal, [P_Source] of 2 bits indicating the power supply status to the source device, and [P_Cable] of 2 bits indicating the power supply status to the cable Consists of

  [Input port Number] is the input terminal number 4 bits of the sink device, and when combined with the initiator physical address in the CDC message, indicates the physical address of the connection source device. In place of the input terminal number, the physical address of the connection destination (that is, the physical address described in the EDID of the corresponding input terminal) 2 bytes may be used, but in order to shorten the communication time by suppressing the message length Input terminal number 4 bits is better.

  [P_Source] has no power supply to the source device, “No Power”, half the specified power supply “Half Power”, the specified power is supplied by the sink device “Power_S”, and the specified power is independent of the sink device "Power_C" supplied from the power supply provided for [P_Cable] indicates “No Power” in which the sink device does not supply power to the cable, “Half Power” that is half the predetermined power, and “Full Power” that supplies the predetermined power.

  [Power_Cable] is a 3-bit [Wire] indicating whether or not the Utility terminals at both ends of the cable are connected to transmit power, a 2-bit [P_Source] indicating the power supply status to the source device, Consists of 2 bits [P_Cable] indicating the power supply status. [Wire] indicates a connection state “Connect” and a non-connection state “No Connect”. [P_Source] and [P_Cable] have the same meaning as the previous [P_Source] parameter, and will not be described.

  In FIG. 4, a state is defined in which the power supplied from the sink device is divided by the source device and the cable. However, for simplicity, this state is deleted, and one of the source device and the sink device receives power. In the case, it is obvious that the exclusive control that the other cannot be accepted may be used.

  FIG. 5 is a diagram illustrating an example of message transmission / reception. Hereinafter, the operation of the transmission system will be described with reference to FIGS.

  First, the power supply unit 218 of the sink device 21 supplies the power for starting up the transmission system, for example, 5 V 65 mA, to the power supply circuit 119 of the source device 11 through the current limiting unit 215, the Utility terminal 335, the cable 32, and the Utility terminal 315 (Step 5). 701).

  The power supply circuit 119 of the source device 11 supplies power to the HPD output unit 216 and the power supply circuit 219 of the sink device 21 through the DDC + 5V supply unit, the DDC + 5V terminal 317, the cable 32, and the DDC + 5V terminal 337 (step 702).

  The HPD output unit 216 to which the power is supplied sends a logic level, for example, “H” indicating that the cable is connected to the HPD detection unit 117 of the source device 11 through the HPD terminal 337, the cable 32, and the HPD terminal 317 (step 703). .

  The cable connection information detected by the HPD detection unit 117 is transmitted to the control unit 118, and the control unit 118 instructs the EDID reading unit 113 to read EDID. The EDID reading unit 113 reads and acquires the EDID in which information about the reception capability of the sink device is described from the EDID storage unit of the sink device 21, and transmits the EDID to the control unit 118 (step 704).

  At this time, the EDID acquisition unit 323 of the cable 32 monitors the signal on the cable, and at least information necessary for the cable 32 among the EDID acquired by the source device, for example, the physical address of the sink device and the input connected to the cable Get information about the physical address of the source device indicated by the combination of terminal numbers. Thus, the source device 11 and the cable 32 obtain the physical address of the source device from the EDID (step 705).

  The 5 V 65 mA supplied by the power supply circuit 218 is, for example, a maximum of 5 mA for circuit block operation in the cable 32 (supplied from the HPD terminal 335), a maximum of 5 mA for circuit block operation in the source device 11, and the source device is a DDC + 5V terminal It is distributed to 55 mA output from the cable 316 to the cable 32 and the sink device 21. The 5V maximum 55 mA supplied by the DDC + 5V supply unit 116 is defined by the DDC standard, but the source device originally supplies the power supplied from the Utility terminal 335 to the cable 32 from the DDC + 5V terminal 316 to the cable 32, and the sink device 21 supplies the power. The usage is to return 50mA.

  Therefore, the sink device 21 that supplies power for system startup from the Utility terminal 335 defines the current consumed from the DDC + 5V terminal 336 as a maximum of 10 mA, and if the insufficient maximum of 40 mA is accommodated in the power supply circuit 219, the cable is connected. Since the flowing current is reduced, the power loss can be suppressed. In this case, the power supplied by the sink device from the Utility terminal 335 for starting up the transmission system is a maximum of 5 mA for the source device, a maximum of 10 mA for the cable (5 mA from the Utility terminal and 5 mA from the DDC + 5V terminal), and a maximum of 10 mA (DDC + 5 V for the sink device). The power supply of the HPD output unit 216 and the EDID storage unit 213 from the terminal) may be 25 mA in total.

  A <CDC_Power_Request_C> [“Connect”, “No Power”, “FullPower”] message 706 for requesting the power required for the cable 32 to transmit the video signal to the sink device 21 is synced from the CEC communication unit 324 of the cable 32. The data is sent to the CEC communication unit 214 of the device 21. In order to simplify the following description, “CEC communication unit” is omitted, and “send a message from the cable 32 to the sink device 21” is described. The message 706 can be received by the source device 11, but since there is no change in the power receiving state of the source device 11, there is no need for an internal control operation or a reply, so the arrow of the message 706 toward the source device is a broken line. Show.

  The power supply circuit 218 of the sink device 21 supplies, for example, 5 V 500 mA to the power supply circuit 326 of the cable 32 through the Utility terminal 335 (step 707). The sink device 21 transmits a <CDC_Power_Status> [“1”, “No Power”, “Full Power”] message 708 to the cable 32 to notify that the power supply for the cable 32 is started, and the power circuit 326 of the cable 32 Starts using 500 mA (step 709). Here, it is assumed that the cable 32 is connected to the input terminal number 1 (not shown) of the sink device 21.

  The power supply circuit 326 supplies power to the electro-optical conversion unit 321 and the photoelectric conversion unit 322. As a result, the video output of the reproduction unit 111 is output as an electrical video signal from the video transmission unit 112 to the video terminal 312, which becomes an optical video signal by the electrical / optical conversion unit 321 and to the photoelectric conversion unit 322 by the optical fiber 327. Sent. By transmitting an optical signal with an optical fiber, long-distance transmission becomes easier than electrical signal transmission. The optical / electric conversion unit 322 converts the video signal into an electrical video signal and outputs it to the video terminal 332, which is received by the video reception unit 212 and displayed on the display unit 211.

  When the source device 11 wants to receive power, a <CDC_Power_Request> [“Need”] message 710 is sent to the sink device 21 and the cable 32. The sink device supplies power to the cable and returns a <CDC_Power_Status> [“1”, “No Power”, “Full Power”] message 711 indicating that power cannot be supplied to the source device 11 to the source device 11. At the same time, the cable 32 informs the source device 11 and the sink device 21 with a <CDC_Power_Request_C> [“Connect”, “No Power”, “FullPower”] message 712 that power is being used.

  Since the message 712 is the same as the message for requesting power supply by the cable, the sink device overlaps with the message 711, but the <CDC_Power_Status> ["1", "No Power", "Full Power"] message 713 is displayed. Reply to cable 32. In order to avoid duplication of the messages 711 and 713, the message 711 can be omitted if the message 712 is sent first as a response message to the message 710. For this reason, the response message to the message 710 is set so that the sink device 21 transmits after the cable 32 so that the sink idle time of the sink device is extended or a reply is waited for a predetermined time, for example, about 0.1 second. Also good.

  At this time, the sink device 21 responds to the message 711 with a <CDC_Power_Notice> [“1”, “Half Power”, “Half Power”] message that is a notice of power distribution change, and the cable 32 continues to maintain the supply of all power. You may make it respond with the message 712 to request.

  As described above, in principle, it is preferable that the power supply side decides the power distribution instruction and prioritizes the power distribution to the currently receiving device. In addition, devices that receive and use electric power should increase the chances of power supply to necessary devices as a principle of promptly returning the electric power supply when the electric power becomes unnecessary.

  When the cable 32 stops using power (eg, the end of video signal transmission) (step 714), the cable 32 syncs a <CDC_Power_Request_C> ["Connect", "No Power", "FullPower"] message 715 indicating that power supply is stopped. Send to equipment. The sink device stops the power supply (step 716), and informs the source device 11 and the cable 32 of the power supply stop with a <CDC_Power_Status> ["1", "No Power", "NoPower"] message 711.

  Even when the source device 11 does not transmit a video signal, for example, when the source device is a mobile device, power may be required for charging a built-in secondary battery. The source device 11 transmits a <CDC_Power_Request> [“Need”] message 718 requesting power supply to the cable 32 and the sink device 21. The utility line that supplies power is connected to the cable 32, and no response is required particularly when it is not necessary to continue to use the power, but <CDC_Power_Request_C> ["Connect", "Power_S", "No Power You may respond with a "] message (not shown).

  The sink device 21 starts supplying a predetermined 5 V 500 mA (step 719), and informs the source device 11 of the start of supply with a <CDC_Power_Status> ["1", "Power_S", "No Power"] message 720. Starts using predetermined power (step 721).

  <CDC_Power_Notice> ["1", "if the sink device 21 uses other functions using the Utility line, for example, transmission of packet signals or audio signals, or if it is desired to stop power supply by user operation, etc. The source device 11 is notified by a “No Power”, “No Power”] message 722. The source device enters the power use stop process, but if a time such as backup is required in the stop process, a <CDC_Power_Request> ["Need"] message 723 requesting power supply is transmitted to the sink device 21.

  When the sink device 21 continues to supply power, a <CDC_Power_Status> [“1”, “Power_S”, “No Power”] message (not shown) is transmitted to the source device. However, when the sink device performs the power supply stop operation, a <CDC_Power_Notice> [“1”, “No Power”, “NoPower”] message 724 is sent to the source device 11 at a predetermined time interval, for example, every 5 seconds. Of course, in an emergency such as when the main power switch of the sink device 21 is turned off, the power supply may be suddenly stopped without issuing this message 724, so the source device 11 considers this in advance. It is necessary to keep.

  After stopping the power use (step 725), the source device 11 transmits a <CDC_Power_Request> ["No Need"] message notifying the power use stop to the sink device 21. After stopping the power supply (step 727), the sink device sends <CDC_Power_Status> ["1", "No Power", "NoPower"] indicating the power supply stop to the source device 11. However, even when the power supply is stopped, when the sink device assumes a restart of the transmission system, it may continue to supply about 5 V 65 mA or 25 mA as standby power for startup (step 701).

  When the source device receives power supply, depending on the cable 32, the resistance of the electric wire connecting the Utility terminals 325 and 315 is high, and the voltage received by the source device 11 with respect to the voltage output from the sink device 21 may greatly decrease. . For example, if the resistance of the electric wire is 5Ω with respect to the 5V output of the sink device 21 and the supply current is 500 mA, a voltage drop of 2.5V occurs and the voltage received by the source device 11 becomes 2.5V. Can be considered.

  As a result, there is a possibility that problems such as malfunction of the source device due to voltage drop and cable heat generation may occur. For this reason, the source device 11 is provided with a voltage detection unit 115, and when a predetermined voltage, for example, 4 V or less, the control unit 118 that receives the detection result of the voltage detection unit 115 controls the power supply circuit 119 to suppress power consumption. Alternatively, a control operation such as stopping is necessary. Furthermore, if the sink device 21 is provided with a current limiter having a margin of about 10% from the predetermined maximum current supply, the protection function is further strengthened.

  In this way, it is possible to realize a transmission system that can supply power not only to the source device but also to the cable that requires external power from the sink device, so a special power supply is prepared for long-distance transmission using optical fiber etc. Since there is no need, usability increases.

  As described above, the cable has been described as an example. However, some HDMI (R) repeater devices copy the EDID indicated by the sink device and transmit it to the source device, and the physical addresses of the source device and the repeater device overlap. May end up. In the case of such a repeater, power can be supplied by using the message for the active cable described so far.

  Another embodiment of the transmission system according to this embodiment will be described with reference to FIGS. FIG. 6 is a block diagram of the cable portion. The cable 34 is used in place of the cable 32 of FIG. 1, and the source device 11 and the sink device 21 are not shown because they have the same configuration.

  The same numbers are assigned to blocks having functions equivalent to those in FIG. The difference from FIG. 1 is that a switch 341 is added between the DDC terminals 313 and 333 for reading out EDID information, the utility terminals 315 and 335 are separated from each other, and power supply circuits 343 and 326 are provided, respectively. In addition, the HPD terminals 317 and 337 are separated and an HPD output unit 344, an HPD detection unit 346, and a DDC + 5V supply unit 345 are added.

  The message structure (FIG. 2), message type (FIG. 3), and message argument (FIG. 4) are the same as in the first embodiment. FIG. 7 shows an example of message transmission / reception.

  The sink device 21 supplies, for example, +5 V maximum 25 mA as standby power to the power supply circuit 326 of the cable 34 through the Utility terminal 335 (step 801). The power supply circuit 326 of the cable 34 supplies + 5V to the sink device 21 through the DDC + 5V supply unit 345 (step 802). The sink device 21 changes the HPD terminal 337 from the “L” level to the “H” level (step 803).

  The HPD detection unit 346 of the cable 34 detects this and transmits it to the control unit 325. After disconnecting the switch 341, the control unit 325 causes the EDID acquisition unit 323 to read and acquire the physical address of the source device included in the EDID information of the sink device 21 (steps 804 and 805).

  In the first embodiment, the source device intercepts the signal when reading the EDID of the sink device. However, in this embodiment, the cable 34 is used to start up the transmission system before the source device enters the EDID reading operation. The EDID acquisition unit can read EDID information independently. At this time, a switch 341 is provided to prevent malfunction of the EDID reading unit of the source device.

  Accordingly, the switch 34 is set to a disconnected state during a period in which the cable 34 alone performs an EDID reading operation while the source device 11 is not reading the EDID. The switch 34 is kept in a connected state so that the DDC communication between the source device 11 and the sink device 21 is not hindered except during a period in which the cable 34 performs an EDID read operation alone. In addition, when the cable length is long, if a buffer is arranged between the DDC terminals 313 and 333, the reliability of the DDC communication can be improved.

  After the cable 34 acquires the physical address, a <CDC_Power_Request_C> [“No Connect”, “No Power”, “FullPower”] message 806 requesting power supply to the sink device 21 is sent. For example, the sink device 21 starts supplying +5 V at a maximum of 500 mA from the Utility terminal 335 to the power supply circuit 326 of the cable 34 (step 807). The sink device transmits <CDC_Power_Status> ["1", "No Power", "Full Power"] to notify the start of power supply to the cable 34, and the cable 34 starts using +5 V maximum 500 mA power (step 809). The optical / electrical converter 322 is made ready for reception.

  When the source device 11 is activated and, for example, 5 V maximum 55 mA is supplied to the DDC terminal 316 (step 810), the power supply circuit 343 supplies the power to the electrical / optical converter 321 and the HPD terminal 337 is “H”. The HPD output unit 344 changes the HPD terminal 317 from the “L” level to the “H” level only while the HPD detection unit 346 detects that there is (step 811).

  Since the EDID information cannot be read from the EDID storage unit of the sink device 21 while the HPD terminal 337 is “L”, the HPD terminal 317 maintains the “L” level. When the HPD terminal becomes “H” level, the source device 11 reads the EDID information of the sink device 21 through the DDC terminals 312 and 333 (steps 812 and 813). At this time, the EDID acquisition unit 323 of the cable 34 intercepts the EDID information, confirms information related to the physical address of the source device 11, and acquires the change information if there is a change. Based on this latest information, messages are transmitted and received below.

  When the source device 11 sends a <CDC_Power_Request> ["Need"] message 814 requesting power supply, the sink device 21 has already supplied power to the cable 34 and supplies power as there is no power supply capacity to the source device 11. Respond with the <CDC_Power_Status> ["1", "No Power", "Full Power"] message 815 that is disabled.

  Not only when there is no power supply capacity, but also when it is known that the Utility line is not connected in the message 806, the same message 815 is responded as power supply is impossible. If it is not clear that the Utility line is disconnected and power is not supplied to the cable, <CDC_Power_Status> ["1", "Power_S", "No Power"] message at the same time as power supply starts In response (not shown).

  When the power supply circuit 343 receives power supply from a power supply unit (not shown), the cable 34 that has received the message 814 starts <power supply to the source device 11 (step 816) and <CDC_Power_Request_C> ["No Connect", The source device 11 and the sink device 21 are notified by a “Full Power”, “FullPower”] message 815.

  The sink device 21 issues a <CDC_Power_Status> [“1”, “Power_C”, “Full Power”] message 817 to confirm the power supply state, and the source device starts using +5 V maximum 500 mA power (step 818). . If they are different, the source device 11 or the cable 34 issues a power request message and corrects it.

  When the sink device 21 stops power supply due to the user's operation of the sink device 21 or the like, a <CDC_Power_Notice> [“1”, “Power_C”, “No Power”] message 819 is issued. The cable 34 having received the power supply stop request accepts the power supply stop from the sink device 21 and notifies the power supply stop to the source device 11 <CDC_Power_Notice_C> ["No Connection", "No Power", "NoPower" ] Message 821 is issued.

  If the cable 34 does not accept the power supply stop from the sink device 21, <CDC_Power_Request_C> ["No Connect", "Power_C", "Full Power"] message, if you want to stop the power supply to the source device first <CDC_Power_Notice_C? ["No Connect", "No Power", "FullPower"] What is necessary is just to respond.

  The sink device 21 considers that the cable 34 has accepted the power supply stop, stops the power supply (step 821), and responds with a <CDC_Power_Status> [“1”, “Power_C”, “No Power”] message 822.

  In response to the message 821, when the source device 11 requests the continuation of power supply, the continuation request <CDC_Power_Request> {"Need"} message 823 is issued. The response message of the sink device 11 to the message 823 is a <CDC_Power_Status> [“1”, “Power_C”, “No Power”] message 822 indicating the current state.

  If the cable 34 continues to stop the power supply to the source device 11, a predetermined time, for example, an interval of about 5 seconds or more is left, and <CDC_Power_Notice_C> [“No Connection”, “No Power”, “NoPower” "] Message 824 is issued. When the source device 11 stops using the +5 V maximum 500 mA power (step 825), it sends a <CDC_Power_Request> ["No Need"] message 826 to notify the use stop to the cable 34 and the sink device 21.

  As a response, the sink device 21 issues a <CDC_Power_Status> ["1", "No Power", "No Power"] message 827. On the other hand, the cable 34 stops the power supply of +5 V maximum 500 mA to the source device 11 (step 828), and responds with a <CDC_Power_Request_C> [“No Connect”, “No Power”, “NoPower”] message 829.

  In response to this message 829, the sink device 21 issues a <CDC_Power_Status> [“1”, “No Power”, “No Power”] message 827 for confirming the current state. If the message 829 of the cable 34 is output before the message 827 of the sink device 21 is output, the message 827 may be omitted and only the message 830 may be substituted. By delaying the timing of issuing the message 827 by, for example, about 0.1 second from the normal response, it is possible to increase the probability of omitting the message 827 and avoid the congestion of the message communication path.

  As described above, power can be supplied from the sink device to the cable and from the cable with an independent power supply to the source device, so the sink device side of the cable and the source device have sufficient power. Since it can be operated even when there is no power source or an original power source, usability is improved.

  A more flexible embodiment in which the current supply amount can be adjusted in stages will be described below. The block diagram, message structure, and message example of the transmission system are the same as those in FIGS. 1, 2, and 3 described in the first embodiment, and detailed description thereof is omitted.

  The message arguments defined in FIGS. 8, 9, and 10 are used instead of those in FIG. Five types of source device maximum current usage [Source_Current], cable maximum current usage [Cable_Current] in the range of 0 to 500 mA in 125 mA units, and 5 mA as a standby mode are prepared. The maximum current supply amount [Sink_Current] of the sink device is set to increase by 25 mA so that 25 mA can be additionally supplied as a standby current.

  However, “0 mA” of [Sink_Current] indicates that the current supply capability is less than 25 mA, indicating that there is no capability to supply standby power. In this embodiment, the supply voltage is assumed to be +5 V, but other voltages may be used if determined in advance. Similarly to the maximum current argument, voltage setting may be added to the argument and defined by a combination of an arbitrary voltage and maximum current.

  In the standby mode, it is assumed that 5 mA each for standby power sources such as the internal control unit of the source device and the cable, and 10 mA to DDC + 5V of the sink device for reading EDID, and reserve current 5 mA (DDC standard) defined by the DDC standard. The source device supplies 55 mA and the sink device uses a maximum of 50 mA), and the supply current of the sink device is 25 mA.

  Furthermore, a checksum is provided for each message, and a message with an incorrect checksum is ignored. Therefore, when a predetermined response message cannot be obtained, a highly reliable transmission system can be realized by resending the message. The argument [Power2] shown in FIG. 10 indicates that power is supplied from the unique power source of the cable unit to the source device. Since the other parameters are the same as those in FIG.

  FIG. 11 is a diagram showing an example of message transmission / reception. The operation will be described below with reference to FIG. In FIG. 11, the description of the argument [Check sum] is omitted. The steps up to step 705 in which the source device 11 and the cable 32 acquire the physical address are the same as those in FIG. 5 described in the first embodiment, and the description thereof is omitted.

  Cable 32 requests current supply of 125 mA <CDC_Power_Request_C> ["Connect", "None", "150 mA", "5 mA", "125 mA"] Send message 736 to sink device 21 and sink device 21 supplies a maximum of 150 mA Start (step 737). The sink device notifies the cable 32 and the source device 11 with a <CDC_Power_Status> [“1”, “150 mA”, “5 mA”, “125 mA”] message 738 that supply of a maximum of 150 mA to the cable has started. The supply start current of the sink device 21 may be more than the required value of the cable 32. For example, a larger amount of current is supplied and the <CDC_Power_Status> ["1", "525mA", "5mA", "125mA"] message Or <CDC_Power_Status> ["1", "400mA", "125mA", "250mA"] messages may be issued. The cable 32 that has received the message 738 starts using a maximum current of 125 mA (step 740).

  Here, in message 736, when the maximum supply current of the sink device exceeds the sum of the maximum current consumed by the source device and the cable (except when the cable has its own power supply), [Check sum] Is not correct, the sink device may not start supplying current, or may start supplying a current that is expected to be reasonable and send an appropriate response message), and message 738 will also indicate the maximum supply current of the sink device. If the sum of the maximum currents consumed by the source device and the cable is exceeded and if [Check sum] is not correct, the cable 32 is connected to the sink device 21 <CDC_Power_Request_C> ["Connect", "None", "150mA By retransmitting the "," 5mA "," 125mA "] message 736, the reliability of the current supply of the transmission system can be improved.

  Next, the source device 11 transmits a <CDC_Power_Request> [“525 mA”, “375 mA”] message 740 to the sink device 21 requesting a current supply of a maximum of 375 mA. The sink device 21 starts supplying a current greater than the total value of the cable 125 mA and the source device 375 mA, for example, 525 mA or more (step 741), and specifies the maximum current used by the source device and the cable <CDC_Power_Status> ["1", " 525mA "," 375mA "," 125mA "] message 742 is notified to the source device 11 and the cable 32. In response to this notification, the source device 11 starts using a current of 375 mA (step 743).

  For example, when the source device 11 uses the current used for the video transmission of the cable in order to stop the video output and charge the built-in rechargeable battery at a high speed, a current of 500 mA is required. <CDC_Power_Request> [“500 mA”, “500 mA”] message 744 is sent to cable 32 and sink device 21.

  The cable 32 stops using the current of 125 mA, uses only the standby current of 5 mA (step 745), and sends a message <CDC_Power_Request_C> [Connect "." None that directs 500 mA of the supply current 525 mA of the sink device 21 to the source device 11 "," 525mA "," 500mA "," 5mA "] message 746 is sent to sink device 21.

  The sink device 21 confirms the message 746 from the cable 32. <CDC_Power_Status> ["1". "525mA", "500mA", "5mA"] The message 747 is sent, and the source device 11 that receives it sends a current of 500 mA. Is started (step 749).

  When the cable 32 stops the current supply to the source device 11, a <CDC_Power_Notice_C> [“Connect”, “None”, “25 mA”, “0 mA”, “5 mA”] message (not shown) is sent to the source device 11. Or send <CDC_Power_Request_C> ["Connect", "None", "25mA", "0mA", "5mA"] message 749 to sink device 21 and send response message <CDC_Power_Notice> ["1 of sink device 21 “,“ 25 mA ”,“ 0 mA ”,“ 5 mA ”] message 750 is transmitted to the source device 11.

  If the source device 11 wants to continue using the current, it sends a <CDC_Power_Request> ["525 mA", "500 mA"] message (not shown) to the sink device and the cable. When the current use is stopped (step 751), a message <CDC_Power_Request> ["25mA," 0mA "] 752 is transmitted to the sink device 21 to that effect.

  The sink device 21 reduces the supply current from 525 mA to 25 mA and sends a <CDC_Power_Status> [“1”, “25 mA”, “0 mA”, “5 mA”] message 754 indicating the current state as a response message to the source device 11 and the cable. Tell 32.

  According to the present embodiment, the current supply amount of the sink device can be flexibly adjusted according to the current usage amount of the source device and the cable. This has the effect of reducing power consumption. Further, the functions of the source device and the cable can be maximized by flexibly accommodating the current used by the source device and the cable.

  FIG. 12 shows another example of message transmission / reception when the cable 34 of FIG. 6 used in the description of the second embodiment is combined with the message arguments of FIGS. 8 to 10 used in the description of the third embodiment. As in FIG. 11, the description of the argument [Check sum] is omitted. The steps from 841 to 853 when the source device 11 and the cable 34 acquire the physical address are the same as those in the embodiment except that a step 850 is added in which the cable 34 supplies standby power, for example, + 5V25 mA to the Utility terminal 315 by an independent power source. This is the same as FIG. 7 described in FIG.

  By adding the power supply step 850, the power supplied from the cable 34 to the Utility terminal can be used as the power to the DDC + 5V terminal 316 supplied by the source device 11.

  <CDC_Power_Request> ["525mA", "500mA without considering special circumstances such as when the source device requests a current of 500 mA, when the cable has its own power supply, or when the Utility line is disconnected. “] A message 855 is sent to the cable 34 and the sink device 21. Since the sink device 21 obtains from the message 846 that the Utility line of the cable 34 has been disconnected, adjustment by the <CDC_Power_Notice> ["1", "525mA", "375mA", "125mA"] message is difficult Therefore, it responds with a <CDC_Power_Status> ["1", "125mA", "5mA", "125mA"] message 856 indicating the current current distribution.

  On the other hand, the cable 34 having its own power supply starts supplying a current of 525 mA to the source device in response to the current request message 855 of the source device (step 857), and then notifies it <CDC_Power_Request_C> ["No Connect", "Independet "," 150mA "," 500mA "," 125mA "] message 858 is issued. The sink device 21 sends a <CDC_Power_Status> [“1”, “150 mA”, “500 mA”, “125 mA”] message 859 to the source device 11 as a response message for confirming the status, and the source device 11 starts using 500 mA. (Step 860).

  If the sink device 21 can supply only the standby current due to user operation or the like, this is notified to the cable 34 by a <CDC_Power_Notice> ["1", 25 mA "," 500 mA "," 5 mA "] message 861. 34, if it is necessary to continue to supply power, <CDC_Power_Request_C> ["No Connect", "Independet", "150mA", "500mA", "125mA"] messages (not shown) are sent to the standby current of 5 mA. If migration is possible, after migration (step 862), the <CDC_Power_Request_C> ["No Connect", "Independet", "25mA", "500mA", "5mA"] message 863 is sent to the sink device 21. The sink device 21 is on standby. Switch to a current 25 mA supply state (step 864) and send a <CDC_Power_Status> ["1", 25mA "," 500mA "," 5mA "] message 865 to confirm the current state.

  When the cable 34 stops the current supply to the source device 11 by the unique power source, the <CDC_Power_Request_C> [“No Connect”, “Independet”, “25 mA”, “0 mA”, “5 mA”] message 863 is sent to the sink device 21. Send to. In response to a request for changing the supply current to the source device 11 via the cable 34, the sink device sends a <CDC_Power_Notice> [“1”, 25 mA ”,“ 0 mA ”,“ 5 mA ”] message 864 to the source device 11.

  The source device stops using the current of 500 mA (step 865), and returns a <CDC_Power_Request> ["25mA", "0mA"] message 866. As a response, the sink device sends a <CDC_Power_Status> [“1”, “25 mA”, “0 mA”, “5 mA”] message 867 to confirm the status. The cable 34 stops the current supply of 525 mA to the source device 11 after receiving the message 866 or 867.

  In this embodiment, there is no need to use the <CDC_Power_Notice_C> message. There is an advantage that the types of messages to be prepared can be reduced.

  As described above, according to this embodiment, even with a cable having a unique power supply, the supply current can be adjusted between the sink device and the source device, so that an easy-to-use transmission system is constructed. it can.

  Another embodiment is shown in FIG. FIG. 13 is a block diagram of the cable. The optical transmitter 41 and the optical receiver 51 are connected by a cable bundle composed of optical fibers 422 and 423 and an electric wire 425. The optical transmitter 41 and the source device 11, and the optical receiver 51 and the sink device 21 are connected by a simple cable. A simple cable does not consume current like the cables 32 and 34, but refers to a cable bundle in which the corresponding terminals of both end plugs are electrically connected by electric wires. Note that the cable 425 can be omitted when the optical transmitter 41 has its own power source such as an AC adapter or when it can operate only from the power source from the source device.

  The optical transmitter 41 includes a video receiving unit 412, a multiplexing unit 411, an electro-optical conversion unit 420, a photoelectric conversion unit 421, a DDC communication unit (including an EDID storage unit) 413, a CEC communication unit 414, a control unit 417, an electric current. A limiting unit 415, a power supply circuit 419, and an HPD output 416 are included.

  The video reception unit 412 receives the video signal received from the source device 11, and the multiplexing unit 411 multiplexes the control information received from the control unit with the video signal. The multiplexing unit may have a function of receiving RGB three primary color signals in parallel and converting them into a serial signal. The output signal of the multiplexing unit 411 is converted into an optical signal by the electro-optical conversion unit 420 and sent to the optical receiver 51 through the optical fiber 422.

  The control information input to the multiplexing unit 411 includes control operation information of the optical receiver 541, reception information of the CEC communication unit 414 and the DDC communication unit 413, and the like. The electro-optical conversion unit 421 converts an optical signal sent from the optical receiver through the optical fiber 423 into an electric signal and sends it to the control unit 417, and is also used as transmission information of the CEC communication unit 414 and the DDC communication unit 413.

  The optical receiver 51 includes an photoelectric conversion unit 520 and a decoding unit 511, a video transmission unit 512, an electro-optical conversion unit 521, a DDC communication unit (including an EDID reading unit) 513, a control unit 518, a CEC communication unit 514, and a voltage detection. Section 515, power supply circuit 519, DDC + 5V supply section 516, and HPD detection section 517.

  The signal photoelectric conversion unit 520 received from the optical transmitter 41 converts the signal into an electric signal, and the decoding unit 511 decodes the multi-divided video signal and control information. The video signal is sent from the video transmission unit 512 to the sink device 21.

  The control information is sent to the control unit 518 and used as control operation information in the optical receiver 51 and transmission information of the CEC communication unit 514 and the DDC communication unit 513. Control operation information in the optical transmitter 41 and reception information of the CEC communication unit 514 and the DDC communication unit 513 are sent to the electro-optical conversion unit 521 through the control unit 518. The electro-optic conversion unit 521 converts it into an optical signal and sends it to the optical fiber 423.

  The main difference between FIG. 13 and FIG. 6 described in the second and fourth embodiments is that the communication is performed using an optical fiber instead of an electric wire for DDC communication or CEC communication, the cable bundle is simplified, and the long distance This is a point that facilitates transmission.

  13 may transfer the EDID information of the sink device 21 when the source device 11 reads the EDID information, or the DDC communication unit 513 of the optical receiver 51 may transfer the EDID information of the sink device 21. May be read and transmitted to the DDC communication unit 413 of the optical transmitter 41, and the data stored in the EDID storage unit in the DDC communication unit 413 may be transmitted. When the EDID information of the sink device 21 is transferred as it is, the messages and arguments described in the first to fourth embodiments may be used as they are.

  FIG. 14 shows an example in which the power supply capability of the device is described in EDID. The physical address ABCD acquired by the connected source device is described in the fourth and fifth bytes. A new area for describing the power supply capability is added to the 9th byte, and the presence / absence of this area is indicated by the 4th bit Power_present flag in the 8th byte.

  When the flag is “1”, there is a description of the power supply capability. In principle, except for the presence / absence flag of the same description area as the description of the power supply capability, the EDID of the sink device is copied as it is and stored in the EDID storage unit of the own device.

  The description of the power supply capability includes a connecting position indicating where the sink device and the source device exist, a power type indicating the power supply type, and a current indicating the maximum supply current amount.

  Connecting position is set to “01”, “02”, “03” in the order of connecting to the sink device by setting the sink device to “00” and adding 1 to the read value to make the value of the own device. It is possible to prevent the connection position from becoming unknown due to duplicate physical addresses for copying and using the EDID. Note that a device that has read “03” prohibits current consumption, and when an EDID is transmitted to an upstream source device, it is described as “03” without increasing the numerical value to prevent malfunction.

  Power type is No power that cannot supply power, Original power that has power supply capability such as own device having AC adapter, etc., and some power that is supplied to video output terminal of own device is consumed by itself and the rest is supplied Provide relay power.

  Current describes the current value in the same way as the argument shown in FIG. 8, and depends on the supply capability of the sink device in the case of the Relay power type. Although Current may be changed in real time, it is better to exchange messages using a bidirectional communication path such as a CEC communication unit for switching the current supply amount.

  FIG. 15 shows an example of a message argument assuming that a plurality of devices are cascaded between the source device and the sink device. The argument added in comparison with FIG. 10 will be described. Assuming the use of "FFFF" with unknown meaning so that the initiator physical address of the CDC message does not overlap with the source device, describe the physical address of the source device for 2 bytes at the beginning of the argument, and connect position Along with the data, it is possible to identify and indicate the connection location of the device itself.

  Since the connecting position can be expressed in the three locations indicated by 1 to 3, [Cable Current] is provided in three locations so that the current used by the three devices can be described. For convenience of explanation, it is expressed as “Cable”, but a repeater device may also be included.

  Specific message exchange is the same as in the first to fourth embodiments, and a description thereof will be omitted.

  As described above, according to this embodiment, even when a plurality of cables or repeater devices are connected in cascade between the source device and the sink device, the transmission of EDID information and the setting of the message exchange current supply can be performed. There is an advantage that it can be formed automatically.

  Another embodiment is shown in FIG. FIG. 16 is a block diagram illustrating an example in which a video signal is wirelessly transmitted from the source device 11 to the sink device 21 by the wireless transmitter 43 and the wireless receiver 53. 13 differs from the optical fiber example in FIG. 13 in that it has a wireless transmission unit 431 and a wireless reception unit 531 instead of electro-optical conversion, has no utility line to transmit power, and has a power supply unit such as an AC adapter in the transmitter 43. 418 is provided. The message, its argument, operation, etc. are the same as in the fifth embodiment.

  In this example, the power supply unit 418 becomes unnecessary if the power of the wireless transmission unit or the like can be covered by the power transmitted by the source device 11 through the DDC + 5V terminal. Therefore, by supplying a message similar to the message exchange for supplying current from the sink device 21 as described above by replacing the sink device 21 and the source device 11, current supply from the source device 11 through the DDC + 5V terminal 316 is performed. The amount can be increased above 55 mA based on the DDC standard.

  As described above, when the sink device 21 and the source device 11 supply power, the AC adapter, which is necessary for the wireless receiver 53 and the wireless transmitter 43, can be omitted, and there is an advantage that the usability is improved.

  Another embodiment is shown in FIG. FIG. 17 is a table showing message arguments, and is another embodiment corresponding to the table of FIG. 4 of the first embodiment. The difference from FIG. 4 is that the setting of the power consumption / supply state of the source and the cable is expressed in combination to avoid an erroneous setting, and the cable connection position description described in the fifth embodiment is added.

  [Supply_Power] indicating the power supply status of the sink device is "No Power" without power supply, "Power for Source" power supply to the source device, "Power for Cable" power supply to the cable, source device and cable It represents "Both", which supplies half power to each. In FIG. 4, it is necessary to make settings by recognizing that the cable supplies power to the source. However, since the operation is not necessary in the example of FIG. 17, the operation of the sink device is lightened.

  [C_Power], which indicates the power consumption and supply of the cable, is “None” for no power consumption in the cable, “Consume Full” for using the maximum power of the sink device, “Consume Half” for half use, and the power from the sink device. Indicates "Consume & Supply" that supplies power from other AC adapters to the source device while using, and "Supply only" that supplies power to the source device without using power from the sink device. .

  As shown in the fifth embodiment, the cable connection position information [Connecting Position] increases the stored data in the EDID by 1 for each connection so that the cable device can confirm the connection position.

  In this method, it is necessary to provide a mechanism for increasing all the cables by 1, which increases the circuit scale. For this reason, a so-called cable with plugs at both ends only copies the connection position information during EDID transmission to the next stage, and only the so-called repeater device with both ends being receptacles (receptacle connectors) has connection position information. It is good to increase by two. In the case of a special repeater device in which one side is an insertion port and the other side is a plug, the connection information may be increased by one.

  When the position information is described in the message, the so-called cable increases the connection position information acquired from the EDID by 1, and the so-called repeater device increases by 2, so that these devices can be distinguished by the [Connecting position] of the message.

  An example of message exchange is the same as in the first embodiment, and a description thereof will be omitted. According to the present embodiment, there is an advantage that there are few erroneous settings and the mechanism of connection position information transmission can be simplified.

  According to each of the embodiments described above, the sink device can supply power not only to the source device but also to a relay device such as a cable or a repeater device. A circuit becomes unnecessary, and a user-friendly device can be provided.

  In addition, since the remaining power consumed by the relay device of the cable or repeater device or the power of the original power source of the relay device can be supplied to the source device, a power circuit such as an AC adapter for the source device becomes unnecessary, We can provide easy-to-use equipment.

11 Source equipment,
21 Sink device,
31,34 cable,
41 optical transmitter 51 optical receiver 43 wireless transmitter 53 wireless receiver 111 reproduction unit,
112, 512 video transmission unit,
113 EDID reading unit,
114, 214, 324, 414, 514 CEC communication unit,
115,515 voltage detector,
116,345,516 DDC + 5V supply part,
117, 346, 517 HPD detection unit,
118, 217, 325, 417, 518 control unit,
119, 219, 326, 343, 419, 519 power supply circuit,
211 display unit,
212, 412 video receiver,
213 EDID storage unit,
215,415 current limiter,
216, 344, 416 HPD output section,
218, 418 power supply unit,
321, 420, 521 electro-optical converter,
322, 421, 520 photoelectric conversion unit,
327, 422, 423 optical fiber,
323 EDID acquisition unit,
341 switch,
411 multiplexing unit,
413, 513 DDC communication unit 431 Wireless transmission unit 531 Wireless reception unit 432, 532 Antenna

Claims (1)

A transmission device that transmits a video signal from a source device to a sink device,
The communication message sent from the transmission device to the source device and / or the sink device indicates whether the terminal that receives current from the sink device and the terminal that sends current to the source device are connected or disconnected. Transmission equipment, including arguments.

Images