JP2012124808A - Bidirectional communication interface device and bidirectional communication interface system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bidirectional communication interface device and a bidirectional communication system, capable of supplying an electric source to an external device or an active cable.SOLUTION: A bidirectional communication interface device comprises: a first connection end including a transmission cable that transmits a first direction and second direction signals by means of two optical fibers for transmitting an optical signal, a first conversion section that converts the signal into the optical signal to transmit the first direction signal, a second conversion section that converts the optical signal into the signal to transmit the second direction signal, and a first power source acquiring section that receives a power source to operate the first conversion section and the second conversion section; and a second connection end including a third conversion section that converts the optical signal into an electric signal to transmit the first direction signal, a fourth conversion section that converts the signal into the optical signal to transmit the second direction signal, and a second power source acquiring section that receives the power source to operate the third conversion section and the fourth conversion section.

Description

  Embodiments described herein relate generally to a bidirectional communication interface device and a power supply device.

  HDMI (High-definition Digital Media Interface) cables are widely used as bidirectional communication interface devices that transmit signals between devices.

  For this reason, when an HDMI cable is used and, for example, a portable terminal device is operated as a source device, the operable time depends on the power supply capacity of the portable terminal device.

JP 2009-44706 A

  Since the HDMI cable of the current standard does not consider supplying power to an external device or an active cable, the operation time is limited.

  However, preparing a new cable or power supply device for power supply increases the burden on the user.

  An object of the present invention is to provide a bidirectional interface device and a power supply device capable of supplying power to an external device or an active cable.

  According to the embodiment, the power supply device includes a first power supply unit including a first power supply and a first connector, a second power supply unit including a second power supply and a second connector, And a transmission cable for connecting the third and fourth contacts to each other.

  The first power supply unit outputs a current having a first current value. The second power supply unit outputs a current having a second current value. In the transmission cable, the third contact is connected to the first contact, the fourth contact is connected to the second contact, and at least one of the first power supply unit and the second power supply unit is output. Transmitting a current having a first current value and a current having a second current value.

Schematic which shows an example of the bidirectional | two-way interface apparatus to which the embodiment is applied. Schematic which shows an example of a structure of the transmission (source device) side connector to which the embodiment is applied. Schematic which shows an example of a structure of the receiving (sink apparatus) side connector to which embodiment is applied. Schematic which shows an example of a structure of the connector to which embodiment is applied. Schematic which shows an example of a structure of the connector to which embodiment is applied. Schematic which shows an example of the bidirectional | two-way interface apparatus to which the embodiment is applied.

  Hereinafter, embodiments will be described with reference to the drawings.

  FIG. 1 shows an example of a bidirectional communication interface system and a power supply apparatus to which the embodiment is applied. The elements, configurations, and functions described below may be realized by hardware, or may be realized by software using a microcomputer (processing device, CPU) or the like.

  The optical transmission cable 101 to which the bidirectional communication interface system is applied includes, for example, a first optical transmission cable (transmission path) 1A that is an optical fiber, a second optical transmission cable (transmission path) 1B that is also an optical fiber, and each optical fiber 1A. , 1B to a source device 111 and a second plug (sink device side connector) 121 to connect each optical fiber 1A, 1B to a sink device. including. Note that the optical transmission cable 101 can transmit a signal using a high-definition digital media interface (HDMI) function corresponding to the current standard by the first optical transmission cable 1A and the second optical transmission cable 1B.

  The first optical fiber 1A transmits a signal from the (first) plug 111 on the source device 201 side to the (second) plug 121 on the sink device 301 side. The second optical fiber 1B transmits a signal from the second plug 121 on the sink device 301 side to the first plug 111 on the source device 201 side.

  The signals transmitted by the optical fibers 1A and 1B include contents, that is, video (video) signals and audio (audio) signals of programs or programs. The video signal and the audio signal may be simply referred to as AV (Audio / Visual) signal.

  The first plug (source device side connector) 111 is, for example, a recorder device, that is, a connector of a source device (transmission unit) 201 that is a recording / playback device capable of recording and playing back content (sometimes referred to as a program) or a program. (Connector) 211 includes a connector plug 112 connected to a receptacle (connector) 212 and a key (identifier) 113 that can identify standard or version information applied to the connector plug 112.

  The source device (recording / playback device) 201 is a recorder device that records and plays back content, that is, a program or video (Video) signal and audio (Audio) signal of the program, or a player device that can only play back content. It may be a game device or a video camera. The source device 201 can also be connected to a personal computer (PC), a PC, a data playback device (optical disc drive device) that plays back data (content) held on an optical disc such as a DVD standard / CD standard, etc. For example, a portable terminal device or digital photo camera device having a reader / writer (data playback device) capable of reading data (contents) from a solid state drive (SSD), a memory device such as an SSD, and the like, It may be a mobile phone device or a navigation device that is mounted on a car or the like or that can be carried by a user.

  The second plug (sink device side connector) 121 is a sink device (reception unit), for example, a television receiver, that is, a connector on the video display device 301 side that can reproduce content (also referred to as a program) or a program. (Connector) 311 includes a connector plug 122 connected to a receptacle 321 provided in 311 and a key (identifier) 123 capable of identifying standard or version information to which the connector plug 122 is applied.

  When the receptacle 211 of the transmission unit (source device side) connector connected to the first plug (source device side connector) 111 supplies an AV signal to the first optical fiber 1A via the connector plug 112, the first optical fiber is connected. An encoder 212 that encodes AV signals in accordance with the 1A transmission standard, and a microcomputer that controls the transfer of control signals (HPD, CEC, Util (utility), SCL (clock), SDA (data)) to and from the sink device (Microcomputer) 213, a key detection mechanism 214 that electrically or mechanically detects the key 113 of the inserted connector plug 111, and a power supply circuit 215 that outputs +5 V to the connected external device. Note that, based on information detected by the key detection mechanism 214, the power supply circuit 215 can change the power supply capacity that can be supplied to the connected device (external device). Among control signals, HPD (Hot Plug Detected) and CEC (HDMI-Consumer Electronics Control) comply with the HDMI (High-definition Digital Media Interface) standard widely used today. Also, the key detection and the function of changing the current capacity to the external device (the function of changing the output of the power supply circuit 215) can be omitted. In this case, power is supplied in accordance with the current HDMI standard.

  The receptacle 321 of the receiving unit (sink device side) connector connected to the second plug (sink device side connector) 121 receives the AV signal from the first optical fiber 1A via the connector plug 122. Decoder 322 that decodes the AV signal transmitted through the microcomputer, microcomputer 323 that controls the transfer of control signals (HPD, CEC, Uti1, SCL, SDA) to and from the source device, and connector plug The key detection mechanism 324 that electrically or mechanically detects the key 123 of 121, the power source (5V line) 325, the SW1 (switching switch) 326, and the performance (reproduction capability) on the sink device 301 side is the source device 201 side. EDID (Extended Display Identification Da) ta) 327 is included. Based on the information detected by the key detection mechanism 324, the SW1 (changeover switch 1) 326 is turned on to supply + 5V power to the external device from the sink (reception unit) 301 side. The information (number and structure) of the key 123 can be used to notify the power supply capacity that can be supplied by the sink device. In this case, the number and shape (structure) of the keys 123 may be changed according to the capacity that can be supplied.

  A connector plug (first plug) 111 connected to the connector 211 on the source device 201 side of the optical transmission cable 101 including the optical fibers 1A and 1B, and a connector plug (second plug) connected to the connector 311 on the sink device 301 side. The plugs 121 further include optical-electrical conversion circuits 114 and 124 for inputting and outputting optical signals to / from the corresponding optical fibers 1A and 1B, respectively, and transmitting information via both optical fibers. And receive.

  The first plug (source device side) connector 111 is further supplied with R (red), G (green) and B (blue) video signals and CK (clock) supplied through the receptor 212 on the source device 201 side. A multiplex control unit (MUX / mixing unit) 115 that mixes four TMDS (Transition-Minimized Differential Signaling) channels composed of a single channel and a multiplex supplied from the sink device 301 side. A separation controller (DeMUX) 116 that separates the signal into four TMDS channels is included between the photoelectric conversion circuit 114 and the plug 111.

  On the other hand, the second plug (sink device side) connector 121 further includes a separation control unit (DeMUX) 125 for separating the multiplexed signal supplied from the source device 201 side into four TMDS channels, and four components toward the source device. A multiplexing control unit (MUX / mixing unit) 126 that multiplexes TMDS channels into one channel is included between the plug 121 and the photoelectric conversion circuit 124.

  The optical transmission cable 101 shown in FIG. 1 can be used by an active cable or the like that requires power supply from both the power supply circuit 315 and the + 5V line on the sink device 301 side from the power source on the source device 201 side. is there. Further, when the external device to be connected is a portable terminal device with a small power supply capacity, it is possible to operate for a long time without requiring an independent power supply device for the external device.

  The power supply capacity (current amount) required by the connection partner (external device) is notified by the above-described shape or number of keys 113 prepared in the first plug 111 of the optical fiber 101. Needless to say, the power supply circuit 15 has a power supply capability capable of supplying the amount of current required by the external device. Even if the key 113 is not prepared, + 5V power (up to 55 mA) is supplied in accordance with the current HDMI standard.

  When power is supplied to the optical-electrical conversion circuit 114, the optical signal is mainly transmitted via a downlink optical fiber (first optical fiber 1A) in charge of AV signal transmission. 124.

  The sink device side photoelectric conversion circuit 124 can operate by receiving power supply from the sink device (ie, SW1 = ON) by the key 123.

  FIG. 2 shows the characteristics of the shape of the key 113 included in the first plug (source device side connector) 111 described with reference to FIG.

  As shown in FIG. 2, an HDMI cable conforming to the current standard is provided by providing, for example, a protrusion (key) 113 at a predetermined position on the outer periphery of the plug 111, for example, a surface having a sloped portion that defines the orientation of the plug. Can be distinguished from each other in appearance, and erroneous insertion into the source device corresponding to the current HDMI cable can be prevented.

  As shown in FIG. 3, by changing the number of keys (protrusions), the power supply capacity (amount of current that can be supplied) can be notified to the counterpart device. That is, when there is a stage in the power supply capacity, for example, by changing the number of keys, for example, if the capacity of 500 mA per one is shown, it can be notified that the capacity is 1.5 A in the case of three.

  FIG. 4 shows the characteristics of the shape of the key 123 included in the second plug (sink device side connector) 121 described with reference to FIG.

  As shown in FIG. 4, for example, by providing a projection 123 on a predetermined position on the outer periphery of the plug 121, for example, a surface having only a plane opposite to the sloped portion that defines the orientation of the plug, the current standard is achieved. It is possible to distinguish externally from a compliant HDMI cable, and it is possible to prevent erroneous insertion into a sink device corresponding to the current HDMI cable.

  As shown in FIG. 5, by providing an arbitrary number of concave portions (or convex portions) in the protrusion and changing the number thereof, the power source capacity (amount of current that can be supplied) can be notified to the counterpart device. That is, when there is a stage in the power supply capability, for example, the number of concave portions (or convex portions) provided in the key, for example, 500 mA per unit (1.5 A for three units) can be notified.

  2 to 5 can be arbitrarily set in the sink device and the source device, and it goes without saying that, for example, it may be opposite to the illustrated example.

  It is to be noted that the recesses that allow coupling with the protrusions (keys) 113 or 123 are provided in the receptacle 211 (source device side) and the receptor 311 (sink device side) to which the plugs 111 and 121 are coupled, respectively. It is possible to notify that the proposed optical transmission cable 101 is provided with a simple mechanism without providing a simple detection mechanism. Further, the protrusions (keys) 113/123 of the plug 111 or 121 are, for example, a mechanism that detects the presence of a switch or a convex portion that is turned on by the pressure from the convex portion (of the plug) in the concave portions of the receptors 212 and 312 (photo By providing an interrupter or the like, detection can be performed more reliably.

  FIG. 6 shows another embodiment of the optical transmission cable shown in FIGS.

  The optical transmission cable shown in FIGS. 1 to 5 requires a key and a mechanism for detecting the key as compared with the cable of the current HDMI standard. Accordingly, FIG. 6 shows an example of a configuration that does not require a key and a mechanism for detecting the key.

  The optical transmission cable 601 shown in FIG. 6 includes the first and second optical fibers 1A and 1B, and the plugs 611 and 621 that connect the source device 701 and the sink device 801, respectively, are the examples shown in FIGS. The key (113 and 123 in FIG. 1) is removed from the configuration. Therefore, the source device 701 and the sink device 801 do not include a key detection mechanism (114 and 124 in FIG. 1).

  Note that the receptacle 821 of the connector of the sink device 801 has a plug detection mechanism (current detection mechanism) 828 that detects insertion of the connector plug 621 (of the optical transmission cable 601) instead of key detection. Further, a monitoring circuit 829 for monitoring the voltages of the CEC line and the Util line is further included. A current capacity setting circuit 716 is provided on the receptacle 711 side of the source device 701. The second plug (sink device side) 621 of the optical transmission cable 601 is provided with a SW 103 (short circuit switch) 627 that short-circuits the CEC line and the Util line.

  The short-circuit switch 627 of the sink device side plug 621 of the optical transmission cable 601 shown in FIG. 6 is turned on when the +5 V power supply (line) 825 supplied to the photoelectric conversion circuit 624 is turned off. Then, the CEC line and Util line are short-circuited. On the other hand, when the + 5V power supply (line) 825 is on, the short-circuit switch 627 is turned off.

  On the sink device 801 side, a current detection mechanism 828 located between the power supply switch / changeover switch (SW1) 824 and the power supply wiring operates in cooperation with the microcomputer 823, and the passing current is below a certain value (for example, 10 mA or less). ) And when the operation under the current has passed for a certain time, the microcomputer 823 turns off the power supply switch (SW1) 826.

  The monitoring circuit 828 has a function of comparing the voltage of the CEC line and the Util line voltage, detects that the CEC line voltage and the Util line voltage are at the same voltage level, and notifies the microcomputer 823 of the result. The microcomputer 823 continuously checks the detection result from the monitoring circuit 828 for a predetermined time or more. If the detection result does not change for a certain time or more, the microcomputer 823 determines that the short-circuit switch (SW103) 627 in the plug 621 is short-circuited, and starts power supply. Therefore, the power supply switch / switch (SW1) 826 is turned on for a certain period of time, and the amount of passing current is monitored by the current detection mechanism 828.

  That is, on the sink device 801 side, when insertion of the connector plug 621 (optical transmission cable 601) is detected by the connector plug detection mechanism (passing current detection mechanism) 829, the monitoring circuit 828 causes the voltages on the CEC line and Util line to be The same is detected by Ex-OR and, for example, “Low” is output.

  Instead of monitoring by the monitoring circuit 829, the microcomputer 823 may compare the voltages of the CEC line and Util line. That is, when the microcomputer 823 detects that the amount of passing current is increased after the power supply is started and the CEC line voltage and the Util line voltage do not change at the same voltage level within a certain time, the microcomputer 823 It is determined that the power supply on the device 701 side has entered normally (the short-circuit switch (SW103) 627 is not short-circuited), and the power supply switch (SW1) 826 is kept on. In other cases, the power supply switch 826 is turned off (shut off), and the power supply to the external device is stopped.

As an example where the microcomputer 823 of the sink device 801 does not continue (cut off) the power supply after the power is turned on for a certain time,
<1> After SW1 (power supply switch) 826 is turned on, if the amount of passing current does not increase even after a certain time has elapsed,
<2> After the SW1 (power supply switch) 826 is turned on, the amount of passing current increases, but the amount of passing current decreases before a certain time elapses, and when it becomes below a certain value,
<3> When the CEC line voltage and the Util line voltage are at the same voltage level even when a certain time has elapsed after SW1 (power supply switch) 826 is turned on (when the switch SW103 is short-circuited). And

  Although the above description has been made assuming that the monitoring circuit 829 is outside the microcomputer 823, it can be integrated by incorporating the function of the monitoring circuit 829 into the microcomputer 823.

  As explained above, this proposal allows external devices such as mobile terminal devices that often have insufficient power capacity or active cables, etc., to be supplied with power independently from both the source device and sink device. it can. Thereby, the electrical connection between the source device and the sink becomes unnecessary, and the influence of electrical noise can be greatly reduced even when a cable having a long connection distance such as an optical transmission cable is used.

  By using the connector plug having the proposed shape, it is possible to prevent erroneous insertion of the connector plug.

  In addition, if the source device or sink device is a source device or sink device that supports only the current HDMI standard-compliant cable with a low power supply capability of the source device or sink device, external devices that require high current supply capability cannot be connected. This prevents the occurrence of malfunctions due to incorrect connection. In other words, since the proposed connector plug (optical transmission cable) cannot be connected to devices that do not have a power supply operation switching function, incorrect connection may cause mistakes that are judged as malfunctioning and confusion to the user. Can be prevented.

  In addition, the key detection mechanism can easily switch the power supply circuit. Further, the insertion error of the connector (optical transmission cable) can be prevented by the key.

  In addition, power can be extracted independently from the source device and sink device. Since the power supply is turned off according to the result of detecting the power consumed by the connected device, a complicated procedure is not necessary.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  DESCRIPTION OF SYMBOLS 1A, 1B ... Optical fiber (transmission path), 101 ... Optical transmission cable (bidirectional communication interface), 111 (611) ... 1st plug (source device side connector), 112 ... Connector plug, 113 ... Key (identifier), DESCRIPTION OF SYMBOLS 114 ... Opto-electric conversion circuit, 115 ... Multiplex control part, 116 ... Separation control part, 121 (621) ... 2nd plug (sink device side connector), 122 ... Connector plug, 123 ... Key (identifier), 124 ... Opto-electric conversion circuit, 125 ... separation control unit, 126 ... multiplexing control unit, 201 (601) ... source device, 211 (711) ... receptacle (connector), 212 (712) ... encoder, 213 (713) ... microcomputer (Microcomputer), 214 ... key detection mechanism, 215 (715) ... power supply circuit, 301 (801) ... sink device 311 (811) ... Connector (connector), 315 ... Power supply circuit, 321 (821) ... Receptacle (connector), 322 ... Decoder, 323 ... Microcomputer (microcomputer), 324 ... Key detection mechanism, 325 (825) ... Power supply (5 V line), 326 (826) ... SW1 (switching switch), 327 ... EDID, 627 ... SW103 (short circuit switch), 716 ... Current capacity setting circuit, 828 ... Plug detection mechanism (current detection mechanism), 829 ... Supervisory circuit.

According to the embodiment, the power supply device includes a first power supply unit including a first power supply and a first connector, a second power supply unit including a second power supply and a second connector, , between a transmission cable connecting the third and fourth connecting child together, and fifth connectors, and sixth connectors, said first connecting element and the third connectors A fifth connector for informing the first current value that can be delivered as a feature of the shape of the first connector and the third connector;
The sixth current value that informs the second current value that can be transferred between the second connector and the fourth connector as a feature of the shape of the second connector and the fourth connector. A connector of
It comprises.

The first power supply unit outputs a current having a first current value. The second power supply unit outputs a current having a second current value. Transmission cable, the third CONNECTORS connected to the first connecting child, the fourth connectors is connected to the second connecting child, at least in the first power supply unit and the second power supply unit The current of the first current value and the current of the second current value output from one side are transmitted. The fifth connector has the first current value that can be transferred between the first connector and the third connector, and the shape of the first connector and the third connector. As a feature of The sixth connector is configured such that the second current value that can be passed between the second connector and the fourth connector is the shape of the second connector and the fourth connector. As a feature of

According to the embodiment, the bidirectional communication interface device includes a first optical fiber and a second optical fiber that transmit an optical signal in each of a first direction and a second direction opposite to the first direction. Including a transmission cable for transmitting signals in the first direction and the second direction, a first converter for converting an input signal into an optical signal for signal transmission in the first direction, and the first A second converter for converting an input optical signal into an electrical signal for signal transmission in two directions, and a first power supply for operating the first converter and the second converter. A first connection end located at one end of the transmission cable, and an electrical signal for transmitting an input optical signal for signal transmission in the first direction. A third conversion unit for converting to the second direction A fourth conversion unit for converting an input signal into an optical signal for signal transmission, a second power acquisition unit for receiving a power supply for operating the third conversion unit and the fourth conversion unit, A second connection end including
It comprises.

In the optical transmission cable 101 shown in FIG. 1, it can be utilized by the active cable or the like which requires the power supply from both the + 5V line of the power supply circuit 215 and the sink device 301 side from the power source device 201 side It is. Further, when the external device to be connected is a portable terminal device with a small power supply capacity, it is possible to operate for a long time without requiring an independent power supply device for the external device.

The power supply capacity (current amount) required by the connection partner (external device) is notified by the above-described shape or number of keys 113 prepared in the first plug 111 of the optical fiber 101. The power supply circuit 215, it is needless to say that with a deliverable power supply capacity of the current amount of the external device requires. Even if the key 113 is not prepared, + 5V power (up to 55 mA) is supplied in accordance with the current HDMI standard.

As shown in FIG. 4 , by changing the number of keys (protrusions), the power supply capacity (amount of current that can be supplied) can be notified to the counterpart device. That is, when there is a stage in the power supply capacity, for example, by changing the number of keys, for example, if the capacity of 500 mA per one is shown, it can be notified that the capacity is 1.5 A in the case of three.

FIG. 3 shows the characteristics of the shape of the key 123 included in the second plug (sink device side connector) 121 described with reference to FIG.

As shown in FIG. 3 , for example, by providing a protrusion 123 on a predetermined position on the outer periphery of the plug 121, for example, a surface having only a plane opposite to the sloped portion that defines the orientation of the plug, the current standard is achieved. It is possible to distinguish externally from a compliant HDMI cable, and it is possible to prevent erroneous insertion into a sink device corresponding to the current HDMI cable.

In addition, if the source device or sink device is a source device or sink device that supports only the current HDMI standard-compliant cable with a low power supply capability of the source device or sink device, external devices that require high current supply capability cannot be connected. It is possible to prevent malfunctions caused by connection errors. In other words, since the proposed connector plug (optical transmission cable) cannot be connected to devices that do not have a power supply operation switching function, incorrect connection may cause mistakes that are judged as malfunctioning and confusion to the user. Can be prevented.

Claims (9)

A first power supply unit including a first power source that outputs a current having a first current value; and a first connector that supplies a current having the first current value to a target device;
A second power supply unit including a second power supply that outputs a current having a second current value; and a second connector that supplies the current having the second current value to the target device;
A third contact connected to the first contact, a fourth contact connected to the second contact, and the third and fourth contacts connected to each other; A transmission cable for transmitting the current of the first current value and the current of the second current value output by at least one of the one power supply unit and the second power supply unit;
A power supply device comprising: The first current value that can be transferred between the first connection end and the third connection end is reported as a feature of the shapes of the first connection end and the third connection end. With a contactor,
The second current value that can be transferred between the second connection end and the fourth connection end is reported as a feature of the shape of the second connection end and the fourth connection end. With a contactor,
The power supply device according to claim 1, further comprising:   The power supply device according to claim 2, wherein the first contact and the second contact respectively notify the first current value and the second current value that can be delivered in a plurality of stages.   The transmission cable includes a first optical fiber that transmits the encoded video signal and audio signal from the first power supply unit to the second power supply unit, and the second power supply unit to the first power supply unit. The power supply apparatus according to any one of claims 1 to 3, further comprising a second optical fiber that transmits a video signal and an audio signal. A first connection end located at one end of the transmission cable;
A second connection end located at the other end of the transmission cable;
A first contact for notifying the connection target device of a power capacity that can be provided to the connection target device connected to the first connection end, as a feature of the shape of the first connection end;
A second contact for notifying the connection target device of the power capacity required by the connection target device connected to the second connection end as a feature of the shape of the second connection end;
A bidirectional communication interface device comprising:   6. The bidirectional communication interface device according to claim 5, wherein the first and second contactors are connectable to a predetermined connection target device.   The bidirectional communication interface device according to claim 6, wherein the first and second contacts include a shape that is not connected to a connection target device different from a predetermined connection target device. An encoder that encodes a video signal and an audio signal, a first power supply that outputs a current having a first current value, and a first power that supplies a signal encoded by the encoder and a current having the first current value to a target device. A first power supply unit including one connector;
A decoder that decodes the video signal and the audio signal encoded by the encoder; a second power source that outputs a current of a second current value; and a signal that the decoder decodes; A second connector for supplying a current to the target device, a second power supply unit,
A third contact connected to the first contact, a fourth contact connected to the second contact, and the third and fourth contacts connected to each other; A transmission cable for transmitting the current of the first current value and the current of the second current value output by at least one of the one power supply unit and the second power supply unit;
A current detection mechanism that is provided in the second power supply unit and detects that the current of the first current value is output from the first power supply unit;
A power supply device comprising: An encoder that encodes a video signal and an audio signal, a first power supply that outputs a current having a first current value, and a first power that supplies a signal encoded by the encoder and a current having the first current value to a target device. A first power supply unit including one connector;
A decoder that decodes the video signal and the audio signal encoded by the encoder; a second power source that outputs a current of a second current value; and a signal that the decoder decodes; A second connector for supplying a current to the target device, a second power supply unit,
A third contact connected to the first contact, a fourth contact connected to the second contact, and the third and fourth contacts connected to each other; A transmission cable for transmitting the current of the first current value and the current of the second current value output by at least one of the one power supply unit and the second power supply unit;
A current detection mechanism that is provided in the second power supply unit and detects that there is no output of the current of the first current value from the first power supply unit;
A power supply device comprising:

Images