Patent Publication Number: US-9893475-B2

Title: Connector system capable of mitigating signal deterioration

Description:
TECHNICAL FIELD 
     The present disclosure relates to a connector, a data receiving apparatus, a data transmitting apparatus, and a data transmitting and receiving system. 
     BACKGROUND ART 
     As information-oriented society has developed in recent years, the amounts of information (amounts of data and amounts of signals) handled by information processing apparatuses such as personal computers (PCs) and servers have explosively increased. According to such increases in data amounts, the need to transfer more data at higher speeds in data transmission and reception performed between apparatuses has grown. 
     However, deterioration in signals is generally caused by increase in the data transmission amounts and increase in data transmission speed. Accordingly, a technology of increasing the data transmission amounts and reducing the deterioration in signals is being desired. 
     For example, Patent Literature 1 discloses a technology of reducing deterioration in signals by adjusting characteristic impedance of a connector mounting unit of a substrate to be connected with a connector applicable to a High-Definition Multimedia Interface (HDMI) (registered trademark) standard, according to change in thickness of the substrate, the connecter transmitting digital signals. 
     CITATION LIST 
     Patent Literature 
     
         
         Patent Literature 1: JP 2009-129649A 
       
    
     SUMMARY OF INVENTION 
     Technical Problem 
     However, the technology described in Patent Literature 1 is a technology of the receptacle-side connector mounting unit in an apparatus. In this technology, an existing technology of a receptacle side connector and plug-side connectors in a cable is used. Accordingly, in a case of trying to increase data transmission amounts more, the technology described in Patent Literature 1 is not sufficient as a measure to reduce the deterioration in signals. 
     Accordingly, the present disclosure proposes a novel and improved connector, data receiving apparatus, data transmitting apparatus, and data transmitting and receiving system that are capable of reducing deterioration in signals. 
     Solution to Problem 
     According to the present disclosure, there is provided a connector including a signal pin that stretches in a first direction and transmits a signal, a substrate that has one surface on which the signal pin is formed, and an electric conductor layer that has ground potential, the electric conductor layer being formed on an opposite surface of the surface of the substrate on which the signal pin is formed. 
     According to the present disclosure, there is provided a data transmitting apparatus including a connector including a signal pin that stretches in a first direction and transmits a signal, a substrate that is formed of a dielectric and has a surface on which the signal pin is formed, and an electric conductor layer that has ground potential, the electric conductor layer being formed on an opposite surface of the surface of the substrate on which the signal pin is formed. A signal is transmitted to any apparatus via the connector. 
     According to the present disclosure, there is provided a data receiving apparatus including a connector including a signal pin that stretches in a first direction and transmits a signal, a substrate that is formed of a dielectric and has a surface on which the signal pin is formed, and an electric conductor layer that has ground potential, the electric conductor layer being formed on an opposite surface of the surface of the substrate on which the signal pin is formed. A signal transmitted from any apparatus is received via the connector. 
     According to the present disclosure, there is provided a data transmitting and receiving system including a data transmitting apparatus that transmits a signal to any device via a connector including a signal pin that stretches in a first direction and transmits a signal, a substrate that is formed of a dielectric and has a surface on which the signal pin is formed, and an electric conductor layer that has ground potential, the electric conductor layer being formed on an opposite surface of the surface of the substrate on which the signal pin is formed, and a data receiving apparatus that receives a signal transmitted from any apparatus via the connector. 
     According to the present disclosure, the electric conductor layer, the substrate (dielectric layer), and the signal pin are stacked in this order, and thereby so-called microstripline is formed. Accordingly, it is possible to reduce effect of current (signal) flowing through a signal pin on another signal pin. 
     Advantageous Effects of Invention 
     As described above, according to the present disclosure, it is possible to reduce deterioration in a signal more. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1A  is a schematic view showing pin arrangement for transmitting a high-speed differential signal in a general Type A HDMI connector or in a general Type D HDMI connector. 
         FIG. 1B  is a schematic view showing an example of pin arrangement in which high-speed differential data lines are newly added in a Type A HDMI connector or in a Type D HDMI connector. 
         FIG. 2A  is a schematic view showing pin arrangement for transmitting a high-speed differential signal in a general Type C HDMI connector. 
         FIG. 2B  is a schematic view showing an example of pin arrangement in which high-speed differential data lines are newly added in a Type C HDMI connector. 
         FIG. 3A  is a cross-sectional view showing a structural example of general Type C HDMI connectors when being cut at a cross section constituted by a y axis and a z axis through signal pins. 
         FIG. 3B  is a cross-sectional view of the general Type C HDMI connectors corresponding to an A-A cross section in  FIG. 3A , the A-A cross section being constituted by an x axis and the y axis. 
         FIG. 3C  is a cross-sectional view of the general Type C HDMI connectors corresponding to a C-C cross section in  FIG. 3B , the C-C cross section being constituted by the x axis and the z axis. 
         FIG. 4A  is a cross-sectional view showing a structural example of connectors according to a first embodiment of the present disclosure when being cut at a cross section constituted by a y axis and a z axis through signal pins. 
         FIG. 4B  is a cross-sectional view of the connectors according to the first embodiment corresponding to an A-A cross section in  FIG. 4A , the A-A cross section being constituted by an x axis and the y axis. 
         FIG. 4C  is a cross-sectional view of the connectors according to the first embodiment corresponding to a C-C cross section in  FIG. 4B , the C-C cross section being constituted by the x axis and the z axis. 
         FIG. 5  is an explanatory diagram illustrating a configuration in which guard lines are disposed. 
         FIG. 6A  is a contour map of an electric field showing electric field distribution in a general Type C HDMI connector structure. 
         FIG. 6B  is a contour map of an electric field showing electric field distribution in the general Type C HDMI connector structure. 
         FIG. 7A  is a contour map of an electric field showing electric field distribution in a connector structure according to the first embodiment. 
         FIG. 7B  is a contour map of an electric field showing electric field distribution in the connector structure according to the first embodiment. 
         FIG. 8A  is a voltage characteristic diagram showing an eye pattern of a general Type C HDMI connector structure. 
         FIG. 8B  is a voltage characteristic diagram showing an eye pattern of the general Type C HDMI connector structure. 
         FIG. 9A  is a voltage characteristic diagram showing an eye pattern of a connector structure according to the first embodiment. 
         FIG. 9B  is a voltage characteristic diagram showing an eye pattern of the connector structure according to the first embodiment. 
         FIG. 9C  is a voltage characteristic diagram showing an eye pattern of a connector structure according to the first embodiment in which guard lines are further arranged. 
         FIG. 9D  is a voltage characteristic diagram showing an eye pattern of the connector structure according to the first embodiment in which guard lines are further arranged. 
         FIG. 9E  is a voltage characteristic diagram showing a crosstalk characteristic of the connector structure according to the first embodiment in which guard lines are further arranged. 
         FIG. 10A  is a cross-sectional view showing a structural example of general Type D HDMI connectors when being cut at a cross section constituted by a y axis and a z axis through signal pins. 
         FIG. 10B  is a cross-sectional view of the general Type D HDMI connectors corresponding to an A-A cross section in  FIG. 10A , the A-A cross section being constituted by an x axis and the y axis. 
         FIG. 10C  is a cross-sectional view of the general Type D HDMI connectors corresponding to a C-C cross section in  FIG. 10B , the C-C cross section being constituted by the x axis and the z axis. 
         FIG. 11A  is a cross-sectional view showing a structural example of connectors according to a second embodiment of the present disclosure when being cut at a cross section constituted by a y axis and a z axis through signal pins. 
         FIG. 11B  is a cross-sectional view of the connectors according to the second embodiment corresponding to an A-A cross section in  FIG. 11A , the A-A cross section being constituted by an x axis and the y axis. 
         FIG. 11C  is a cross-sectional view of the connectors according to the second embodiment corresponding to a C-C cross section in  FIG. 11B , the C-C cross section being constituted by the x axis and the z axis. 
         FIG. 12A  is a contour map of an electric field showing electric field distribution in a general Type D HDMI connector structure. 
         FIG. 12B  is a contour map of an electric field showing electric field distribution in the general Type D HDMI connector structure. 
         FIG. 13A  is a contour map of an electric field showing electric field distribution in a connector structure according to the second embodiment. 
         FIG. 13B  is a contour map of an electric field showing electric field distribution in the connector structure according to the second embodiment. 
         FIG. 14A  is a voltage characteristic diagram showing an eye pattern of a general Type D HDMI connector structure. 
         FIG. 14B  is a voltage characteristic diagram showing an eye pattern of a general Type D HDMI connector structure. 
         FIG. 15A  is a voltage characteristic diagram showing an eye pattern of a connector structure according to the second embodiment in which guard lines are further arranged. 
         FIG. 15B  is a voltage characteristic diagram showing an eye pattern of the connector structure according to the second embodiment in which guard lines are further arranged. 
         FIG. 15C  is a voltage characteristic diagram showing a crosstalk characteristic of the connector structure according to the second embodiment in which guard lines are further arranged. 
         FIG. 16A  is a schematic view showing an example of signal pin arrangement in a modification of the connector according to the first embodiment. 
         FIG. 16B  is a schematic view showing a structural example of the connectors shown in  FIG. 16A  when being cut at a cross section constituted by a y axis and a z axis through signal pins. 
         FIG. 16C  is a schematic view of the connectors shown in  FIG. 16A  corresponding to an A-A cross section in  FIG. 16B , the A-A cross section being constituted by an x axis and the y axis. 
         FIG. 16D  is a schematic view showing a modification of the connectors corresponding to  FIG. 16C , in which a cross-sectional area of a signal pin is expanded only in a region other than a fitting part. 
         FIG. 17  is a schematic view in which devices are provided on substrates in the connectors according to the first embodiment. 
         FIG. 18A  is a schematic view showing an example of a circuit configuration of an AC/DC conversion circuit that is a device according to modifications of the first embodiment and the second embodiment. 
         FIG. 18B  is a schematic view showing an example of configurations of a register and a communication circuit that are devices according to modifications of the first embodiment and the second embodiment. 
         FIG. 18C  is a schematic view showing an example of a configuration of a battery that is a device according to modifications of the first embodiment and the second embodiment. 
         FIG. 19  is an explanatory diagram illustrating a data configuration example of each channel transmitted between a disk recorder and a television receiver by an HDMI cable. 
         FIG. 20  is a sequence diagram showing a sequence example of CEC control in a case where a source device and a sink device are connected. 
         FIG. 21  is a flowchart showing a CEC compliance check procedure in each device in a case where devices connected via an HDMI cable are detected. 
         FIG. 22  is a functional block diagram showing a configuration example of a communication system including a source device and a sink device, in power supply control. 
         FIG. 23  is a sequence diagram showing a control sequence in power supply control. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the appended drawings. Note that, in this specification and the appended drawings, structural elements that have substantially the same function and structure are denoted with the same reference numerals, and repeated explanation of these structural elements is omitted. 
     Note that, in the following explanation, a connector (hereinafter, referred to as an HDMI connector), a data receiving apparatus, a data transmitting apparatus, and a data transmitting and receiving system that are applicable to a High-Definition Multimedia Interface (HDMI) standard are used as an example of a connector, a data receiving apparatus, a data transmitting apparatus, and a data transmitting and receiving system according to an embodiment of the present disclosure. However, the present embodiment is not limited thereto, and can be applied to a connector, a data receiving apparatus, a data transmitting apparatus, and a data transmitting and receiving system that are based on another communication method or another communication standard. 
     In addition, the connector according to an embodiment of the present disclosure can be applied to any of plug-side connectors in a cable or receptacle-side connectors in a data receiving apparatus and a data transmitting apparatus. In the following explanation, the plug-side connectors in the cable are simply referred to as a “plug-side connectors”, and the receptacle-side connectors in the data receiving apparatus and the data transmitting apparatus are simply referred to as “receptacle-side connectors.” In addition, a “connector” simply means any of a plug-side connector and a receptacle-side connector unless particularly stated. Moreover, in the following explanation, the plug-side connector has a so-called male terminal shape, and the receptacle-side connector has a so-called female terminal shape. However, the present embodiment is not limited thereto. Relation between the terminal shape of the plug-side connector and the terminal shape of the receptacle-side connector may be reversed. 
     Note that the description is given in the following order. 
     1. Study on Increase in Transmission Data Amount 
     2. First Embodiment 
     2.1. Structural Example of General Type C Connector 
     2.2. Structural Example of Connector according to First Embodiment 
     2.3. Comparison of Characteristic 
     3. Second Embodiment 
     3.1. Structural Example of General Type D Connector 
     3.2. Structural Example of Connector according to Second Embodiment 
     3.3. Comparison of Characteristic 
     4. Modification 
     4.1. Expansion of Cross-sectional Area of Signal Pin 
     4.2. Mounting of Device on Substrate 
     5. Application Example 
     5.1. CEC Control 
     5.2. Power Supply Control 
     6. Conclusion 
     1. Study on Increase in Transmission Data Amount 
     In this section, a background led the present inventors to arrive at the present invention is first explained so as to clarify the present disclosure. 
     Recently, HDMI has been widespread as a communication interface for transmitting video signals (video data, audio data, or the like) between video devices at high speed. In communication based on the HDMI standard, a device that is a video signal source such as a disk reproduction apparatus is generally connected to a display device (monitor receiver, television receiver, or the like) via an HDMI cable. Note that, in the following explanation, a device for outputting signals such as a video signal is referred to as a source device, an output apparatus, a transmitting apparatus, or the like, and a device to which the signal such as the video signal is input is referred to as a sink device, an input apparatus, a receiving device, or the like. 
     Such as the disk reproduction apparatus and the display device, demand for consumer electrics (CEs) that can handle a video with higher-quality images and higher-quality sounds has been increasing. Thus, recently, transmission of larger amount of data has been desired with regard to the video signal such as video data and audio data, when the data is transmitted on the basis of the HDMI standard. 
     According to the HDMI standard, an HDMI connector has 19 pins. In a general HDMI connector, 12 of the pins are used for transmitting video signals, and the other pins are used for consumer electrics control (CEC), a power source, a hot plug detector (HPD), and the like. For details of the HDMI standard including pin arrangement in a general HDMI connector, “HDMI Specification Version 1.4” can be referred, for example. 
     Here, with reference to  FIG. 1A , pin arrangement in a general Type A HDMI connector is explained. Note that, pin arrangement in a Type D HDMI connector is similar to the pin arrangement in the Type A HDMI connector. 
       FIG. 1A  is a schematic view showing pin arrangement for transmitting a high-speed differential signal in a general Type A HDMI connector or in a general Type D HDMI connector. Note that,  FIG. 1A  shows only 12 signal pins relating to video signal transmission, and the other signal pins are not shown. In addition,  FIG. 1A  shows a terminal surface of a receptacle-side HDMI connector in an input apparatus. 
     With reference to  FIG. 1A , signal pins  941  are arranged in two lines in zigzag on the terminal surface of the general Type A HDMI connector, the signal pins  941  being embedded in a dielectric  942  covered by an outer shell (shell)  943 . To each of the signal pins  941 , a different kind of signal is applied, and  FIG. 1A  shows the kinds of signals. 
     Specifically, “Data 2 +”, “Data 2  Shield”, and “Data 2 −” are allocated to the signal pins # 1 , # 2 , and # 3 , respectively. In a similar way, “Data 1 +”, “Data 1  Shield”, and “Data 1 −” are allocated to the signal pins # 4 , # 5 , and # 6 , respectively. In addition, in a similar way, “Data 0 +”, “Data 0  Shield”, and “Data 0 −” are allocated to the signal pins # 7 , # 8 , and # 9 , respectively. In addition, “clock+”, “clock Shield”, and “clock−” are allocated to the signal pins # 10 , # 11 , and # 12 , respectively. 
     That is, each of the data lines (Data 0 / 1 / 2 ) and the clock is constituted by three lines including differential lines Datai+, Datai−, and Datai Shield (i=0, 1, 2). When data is transmitted, the differential lines Datai+ and Datai− generates coupling between differential signals (differential coupling is generated). By using Data 0 / 1 / 2 , an HDMI source device transmits, to an HDMI sink device, each of digital video data sets (video data) of R (red), G (green), and B (blue) as serial data at maximum 3.425 Gbps, and pixel clock (maximum 340.25 MHz) that is 10-frequency division of the serial video data as clock. 
     Here, in the following description, coordinate axes are defined, and an explanation of the connector is provided. Specifically, a direction in which the signal pins are arranged on the terminal surface of the connector is defined as an x axis direction. A direction in which a pair of connectors fit with each other is defined as a y axis direction. A direction perpendicular to the x axis and the y axis is defined as a z axis direction, 
     With regard to positive and negative directions of the x axis, a direction in which a signal pin number becomes larger (left in  FIG. 1A ) is defined as a positive direction of the x axis in conformity with the HDMI standard. With regard to positive and negative directions of the y axis, a direction from the plug-side connector to the receptacle-side connector (toward a plane of a paper of  FIG. 1A  in a direction perpendicular to the plane of the paper) is defined as a positive direction of the y axis. With regard to positive and negative directions of the z axis, an upper direction of  FIG. 1A  is defined as a positive direction of the z axis. 
     Here, as a way to transmit more video signals, change in allocation of signal pins can be considered. Specifically, in  FIG. 1A , it can be considered that “Data 2  Shield”, “Data 1  Shield”, and “Data 0  Shield” that are signal pins used as shields of differential line (differential data lane) pairs, and “clock+”, “clock-”, and “clock Shield” that are signal pins for transmitting clock signals are used as signal pins corresponding to new data lines. 
       FIG. 1  B shows an example of such way to change allocation of signal pins.  FIG. 1B  is a schematic view showing an example of pin arrangement in which high-speed differential data lines are newly added in a Type A HDMI connector or in a Type D HDMI connector. 
     With reference to  FIG. 1B , new differential line pairs “Data 3 +”, “Data 3 −”, “Data 4 +”, and “Data 4 −” are respectively allocated to the signal pins # 2 , # 5 , # 8 , and # 11  that are used as the shields in  FIG. 1A . In addition, a new differential line pair “Data 5 +” and “Data 5 −” are respectively allocated to the signal pins # 10  and # 12  that are used as the clock in  FIG. 1A . 
     A shield of a cable can be secured by connecting a drain wire of an STP cable to a shell part of the plug-side connector and by connecting and grounding shell parts of the receptacle-side connectors of the source device and the sink device, the drain wire being connected as a shield in the general signal pin arrangement as shown in  FIG. 1A . With regard to the clock, the sink device extracts bit clock from data in an individual data lane, the frequency of the extracted bit clock is divided by 10, and the sink device generates pixel clock by itself. 
     As explained above, by expanding the number of the differential line pairs from three to six, the data transmission amounts can be doubled while keeping the transmission speed of the individual line the same. However, signals to be transmitted may deteriorate in the pin arrangement shown in  FIG. 1B . 
     It is because, with regard to the new defined signal pins “Data 3 +”, “Data 3 −”, “Data 4 +”, and “Data 4 −”, physical distances between the differential lines to be paired are more separated than the initial differential line pairs, as shown in  FIG. 1B . Accordingly, in the new defined signal pins, coupling is less likely to occur between differential signals, and impedance mismatches may occur. 
     Moreover, there is no line functioning as a shield between each of the differential line pairs. Accordingly, each of the differential line pairs is likely to be affected by crosstalk from adjacent lines, and it is highly possible that signals deteriorate. 
     As a measure against the deterioration in signals, for example, shapes of the signal pins and positions where the signal pins are disposed in the connector are improved so as to reduce the deterioration in the signals. Specifically, for example, wiring width of the signal pins is narrowed. Accordingly, intervals between the signal pins are relatively widened, and the crosstalk effect is reduced. 
     Alternatively, for example, the deterioration in the signals can be reduced by stretching the signal pins near a ground conductor that constitutes a periphery of the connector and by transmitting differential signals applied to the signal pins with single end. 
     Here, the HDMI connectors include different types of connectors from Type A to Type E. The Type C HDMI connector and the Type D HDMI connector are referred to as a mini-HDMI connector and a micro-HDMI connector, respectively. In addition, the Type C HDMI connector and the Type D HDMI connector are smaller than a standard Type A HDMI connector. For example, an area of a terminal surface of the Type A HDMI connector is set to be 14 mm×4.5 mm, an area of a terminal surface of the Type C HDMI connector is set to be 10.5 mm×2.5 mm, and an area of a terminal surface of the Type D HDMI connector is set to be 5.8 mm×2.0 mm. 
     Thus, the measure against the deterioration in signals is effective in a case where a size of a connector is comparatively large like the Type A HDMI connector and shapes of signal pins and signal pin arrangement can be freely changed. However, in a case where a size of a connector is comparatively small like the Type C HDMI connector or the Type D HDMI connector, shapes of signal pins and signal pin arrangement are less freely changed, and the measure may not be sufficiently effective for reducing the deterioration in signals. 
     As explained above, a conclusion of the study is that a way to change allocation of signal pins in an HDMI connector can be considered for increasing the data transmission amounts. However, signals may deteriorate due to increase in the number of data lines allocated to the signal pins. It is difficult for a relatively small HDMI connector such as the Type C HDMI connector or the Type D HDMI connector to achieve sufficient effect by the way to change shapes of the signal pins or signal pin arrangement position so as to reduce the deterioration in signals. Accordingly, a more versatile way to reduce deterioration in signals has been desired, the way being applicable to more diverse types of connectors. 
     On the basis of the above-described study, the present inventors have arrived at the connector, data receiving apparatus, data transmitting apparatus, and data transmitting and receiving system according to the present disclosure that are capable of reducing deterioration in signals. Next, preferred embodiments are explained. 
     2. First Embodiment 
     First, a structure of a connector according to a first embodiment of the present disclosure is explained. Note that, the connector according to the first embodiment corresponds to the Type C HDMI connector. 
     The Type C HDMI connector has different signal pin arrangement position on a terminal surface from that of the Type A HDMI connector shown in  FIGS. 1A and 1B . Here, with reference to  FIGS. 2A and 2B , pin arrangement in the Type C HDMI connector is explained.  FIG. 2A  is a schematic view showing pin arrangement for transmitting a high-speed differential signal in a general Type C HDMI connector.  FIG. 2B  is a schematic view showing an example of pin arrangement in which high-speed differential data lines are newly added in a Type C HDMI connector. Note that,  FIGS. 2A and 2B  show only signal pins relating to video signal transmission, and the other signal pins are not shown. In addition,  FIGS. 2A and 2B  show terminal surfaces of receptacle-side connectors. 
     In the following explanation about pin arrangement in the Type C HDMI connector, differences from the pin arrangement in the Type A HDMI connector that has been explained with reference to  FIGS. 1A and 1B  are mainly explained, and detailed explanations about overlapping configuration and function are omitted. 
     First, with reference to  FIG. 2A , signal pins  971  are embedded in a dielectric  972  covered by an outer shell (shell)  973 , in a terminal surface of the general Type C HDMI connector. However, in contrast to the pin arrangement in the general Type A HDMI connector shown in  FIG. 1A , the signal pins  971  are arranged in a line on the terminal surface of the general Type C HDMI connector in an x axis direction. In addition, a different kind of signal is applied to each of the signal pins  971 , and  FIG. 2A  shows the kinds of signals. 
     Specifically, “Data 2  Shield”, “Data 2 +”, and “Data 2 −” are allocated to the signal pins # 1 , # 2 , and # 3 , respectively. In a similar way, “Data 1  Shield”, “Data 1 +”, and “Data 1 −” are allocated to the signal pins # 4 , # 5 , and # 6 , respectively. In addition, in a similar way, “Data 0  Shield”, “Data 0 +”, and “Data 0 −” are allocated to the signal pins # 7 , # 8 , and # 9 , respectively. In addition, “clock Shield”, “clock+”, and “clock−” are allocated to the signal pins # 10 , # 11 , and # 12 , respectively. 
     That is, each of the data lines (Data 0 / 1 / 2 ) and the clock is constituted by three lines including differential lines Datai+, Datai−, and Datai Shield (i=0, 1, 2). When data is transmitted, the differential lines Datai+ and Datai− generates coupling between differential signals (differential coupling is generated). Note that, functions of the data lines (Data 0 / 1 / 2 ) and the clock are similar to those in pin arrangement in the general Type A HDMI connector shown in  FIG. 1A . Accordingly, detailed explanation is omitted here. 
     Next, with reference to  FIG. 2B , the number of data lines allocated to the signal pins are increased in the pin arrangement in the connector according to the first embodiment of the present disclosure, in comparison with the pin arrangement in the general Type C HDMI connector shown in  FIG. 2A . 
     Specifically, new differential line pairs “Data 3 +”, “Data 3 −”, “Data 4 +”, and “Data 4 −” are respectively allocated to the signal pins # 1 , # 4 , # 7 , and # 10  that are used as the shields in  FIG. 2A . In addition, a new differential line pair “Data 5 +” and “Data 5 −” are respectively allocated to the signal pins # 11  and # 12  that are used as the clock in  FIG. 2A . As explained above, by expanding the number of the differential line pairs from three to six, the data transmission amounts can be doubled while keeping the transmission speed of the individual line the same. Note that, the way to secure the shields in the cable and the way to generate the clock are similar to those of the general Type A HDMI connector explained with reference to  FIG. 1B . Accordingly, detailed explanation is omitted here. 
     With reference to  FIGS. 2A and 2B , pin arrangement in the Type C HDMI connector has been explained. Here, when the pin arrangement in which the data lines are newly added as shown in  FIG. 2B  is applied to the Type C HDMI connector having a general connector structure, deterioration in signals occurs like the Type A HDMI connector explained in &lt;1. Study on Increase in Transmission Data Amount&gt;. On the other hand, a connector structure (to be described later) according to the first embodiment of the present disclosure can reduce the deterioration in signals even in a case of pin arrangement in which data lines are newly added as shown in  FIG. 2B . 
     In order to clearly explain the structure of the connector according to the first embodiment, a structural example of the general Type C HDMI connector is firstly explained in [2.1. Structural Example of General Type C Connector]. Next, in [2.2. Structural Example of Connector according to First Embodiment], a structural example of the connector according to the first embodiment of the present disclosure and differences in structure from the general Type C HDMI connector are explained. Subsequently, characteristics of signals transmitted in the both structures are compared in [2.3. Comparison of Characteristic], and effect to reduce deterioration in signals in the connector according to the first embodiment is explained. 
     [2.1. Structural Example of General Type C Connector] 
     First, with reference to  FIGS. 3A to 3C , a structural example of the general Type C HDMI connectors is explained.  FIG. 3A  is a cross-sectional view showing a structural example of a general Type C HDMI connectors when being cut at a cross section constituted by a y axis and a z axis through signal pins.  FIG. 3B  is a cross-sectional view of the general Type C HDMI connectors corresponding to an A-A cross section in  FIG. 3A , the A-A cross section being constituted by an x axis and the y axis.  FIG. 3C  is a cross-sectional view of the general Type C HDMI connectors corresponding to a C-C cross section in  FIG. 3B , the C-C cross section being constituted by the x axis and the z axis. Note that, in  FIGS. 3A to 3C , the plug-side connector and the receptacle-side connector are fitted with each other. 
     First, a structure of the plug-side connector is explained. With reference to  FIGS. 3A to 3C , a plug-side connector  810  of the general Type C HDMI connector includes signal pins  811 , a dielectric  812 , and an outer shell (shell)  813 . The signal pins  811  extend in the first direction, in other words, the y axis direction. Parts of the signal pins  811  are embedded in the dielectric  812 . 
     The shell  813  covers the signal pins  811  and the dielectric  812 . One surface of the shell  813  in the positive direction of the y axis is an open surface open to an outside. As shown in  FIGS. 3A to 3C , the plug-side connector  810  and a receptacle-side connector  820  (to be described later) are connected via the open surface of the shell  813 . In addition, the shell  813  is formed of an electric conductor. Potential of the shell  813  is fixed to, for example, the ground potential via the receptacle-side connector  820  (to be described later). 
     In a predetermined region near the open surface of the shell  813 , tips of the signal pins  811  are exposed from the dielectric  812 . The exposed part constitutes a protrusion protruded toward the open surface of the shell  813 . When the plug-side connector  810  and the receptacle-side connector  820  (to be described later) are fitted with each other, the protrusion of the signal pins  811  contacts signal pins  821  of the receptacle side connector  820  (to be described later). Accordingly, the plug-side connector  810  and the receptacle-side connector  820  (to be described later) are electrically connected to each other. Note that, a contact part may be provided on a part of a region of the protrusion of the signal pins  811 , the contact part further protruding toward the signal pins  821  of the receptacle-side connector  820 . Thus, the signal pins  811  of the plug-side connector  810  and the signal pins  821  of the receptacle-side connector may contact to each other via the contact part. 
     Next, a structure of the receptacle-side connector is explained. With reference to  FIGS. 3A to 3C , the receptacle-side connector  820  of the general Type C HDMI connector includes the signal pins  821 , a dielectric  822 , and an outer shell (shell)  823 . The signal pins  821  extend in the first direction, in other words, the y axis direction. Parts of the signal pins  811  are embedded in the dielectric  822 . 
     The shell  823  covers the signal pins  821  and the dielectric  822 . One surface of the shell  823  in the negative direction of the y axis is an open surface open to an outside. In addition, the shell  823  is formed of an electric conductor. Potential of the shell  823  is fixed to, for example, the ground potential. 
     An area of an opening of the open surface of the shell  823  is slightly larger than the cross-sectional area of the open surface of the shell  813  of the plug-side connector  810 . As shown in  FIGS. 3A to 3C , an end provided with the open surface of the shell  813  of the plug-side connector  810  is inserted into the opening of the open surface of the shell  823  of the receptacle-side connector  820 , and the plug-side connector  810  and the receptacle-side connector  820  are fitted with each other. Note that, a region indicated by a dotted line in  FIGS. 3A and 3B  represents a fitting part S of the plug-side connector  810  and the receptacle-side connector  820 . 
     In a predetermined region near the open surface, the signal pins  821  include an exposed part in which parts of regions of surfaces of the signal pins  821  is exposed from the dielectric  822 . When the plug-side connector  810  and the receptacle-side connector  820  are fitted with each other, the exposed part of the signal pins  821  contacts the protrusion (contact part) of the signal pins  811  of the plug-side connector  810 . 
     With reference to  FIGS. 3A to 3C , a structure of the general Type C HDMI connector has been explained. 
     [2.2. Structural Example of Connector According to First Embodiment] 
     Next, with reference to  FIGS. 4A to 4C , a structural example of connectors according to the first embodiment of the present disclosure is explained.  FIG. 4A  is a cross-sectional view showing a structural example of connectors according to a first embodiment when being cut at a cross section constituted by a y axis and a z axis through signal pins.  FIG. 4B  is a cross-sectional view of the connectors according to the first embodiment corresponding to an A-A cross section in  FIG. 4A , the A-A cross section being constituted by an x axis and the y axis.  FIG. 4C  is a cross-sectional view of the connectors according to the first embodiment corresponding to a C-C cross section in  FIG. 4B , the C-C cross section being constituted by the x axis and the z axis. Note that, in  FIGS. 4A to 4C , a plug-side connector and a receptacle-side connector are fitted with each other. 
     First, a structure of the plug-side connector is explained. With reference to  FIGS. 4A to 4C , a plug-side connector  10  according to the first embodiment includes signal pins  110 , a dielectric  120 , a substrate  130 , and an outer shell (shell)  140 . 
     The signal pins  110  extend in a first direction, in other words, a y axis direction. In addition, the signal pins  110  are formed as a wiring pattern on a surface of the substrate  130  formed of dielectric. 
     The shell  140  covers the signal pins  110  and the substrate  130 . One surface of the shell  140  in the positive direction of the y axis is an open surface open to an outside. As shown in  FIGS. 4A to 4C , the plug-side connector  10  and a receptacle-side connector  20  (to be described later) are connected via the open surface of the shell  140 . In addition, the shell  140  is formed of an electric conductor. Potential of the shell  140  is fixed to, for example, a ground potential via the receptacle-side connector  20  (to be described later). 
     An electric conductor layer having a ground potential is formed on a rear surface of the substrate  130 , in other words, an opposite surface of a surface on which the signal pins  110  are formed. With reference to  FIGS. 4A to 4C , according to the present embodiment, a surface of a shell  140  that faces the rear surface of the substrate is thicker than other surfaces, and is in contact with the rear surface of the substrate  130 . Thus, the electric conductor layer formed on the rear surface of the substrate  130  is integrated with the shell  140 . Note that, in the present embodiment, it is only necessary to form the electric conductor layer having a ground potential on the rear surface of the substrate  130 . The structure of the electric conductor layer is not limited to the above example. Accordingly, the surface of the shell  140  is not necessarily thickened. For example, the electric conductor layer formed on the rear surface of the substrate  130  may be electrically connected to the shell  140  through a via hole or the like. 
     In addition, the dielectric may be stacked above (in positive direction of the z axis) the signal pins  110  formed on the substrate  130 . Note that, when the dielectric  120  is formed, the dielectric  120  does not cover the entire surfaces of the signal pins  110 , and parts of regions of the signal pins  110  are exposed in a predetermined region near the open surface of the shell  140 . When the plug-side connector  10  and the receptacle-side connector  20  (to be described later) are fitted with each other, the exposed parts of the signal pins  110  of the plug-side connector contact signal pins  210  (wiring pattern) of the receptacle side connector  20 . Accordingly, the plug-side connector  10  and the receptacle-side connector  20  (to be described later) are electrically connected to each other. Note that, contact parts may be provided on parts of regions of the exposed parts of the signal pins  110 , the contact parts protruding toward the signal pins  210  of the receptacle-side connector  20 . Thus, the signal pins  110  of the plug-side connector  10  and the signal pins  210  of the receptacle-side connector  20  may contact to each other via the contact parts. 
     Next, a structure of the receptacle-side connector is explained. With reference to  FIGS. 4A to 4C , the receptacle-side connector  20  according to the first embodiment includes signal pins  210 , a dielectric  220 , a substrate  230 , and an outer shell (shell)  240 . 
     The signal pins  210  extend in a first direction, in other words, the y axis direction. In addition, the signal pins  210  are formed as a wiring pattern on a surface of the substrate  230  formed of dielectric. 
     The shell  240  covers the signal pins  210  and the substrate  230 . One surface of the shell  240  in the negative direction of the y axis is an open surface open to an outside. In addition, the shell  240  is formed of an electric conductor. Potential of the shell  240  is fixed to, for example, a ground potential. 
     An area of an opening of the open surface of the shell  240  is slightly larger than the cross-sectional area of the open surface of the shell  140  of the plug-side connector  10 . As shown in  FIGS. 4A to 4C , an end provided with the open surface of the shell  140  of the plug-side connector  10  is inserted into the opening of the open surface of the shell  240  of the receptacle-side connector  20 , and the plug-side connector  10  and the receptacle-side connector  20  are fitted with each other. Note that, regions indicated by dotted lines in  FIGS. 4A and 4B  represent a fitting part T of the plug-side connector  10  and the receptacle-side connector  20 . 
     An electric conductor layer having a ground potential is formed on a rear surface of the substrate  230 , in other words, an opposite surface of a surface on which the signal pins  210  are formed. With reference to  FIGS. 4A to 4C , according to the present embodiment, a surface of a shell  240  that faces the rear surface of the substrate  230  is thicker than other surfaces, and is in contact with the rear surface of the substrate  230 . Thus, the electric conductor layer formed on the rear surface of the substrate  230  is integrated with the shell  240 . Note that, in the present embodiment, it is only necessary to form the electric conductor layer having a ground potential on the rear surface of the substrate  230 . The structure of the electric conductor layer is not limited to the above example. Accordingly, the surface of the shell  240  is not necessarily thickened. For example, the electric conductor layer formed on the rear surface of the substrate  230  may be electrically connected to the shell  240  through a via hole or the like. 
     In addition, the dielectric  220  may be stacked above (in positive direction of the z axis) the signal pins  210  formed on the substrate  230 . Note that, when the dielectric  220  is formed, parts of regions of the signal pins  210  are exposed in a predetermined region near the open surface of the shell  240 . The exposed parts of the signal pins  210  of the receptacle-side connector  20  contact the exposed parts and/or the contact parts of the signal pins  110  (wiring pattern) of the receptacle side connector  10 . Accordingly, the plug-side connector  10  and the receptacle-side connector  20  are electrically connected to each other. 
     With reference to  FIG. 4B , among the signal pins  110  of the plug-side connector  10  and the signal pins  210  of the receptacle-side connector, intervals between pairs of the signal pins  110  and  210  that transmit differential signals and adjacently extend are shorter than intervals from other signal pins  110  and  210  adjacent to the pairs of the signal pins  110  and  210 . Note that, the intervals of the signal pins  110  and the intervals of the signal pins  210  may be identical in the fitting part T. On the other hand, in a region other than the fitting part T, the intervals between the pairs of the signal pins  110  and  210  that transmit the differential signal and adjacently extend may be shorter than the intervals from other signal pins  110  and  210  adjacent to the pairs of the signal pins  110  and  210 . 
     The wiring intervals between the signal pins  110  and the wiring intervals between the signal pins  210  in the fitting part T may be similar to the wiring intervals of the signal pins  811  and the wiring intervals of the signal pins  821  in the fitting part S shown in  FIGS. 3A to 3C . Thus, the signal pins of the connector according to the first embodiment and the signal pins of the general Type C HDMI connector may have identical wiring intervals in the fitting parts. 
     As explained with reference to  FIGS. 4A to 4C , the connector according to the first embodiment and the general Type C HDMI connector are different as follows: The connector according to the first embodiment are formed of the dielectric, and includes signal pins (wiring pattern corresponding to the signal pins) on one surface and the substrate, in which the electric conductor layer having the ground potential is formed, on the other surface. In addition, among the signal pins in the connector according to the first embodiment, the intervals between pairs of the signal pins that transmit the differential signals and adjacently extend are shorter than the intervals from other signal pins adjacent to the pairs of the signal pins. Next, effects of the connector according to the first embodiment achieved due to such configuration are explained. 
     As explained above, in the connectors  10  and  20  according to the first embodiment, signal pins  110  and  210  are formed on the substrates  130  and  230  formed of the dielectric, and the electric conductor layers having the ground potential are formed on the opposite sides of the surfaces of the substrates  130  and  230  on which the signal pins  110  and  210  are formed. Accordingly, the connectors according to the first embodiment have configurations in which ground planes (electric conductor layers), dielectric layers (substrate  130  and  230 ), and wiring (signal pins  110  and  210 ) are stacked in this order. According to such configurations, an electromagnetic field due to current (signal) flowing in the signal pins  110  and  210  is trapped between the substrates  130  and  230  and the electric conductors, and the so-called microstripline (microstrip structure) is formed. Thus, in the connector according to the first embodiment, it is possible to reduce effects of the current (signal) flowing through the signal pins  110  and  210  on other signal pins  110  and  210 , and the deterioration in signals can be reduced. 
     In addition, as explained above, among the signal pins  110  and  210  in the connectors  10  and  20  according to the first embodiment, intervals between pairs of the signal pins  110  and  210  that transmit differential signals and adjacently extend may be shorter than intervals from other signal pins  110  and  210  adjacent to the pairs of the signal pins  110  and  210 . Since the intervals between pairs of signal pins  110  and  210  that transmit differential signals to be paired are narrowed more, an electromagnetic field due to current (signal) flowing in the pairs of the signal pins  110  and  210  is trapped between the pairs of signal pins  110  and  210  and between the substrates  130  and  230  and the electric conductors, and so-called differential stripline (differential strip structure) is formed. Note that, a return path of the differential coupling is secured on the ground plane at a rear surface of the wiring surface. Accordingly, since the coupling is generated between the differential data lines, it is possible to narrow the wiring width and the wiring intervals between the signal pins, while the differential impedance is maintained. Thus, intervals from a different kind of adjacent signal wiring can be widened. Accordingly, the crosstalk can be reduced and signal quality can be improved. Thus, in the connectors according to the first embodiment, it is possible to further reduce effects of the current (signal) flowing through the pair of the signal pins  110  and  210  that transmit a differential signal, on other signal pins  110  and  210 . In addition, the deterioration in signals can be reduced more. 
     Note that, in a case where the pin arrangement shown in  FIG. 2B  in which the data lines are newly added is applied to the connector according to the first embodiment, signal pins to which a pair of differential signals “Data 3 +” and “Data 3 −”, and a pair of differential signals “Data 4 +” and “Data 4 −” are allocated are not arranged at positions where the pairs of the differential signals are next to each other, from among the newly added pairs of the differential signals. Thus, in the connector according to the first embodiment, pairs of adjacent signal pins to which a “Data 0 ” and “Data 0 −” pair, a “Data 1 +” and “Data 1 −” pair, a “Data 2 +” and “Data 2 −” pair, and a “Data 5 +” and “Data 5 −” pair are applied transmit signals using the differential striplines. On the other hand, pairs of nonadjacent signal pins to which a “Data 3 +” and “Data 3 −” pair and a “Data 4 +” and “Data 4 −” pair are applied transmit signals using single-ended microstriplines. 
     In addition, as explained above, the connector according to the first embodiment of the present disclosure can be more effective in the case of the pin arrangement as shown in  FIG. 2B  in which the data lines are newly added. However, the connector according to the first embodiment also can be applied to the general pin arrangement as shown in  FIG. 2A . Even if the connector according to the first embodiment of the present disclosure is applied to the general pin arrangement shown in  FIG. 2A , effects of current (signals) flowing through the signal pins  110  and  210  on other signals  110  and  210  and deterioration in the signals can be reduced by forming a microstripline and a differential stripline with regard to each signal pin. 
     Note that, as explained with reference to  FIG. 4B , the intervals between the signal pins  110  and the intervals between the signal pins  210  in the fitting part T of the connectors according to the first embodiment of the present disclosure may be identical to the intervals between the signal pins  811  and the intervals between the signal pins  821  in the fitting part S of the general Type C HDMI connectors. According to such configuration, it is possible to ensure compatibility between the connector according to the first embodiment and the general Type C HDMI connector. Thus, when the connector according to the first embodiment and the general Type C HDMI connector are fitted with each other, predetermined signal pins defined by the HDMI standard are electrically connected. Accordingly, the connector according to the first embodiment also can be applied to a case where signals transmission corresponding to the general pin arrangement shown in  FIG. 2A  are performed. 
     Here, with reference to  FIG. 5 , a modification of connectors according to the first embodiment of the present disclosure is explained. In the connector according to the first embodiment of the present disclosure, guard lines having ground potential may further extend at positions for sandwiching a signal pin in a manner that the guard lines are substantially parallel to the signal pin. In addition, the guard lines may be disposed so as to sandwich a signal pin that transmits a signal with single end.  FIG. 5  is an explanatory diagram illustrating a configuration in which guard lines are disposed. 
       FIG. 5  shows a configuration in which guard lines are newly disposed in the connectors according to the first embodiment shown in  FIG. 4B . Thus,  FIG. 5  shows the configuration in which guard lines are provided in the connector according to the first embodiment when viewed from the positive direction of the z axis. With reference to  FIG. 5 , for example, guard lines  150  are disposed so as to sandwich a signal pin  110  that transmits a signal by single coupling in a plug-side connector  10 . For example, in a similar way, guard lines  250  are disposed so as to sandwich a signal pin  210  that transmits a signal with single end in a receptacle-side connector  20 . Potential of the guard lines  150  and  250  are set to the ground potential. Since the guard lines  150  and  250  are provided, it is possible to reduce effects of the current (signal) flowing through the signal pins  110  and  210  on other signal pins  110  and  210 , and the deterioration in signals can be reduced. 
     [2.3. Comparison of Characteristic] 
     Next, a result of comparison between a characteristic of a signal flowing a signal pin in the general Type C HDMI connector structure shown in  FIGS. 3A to 3C  and a characteristic of a signal flowing a signal pin in the connector structure according to the first embodiment of the present disclosure shown in  FIGS. 4A to 4C  is explained. Note that, the following  FIGS. 6A to 6B ,  FIGS. 7A to 7B ,  FIGS. 8A to 8B , and  FIGS. 9A to 9E  each show a result of flowing a signal corresponding to pin arrangement in which data lines are newly added as shown in  FIG. 2B . 
     First, with reference to  FIGS. 6A to 6B  and  FIGS. 7A to 7B , difference in electric field distribution near signal pins between the general Type C HDMI connector and the connector according to the first embodiment is explained. 
       FIGS. 6A to 6B  and  FIGS. 7A to 7B  each show electric field distribution near signal pins in a case where a predetermined signal for transmitting a video signal decided by the HDMI standard is applied to each connector.  FIGS. 6A and 6B  are each a contour map of an electric field showing electric field distribution in the general Type C HDMI connector structure.  FIGS. 7A and 7B  are each a contour map of an electric field showing electric field distribution in the connector structure according to the first embodiment. In  FIGS. 6A to 6B  and  FIGS. 7A to 7B , strength of the electric field distribution is schematically represented by shades of hatching. A dark hatched region represents a region in which the electric field is concentrated. 
       FIG. 6A  is a contour map of an electric field at a cross-section corresponding to  FIG. 3A , in the general Type C HDMI connector structure.  FIG. 6B  is a contour map of an electric field at a D-D cross-section shown in  FIG. 6A . 
       FIG. 7A  is a contour map of an electric field at a cross-section corresponding to  FIG. 4A , in the connector structure according to the first embodiment.  FIG. 7B  is a contour map of an electric field at a D-D cross-section shown in  FIG. 7A . Note that, the contour maps of the electric field shown in  FIGS. 7A and 7B  determine the electric field distribution of the connector structure according to the first embodiment in which the guard lines are further provided as shown in  FIG. 5 . 
     The contour maps of the electric fields in  FIGS. 6A to 6B  and  FIGS. 7A to 7B  each show a simulation result of an electric field distribution near the signal pins in a case where a model in which permittivity corresponding to each region (signal pin, substrate, outer shell, dielectric, or the like) at each cross-section described above is set is formed, and a predetermined signal when a video signal decided by the HDMI standard is transmitted is applied. 
     With reference to  FIG. 6A , in the general Type C HDMI connector structure, there is few difference in the electric field distribution between a front surface (surface that stretches in the y axis direction and that is positioned in the positive direction of the z axis) and a rear surface (surface that stretches in the y axis direction and that is positioned in the negative direction of the z axis) of each of the signal pins  811  and  821 . On the other hand, with reference to  FIG. 6B , in the general Type C HDMI connector structure, electric field is concentrated and coupling occurs between a part of the signal pins  110  as shown in a region E for example. However, in a region F (region across “Data 0 −”, “Data 4 −”, and “Data 5 +”) and a region G (region across “Data 1 −”, “Data 4 +”, and “Data 0 +”), electric fields are also concentrated in regions other than a differential signal pair, and current (signal) flowing through signal pins  811  affects other signal pins  811 . 
     On the other hand, with reference to  FIG. 7A , in the connector structure according to the first embodiment, electric field is concentrated between the signal pins  110  and  210  and the substrates  130  and  230 , and the so-called microstripline is formed. In addition, with reference to  FIG. 7B , in the connector structure according to the first embodiment, electric fields are concentrated between the adjacently disposed pairs of signal pins  110  and  210  “Data 0 ”, “Data 1 ”, “Data 2 ”, and “Data 5 ”, and the so-called differential striplines are formed. With regard to the signal pins  110  and  210  “Data 3 −”, “Data 3 +”, “Data 4 −”, and “Data 4 +”, electric fields are concentrated in the substrate between the signal pins  110  and  210  and a GND conductor (shell  140 ), and a single-ended electric field is formed. Accordingly, effects of current (signal) flowing through signal pins  110  and  210  on other signal pins  110  and  210  are reduced. 
     Next, with reference to  FIGS. 8A to 8B  and  FIGS. 9A to 9E , difference in signal transmission characteristics as represented by an eye pattern and crosstalk, between the general Type C HDMI connector and the connector according to the first embodiment is explained. 
       FIGS. 8A and 8B  are each a voltage characteristic diagram showing an eye pattern of the general Type C HDMI connector structure shown in  FIGS. 3A to 3C .  FIG. 8A  shows an eye pattern of the “Data  2 ” line shown in  FIG. 2B  and  FIG. 8B  shows an eye pattern of the “Data  4 ” line shown in  FIG. 2B . 
       FIGS. 9A and 9B  are each a voltage characteristic diagram showing an eye pattern of the connector structure according to the first embodiment shown in FIGS.  4 A to  4 C.  FIG. 9A  shows an eye pattern of the “Data  2 ” line shown in  FIG. 2B  and  FIG. 9B  shows an eye pattern of the “Data  4 ” line shown in  FIG. 2B . 
       FIGS. 9C and 9D  is each a voltage characteristic diagram showing an eye pattern of a connector structure according to the first embodiment in which guard lines are further arranged as shown in  FIG. 5 .  FIG. 9C  shows an eye pattern of the “Data  2 ” line shown in  FIG. 2B  and  FIG. 9D  shows an eye pattern of the “Data  4 ” line shown in  FIG. 2B .  FIG. 9E  is a voltage characteristic diagram showing a crosstalk characteristic of a connector structure according to the first embodiment in which guard lines are further arranged as shown in  FIG. 5 . 
     In  FIGS. 8A to 8B  and  FIGS. 9A to 9E , the eye pattern corresponding to “Data 2 ” represents a transmission characteristic of data lines (existing data lines) that already exist in the general pin arrangement shown in  FIG. 2A , and the eye pattern corresponding to “Data 4 ” represents a transmission characteristic of data lines (new data lines) that are newly added in the pin arrangement in which data lines are newly added as shown in  FIG. 2B . 
     When the  FIGS. 8A and 8B  are compared and  FIGS. 9A and 9B  are compared, the signal transmission characteristic is improved due to the connector structure according to the first embodiment, in addition to the existing data line “Data 2 ” and the new data line “Data 4 ”. Thus, the deterioration in signals is reduced by the connector structure according to the first embodiment. 
     When the  FIGS. 9A and 9B  are compared and  FIGS. 9C and 9D  are compared, the signal transmission characteristic is further improved by providing the guard lines  150 , in addition to the existing data line “Data 2 ” and the new data line “Data 4 ”. Thus, the deterioration in signals is reduced by further providing the connector structure according to the first embodiment with the guard lines  150 . In addition, with reference to  FIG. 9E , a good crosstalk characteristic can be obtained in the connector structure according to the first embodiment. 
     3. Second Embodiment 
     Next, a structure of a connector according to a second embodiment of the present disclosure is explained. Note that, the connector according to the second embodiment corresponds to the Type D HDMI connector. 
     As explained with reference to  FIGS. 1A and 1B , the Type D HDMI connector has pin arrangement shown in  FIGS. 1A and 1B . Here, when the pin arrangement in which the data lines are newly added as shown in  FIG. 1B  is applied to the Type D HDMI connector, deterioration in signals occurs like the Type A HDMI connector explained in &lt;1. Study on Increase in Transmission Data Amount&gt;. On the other hand, a connector structure (to be described later) according to the second embodiment of the present disclosure can reduce the deterioration in signals even in a case of pin arrangement in which data lines are newly added as shown in  FIG. 1B . 
     In order to clearly explain the structure of the connector according to the second embodiment, a structural example of the general Type D HDMI connector is firstly explained in [3.1. Structural Example of General Type D Connector]. Next, in [3.2. Structural Example of Connector according to Second Embodiment], a structural example of the connector according to the second embodiment of the present disclosure and differences from the general Type D HDMI connector are explained. Subsequently, characteristics of signals transmitted in the both structures are compared in [3.3. Comparison of Characteristic], and effect to reduce deterioration in signals in the connector according to the second embodiment is explained. 
     As shown in  FIGS. 1A and 1B , signal pins are arranged along the x axis direction in two lines in the z axis direction in zigzag on the terminal surface, in the pin arrangement according to the general Type D HDMI connector. In addition, in a vertical direction of  FIGS. 1A and 1B , signal pins formed on the upper line (upper direction in the z axis direction) and signal pins formed on the lower line (lower direction in the z axis direction) are horizontal line symmetry although disposition positions in the x axis are different. Accordingly, with regard to the following  FIGS. 10A to 10C  and  FIGS. 11A to 11C , structures of signal pins at a lower side in the z axis direction (signal pins formed at the lower line in  FIGS. 1A and 1B ) are mainly explained. An explanation of the signal pins at the upper side in the z axis direction (signal pins formed at the upper line in  FIGS. 1A and 1B ) is omitted since the signal pins correspond to a structure obtained by folding the structure of the signal pins at the lower side. 
     [3.1. Structural Example of General Type D Connector] 
     First, with reference to  FIGS. 10A to 10C , a structural example of a general Type D HDMI connectors is explained.  FIG. 10A  is a cross-sectional view showing a structural example of general Type D HDMI connectors when being cut at a cross section constituted by a y axis and a z axis through signal pins.  FIG. 10B  is a cross-sectional view of the general Type D HDMI connectors corresponding to an A-A cross section in  FIG. 10A , the A-A cross section being constituted by an x axis and the y axis.  FIG. 10C  is a cross-sectional view of the general Type D HDMI connectors corresponding to a C-C cross section in  FIG. 10B , the C-C cross section being constituted by the x axis and the z axis. Note that, in  FIGS. 10A to 10C , a plug-side connector and a receptacle-side connector are fitted with each other. 
     First, a structure of the plug-side connector is explained. With reference to  FIGS. 10A to 10C , a plug-side connector  910  of the general Type D HDMI connector includes signal pins  911 , a dielectric  912 , and an outer shell (shell)  913 . The signal pins  911  extend in the first direction, in other words, the y axis direction. Parts of the signal pins  811  are embedded in the dielectric  912 . 
     The shell  913  covers the signal pins  911  and the dielectric  912 . One surface of the shell  913  in the positive direction of the y axis is an open surface open to an outside. As shown in  FIGS. 10A to 10C , the plug-side connector  910  and a receptacle-side connector  920  (to be described later) are connected via the open surface of the shell  913 . In addition, the shell  913  is formed of an electric conductor. Potential of the shell  813  is fixed to, for example, the ground potential via the receptacle-side connector  920  (to be described later). 
     In a predetermined region near the open surface of the shell  913 , tips of the signal pins  911  are exposed from the dielectric  912 . The exposed parts constitute bent parts bent toward the positive direction of the z axis at a predetermined angle. When the plug-side connector  910  and the receptacle-side connector  920  (to be described later) are fitted with each other, the bent parts of the signal pins  911  contact signal pins  921  of the receptacle side connector  920  (to be described later). Accordingly, the plug-side connector  910  and the receptacle-side connector  920  (to be described later) are electrically connected to each other. 
     Note that, the signal pins  921  at the upper side in the z axis direction have a structure that is horizontal line symmetrical to the signal pins at the lower side as described above. Accordingly, bent parts of the signal pins  921  are formed so as to be bent toward the negative direction of the z axis at the predetermined angle. 
     Next, a structure of the receptacle-side connector is explained. With reference to  FIGS. 10A to 10C , the receptacle-side connector  920  of the general Type D HDMI connector includes the signal pins  921 , a dielectric  922 , and an outer shell (shell)  923 . The signal pins  921  extend in the first direction, in other words, the y axis direction. Parts of the signal pins  921  are embedded in the dielectric  922 . 
     The shell  923  covers the signal pins  921  and the dielectric  922 . One surface of the shell  923  in the negative direction of the y axis is an open surface open to an outside. In addition, the shell  923  is formed of an electric conductor. Potential of the shell  923  is fixed to, for example, the ground potential. 
     An area of an opening of the open surface of the shell  923  is slightly larger than the cross-sectional area of the open surface of the shell  913  of the plug-side connector  910 . As shown in  FIGS. 10A to 10C , an end provided with the open surface of the shell  913  of the plug-side connector  910  is inserted into the opening of the open surface of the shell  923  of the receptacle-side connector  920 , and the plug-side connector  910  and the receptacle-side connector  920  are fitted with each other. Note that, regions indicated by dotted lines in  FIGS. 10A and 10B  represent a fitting part U of the plug-side connector  910  and the receptacle-side connector  920 . 
     In a predetermined region near the open surface of the shell  923 , the signal pins  921  include exposed parts in which parts of regions of surfaces of the signal pins  921  are exposed from the dielectric  922 . When the plug-side connector  910  and the receptacle-side connector  920  are fitted with each other, the exposed parts of the signal pins  921  contact the bent parts of the signal pins  911  of the plug-side connector  910 . 
     Note that, as described above, in the general Type D connector, structural elements similar to the signal pins  911  and  921  and the dielectrics  912  and  922  are additionally and horizontal-line symmetrically provided inside the shells  913  and  923  as signal pins  911  and  921  and dielectrics  912  and  922  at the upper side in the z axis direction. 
     With reference to  FIGS. 10A to 10C , a structure of the general Type D HDMI connector has been explained. 
     [3.2. Structural Example of Connector According to Second Embodiment] 
     Next, with reference to  FIGS. 11A to 11C , a structural example of connectors according to the second embodiment of the present disclosure is explained.  FIG. 11A  is a cross-sectional view showing a structural example of connectors according to the second embodiment of the present disclosure when being cut at a cross section constituted by a y axis and a z axis through signal pins.  FIG. 11B  is a cross-sectional view of the connectors according to the second embodiment corresponding to an A-A cross section in  FIG. 11A , the A-A cross section being constituted by an x axis and the y axis.  FIG. 11C  is a cross-sectional view of the connectors according to the second embodiment corresponding to a C-C cross section in  FIG. 11B , the C-C cross section being constituted by the x axis and the z axis. 
     First, a structure of the plug-side connector is explained. With reference to  FIGS. 11A to 11C , a plug-side connector  30  according to the second embodiment includes signal pins  310 , dielectrics  320 , substrates  330 , and an outer shell (shell)  340 . 
     The signal pins  310  extend in a first direction, in other words, a y axis direction. In addition, the signal pins  310  are formed as a wiring pattern on surfaces of the substrates  330  formed of dielectric. 
     The shell  340  covers the signal pins  310  and the substrates  330 . One surface of the shell  340  in the positive direction of the y axis is an open surface open to an outside. As shown in  FIGS. 11A to 11C , the plug-side connector  30  and a receptacle-side connector  40  (to be described later) are connected via the open surface of the shell  340 . In addition, the shell  340  is formed of an electric conductor. Potential of the shell  340  is fixed to, for example, the ground potential via the receptacle-side connector  40  (to be described later). 
     Electric conductor layers having ground potential are formed on rear surfaces of the substrates  330 , in other words, opposite surfaces of surfaces on which the signal pins  310  are formed. With reference to  FIGS. 11A to 11C , according to the present embodiment, a surface of a shell  340  that faces the rear surfaces of the substrates  330  is thicker than other surfaces, and is in contact with the rear surfaces of the substrates  330 . Thus, the electric conductor layers formed on the rear surfaces of the substrates  330  are integrated with the shell  340 . Note that, in the present embodiment, it is only necessary to form the electric conductor layers having ground potential on the rear surfaces of the substrates  330 . The structures of the electric conductor layers are not limited to the above example. Accordingly, the surface of the shell  340  is not necessarily thickened. For example, the electric conductor layers formed on the rear surfaces of the substrates  330  may be electrically connected to the shell  340  through via holes or the like. 
     In addition, the dielectrics  320  may be stacked above (in positive direction of the z axis) the signal pins  310  formed on the substrate  330 . Note that, when the dielectrics  320  are formed, the dielectrics  320  do not cover the entire surfaces of the signal pins  310 . Parts of regions of surfaces of the signal pins  310  are exposed in a predetermined region near the open surface of the shell  340 . When the plug-side connector  30  and the receptacle-side connector  40  (to be described later) are fitted with each other, the exposed parts of the signal pins  310  of the plug-side connector contact signal pin  410   s  of the receptacle side connector  40 . Accordingly, the plug-side connector  30  and the receptacle-side connector  40  (to be described later) are electrically connected to each other. Note that, contact parts may be provided on parts of regions of the exposed parts of the signal pins  310 , the contact part protruding toward the signal pins  410  of the receptacle-side connector  40 . Thus, the signal pins  410  of the plug-side connector  30  and the signal pins  410  of the receptacle-side connector  40  may contact to each other via the contact parts. 
     Next, a structure of the receptacle-side connector is explained. With reference to  FIGS. 11A to 11C , the receptacle-side connector  40  according to the second embodiment includes a signal pins  410 , a dielectric  420 , substrates  430 , and an outer shell (shell)  440 . 
     The signal pins  410  extend in a first direction, in other words, a y axis direction. In addition, the signal pins  410  are formed as a wiring pattern on surfaces of the substrates  430  formed of dielectric. 
     The shell  440  covers the signal pins  410  and the substrates  430 . One surface of the shell  440  in the negative direction of the y axis is an open surface open to an outside. In addition, the shell  440  is formed of an electric conductor. Potential of the shell  440  is fixed to, for example, the ground potential. 
     An area of an opening of the open surface of the shell  440  is slightly larger than the cross-sectional area of the open surface of the shell  340  of the plug-side connector  30 . As shown in  FIGS. 11A to 11C , an end provided with the open surface of the shell  340  of the plug-side connector  30  is inserted into the opening of the open surface of the shell  440  of the receptacle-side connector  40 , and the plug-side connector  30  and the receptacle-side connector  40  are fitted with each other. Note that, regions indicated by dotted lines in  FIGS. 11A and 11B  represent a fitting part V of the plug-side connector  30  and the receptacle-side connector  40 . 
     Electric conductor layers having ground potential are formed on rear surfaces of the substrates  430 , in other words, opposite surfaces of surfaces on which the signal pins  410  are formed. With reference to  FIGS. 11A to 11C , according to the present embodiment, a surface of a shell  440  that faces the rear surfaces of the substrates  430  is thicker than other surfaces, and is in contact with the rear surfaces of the substrates  430 . Thus, the electric conductor layers formed on the rear surfaces of the substrates  430  are integrated with the shell  440 . Note that, in the present embodiment, it is only necessary to form the electric conductor layers having ground potential on the rear surfaces of the substrates  430 . The structure of the electric conductor layers is not limited to the above example. Accordingly, the surface of the shell  440  is not necessarily thickened. For example, the electric conductor layers formed on the rear surfaces of the substrates  430  may be electrically connected to the shell  440  through via holes or the like. 
     In addition, the dielectric  420  may be stacked above (in positive direction of the z axis) the signal pins  410  formed on the substrate  430 . Note that, when the dielectric  420  is formed, parts of regions of the signal pins  410  are exposed in a predetermined region near the open surface of the shell  440 . The exposed parts of the signal pins  410  of the receptacle-side connector  40  contact the exposed parts and/or the contact parts of the signal pins  310  of the receptacle side connector  30 . Accordingly, the plug-side connector  30  and the receptacle-side connector  40  are electrically connected to each other. 
     Note that, as described above, structural elements similar to the signal pins  310  and  410 , the dielectrics  320  and  420 , the substrates  330  and  430 , and the electric conductor layers are additionally and horizontal-line symmetrically provided inside the shells  340  and  440  as signal pins  310  and  410 , dielectrics  320  and  420 , substrates  330  and  430 , and an electric conductor layers at the upper side in the z axis direction, in the connectors according to the second embodiment. Thus, the connector structure according to the second embodiment corresponds to a structure having two sets of the signal pins  110  and  210 , the dielectrics  120  and  220 , the substrates  130  and  230 , and the electric conductor layers that are in the connector structure according to the above-explained first embodiment. 
     With reference to  FIG. 11B , among the signal pins  310  of the plug-side connector  30  and the signal pins  410  of the receptacle-side connector  40 , intervals between pairs of the signal pins  310  and  410  that transmit differential signals and adjacently extend may be shorter than intervals from other signal pins  310  and  410  adjacent to the pairs of the signal pins  310  and  410 . Note that, the intervals between the signal pins  310  and the intervals between the signal pins  410  may be identical in the fitting part V. On the other hand, in a region other than the fitting part V, the intervals between pairs of the signal pins  310  and  410  that transmit differential signals and adjacently extend may be shorter than the intervals from other signal pins  310  and  410  adjacent to the pairs of the signal pins  310  and  410 . 
     The wiring intervals between the signal pins  310  and the wiring intervals between the signal pins  410  in the fitting part V may be similar to the wiring intervals of the signal pins  911  and the wiring intervals of the signal pins  921  in the fitting part U shown in  FIGS. 10A to 10C . Thus, the signal pins of the connector according to the second embodiment and the signal pins of the general Type D HDMI connector may have identical wiring intervals in the fitting parts. 
     As explained with reference to  FIGS. 11A to 11C , the structure of the connector according to the second embodiment and the structure of the general Type D HDMI connector are different as follows: The connector according to the second embodiment includes the substrates that are formed of the dielectric and that include signal pins (wiring pattern corresponding to the signal pins) on one surfaces and include the electric conductor layers having the ground potential on the other surfaces. In addition, among the signal pins in the connector according to the second embodiment, the intervals between the pairs of the signal pins that transmit differential signals and adjacently extend are shorter than the intervals from other signal pins adjacent to the pairs of the signal pins. In a way similar to the connector according to the first embodiment, the connector according to the second embodiments has such configuration and achieves the following effects. 
     As explained above, in the connectors  30  and  40  according to the second embodiment, signal pins  310  and  410  are formed on the substrates  330  and  430  formed of the dielectric, and the electric conductor layers having the ground potential are formed on the opposite sides of the surfaces of the substrates  330  and  430  on which the signal pins  310  and  410  are formed. Accordingly, the connectors according to the second embodiment have configurations in which ground planes (electric conductor layers), dielectric layers (substrate  330  and  430 ), and wirings (signal pins  310  and  410 ) are stacked in this order. According to such configurations, an electromagnetic field due to current (signal) flowing through the signal pins  310  and  410  is trapped between the substrates  330  and  430 , and the so-called microstripline (microstrip structure) is formed. Thus, in the connectors according to the second embodiment, it is possible to reduce effects of the current (signal) flowing through the signal pins  310  and  410  on other signal pins  310  and  410 , and the deterioration in signals can be reduced. 
     In addition, as explained above, among the signal pins  310  and  410  in the connectors  30  and  40  according to the second embodiment, the intervals between pairs of the signal pins  310  and  410  that transmit differential signals and adjacently extend may be shorter than the intervals from other signal pins  310  and  410  adjacent to the pairs of the signal pins  110  and  410 . Since the intervals between the pair of signal pins  310  and  410  that transmit differential signals to be paired are narrowed more, an electromagnetic field due to current (signal) flowing through the pair of signal pins  310  and  410  is trapped between the pairs of signal pins  310  and  410  and between the substrates  330  and  430 , and so-called differential stripline (differential strip structure) is formed. Note that, a return path of the differential coupling is secured on the ground plane at a rear surface of the wiring surface. Accordingly, since the coupling is generated between the differential data lines, it is possible to narrow the wiring width and the wiring intervals between the signal pins, while the differential impedance is maintained. Thus, intervals from a different kind of adjacent signal wirings can be widened. Accordingly, the crosstalk can be reduced and signal quality can be improved. Thus, in the connectors according to the second embodiment, it is possible to further reduce effects of the current (signal) flowing through the pair of the signal pins  310  and  410  that transmit a differential signal, on other signal pins  310  and  410 . In addition, the deterioration in signals can be reduced. 
     Note that, in a case where the pin arrangement shown in  FIG. 1B  in which the data lines are newly added is applied to the connector according to the second embodiment, signal pins to which a pair of differential signals “Data 3 +” and “Data 3 −”, and a pair of differential signals “Data 4 +” and “Data 4 −” are allocated are not arranged at a positions where the pairs of the differential signals are next to each other, among the newly added pairs of the differential signals. Thus, in the connectors according to the second embodiment, pairs of adjacent signal pins to which a “Data 0 ” and “Data 0 −” pair, a “Data 1 +” and “Data 1 −” pair, a “Data 2 +” and “Data 2 −” pair, and a “Data 5 +” and “Data 5 −” pair are applied transmit signals using the differential striplines. On the other hand, pairs of nonadjacent signal pins to which a “Data 3 +” and “Data 3 − pair and a “Data 4 +” and “Data 4 −” pair are applied may transmit signals using single-ended microstrip lines. 
     In addition, as explained above, the connector according to the second embodiment of the present disclosure can be more effective in the case of the pin arrangement as shown in  FIG. 1B  in which the data lines are newly added. However, the connector according to the first embodiment also can be applied to the general pin arrangement as shown in  FIG. 1A . Even if the connector according to the second embodiment of the present disclosure is applied to the general pin arrangement shown in  FIG. 1A , effects of current (signals) flowing through the signal pins  310  and  410  on other signals  310  and  410  and deterioration in the signals can be reduced by forming a microstripline and a differential stripline with regard to each signal pin. 
     Note that, as explained with reference to  FIG. 11B , the intervals between the signal pins  310  and the intervals between the signal pins  410  in the fitting part V of the connectors according to the second embodiment of the present disclosure may be identical to the intervals between the signal pins  911  and the intervals between the signal pins  921  in the fitting part U of the general Type D HDMI connectors. According to such configuration, it is possible to ensure compatibility between the connector according to the second embodiment and the general Type D HDMI connector. Thus, when the connector according to the second embodiment and the general Type D HDMI connector are fitted with each other, predetermined signal pins defined by the HDMI standard are electrically connected. Accordingly, the connector according to the second embodiment also can be applied to a case where signals transmission corresponding to the general pin arrangement shown in  FIG. 1A  are performed. 
     In a way similar to the modification of the connector according to the first embodiment, guard lines having ground potential may further extend at positions for sandwiching a signal pin in a manner that the guard lines are substantially parallel to the signal pin, in the connector according to the second embodiment of the present disclosure. In addition, the guard lines may be disposed so as to sandwich a signal pin that transmits a signal with single end. Note that, as described above, the connector according to the second embodiment shown in  FIGS. 11A to 11C  corresponds to a structure having two sets of the signal pins, the substrate, and the electric conductor layer that are in the connector structure according to the first embodiment shown in  FIGS. 4A to 4C . Accordingly, in a case where the guard lines are provided in the connector according to the second embodiment, the configuration of the signal pins (wiring pattern) on the substrate is similar to the connector according to the first embodiment. Thus, as shown in  FIG. 5 , in both the plug-side connector and the receptacle-side connector according to the second embodiment, guard lines may be disposed so as to sandwich a signal pin that transmits a signal with single end. In addition, potential of the guard lines is set to the ground potential. Since the guard lines are provided, it is possible to reduce effects of the current (signal) flowing through the signal pins  310  and  410  on other signal pins  310  and  410 , and the deterioration in signals can be reduced. 
     The effects of the connector according to the second embodiment have been explained. As explained above, even if the connector includes a plurality of sets of the signal pins, the substrate and the electric conductor layer (microstrip structure), the connector can achieve the effects similar to the first embodiment. 
     [3.3. Comparison of Characteristic] 
     Next, a result of comparison between a characteristic of a signal flowing through a signal pin in the general Type D HDMI connector structure shown in  FIGS. 10A to 10C  and a characteristic of a signal flowing through a signal pin in the connector structure according to the second embodiment of the present disclosure shown in  FIGS. 11A to 11C  is explained. Note that, the following  FIGS. 12A to 12B ,  FIGS. 13A to 13B ,  FIGS. 14A to 14B , and  FIGS. 15A to 15C  each show a result of flowing a signal corresponding to pin arrangement in which data lines are newly added as shown in  FIG. 2B . 
     First, with reference to  FIGS. 12A to 12B  and  FIGS. 13A to 13B , difference in electric field distribution near signal pins between a general Type D HDMI connector and the connector according to the second embodiment is explained. 
       FIGS. 12A to 12B  and  FIGS. 13A to 13B  each show electric field distribution near signal pins in a case where a predetermined signal for transmitting a video signal decided by the HDMI standard is applied to each connector.  FIGS. 12A and 12B  are each a contour map of an electric field showing electric field distribution in the general Type D HDMI connector structure.  FIGS. 13A and 13B  are each a contour map of an electric field showing electric field distribution in the connector structure according to the second embodiment. In  FIGS. 12A to 12B  and  FIGS. 13A to 13B , strength of the electric field distribution is schematically represented by shades of hatching. A dark hatched region represents a region in which the electric field is concentrated. 
       FIG. 12A  is a contour map of an electric field at a cross-section corresponding to  FIG. 10A , in the general Type D HDMI connector structure.  FIG. 12B  is a contour map of an electric field at a D-D cross-section shown in  FIG. 12A . 
       FIG. 13A  is a contour map of an electric field at a cross-section corresponding to  FIG. 11A , in the connector structure according to the second embodiment.  FIG. 13B  is a contour map of an electric field at a D-D cross-section shown in  FIG. 13A . Note that, the contour maps of the electric fields shown in  FIGS. 13A and 13B  determine the electric field distribution of the connector structure according to the second embodiment in which the guard lines are further provided as shown in  FIG. 5 . 
     The contour maps of the electric fields in  FIGS. 12A to 12B  and  FIGS. 13A to 13B  each show a simulation result of an electric field distribution near the signal pins in a case where a model in which permittivity corresponding to each region (signal pin, substrate, outer shell, dielectric, or the like) at each cross-section described above is set is formed, and a predetermined signal when a video signal decided by the HDMI standard is transmitted is applied. 
     With reference to  FIG. 12A , in the general Type D HDMI connector structure, there is few difference in the electric field distribution between a front surface (surface that stretches in the y axis direction and that is positioned in the positive direction of the z axis) and a rear surface (surface that stretches in the y axis direction and that is positioned in the negative direction of the z axis) of each of the signal pins  310  and  410 . On the other hand, with reference to  FIG. 12B , in the general Type D HDMI connector structure, as shown in a region H (region across “Data 1 +”, “Data 1 −”, and “Data 4 +”) and a region I (region near Data 4 −), electric fields are also concentrated in regions other than a differential signal pair, and current (signal) flowing through signal pins  310  affects other signal pins  310 . 
     On the other hand, with reference to  FIG. 13A , in the connector structure according to the second embodiment, electric field is concentrated between the signal pins  310  and  410  and the shells  340  and  440 , in other words, electric field is concentrated in the substrates  330  and  430 . Accordingly, the so-called microstripline is formed. In addition, with reference to  FIG. 13B , in the connector structure according to the second embodiment, electric fields are concentrated between an actuation signal pair of the adjacently disposed signal pins  310  and  410  of “Data 1 ”, and the so-called differential stripline is formed. In the signal pins  310  and  410  of “Data 4 −” and “Data 4 +”, electric fields are concentrated between the signal pins  310  and  410  and the shells  340  and  440 , in other words, electric fields are concentrated in the substrate  330  and  430 , and single-ended electric field distribution is formed. Accordingly, effect of current (signal) flowing through signal pins  310  and  410  on other signal pins  310  and  410  is reduced. 
     Next, with reference to  FIGS. 14A to 14B  and  FIGS. 15A to 15C , difference in signal transmission characteristics as represented by an eye pattern and crosstalk, between the general Type D HDMI connector and the connector according to the second embodiment is explained. 
       FIGS. 14A and 14B  are each a voltage characteristic diagram showing an eye pattern of the general Type D HDMI connector structure shown in  FIGS. 10A to 10C .  FIG. 14A  shows an eye pattern of the “Data  1 ” line shown in  FIG. 1B  and  FIG. 14B  shows an eye pattern of the “Data  4 ” line shown in  FIG. 1B . 
       FIGS. 15AC and 15B  is each a voltage characteristic diagram showing an eye pattern of a connector structure according to the second embodiment in which guard lines are further arranged as shown in  FIG. 5 .  FIG. 15A  shows an eye pattern of the “Data  1 ” line shown in  FIG. 1B  and  FIG. 15B  shows an eye pattern of the “Data  4 ” line shown in  FIG. 1B .  FIG. 15C  is a voltage characteristic diagram showing crosstalk of a connector structure according to the second embodiment in which guard lines are further arranged as shown in  FIG. 5 , for example. 
     In  FIGS. 14A to 14B  and  FIGS. 15A to 15C , the eye pattern corresponding to “Data 1 ” represents a transmission characteristic of data lines (existing data lines) that already exist in the general pin arrangement shown in  FIG. 1A , and the eye pattern corresponding to “Data 4 ” represents a transmission characteristic of data lines (new data lines) that is newly added in the pin arrangement in which data lines are newly added as shown in  FIG. 1B . 
     When the  FIGS. 14A and 14B , and  FIGS. 15A and 15B  are compared, the signal transmission characteristic is improved due to the connector structure according to the second embodiment, in addition to the existing data line “Data 1 ” and the new data line “Data 4 ”. Thus, the deterioration in signals is reduced by the connector structure according to the second embodiment. In addition, with reference to  FIG. 15C , a good crosstalk characteristic can be obtained in the connector structure according to the second embodiment. 
     4. Modification 
     Next, modifications of connectors according to the first embodiment and the second embodiment of the present disclosure are explained. 
     [4.1. Expansion of Cross-Sectional Area of Signal Pin] 
     With regard to the connectors according to the first embodiment and the second embodiment of the present disclosure, a cross-sectional area of a signal pin may be expanded. With reference to  FIGS. 16A to 16D , a modification in which a cross-sectional area of a signal pin is expanded is explained. Note that, in the following explanation with reference to  FIGS. 16A to 16D , the connector according to the first embodiment of the present disclosure is used as an example. However, the present modification also can be applied to the connector according to the second embodiment of the present disclosure. 
       FIG. 16A  is a schematic view showing an example of related signal pin arrangement in a modification of the connector according to the first embodiment. Note that,  FIG. 16A  shows only signal pins arranged at and near the most end part of the terminal surface of the connector, the signal pins being necessary for explaining the present modification. The other signal pins are not shown in  FIG. 16A . In addition,  FIG. 16A  shows the terminal surfaces of the plug-side connector. 
     For example, with reference to  FIG. 16A , wiring width of an HPD signal pin positioned at the most end part of the terminal surface is larger than wiring width of other signal pins  991 . The wiring width of the signal pin  991  arranged at the most end part of the terminal surface is expanded toward the outer shell (shell)  993  in the positive direction of the x axis. Accordingly, the wiring width can be expanded without changing wiring intervals between the signal pins  991 . 
     Note that, as described above, the connector according to the first embodiment of the present disclosure (connector corresponding to Type C HDMI connector) is used as an example in  FIG. 16A . Thus, the signal pins are arranged in one line in the x axis direction. Accordingly,  FIG. 16A  shows the HPD signal pin as the signal pin that is positioned at the most end part of the terminal surface and whose wiring width may be expanded. Alternatively, with regard to another kind of connector, the signal pin that is positioned at the most end part of the terminal surface and whose cross-sectional area is expanded may be a signal pin to which any kind of signal is applied. For example, in Type A, Type D and Type E HDMI connectors, signal pins are arranged in two lines in the x axis direction in zigzag. Therefore, cross-sectional areas of power signal pins (+5V power pins) may be expanded in addition to the HPD signal pins. 
       FIG. 16B  is a schematic view showing a structural example of the connectors shown in  FIG. 16A  when being cut at a cross section constituted by a y axis and a z axis through signal pins.  FIG. 16C  is a schematic view of the connectors shown in  FIG. 16A  corresponding to an A-A cross section in  FIG. 16B , the A-A cross section being constituted by an x axis and the y axis.  FIGS. 16B and 16C  correspond to the above-explained  FIGS. 11A and 11B . Accordingly, a detailed explanation of the configuration already explained with reference to  FIGS. 11A and 11B  is omitted. In  FIGS. 16  B and  16 C, respective structural elements of the connector are schematically shown so as to simplify the explanation of the present modification. 
     In  FIGS. 16B and 16C , outer shells of a plug-side connector and a receptacle-side connector are not shown so as to simplify the explanation. In addition, so as to simplify the explanation,  FIG. 16C  shows only the signal pins arranged at and near the signal pin that is positioned at the end part in the connector and whose cross-sectional area is expanded. Other signal pins are not shown in  FIG. 16C . 
     With reference to  FIGS. 16B and 16C , cross-sectional areas of signal pins  110  and  210  to which the HPD signals are applied are expanded in the plug-side connector  10  and the receptacle-side connector  20 . The direction in which the cross-sectional areas of the signal pins  110  and  210  are expanded may be a direction toward the outer shell in the positive direction of the x axis as shown in  FIGS. 16A and 16C , or may be the z axis direction as shown in  FIG. 16B . 
     However, as shown in  FIG. 16B , when the plug-side connector  10  and the receptacle-side connector  20  are fitted with each other, the width (height) of the signal pins  110  and  210  in the z axis direction is not changed at the fitting part, so as to keep the contact of the signal pin  110  of the plug-side connector and the signal pin  210  of the receptacle-side connector  20 . Since the width (height) of the signal pins  110  and  210  in the z axis direction is not changed in the fitting part, connection between the connector to which the present modification is applied and a connector to which the present modification is not applied can be ensured. 
     With reference to  FIG. 16B , the signal pin  110  of the plug-side connector  10  stretches in the negative direction of the y axis, and is connected to wiring in a cable. On the other hand, the signal pin  210  of the receptacle-side connector  20  stretches in the positive direction of the y axis, and is connected to a predetermined substrate in the receiving apparatus or the transmitting apparatus. 
     Thus, in the present modification, the cross-sectional area of the signal pin  110  is expanded in the plug-side connector  10 , and the signal pin  110  is directly connected to the wiring in the cable. In addition, the cross-sectional area of the signal pin  210  is expanded in the plug-side connector  20 , and the signal pin  210  is connected to the substrate in the apparatus. 
     As explained above, the cross-sectional area of the signal pin  110  is expanded in the present modification. Accordingly, it is possible to flow larger current through the signal pin while attenuation is suppressed more, and reliability of the connector is improved. Here, the HPD signal pin and the power signal pin are power-supply-voltage application pins to which +5V power-supply voltage is applied. As explained above, more effect of the present modification can be obtained by applying the present modification to the power-supply-voltage application pin to which relatively high voltage is applied, such as the HPD signal pin and/or the power signal pin. 
     In addition, as described in the following &lt;5. Application Example&gt;, apparatuses connected via an HDMI connector are able to have a function of supplying power to each other by using the signal pins. The present modification can be appropriately applied to signal pins serving as a power supply path during power supply between such apparatuses. 
     Moreover, with regard to the modification of the connector according to the first embodiment of the present disclosure, cross-sectional areas of signal pins may be expanded only in a region other than the fitting part of the plug-side connector and the receptacle-side connector.  FIG. 16D  shows a modification in which wiring width of signal pins are expanded only in a region other than a fitting part of a plug-side connector and a receptacle-side connector.  FIG. 16D  is a schematic view showing a modification, in which cross-sectional areas of a signal pins are expanded only in a region other than the fitting part, of the connectors corresponding to  FIG. 16C . 
     With reference to  FIG. 16D , in a fitting part, cross-sectional areas of a signal pin  110  of the plug-side connector  10  and a signal pin  210  of the receptacle-side connector  20  is not changed also in the x axis direction. Thus, the fitting part secures dimension and shape of the signal pins according to the standard to which the connectors belong, and connection to a general connector conforming to the same standard is also secured. 
     [4.2. Mounting of Device on Substrate] 
     As shown in  FIGS. 4A to 4C  and  FIGS. 11A to 11C , the connectors according to the first embodiment and the second embodiment of the present disclosure include substrates  130 ,  230 ,  330 , and  430  in the connectors. As described above, the signal pins  110 ,  210 ,  310 , and  410  are formed on front surfaces of the substrate  130 ,  230 ,  330 , and  430 . However, free regions in which the signal pins  110 ,  210 , 310 , and  410  are not formed also exist. With regard to the connectors according to the first embodiment and the second embodiment of the present disclosure, various kinds of devices (circuits) that act on transmission of signals in the signal pins may be mounted in the free regions in the front surfaces of the substrates  130 ,  230 ,  330 .  430 . 
     With reference to  FIGS. 17 and 18A to 18C , a modification in which various kinds of devices are mounted on substrates is explained. Note that, in the following explanation with reference to  FIGS. 17 and 18A to 18C , the connectors according to the first embodiment of the present disclosure are used as an example. However, the present modification can also be applied to the connectors according to the second embodiment of the present disclosure. 
     In  FIG. 17 , various kinds of devices (circuits) are mounted in free regions of front surfaces of the substrates of the connectors according to the first embodiment of the present disclosure.  FIG. 17  is a schematic view in which a device is provided on a substrate in the connector according to the first embodiment of the present disclosure. 
     As shown in  FIG. 17 , a device  160  that acts on transmission of signals in the signal pins  110  may be mounted in the region in which the signal pins  110  are not formed (free region) in the front surfaces of the substrate  130  in the plug-side connector  10 . On the other hand, a device that acts on transmission of signals in the signal pins  210  may be mounted in the region in which the signal pins  210  are not formed (free region) in the front surfaces of the substrate  230  in the receptacle-side connector  20 , although the device is not shown in  FIG. 17 . 
     Hereinafter, a specific configuration example of the devices provided in the free regions of the substrates  130  and  230  according to the present modification is explained with reference to  FIGS. 18A to 18C . 
     For example, an AC/DC conversion circuit that converts AC transmission into DC transmission of signals to be transmitted by the signal pins may be provided in the free regions of the front surfaces pf the substrates  130  and  230 .  FIG. 18A  shows an example of a circuit configuration of such AC/DC conversion circuit.  FIG. 18A  is a schematic view showing an example of a circuit configuration of an AC/DC conversion circuit that is a device according to modifications of the first embodiment and the first embodiment of the present disclosure. 
     With reference to  FIG. 18A , for example, a data transmitting apparatus  510  that performs AC coupling transmission and a data receiving apparatus  520  that performs DC coupling transmission are connected via a cable  530 . The data transmitting apparatus  150  includes a differential driver  511  and a DC component removal filter (capacitor)  512 , and can transmit a predetermined DC signal generated by the differential driver  511  to the data receiving apparatus  520  that is a connection partner, via the DC component removal filter  512 . 
     The data receiving apparatus  520  includes a differential receiver  521  and a pull-up register  522  for DC bias, and can receive the DC signal transmitted from the data receiving apparatus  520 . 
     Here, connectors  10  and  20  are provided between the data transmitting apparatus  510  and the cable  530 . In addition, registers  531  for generating common-mode voltages and a switch  532  are provided in free regions of substrates  130  and  230  of the connector  10  and  20 . 
     The registers  531  for generating common-mode voltages are voltage shift registers for removing, by using the AC coupling transmission, a common-mode component which occurs in bias voltage applied by the pull-up register  522  for DC bias of the receiving device. The switch  532  causes the registers  531  for generating common-mode voltages to operate as terminators for reducing output voltage to 0 level, while the signal transmission is not performed. 
     As explained above, since a circuit such as a level shift register is provided in the free regions of the substrates  130  and  230  of the connectors  10  and  20 , a function of ensuring the compatibility for performing the AC coupling transmission with regard to a DC coupling interface in the cable is achieved, necessity for mode conversion in the transmitting apparatus and the receiving apparatus is removed, and connection of the transmitting apparatus and the receiving apparatus is facilitated. 
     Alternatively, for example, a register holding information on characteristics of signals to be transmitted by signal pins and a communication circuit may be provided in the free regions of the front surfaces of the substrates  130  and  230 , the communication circuit notifying any apparatus connected via the connector of the information held by the register. An example of configurations of such register and communication circuit is shown in  FIG. 18B .  FIG. 18B  is a schematic view showing an example of configurations of the register and the communication circuit that are devices according to modifications of the first embodiment and the second embodiment of the present disclosure. 
     With reference to  FIG. 18B , a capability register  570  and a communication circuit  580  may be provided in the free regions of the front surface of the substrates  130  and  230 . The capability register  570  has information on characteristics of signals transmitted by the signal pins  110  and  210 . The information on characteristics of signals transmitted by the signal pins  110  and  210  may be information on bands of the signals, for example. Thus, the capability register  570  can hold information on performance and characteristics of the connector (cable) in which the capability register  570  is mounted. 
     Via the signal pins  110  and  210 , the communication circuit  580  can notify a connection partner apparatus of the information on the characteristic of the signal that the capability register  570  holds. The communication circuit  580  may be an I2C circuit, for example. However, a kind of the communication circuit  580  is not specifically limited, and every known communication circuit may be used. 
     As described above, since the register and the communication circuit are provided in the connectors, the connection partner apparatus can be notified of the information on performance and characteristics of the connectors (cable) via the communication circuits, the information being held by the register. Accordingly, it is possible to decide a data transmission method in accordance with the characteristics of the cable between the apparatuses connected via the connectors, and more secure data transmission with less transmission deterioration is achieved. 
     In addition, the capability register  570  may hold authentication data of the connector (cable) in which the capability register  570  is mounted. By using the authentication data, it can be determined whether the connector and the cable are official products between apparatuses connected via the connector. 
     In addition, memory may be mounted in the free regions of the front surface of the substrates  130  and  230 . The memory may temporarily store various kinds of information on data transmission. Since the memory is mounted in the connector, temporal communication using the information stored in the memory is possible between the apparatuses connected via the connector. 
     For example, a battery for supplying a power signal may be provided in the free regions of the surfaces of the substrates  130  and  230 . An example of a configuration of such battery is shown in  FIG. 18C .  FIG. 18C  is a schematic view showing an example of a configuration of a battery that is a device according to modifications of the first embodiment and the second embodiment of the present disclosure. 
     As shown in  FIG. 18C , a battery  590  is mounted in the free region of the front surfaces of the substrates  130  and  230 . Voltage corresponding to power-supply voltage may be supplied from the battery  590  to at least any one of the signal pins  110  and  210 . Since the battery  590  is mounted in the free region of the front surface of the substrates  130  and  230  and supplies power, the apparatus connected via the connector in which the battery  590  is mounted can execute only a minimal function, for example, in a case where the power supply from the apparatus is stopped due to some kind of trouble. 
     The battery  590  may be a rechargeable secondary battery. In the case where the battery  590  is a secondary battery, the battery  590  may be charged by power supply from the apparatus connected via the connector in which the battery  590  is mounted. 
     Note that, an equalizer corresponding to the characteristics of the connector (cable) may be provided in the free region of the front surface of the substrates  130  and  230 . Since the equalizer is provided in the free region of the front surfaces of the substrates  130  and  230 , more stable data transmission can be achieved. 
     The modification in which various kinds of devices are mounted on the substrates in the connectors according to the first embodiment and the second embodiment of the present disclosure has been described. By mounting the various kinds of devices in the free regions of the substrates, the connectors themselves can perform various kinds of signal processing. Accordingly, it is possible to simplify the signal processing in the transmitting apparatus and the receiving apparatus that are connected via the connectors. 
     Note that, the above-explained device is an example of devices to be mounted on the substrates. The connectors according to the first embodiment and the second embodiment of the present disclosure are not limited thereto, and any device can be mounted. 
     5. Application Example 
     Next, an application example of the connectors according to the first embodiment and the second embodiment of the present disclosure to a data receiving apparatus and/or a data transmitting apparatus is explained. 
     Diverse applications have been developed with regard to communication between apparatuses that use HDMI interfaces. The connectors according to the first embodiment and the second embodiment of the present disclosure can be suitably applied to various kinds of applications with regard to communication between apparatuses that use the HDMI interfaces. In the following, “CEC control” and “power supply control” are used as examples of the applications in the communication between the apparatuses that use the HDMI interfaces. Note that, the connectors according to the first embodiment and the second embodiment of the present disclosure are not limited thereto, and can be applied to all other applications with regard to communication between the apparatuses that use the HDMI interfaces. 
     [5.1. CEC Control] 
     First, the CEC control is explained. In a transmission line of the HDMI standard, a line that is capable of bi-directionally transmitting control data and that is referred to as a Consumer Electrics Control (CEC) line is prepared for control between a source device and a sink device, in addition to a video data transmission line. By using the CEC line, it is possible to control a partner&#39;s device. In addition, when executing the CEC control, it is possible to automatically perform whether control using a CEC line of a HDMI cable can be executed, in a device on the basis of processing performed at connection authentication using a DDC line. 
     In the following explanation of the CEC control, a case where the source device is a disk recorder and the sink device is a television receiver is used as a specific example. The disk recorder and the television receiver include the connectors according to the first embodiment or the second embodiment of the present disclosure, as receptacle-side connectors. In addition, an HDMI cable for connecting the disk recorder and the television receiver includes the connector according to the first embodiment or the second embodiment of the present disclosure, as a plug-side connector. 
     First, with reference to  FIG. 19 , a data configuration example of each channel transmitted between a disk recorder  60  and a television receiver  70  via an HDMI cable  1  is explained. In the HDMI standard, three channels including a channel  0  (Data 0 ), a channel  1  (Data 1 ), and a channel  2  (Data 2 ) are prepared as channels for transmitting video data, and a clock channel (clock) for transmitting pixel clock is further prepared. In addition, a DDC and CEC are prepared as a power transmission line and a control-data transmission channel. The Display Data Channel (DDC) is mainly a data channel for display control, and Consumer Electrics Control (CEC) is mainly a data channel for transmitting control data used for controlling a partner&#39;s device connected via the cable. 
     Configurations of respective channels are explained. The channel  0  transmits pixel data of B data (blue data), vertical synchronization data, horizontal synchronization data, and auxiliary data. The channel  1  transmits pixel data of G data (green data), two kinds of control data (CTL 0  and CTL 1 ), and auxiliary data. The channel  2  transmits pixel data of R data (red data), two kinds of control data (CTL 2  and CTL 3 ), and auxiliary data. Note that, under the HDMI standard, primary color data that is subtractive mixture of cyan, magenta and yellow can be transmitted instead of the blue data, the green data, and the red data. 
     The CEC serving as the control data transmission channel is a channel in which data transmission is bi-directionally performed at a clock frequency lower than the channels (channels  0 ,  1 , and  2 ) for transmitting the video data. 
     A configuration of data to be transmitted by channels (channel  0 , channel  1 , channel  2 , clock channel, and DDC) other than the CEC is identical to a configuration of data to be transmitted through an HDMI scheme in practical use. 
     The source device  60  and the sink device  70  include HDMI transmission units  610  and  710  for performing data transmission, and EDID ROM  610   a  and  710  a serving as storage units for storing Enhanced Extended Display Identification Data (E-EDID) information. The E-EDID information stored in the EDID ROM  610   a  and  710   a  is information in which a format of video data (that is, displayable or recordable data) treated by devices is written. However, in the present example, the E-EDID information is expanded, and information on details of the devices, specifically, control function corresponding information is stored. In a case where connection via the HDMI cable  1  is detected in the present example, storage information of E-EDID ROM  610   a  or  710   a  of the partner&#39;s devices is read out, and collation of the E-EDID information is performed. 
     The source device  60  and the sink device  70  include CPUs  620  and  720  that are control units for performing operation control of the entire source device  60  and the entire sink device  70 . In addition, the source device  60  and the sink device  70  include memory  630  and  730  for temporarily storing programs to be executed by the CPUs  620  and  720  and various kinds of information to be processed by the CPUs  620  and  720 . Data to be transmitted via the DDC line and the CEC line of the HDMI cable  1  is transmitted and received under control of the CPUs  620  and  720 . 
     Next,  FIG. 20  shows a sequence example of the CEC control in a case where the source device and the sink device are connected. Here, “Record TV Screen” that is an optional function based on the CEC standard is used for an explanation. 
     When a user&#39;s operation gives an instruction of content for executing program recording of a same channel as a screen of the television receiver, to the disk recorder that is the source device connected via the HDMI cable  1  (Step S 1 ), the source device transmits a “Record TV Screen” command to the sink device via the CEC line, and gives a request to the sink device (Step S 2 ). 
     In response to the request in Step S 2 , the sink device replies service information of currently displayed digital broadcasting program (Step S 3 ). Alternatively, the sink device replies information indicating that the source device is a video source (Step S 4 ) in a case where the program that is being displayed by the sink device is input from the source device via the HDMI cable  1 . In response to the reply in Step S 3  or S 4 , the source device returns a status of recording execution to the sink device (Step S 5 ), or returns a massage that the function is not executed to the sink device (Step S 6 ). Note that, it is also possible to perform the user operation in Step S 1  on the sink device (television receiver). 
     Next, with reference to the flowchart in  FIG. 21 , a process example when devices are connected via the HDMI cable  1  is explained. 
       FIG. 21  shows a CEC compliance check process procedure in each device in a case where the device connected via an HDMI cable is detected. In the present example, the check process is performed by both the source device and the sink device. 
     The process of the flowchart in  FIG. 21  is explained. As a function decided by the HDMI status, there is a function referred to as hot plug detect. The function detects connection between the source device and the sink device since the source device observes voltage of an HPD terminal pulled up to a power source of +5V in the sink device, the voltage being transmitted from the source device, and the voltage becomes “H” voltage when the source device is connected to the HDMI connector. 
     By using the function, it is determined whether a device is connected via the HDMI cable  1  (Step S 11 ). In a case where the device connection has not been detected, the process ends. In a case where the device connection has been detected, E-EDID data stored in EDID ROM of a partner device is read out using the DDC line (Step S 12 ). Subsequently, the read-out data is compared with E-EDID database stored in the own device (Step S 13 ). 
     On the basis of the comparison, it is determined whether (Step S 14 ). In a case where the data is not present, the device is determined to be a newly connected device, and the newly read-out E-EDID data is registered in the database (Step S 17 ). In a case where the data is present, it is subsequently determined whether the data are identical to each other (Step S 15 ). In a case where the data are identical to each other, it is determined that a CEC compliance of the partner device is not changed. Accordingly, the process ends. In a case where the data are different, a new data is overwritten and updated in the database storing the read-out data (Step S 16 ), and the process ends. As described above, it is possible to recognize the latest CEC compliance status since each device reads out E-EDID data of each connected device. 
     With reference to  FIGS. 19 to 21 , the example of the CEC control of communication between the devices using the HDMI interface has been explained. When the connectors according to the first embodiment and the second embodiment of the present disclosure are used for connectors of the source device  60 , the sink device  70  and the HDMI cable  1 , it is possible to reduce the deterioration in signals even if larger amounts of data are transmitted at higher speed. Thus, more reliable CEC control can be performed. 
     Note that, details of the CEC control can be referred to by JP 4182997B. 
     [5.2. Power Supply Control] 
     Next, the power supply control is explained. In the HDMI standard, power-supply voltage and electric current are prescribed so as to supply power to a device connected via an HDMI connector. For example, under the HDMI standard, +5V power can be supplied from the source device to the sink device by 55 mA at a minimum and by 500 mA at a maximum. In addition, with regard to the receiving apparatus and the transmitting apparatus that are connected via the HDMI connector, the transmitting apparatus transmits, to the receiving apparatus, request information for requesting power supply. According to the transmitting of the request information, the receiving device can supply power to an internal circuit in the transmitting apparatus via the HDMI cable. 
     Note that, in the following explanation of power supply, the source device and the sink device include the connectors according to the first embodiment or the second embodiment of the present disclosure, as receptacle-side connectors. In addition, the HDMI cable for connecting the source device and the sink device includes the connectors according to the first embodiment or the second embodiment of the present disclosure, as plug-side connectors. 
     Here, with reference to  FIGS. 22 and 23 , an embodiment of power supply control is explained.  FIG. 22  shows a configuration example of a communication system as an embodiment. 
     The communication system includes a source device  80  and a sink device  90 . The source device  80  and the sink device  90  are connected via an HDMI cable  500 . For example, although an imaging unit and a recoding unit are not shown in  FIG. 22 , the source device  80  is a battery-powered mobile device such as a digital camera recorder or a digital still camera, and the sink device  90  is a television including a power supply circuit with sufficient performance. 
     The source device  80  includes a control unit  851 , a reproduction unit  852 , an HDMI transmitter (HDMI source)  853 , a power supply circuit  854 , a switching circuit  855 , and HDMI connector  856 . The control unit  851  controls operation of the reproduction unit  852 , the HDMI transmitter  853 , and the switching circuit  855 . From a recording medium (not shown), the reproduction unit  852  reproduces a baseband image data (uncompressed video signals) of predetermined content and audio data (audio signals) attached to the image data, and supplies to the HDMI transmitter  853 . The control unit  851  controls selection of reproduction content in the reproduction unit  852  on the basis of a user&#39;s operation. 
     Through communication compliant with the HDMI, the HDMI transmitter (HDMI source)  853  transmits the baseband image and audio data that are supplied from the reproduction unit  852  from the HDMI connector  856  to the sink device  90  in one direction via the HDMI cable  500 . 
     The power supply circuit  854  generates power to be supplied to the internal circuit of the source device  80  and the sink device  90 . The power supply circuit  854  is, for example, a battery circuit that generates power from a battery. The switching circuit  855  selectively supplies the power generated by the power supply circuit  854  to the internal circuit and the sink device  90 , and selectively supplies the power supplied from the sink device  90  to the internal circuit. The switching circuit  855  constitutes a power supply unit and a power switching unit. 
     The sink device  90  includes an HDMI connector  951 , a control unit  952 , a storage unit  953 , an HDMI receiver (HDMI sink)  954 , a display unit  955 , a power supply circuit  956 , and a switching circuit  957 . The control unit  952  controls operation of the HDMI receiver  954 , the display unit  955 , the power supply circuit  956 , and the switching circuit  957 . The storage unit  953  is connected to the control unit  952 . The storage unit  953  stores information necessary for control performed by the control unit  952 , such as Enhanced extended display identification (E-EDID). 
     Through communication compliant with the HDMI, the HDMI receiver (HDMI sink)  954  receives the baseband image and audio data that are supplied to the HDMI connector  951  via the HDMI cable. The HDMI receiver  954  supplies the received image data to the display unit  955 . In addition, the HDMI receiver  954  supplies the received audio data, for example, to a speaker (not shown). Details of the HDMI receiver  954  are described later. 
     The power supply circuit  956  generates power to be supplied to the internal circuit of the sink device  90  and the source device  80 . The power supply circuit  956  is, for example, a power supply circuit with sufficient performance for generating power (AC power) from an AC power. The switching circuit  957  selectively supplies power generated in the power supply circuit  956  to the internal circuit and the source device  80 , and selectively supplies power to be supplied from the source device  80  to the sink device  90  to the internal circuit. The switching circuit  957  constitutes a power supply unit. 
     Next, with reference to  FIG. 23 , a control sequence in power supply control is explained. 
     With reference to  FIG. 23 , first, (a) the switching circuit  855  of the source device  80  is switched to a state in which power from the power supply circuit  854  of the source device  80  is supplied to the internal circuit and the HDMI connector  856  of the source device  80 . In addition, (b) the switching circuit  957  of the sink device  90  is switched to a state in which power from the power supply circuit  854  of the source device  80  is supplied to the internal circuit of the sink device  90  via the HDMI cable  500 . When the sink device  90  is connected to the source device  80  via the HDMI cable  500  in the state of (a) and (b), (c) +5V power is supplied from the power supply circuit  854  of the source device  80  to the internal circuit of the sink device  90  via the HDMI cable  500 . Note that, to the internal circuit of the source device  80 , +5V power is supplied from the power supply circuit  854  of the source device  80 . 
     (d) In this case, voltage of a pin  19  (HPID) of the HDMI connector of the sink device  90  becomes high, and correspondingly voltage of a pin  19  (HPD) of the HDMI connector  856  of the source device  80  becomes high. Thus, the control unit  851  of the source device  80  can recognize the connection to the sink device  90 . 
     (e) Subsequently, on the basis of a user operation, information on remaining amount of battery constituting the power supply circuit  854 , or the like, the source device  80  transmits a &lt;Request Power Supply&gt; command that is a power supply request, to the sink device  90  via the CEC line. 
     (f) The sink device  90  determines whether it is possible to supply a voltage value and a current value that are requested by the &lt;Request Power Supply&gt; command, and (g) transmits a &lt;Response Power Supply&gt; command that is a power supply response including a result of the determination to the source device  80  via the CEC line. 
     (h) In a case where it is possible to supply the requested voltage value and current value, the sink device  90  controls the voltage value and the current value of the power supply from the power supply circuit  956  in a manner that the voltage value and the current value of the power supply from the power supply circuit  956  correspond to the voltage value and the current value that have been requested by the source device  80 , and switches the switching circuit  957  to a state in which the power from the power supply circuit  956  of the sink device  90  is supplied to the internal circuit and the HDMI connector  951  of the sink device  90 . (i) Accordingly, power from the power supply circuit  956  of the sink device  90  is supplied to the source device  80  via the HDMI cable. 
     (j) The source device  80  determines the &lt;Response Power Supply&gt; command transmitted from the sink device  90 . (k) In a case where a response indicates that supply is possible, the source device  80  switches the switching circuit  855  to a state in which power from the power supply circuit  956  of the sink device  90  is supplied to the internal circuit of the source device  80  via the HDMI cable  500 . Thus, the power supplied from the sink device  90  is supplied to the internal circuit of the source device  80 . 
     (l) Subsequently, when the power in the source device  80  becomes not necessary, the source device  80  transmits, to the sink device  90 , a &lt;Request Power Supply&gt; command indicating that the power supply is not necessary. (m) The sink device  90  detects the &lt;Request Power Supply&gt; command, and returns a &lt;Response Power Supply&gt; command to the source device  80 . (n) Correspondingly, the source device  80  puts the switching circuit  855  back to the state of (a), and (q) the sink device  90  puts the switching circuit  957  back to the state of (b). Accordingly, the power supply states of the source device  80  and the sink device  90  are put back to the initial states. 
     With reference to  FIGS. 22 to 23 , the power supply control in the communication between the devices using the HDMI interfaces has been explained. When the connector according to the first embodiment and the second embodiment of the present disclosure is used for connectors of the source device  80 , the sink device  90  and the HDMI cable  500 , it is possible to reduce the deterioration in signals even if larger amounts of data are transmitted at higher speed. Thus, more reliable power supply control can be performed. In addition, the reliability can be improved more by applying the modification explained in [4.1. Expansion of Cross-sectional Area of Signal Pin] to the signal pins used as the power supply path during the power supply control. 
     Note that, details of the power supply control can be referred to by JP 2009-44706A for example. 
     6. Conclusion 
     As explained above, in the connectors according to the first embodiment and the second embodiment of the present disclosure, signal pins are formed on the substrates formed of the dielectric, and the electric conductor layers having the ground potential are formed on the opposite sides of the substrate surfaces on which the signal pins are formed. According to such configuration, the microstripline is formed by the signal pins, the substrates and the electric conductor layers. Thus, it is possible to reduce effects of the current (signal) flowing through the signal pins, on other signal pins. In addition, the deterioration in signals can be reduced. 
     In addition, among the signal pins in the connectors according to the first embodiment and the second embodiment of the present disclosure, the intervals between the pairs of the signal pins that transmit differential signals and adjacently extend are shorter than the intervals from other signal pins adjacent to the pairs of the signal pins. According to such configuration, the differential stripline (differential strip structure) is formed by the pair of the signal pins having the short intervals. Thus, it is possible to reduce effects of the current (signal) flowing through the pair of the signal pins, on other signal pins. In addition, the deterioration in signals can be reduced. Moreover, since the intervals between the pairs of the signal pins are short, intervals from a different kind of adjacent signal wirings can be widen. Accordingly, the crosstalk can be reduced and signal quality can be improved. 
     Thus, the connectors according to the first embodiment and the second embodiment of the present disclosure can transmit data without deterioration in signals, even in the case of the pin arrangement in which data lines are newly added such as a pin arrangement in which data lines are newly allocated to a signal pin used as a shield and a signal pin used as a clock. 
     In addition, in the connectors according to the first embodiment and the second embodiment of the present disclosure, guard lines having ground potential may further extend at positions for sandwiching a signal pin in a manner that the guard lines are substantially parallel to the signal pin. According to such configuration, it is possible to reduce effects of the current (signal) flowing through the signal pins on other signal pins, and the deterioration in signals can be reduced. 
     Meanwhile, in the connector according to the first embodiment and the second embodiment of the present disclosure, the wiring intervals between the signal pins in the fitting part of the plug-side connector and the receptacle-side connector may be identical to the wiring intervals between the signal pins in the fitting part of the general HDMI connector. According to such configuration, it is possible to ensure compatibility between the connectors according to the first embodiment and the second embodiment of the present disclosure and the general HDMI connector. Thus, the user can connect apparatuses without considering types of connectors, and convenience of the user can be improved. 
     In addition, with regard to the connectors according to the first embodiment and the second embodiment of the present disclosure, cross-sectional areas of the signal pins may be expanded. According to such configuration, it is possible to flow larger current through the signal pins while attenuation is suppressed more, and reliability of the connectors is improved. With regard to the HDMI connector, more effect can be obtained by expanding cross-sectional areas of a HPD signal pin and a power supply signal pin to which power-supply voltage is applied. 
     In addition, substrates are provided inside the connectors according to the first embodiment and the second embodiment of the present disclosure. Accordingly, various kinds of devices (circuits) that act on transmission of signals in the signal pins can be mounted on the substrates. According to such configuration, the connectors themselves can perform various kinds of signal processing. Accordingly, it is possible to simplify the signal processing in the transmitting apparatus and the receiving apparatus that are connected via the connectors. 
     In addition, the connectors according to the first embodiment and the second embodiment of the present disclosure can be suitably applied to various kinds of applications with regard to communication between apparatuses that use the HDMI interfaces. 
     Although preferred embodiments of the present disclosure have been described in detail above with reference to the appended drawings, the technical scope of the embodiments of the present disclosure is not limited to the above example. It is obvious to those with a general knowledge of the technical field of the embodiments of the present disclosure that various modifications and alterations may occur within the technical scope defined in the claims, and that these modifications and alterations are encompassed within the technical scope of the embodiments of the present disclosure. 
     For example, according to the embodiments described above, the Type C HDMI connector and the Type D HDMI connector have been explained as an example of connectors. However, the present technology is not limited thereto. For example, the connector according to the present embodiments may be another type of HDMI connector. In addition, the connector according to the present embodiments is not limited to the HDMI connector. For example, a connector based on standard other than the HDMI standard may be used. 
     Additionally, the present technology may also be configured as below. 
     (1) 
     A connector including: 
     a signal pin that stretches in a first direction and transmits a signal; 
     a substrate that has one surface on which the signal pin is formed; and 
     an electric conductor layer that has ground potential, the electric conductor layer being formed on an opposite surface of the surface of the substrate on which the signal pin is formed. 
     (2) 
     The connector according to (1), including: 
     a plurality of the signal pins, 
     wherein, among the plurality of signal pins, an interval between a pair of the signal pins that transmit a differential signal and adjacently extend is shorter than an interval from another signal pin adjacent to the pair of signal pins. 
     (3) 
     The connector according to (1) or (2), further including: 
     an outer shell that covers the signal pin and the substrate, the outer shell including an open surface open to an outside in the first direction, 
     wherein the outer shell is formed of an electric conductor that has ground potential, and 
     wherein the electric conductor layer is electrically connected to the outer shell. 
     (4) 
     The connector according to (3), 
     wherein the electric conductor layer constitutes at least a part of the outer shell. 
     (5) 
     The connector according to any one of (1) to (4), 
     wherein guard lines that have ground potential further extend at positions for sandwiching the signal pin on the substrate in a manner that the guard lines are substantially parallel to the signal pin. 
     (6) 
     The connector according to any one of (1) to (5), 
     wherein the signal pin extends with a substantially equal wiring interval in a fitting part of the connector that fits another connector to be paired with the connector. 
     (7) 
     The connector according to any one of (1) to (6), including: 
     a plurality of the signal pins, 
     wherein, among the plurality of signal pins, a cross-sectional area of a cross section of a power signal pin to which a power signal is applied is larger than a cross-sectional area of the signal pin other than the power signal pin, the cross section being substantially perpendicular to the first direction. 
     (8) 
     The connector according to (7), 
     wherein the cross-sectional area of the power signal pin is larger than the cross-sectional area of the signal pin other than the power signal pin, in a region other than a fitting part of the connector that fits another connector to be paired with the connector. 
     (9) 
     The connector according to any one of (1) to (8), 
     wherein a device that acts on transmission of a signal in the signal pin is mounted on the substrate. 
     (10) 
     The connector according to (9), 
     wherein the device is an AC/DC conversion circuit that converts AC transmission into DC transmission of a signal to be transmitted by the signal pin. 
     (11) 
     The connector according to (9), 
     wherein the device is a register that holds information on a characteristic of a signal to be transmitted by the signal pin, and a communication circuit that notifies any apparatus connected via the connector of the information held by the register. 
     (12) 
     The connector according to (9), 
     wherein the device is a battery that supplies at least any of the signal pins with power-supply voltage. 
     (13) 
     A data transmitting apparatus including: 
     a connector including
         a signal pin that stretches in a first direction and transmits a signal,   a substrate that is formed of a dielectric and has a surface on which the signal pin is formed, and   an electric conductor layer that has ground potential, the electric conductor layer being formed on an opposite surface of the surface of the substrate on which the signal pin is formed,       

     wherein a signal is transmitted to any apparatus via the connector. 
     (14) 
     A data receiving apparatus including: 
     a connector including
         a signal pin that stretches in a first direction and transmits a signal,   a substrate that is formed of a dielectric and has a surface on which the signal pin is formed, and   an electric conductor layer that has ground potential, the electric conductor layer being formed on an opposite surface of the surface of the substrate on which the signal pin is formed,       

     wherein a signal transmitted from any apparatus is received via the connector. 
     (15) 
     A data transmitting and receiving system including: 
     a data transmitting apparatus that transmits a signal to any device via a connector including
         a signal pin that stretches in a first direction and transmits a signal,   a substrate that is formed of a dielectric and has a surface on which the signal pin is formed, and   an electric conductor layer that has ground potential, the electric conductor layer being formed on an opposite surface of the surface of the substrate on which the signal pin is formed; and       

     a data receiving apparatus that receives a signal transmitted from any apparatus via the connector. 
     REFERENCE SIGNS LIST 
     
         
           10 ,  20 ,  30 ,  40  connector 
           110 ,  210 ,  310 ,  410  signal pin 
           120 ,  220 ,  320 ,  420  dielectric 
           130 ,  230 ,  330 ,  430  substrate 
           140 ,  240 ,  340 ,  440  outer shell (shell) 
           150 ,  250  guard line 
           160  device