Converter cables and electronics

Abstract

A conversion cable is provided, comprising: a connector connected to an electronic device that outputs a digital audio signal; an IC having a function of converting the digital audio signal provided through the connector into an analog audio signal; and an output unit for the analog audio signal output from the IC, wherein the IC holds an encryption key for allowing the electronic device to output a digital audio signal requiring copyright protection.

Description

Technical Field

[0001] The technology relates to a conversion cable and electronic equipment with digital-to-analog conversion function. Background Art

[0002] Conventionally, a jack with a diameter of 3.5 mm for analog output (so-called mini jack) has been used for audio output of electronic devices such as smartphones and tablets. Digital output has not yet been implemented, and copyright protection has not yet been required. However, due to the influence of the increase in the number of antennas installed due to multi-lens cameras, the increase in battery size, and the increase in compatible frequencies, the jack with a diameter of 3.5 mm is being removed mainly from overseas smartphones, and a similar trend can be found in China.

[0003] Now, there are more and more cases where connecting cables are used instead of these jacks to improve the quality of audio signals output from smartphones. The connecting cable includes an amplifier with a built-in digital-to-analog converter (called DAC when appropriate). The connecting cable can be connected to a Lightning terminal or a Universal Serial Bus (USB) terminal of a smartphone. The digital audio signal output from the smartphone is converted into an analog audio signal by the DAC, amplified by the amplifier, and then output. Moreover, the connecting cable includes a jack (e.g., with a diameter of 3.5 mm) for analog audio signals. The user can connect his / her headphones to the connecting cable.

[0004] For music content, digital rights management (DRM) (a management system for digital content) has been abolished. There is no problem if a digital audio signal is output from a smartphone. However, because copyright protection is required, digital output of sound from terrestrial digital broadcasts is prohibited. Therefore, for example, in the case of outputting digital sound through a USB Type-C connector, there is no problem for music, but there is a problem that the sound of terrestrial digital broadcasts cannot be output. For example, Patent Document 1 discloses a technology for authenticating an accessory device.

[0005] Reference List

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 2010-183671 Summary of the invention

[0008] Technical Problems to be Solved by the Invention

[0009] As described above, in the case where a digital audio signal is output from an electronic device, there are mixed digital audio signals that require copyright protection and digital audio signals that do not require copyright protection. In this form, it is less necessary to authenticate the attached device at all times.

[0010] Therefore, an object of the present technology is to provide a conversion cable and electronic equipment capable of performing authentication only when a digital audio signal requiring copyright protection is output.

[0011] Solutions to the problem

[0012] The present technology relates to a conversion cable, comprising:

[0013] A connector for connecting to an electronic device that outputs a digital audio signal;

[0014] an IC having a function of converting a digital audio signal provided through the connector into an analog audio signal; and

[0015] an output unit for outputting an analog audio signal from the IC,

[0016] The IC holds an encryption key for allowing the electronic device to output a digital audio signal requiring copyright protection.

[0017] In addition, the present technology relates to an electronic device in which an application for outputting a digital audio signal requiring content protection is installed, the electronic device authenticates a conversion cable based on a key held by an IC of a connected conversion cable by using the application, and the digital audio signal is output to the conversion cable only when the conversion cable is authenticated.

[0018] Effects of the Invention

[0019] According to at least one embodiment, a digital audio signal requiring copyright protection can be output only to a conversion cable that has been certified. Note that the effects described herein are not necessarily restrictive, but may be any effect described in the present technology or an effect different therefrom. Furthermore, the content of the present technology is not limited by the effects exemplified in the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a schematic diagram used to illustrate the usage mode of this technology.

[0021] Figure 2 is a block diagram for explaining a system in the case of outputting a digital audio signal that does not require copyright protection.

[0022] Figure 3 is a block diagram for explaining a system in the case of outputting a digital audio signal requiring copyright protection.

[0023] Figure 4 It is a schematic diagram for explaining the usage state in the first embodiment of the present technology.

[0024] Figure 5 : is a flowchart for explaining the process of outputting a digital audio signal that does not require copyright protection.

[0025] Figure 6 is a flowchart for explaining one example of a process of outputting a digital audio signal requiring copyright protection.

[0026] Figure 7 is a flowchart for explaining another example of the process of outputting a digital audio signal requiring copyright protection.

[0027] Figure 8 is a schematic diagram for explaining an example of authentication processing using an encryption key.

[0028] Fig. 9 is a flowchart for explaining another example of the process of outputting a digital audio signal requiring copyright protection.

[0029] Fig.10 is a flowchart for explaining another example of the process of outputting a digital audio signal requiring copyright protection.

[0030] Fig.11 is a schematic diagram for explaining another example of the authentication process using an encryption key.

[0031] Fig.12 It is a schematic diagram for explaining the second embodiment of the present technology.

[0032] Fig.13 It is a schematic diagram for explaining the third embodiment of the present technology. DETAILED DESCRIPTION

[0033] The following embodiments are preferred specific examples of the present technology, and various technically preferred limitations are given. However, the scope of the present technology is not limited to these embodiments unless it is indicated in the following description that the present technology is particularly limited.

[0034] Note that the present technology will be described in the following order.

[0035] <1. First embodiment of the present technology>

[0036] <2. Second embodiment of the present technology>

[0037] <3. Third embodiment of the present technology>

[0038] <4. Modification>

[0039] <1. First embodiment of the present technology>

[0040] "Usage Mode"

[0041] Reference Figure 1The conventional usage mode and the usage mode of the first embodiment are summarized. Figure 1 As shown in FIG. 1 , stereo headphones 1R and 1L (referred to as headphones 1 in short when there is no need to distinguish between the two) have been conventionally used to listen to analog sound output of an electronic device 10. The headphones 1 include a headphone plug 2 and a headphone cable 3. The headphone plug 2 is to be inserted into an audio jack having a diameter of 3.5 mm. The audio jack is provided for the device 10 to output sound. The electronic device 10 includes, for example, a smartphone, a tablet computer, a PC, or a digital audio player. Note that a headset having a combination of headphones and a microphone may be used instead of the headphones 1.

[0042] In recent years, the number of models that do not include a headphone jack but only include a USB Type-C connector has increased due to the problem of space efficiency of the electronic device 10. The present technology provides a conversion cable applied to such an electronic device. Figure 1 As shown in FIG. 1B , the present technology is applied to a case where sound is output from a terminal (e.g., a USB connector (USB socket) of USB Type-C) provided in an electronic device (hereinafter, referred to as a device when appropriate). Moreover, the present technology is not limited to a USB interface. The present technology can also be implemented by a connector (including lightning) for connecting a mobile device and an external device.

[0043] The electronic device 100 includes, for example, a smartphone, a tablet computer, a PC, or a digital audio player. The connector of the conversion cable 101 (for example, a plug of USB Type-C) can be connected to the connector of the device 100 (for example, a connector of USB Type-C). The conversion cable 101 includes an integrated circuit (IC) having a function of converting a digital audio signal provided through the connector into an analog audio signal. The headphone jack 12 is connected to the IC. The headphone jack 12 is used as an output unit for analog audio signals via a relay cable 13. The IC holds an encryption key for allowing the electronic device 100 to output a digital audio signal that requires copyright protection.

[0044] In the first embodiment, the plug and the IC are integrated in consideration of the fact that the encryption key is more likely to be stolen when the IC is separated from the device 100. In the following description, this part is referred to as a USB plug 11 with a DAC. An earphone 1 similar to a conventional earphone can be connected to the earphone jack 12. The DAC is a circuit for converting a digital audio signal into an analog audio signal, and also has a function of an amplifier that amplifies the audio signal when necessary. Moreover, the USB plug 11 with a DAC has a function of performing communication and authentication processing described later.

[0045] Note that the USB plug and the DAC may be configured separately instead of being integrated. Also, an IC having a function for performing a communication function and a function for authentication processing may be provided separately. Also, as a variation of the conversion cable 101, a configuration without the relay cable 13 is possible. Also, although the headphone jack 12 is provided so that the conventional headphone 1 can be used directly, the headphone jack 12 may be omitted and the headphone 1 may be connected to the USB plug 11 with the DAC. Also, a speaker may be connected instead of the headphone 1. Also, a headset may be used instead of the headphone.

[0046] The present technology is applied to a case where a digital audio signal requiring copyright protection is output from the device 100. For example, a method of viewing terrestrial digital broadcasting using the device 100 (eg, a smartphone) includes the method described below.

[0047] In the first method, viewing is performed using a tuner installed in the device 100 .

[0048] In the second method, viewing is performed via Wi-Fi (registered trademark) by using a router with a built-in tuner.

[0049] In the third method, in a LAN and mobile environment, a broadcasted program is transmitted from a dedicated terminal via DTCP-IP to the device 100 for real-time viewing, or a pre-transmitted program is viewed.

[0050] In either of these viewing methods, device 100 has limitations in outputting the digital audio signal of the program.

[0051] "System structure"

[0052] Figure 2 The structure of the device 100 and the USB plug 11 with DAC of the conversion cable 13 and the connection relationship between the two are described. The device 100 includes an application program (hereinafter, appropriately referred to as an application) 15 and an audio class driver 22 for USB. The application program 15 is installed to output a digital audio signal that does not require copyright protection. The USB plug 11 with DAC is connected to the USB connector of the device 100 to form a USB bus 102. Figure 2 An example of using a headset is described. Figure 2 The path of the audio signal output from the USB plug 11 with DAC to the earphone (earphone jack 12) and the path of the audio signal provided from the microphone (not shown) are illustrated. Moreover, the digital audio signals corresponding to these audio signals are input / output through the USB bus 102 between the device 100 and the USB plug 11 with DAC.

[0053] If the device 100 and the USB plug 11 with DAC of the conversion cable 101 are inserted into the USB connector of the device 100, according to the USB audio standard, the conversion cable 101 is recognized by the audio class driver 22 for USB included in the operating system (OS) in the device 100. In the case where sound reproduction (OUT transmission) is required on the device 100 side, the output data from the application 15 is converted into a format (packet) that conforms to the USB communication format via the audio class driver 22 and sent to the USB bus 102.

[0054] The USB plug 11 with DAC on the conversion cable 101 side decrypts the audio signal from the packet data of the received digital audio signal, and outputs the decrypted audio signal as an analog audio signal to the earphone 1. Moreover, in the case where IN transmission is requested in a cable with a headset (the headset is used for a mobile phone and includes a microphone in addition to the earphone 1), the audio signal obtained by the device from, for example, a microphone is converted into a packet via the DAC IC provided in the conversion cable 101, and is transferred to the device 100 side via the USB bus 102. The audio class driver 22 on the device 100 side extracts the sound data from the received packet and transfers the sound data to the application.

[0055] The above-mentioned processing is a method for outputting a digital audio signal that complies with the USB audio standard without copyright protection. The present technology is applied to a situation where the digitally output audio signal requires copyright protection. In the present technology, an application for outputting a digital audio signal that requires copyright protection (for example, an application 21 for viewing digital broadcasting) is pre-installed in the device 100.

[0056] Application 21 has an encryption key. Application 21 compares the encryption key pre-stored in the IC provided in the USB plug 11 with DAC with the encryption key of application 21 itself. The digital audio signal is allowed to be output to the USB plug 11 with DAC only when there is no problem with the correspondence between the two. Moreover, by performing monitoring in which the device 100 side periodically checks the encryption key on the USB plug 11 with DAC, the effectiveness of protection can be increased. Note that the encryption key is a key used to allow application 21 of device 100 to authenticate the conversion cable 101. The key can be encrypted, but encryption is not required. In addition, the digital audio signal output by device 100 is not encrypted. Note, however, that the digital audio signal can be encrypted.

[0057] The present technology as described above has the following effects.

[0058] Due to the difference between applications, the copyright can be protected only when the sound information requires copyright protection without changing the conversion cable 101. Therefore, the versatility of the conversion cable can be prevented from being reduced, and there is no need to make additional user operations.

[0059] A processing unit for encrypting and / or decrypting audio signals is not necessary. This enables simplified construction and cost reduction.

[0060] This technology requires only minor changes from traditional construction.

[0061] It should be noted that the digital audio signal output by the apparatus 100 may be encrypted, but in the case of, for example, terrestrial digital broadcasting, sound processing may be time consuming and the video and audio may be out of sync. Means to address this problem are required, which may complicate the construction.

[0062] "Processing in the first embodiment"

[0063] Next, the processing in one embodiment of the present technology will be described. Figure 4 As shown in , by inserting the USB plug 11 with DAC of the conversion cable 101 into the device 100 (e.g., a smartphone) and connecting the headphone plug 2 of the headset 1 to the headphone jack 12 of the conversion cable 101, the digital audio signal output by the smartphone 110 can be heard. The output digital audio signal includes a digital audio signal that does not require copyright protection and a digital audio signal that requires copyright protection. In the present technology, any digital audio signal can be heard with the headset 1 depending on the type of application enabled. The digital audio signal that requires copyright protection is, for example, sound data of terrestrial digital broadcasting.

[0064] Will refer to Figure 5 The flowchart of describes one example of processing in the case where a digital audio signal requiring no copyright protection is heard. The processing in the flowchart is performed under the control of the application 15 of the device 100.

[0065] Step S1: The USB plug 11 with DAC of the conversion cable 101 is inserted into the USB connector of the device 100. The headphone plug 2 is inserted into the headphone jack 12 of the conversion cable 101. The conversion cable 101 is recognized as a USB audio compatible device by the USB audio class driver of the device 100. The application 15 is enabled according to the user operation.

[0066] Step S2 : The sound is reproduced by the application 15 of the device 100 , and a digital audio signal is output from the device 100 .

[0067] Step S3: The DAC in the USB plug with DAC 11 converts the digital audio signal into an analog audio signal. The analog audio signal is provided to the earphone 1, and the audio signal can be heard through the earphone 1.

[0068] Will refer to Figure 6 The flowchart of describes an example of processing in the case where a digital audio signal requiring copyright protection is heard. The processing in the flowchart is performed under the control of the application 21 of the device 100. This type of digital audio signal can only be heard using a legal conversion cable that has a predetermined encryption key pre-stored in the DAC IC or externally with a high degree of security.

[0069] Step 11: The USB plug 11 with DAC of the conversion cable 101 is inserted into the USB connector of the device 100. The earphone plug 2 is inserted into the earphone jack 12 of the conversion cable 101.

[0070] Step S12: Authenticate whether the conversion cable 101 is a USB audio compatible device through the USB audio class driver of the device 100. Figure 5 The process is shown in the flowchart, but the cable authentication process is performed.

[0071] Step S13: When the conversion cable 101 is not authenticated as a compatible device in step S12 (NG), information indicating that the conversion cable 101 is not a compatible device is displayed on the screen. Then, the process returns to step S11.

[0072] Step S14: In the case where the conversion cable is authenticated as a USB audio compatible device (OK) in step 12, an application according to a user operation (for example, application 21 for viewing terrestrial digital broadcasting) is enabled.

[0073] Step S15: Check the encryption key. That is, whether the conversion cable 101 is a legitimate conversion cable is authenticated by judging whether the encryption key on the application side and the encryption key on the conversion cable side match each other. It should be noted that although match / mismatch is used as the verification result in the following description, in the case where the two encryption keys have a predetermined relationship, the verification result can be set to OK even if the verification result is a mismatch. A specific example of the verification process for the encryption key will be described later. The application side controls the timing of the verification. For example, the verification is performed regularly, when the cable connection / disconnection is detected, when the device performs screen conversion, or when the sound is not interrupted.

[0074] Step S16: When it is determined that the conversion cable is legal, that is, when the result of the check in step S15 is OK, the digital sound data of the terrestrial digital broadcast program is output from the device 100.

[0075] Step S17: When the result of the check in step S16 is that the encryption key on the application side and the encryption key on the conversion cable side do not match, a message prompting to insert a legal conversion cable is displayed, and the application is exited. Then, the process returns to step S11.

[0076] Step S18: Although the encryption key is checked in step S15, in the case where the result of the initial check alone is considered to be unreliable, the encryption key is monitored. After the encryption key is checked, the encryption key is checked during the output of the digital sound. In the case where the result of the check is NG, the process of step S17 is performed. The monitoring process is not necessarily performed.

[0077] Step S19: If the digital sound data is output in step S16, the digital sound data is converted into an analog audio signal by the DAC in the USB plug with DAC 11.

[0078] Step S20 : ​​The analog audio signal is provided to the earphone 1 via the earphone cable, and the sound can be heard through the earphone 1 .

[0079] In this way, the encryption key on the application side and the encryption key on the conversion cable side are checked. Therefore, only when a legitimate conversion cable is inserted into the device, the digital sound data is output from the device.

[0080] Figure 7 It is explained by partial modification Figure 6 A flowchart of the processing obtained by the processing in Figure 6 In the process in , the platform (OS) of the device 100 performs the cable authentication process (step S12). Figure 7 In the process in FIG. 1 , an application (e.g., application 21 for viewing terrestrial digital broadcasting) is first activated in response to a user operation (step S14). Thereafter, the USB plug 11 with DAC of the conversion cable 101 is inserted into the USB connector of the device 100 (step S11). Then, the application 21 performs a cable authentication process (step S12). The subsequent process is similar to the process in FIG. 1 . Figure 6 Similar to .

[0081] Will refer to Figure 8 The verification process for the encryption key (step S15) is described. The USB plug with DAC 11 in the case of a legitimate conversion cable has a known encryption key. "Known" means that the key information is shared between the application 21 of the device 100 and the IC of the conversion cable 101.

[0082] Step S31: The application 21 of the device 100 inquires the USB plug with DAC 11 for an encryption key. It should be noted, however, that the encryption key may be sent from the USB plug with DAC 11 to the application 21 in the case where the USB plug with DAC 11 is inserted without inquiry.

[0083] Step S32 : The USB plug 11 with DAC responds to send the encryption key to the device 100 .

[0084] Step S33: A check process is performed to determine whether the encryption key matches the encryption key of the application 21. In the case where a known encryption key is received, the encryption keys match each other. A check result (OK / NG) is acquired.

[0085] Will refer to Fig. 9 The flowchart of FIG. 1 describes another example of the process in the case where a digital audio signal requiring copyright protection is heard. The same reference numerals are given to the examples corresponding to the above-mentioned processes.

[0086] Step S11 : The USB plug 11 with DAC of the conversion cable 101 is inserted into the USB connector of the device 100 . The earphone plug 2 is inserted into the earphone jack 12 of the conversion cable 101 .

[0087] Step S12: The USB audio class driver of the device 100 authenticates whether the conversion cable 101 is a USB audio compatible device.

[0088] Step S13: When the conversion cable 101 is not authenticated as a compatible device in step S12 (NG), information indicating that the conversion cable 101 is not a compatible device is displayed on the screen.

[0089] Step S14: In a case where the conversion cable is authenticated as a USB audio compatible device (OK) in step S12, an application according to a user operation (eg, an application for watching TV) is enabled.

[0090] Step S15: Check the encryption key. That is, whether the conversion cable 101 is a legitimate conversion cable is authenticated by judging whether the encryption key on the application side and the encryption key received from the conversion cable match each other. A specific example of the verification process for the encryption key will be described later. The application side controls the timing of the verification. For example, the verification is performed regularly, when the cable connection / disconnection is detected, when the device performs screen conversion, or when the sound is not interrupted.

[0091] Step S16: When it is confirmed that the conversion cable is legitimate, that is, when the result of the check in step S15 is OK, the digital sound data is output from the device 100.

[0092] Fig.10 It is explained by partial modification Fig. 9 A flowchart of the processing obtained by the processing in Fig. 9 In the process of , the platform (OS) of the device 100 performs the cable authentication process (step S12). Fig.10 In the process in FIG. 1 , an application (e.g., application 21 for viewing terrestrial digital broadcasting) is first activated in response to a user operation (step S14). Thereafter, the USB plug 11 with DAC of the conversion cable 101 is inserted into the USB connector of the device 100 (step S11). Then, the application 21 performs a cable authentication process (step S12). The subsequent process is similar to the process in FIG. 1 . Fig. 9 Similar to .

[0093] Will refer to Fig.11 The verification process for the encryption key (steps S21 and S22) is described. The USB plug with DAC 11 of the conversion cable 101 has a known initial encryption key. The application 21 has known encryption key information and solid encryption key information.

[0094] Step S41: When the conversion cable 101 is inserted into the device 100, the application 21 of the device 100 inquires the USB plug with DAC 11 for an initial encryption key.

[0095] Step S42 : The USB plug 11 with DAC responds to send the initial encryption key to the device 100 .

[0096] Step S43: The application 21 determines whether the received key matches the initial encryption key.

[0097] Step S44: In the case where the received key is an initial encryption key, the application 21 transfers the solid-state encryption key to the USB plug with DAC 11 .

[0098] Step S45: Store the reliable encryption key received by the USB plug with DAC 11, and notify the application 21 of the stored solid encryption key.

[0099] Step S46: The application 21 determines whether the encryption key stored by the USB plug with DAC 11 matches the solid encryption key delivered in step S44. In the case where the solid encryption key stored by the USB plug with DAC 11 matches the encryption key delivered by the application 21, the USB plug with DAC 11 and the application 21 are paired. Unless the USB plug with DAC 11 is paired (authenticated), digital sound data is not output.

[0100] In another example of the above encryption key verification process, the application 21 transmits the encryption key to the USB plug with DAC 11 of the conversion cable 101, and registers the encryption key received by the USB plug with DAC 11. Therefore, the conversion cable with the initial encryption key can be paired with different devices, thereby improving the versatility of the conversion cable 101.

[0101] <2. Second embodiment of the present technology>

[0102] Will refer to Fig.12 A second embodiment of the present technology is described. In the second embodiment, a conversion cable 101 is used in a similar manner to the first embodiment. The conversion cable 101 has a structure in which a USB plug 11 with a DAC and a headphone jack 12 are connected via a relay cable 13. Moreover, an antenna (for example, a receiving antenna for terrestrial digital broadcasting) is constructed by using the conversion cable 101.

[0103] Fig.12 A USB plug, for example, a plug PL of USB Type-C and a DAC 51 are illustrated. DAC 51 is an IC having a function of converting a digital audio signal into an analog audio signal and a function of communicating with the device 100 to perform authentication. Among the pins of the plug PL, the connection relationship of the pins related to the present technology is illustrated. Note that the present technology can also be applied to reversible specifications other than the USB Type-C standard, such as the lightning specification. Moreover, in this specification, the term RF signal or antenna signal is used for, for example, the output signal of the antenna itself (including an amplified signal), an image signal from an external antenna provided via an RF connector, and a signal transmitted wirelessly by converting the frequency of the antenna signal.

[0104] In one example, the four poles of the headphone plug 55 can be inserted into the headphone jack 12. In this case, five transmission lines are formed in the relay cable 13. The transmission lines include a left channel signal (LEFT) and a right channel signal (RIGHT). Moreover, a cable including a shielded wire 52 of braided copper wire is used as the relay cable 13. An antenna cable is formed by the shielded wire 52. The antenna cable is connected to the antenna signal input terminal of the tuner of the device 100. A high-frequency shielding component 53 is inserted between the USB plug 11 with DAC and the relay cable 13. The high-frequency shielding component 53 has high impedance at the frequency desired to be received, and includes, for example, an inductor and a ferrite bead.

[0105] USB Type-C

[0106] USB Type-C is a reversible connector that can be inserted into a socket with either the front or back side facing up, and has power transmission and high-speed transmission. Fig.12The two arrays of pins of the plug PL of USB Type-C are described. One array (A side) and the other array (B side) each have 12 pins. Similar to the side (socket) to be inserted into the plug PL, 12 contacts are provided on each of the A side and the B side. The A side and the socket of the plug can be connected, or the A side and the B side can be connected.

[0107] In USB Type-C, pin assignments are defined as follows.

[0108] Side A

[0109] A1: GND: Ground

[0110] A2:SSTXp1: The + side of the data transfer defined by USB 3.1

[0111] A3:SSTXn1: Side of data transmission defined by USB 3.1

[0112] A4:VBUS: bus power

[0113] A5:CC1:Configuration Channel

[0114] A6: Dp1 (or D+): The + side of data transmission defined by USB 2.0

[0115] A7: Dn1 (or D-): The - side of data transmission defined by USB 2.0

[0116] A8:SBU1:Sideband Use

[0117] A9:VBUS: bus power

[0118] A10:SSRXn2: Side of data transfer defined by USB 3.1

[0119] A11:SSRXp2: The + side of the data transfer defined by USB 3.1

[0120] A12: GND: Ground

[0121] B-side

[0122] B12: GND: Ground

[0123] B11:SSRXp2: The + side of the data transfer defined by USB 3.1

[0124] B10:SSRXn2: side of data transfer defined by USB 3.1

[0125] B9:VBUS: bus power

[0126] B8:SBU2:Sideband Use

[0127] B7: Dn2 (or D+): The + side of data transmission defined by USB 2.0

[0128] B6: Dp2 (or D-): The - side of data transmission defined by USB 2.0

[0129] B5:CC2:Configuration Channel

[0130] B4:VBUS: bus power

[0131] B3:SSTXn2: side of data transmission defined by USB 3.1

[0132] B2:SSTXp2: The + side of the data transfer defined by USB 3.1

[0133] B1:GND: Ground

[0134] In one example, data from pin A6 (Dp1) and pin A7 (Dn1) of the plug PL are input to the DAC 51 through differential transmission. Moreover, pin A5 (CC1) and pin A9 (VBUS) of the plug PL are connected to the DAC 51. Five analog signals are output from the DAC 51. The relay cable 13 (shielded wire 52) is set to have a length corresponding to the frequency expected to be received. That is, the shielded wire 52 is used as a monopole antenna. For example, the relay cable 13 is set to have a length of approximately λ / 4 (λ: wavelength of the received frequency). The shielded wire 52 is connected to pins A1 and B1 of the plug PL. Therefore, the antenna signal is provided to pins A1 and B1 of the plug PL1. These pins A1 and B1 are diagonally positioned in the pin array.

[0135] The above-mentioned conversion cable 101 in the second embodiment operates as a cable with an antenna. For example, while a television broadcast is received by the device 100, the sound of the program being viewed can be heard through the earphone 1. Moreover, with the plug PL inserted into the socket, no matter which side of the front and back faces upward, the antenna signal is input to the tuner from one of the pins A1 and B1.

[0136] <3. Third embodiment of the present technology>

[0137] Will refer to Fig.13 A and 13B describe a third embodiment of the present technology. The third embodiment is an example of using a receiving unit (referred to as a converter or adapter) 201 that can be connected to a connection terminal (USB terminal or lightning) of the device 100. In the case where the device 100 does not have a function of receiving terrestrial digital broadcasting, connecting the receiving unit 201 enables reception of terrestrial digital broadcasting.

[0138] like Fig.13 As shown in FIG. 1A , the sound can be heard by inserting the USB plug 11 with DAC of the conversion cable 101 described above into the USB connector of the device 100. The USB plug 11 of the conversion cable 101 can be inserted into the receiving unit 201 without being inserted into the USB connector. Fig.13 As shown in FIG. 2B , the present technology can be applied to a situation where the sound output of the receiving unit 201 can be heard through the wireless headset 202 .

[0139] <4. Deformation>

[0140] Although the embodiments of the present technology have been specifically described above, the present technology is not limited to each of the above embodiments, and various modifications based on the technical concept of the present technology are feasible. Moreover, the configurations, methods, processes, shapes, materials, numerical values, etc. of the above embodiments may be combined with each other as long as the combination does not deviate from the spirit of the present technology.

[0141] Reference numerals

[0142] 1 Headphones

[0143] 2 Headphone jack

[0144] 3 Headphone cable

[0145] 10.100 Electronic equipment

[0146] 101 conversion cable

[0147] 12 Headphone jack

[0148] 13 Relay cable

[0149] 15.21 Applications

[0150] 51 DAC

[0151] 52 shielded wire.

Claims

1. A conversion cable, comprising: a connector connected to a connector of an electronic device that outputs a digital audio signal; An IC having a function of converting a digital audio signal provided through the connector into an analog audio signal; and an output unit for outputting an analog audio signal from the IC, wherein the IC holds an encryption key for allowing the electronic device to output a digital audio signal requiring copyright protection, wherein the conversion cable is used to constitute a receiving antenna for digital broadcasting, and The connector has a plug structure, the RF signal of the digital broadcast is provided to the plug, a first array including a plurality of pins and a second array including a plurality of pins are arranged substantially in parallel in the plug, and both or either of the first pin and the second pin are set to provide the RF signal, the first pin is included in the first array, and the second pin is included in the second array and is located at a diagonal angle to the first pin.

2. The conversion cable according to claim 1, wherein: In the case where the electronic device executes an application program for outputting a digital audio signal requiring the copyright protection, an authentication process using the encryption key is performed.

3. The conversion cable according to claim 1, wherein: In the case where the electronic device executes an application for outputting a digital audio signal that does not require copyright protection, an authentication process using the encryption key is not performed.

4. The conversion cable according to claim 1, wherein a signal line between the electronic device and the connector is differential transmission.

5. The conversion cable according to claim 1, wherein the output unit for the audio signal is a headphone jack, a headphone, a headset, or a speaker for an analog signal.

6. The conversion cable according to claim 1, wherein the IC and the output unit are connected by a relay cable.

7. The conversion cable according to claim 6, wherein the relay cable is a coaxial structure line, and a shielded line of the coaxial structure line is used as an antenna for receiving the digital broadcast.

8. An electronic device, wherein The electronic device is connected to the conversion cable according to claim 1, and The electronic device is installed with an application for outputting a digital audio signal requiring content protection, and the electronic device authenticates the conversion cable by using the application and based on a key held by the IC of the connected conversion cable, and the digital audio signal is output to the conversion cable only when the conversion cable is authenticated.

9. The electronic device according to claim 8, wherein the electronic device is a mobile device. 10 . The electronic device according to claim 9 , wherein the electronic device is a smart phone or a tablet computer.

11. The electronic device according to claim 8, wherein a receiving unit is freely connectable to a connection terminal, and in a case where the conversion cable is authenticated, a digital audio signal is output from the receiving unit to the conversion cable.

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