Adapter apparatus, electronic apparatus and communication method

According to one embodiment, an adapter apparatus includes a first connector conforming to the first standard, a second connector conforming to the second standard, a first transmitter and circuitry. The first transmitter transmits a first signal to a first external apparatus connected via the first connector. The first signal associates with a request to determine whether a first mode is supported by the first external apparatus. The first mode corresponds to a communication mode that conforms to a second standard via the first connector. The circuitry generates a second signal when the first external apparatus does not support the first mode. The second signal is used to make an indication representing that the first external apparatus does not support the first mode.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2016-125749, filed Jun. 24, 2016, the entire contents of which are incorporated herein by reference.

FIELD

Embodiments described herein relate generally to an adapter apparatus, an electronic apparatus and a communication method.

BACKGROUND

Universal Serial Bus (USB) Type-C connectors, which are expected to be used in mobile computers and smartphones, allow use in conformity with not only USB but also other protocols. Thus, a USB Type-C connector can be shared by a plurality of protocols. Protocols such as Mobile High-definition Link (MHL), DisplayPort and Thunderbolt are already usable in USB TYPE-C connectors as alternative modes (hereinafter “Altmode”). High-Definition Multimedia Interface (HDMI [registered trademark]), which is the de facto video interface standard, will probably also be defined as an Altmode and available in USE TYPE-C connectors.

DETAILED DESCRIPTION

In general, according to one embodiment, an adapter apparatus conforms to a first standard and a second standard. The adapter apparatus comprises a first connector, a second connector, a first transmitter and circuitry. The first connector comprises a first shape conforming to the first standard. A first signal line is to be connected to the first connector. The second connector comprises a second shape conforming to the second standard. A second signal line is to be connected to the second connector. The second shape differs from the first shape. The first transmitter is configured to transmit a first signal to a first external device connected via the first connector. The first signal associates with a request to determine whether a first mode is supported by the first external apparatus. The first mode corresponds to a communication mode that conforms to the second standard via both the first connector and the first signal line. The circuitry is configured to generate a second signal when the first external apparatus does not support the first mode. The second signal is used to make an indication representing that the first external apparatus does not support the first mode.

First Embodiment

A first embodiment is explained below.

FIG. 1is an exemplary view showing the configuration of an adapter apparatus1as well as the connection form of the adapter apparatus1according to the present embodiment.

By the adapter apparatus1, an electronic apparatus which operates as a video output device capable of outputting an image through a USB Type-C connector, such as a Digital Versatile Disc (DVD) player, is connected to an electronic apparatus which operates as a video input device capable of inputting an image through an HDMI Type-A connector, such as a television receiver. To realize this function, the adapter apparatus1comprises a USB TYPE-C connector11and an HDMI TYPE-A connector12. The USB TYPE-C connector11and the HDMI TYPE-A connector12may each be formed as a plug, or may each be formed as a receptacle. Thus, in the adapter apparatus1, the USB TYPE-C connector11and the HDMI TYPE-A connector12may be combined in four ways: (1) plug-plug; (2) plug-receptacle; (3) receptacle-plug; and (4) receptacle-receptacle.

The adapter apparatus1assumes the following situation. The electronic apparatus which is connected via the USB TYPE-C connector11and operates as a video output device supports the HDMI Altmode for performing communication conforming to the HDMI standard via a USB TYPE-C cable, and operates at the HDMI Altmode. In this specification, the electronic apparatus which is connected via the USB TYPE-C connector11and operates as a video output device (a source conforming to the HDMI standard) is called a USB TYPE-C source device2. The electronic apparatus which is connected via the HDMI TYPE-A connector12and operates as a video input device (a sink conforming to the HDMI standard) is called an HDMI sink device3.

FIG. 1shows only the main signal lines of the USB TYPE-C connector11and the HDMI TYPE-A connector12regarding the explanation of the adapter apparatus1. In this regard,FIG. 2exemplarily shows the details of the correspondence between the signal lines of the USB TYPE-C connector11and the signal lines of the HDMI TYPE-A connector12in the adapter apparatus1. InFIG. 2, two columns are shown for the USB TYPE-C connector to correspond to a flip (reverse insertion) of the USB TYPE-C connector. In the columns of the USB TYPE-C connector, “Via PD” indicates that data is converted into a USB Power Delivery (PD) protocol message and transferred.

The adapter apparatus1comprises a USB PD controller13, an HDMI controller14, a power source connector15and a power supply controller (PSC)16. Here, the adapter apparatus1comprises the USB PD controller13and the HDMI controller14. The adapter apparatus1may comprise a controller having both the function of the USB PD controller13and the function of the HDMI controller14. The USB PD controller13and the HDMI controller14realize various functions when, for example, a processor executes the firmware stored in a memory.

In place of the HDMI sink device3, the USB PD controller13performs communication conforming to the USB PD protocol with the USB TYPE-C source device2(more specifically, a USB PD controller21provided in the USB TYPE-C source device2). The communication with the USB TYPE-C source device2is performed by using, for example, a configuration channel (CC). For example, the operation of the USB PD controller13enables the USB TYPE-C source device2in a standby state to be activated, or enables the USB TYPE-C source device2to transition to the HDMI Altmode. An Altmode transition processor131is responsible for the transition process of the USB TYPE-C source device2to the HDMI Altmode.

The USB PD controller13comprises a function for detecting the connection of the USB TYPE-C source device2to the USB TYPE-C connector11and a function for detecting the connection of the HDMI sink device3to the HDMI TYPE-A connector12. The detection of the connection of the USB TYPE-C source device2is performed by using, for example, a CC. The detection of the connection of the HDMI sink device3is performed by using, for example, a hot plug detect (HPD) signal. Moreover, the USB PD controller13comprises a function for communicating with the HDMI controller14. In other words, the HDMI controller14comprises a function for communicating with the USB PD controller13.

The HDMI controller14comprises a function for obtaining extended display identification data (EDID) indicating the display capability of the HDMI sink device3by communication using a display data channel (DDC [SCL, SDA]) when the detection of the connection of the HDMI sink device3is reported from the USB PD controller13. The EDID obtained by the HDMI controller14is transmitted to the USE TYPE-C source device2via the USB PD controller13. Based on the EDID, a video signal suitable for the HDMI sink device3is output from the USB TYPE-C source device2. The HDMI controller14relays the video signal to the HDMI sink device3([Tx, Rx]→[TMDS]).

The HDMI controller14comprises a function for receiving a consumer electronics control (CEC) signal from the HDMI sink device3. A CEC signal is defined in the HDMI CEC standard and allows the HDMI sink device3to control the USE TYPE-C source device2. A CEC signal is transmitted from the HDMI sink device3when, for example, an operation for the USB TYPE-C source device2is performed by the remote controller of the HDMI sink device3. The CEC signal received by the HDMI controller14is transmitted to the USE TYPE-C source device2via the USB PD controller13. The number of pins usable in the USB TYPE-C connector11is less than that used in the HDMI standard. Therefore, when the CEC signal received from the HDMI controller14is transmitted to the USB TYPE-C source device2, the USB PD controller13performs a conversion process into a signal suitable for the USB PD protocol to reduce the number of pins to be used for transmitting the CEC signal. The path which is constructed in the adapter apparatus1to transfer the CEC signal from the HDMI sink device3to the USB TYPE-C source device2is also used for the communication for authentication conforming to the HDMI standard between the USB TYPE-C source device2which has transitioned to the HDMI Altmode and the HDMI sink device3.

The power source connector15is a terminal for allowing connection to an external power source4. In place of the power source connector15, a power source cord for the connection to the external power source4may be provided. When the external power source4is a battery, the power source connector15may be structured as a storage portion for storing the external power source4.

The PSC16generates power for operating the USB PD controller13and power for operating the HDMI controller14, using the power input from the external power source4via the power source connector15. The PSC16supplies the generated power to the USB PD controller13and the HDMI controller14. The power source is not limited to an external power source. Power may be supplied from the USB VBUS.

In the adapter apparatus1having the above structure, when the USB TYPE-C source device2is connected to the USB TYPE-C connector11, and when the HDMI sink device3is connected to the HDMI TYPE-A connector12, the USB TYPE-C source device2transitions to the HDMI Altmode and outputs a video signal suitable for the HDMI sink device3. The HDMI sink device3displays an image based on the video signal. Thus, transfer of a video signal from the USB TYPE-C source device2to the HDMI sink device3is realized. In addition, transfer of a CEC signal, which is used for the HDMI sink device3to control the USB TYPE-C source device2, from the HDMI sink device3to the USB TYPE-C source device2is realized.

Every electronic apparatus which comprises a USE TYPE-C connector and is capable of outputting a video signal from the USB TYPE-C connector does not necessarily conform to the HDMI Altmode (in other words, does not necessarily support the HDMI Altmode). For example, when the user connects an electronic apparatus which does not conform to the HDMI Altmode (and comprises a USB TYPE-C connector) to the USB TYPE-C connector11of the adapter apparatus1as the USB TYPE-C source device2, no image is displayed on the HDMI sink device3connected to the HDMI TYPE-A connector12of the adapter apparatus1. When this problem has occurred, there is a high possibility that the user cannot specify because of which element the intended image display is not performed, specifically, because of the USB TYPE-C source device2, the adapter apparatus1, the HDMI sink device3, the cable between the USB TYPE-C source device2and the adapter apparatus1, or the cable between the adapter apparatus1and the HDMI sink device3.

In the present embodiment, when the electronic apparatus connected to the USB TYPE-C connector11does not conform to the HDMI Altmode, in place of the electronic apparatus connected as the USB TYPE-C source device2, the adapter apparatus1outputs, to the HDMI sink device3, a video signal for notifying the user that the electronic apparatus connected to the USB TYPE-C connector11does not conform to the HDMI Altmode. To realize this function, the HDMI controller14of the adapter apparatus1comprises a warning processor141. In this specification, to simplify the explanation, the electronic apparatus which is connected to the USB TYPE-C connector11and does not conform to the HDMI Altmode may also be called a USB TYPE-C source device2.

As described above, the connection of the USE TYPE-C source device2to the USB TYPE-C connector11is detected by the USB PD controller13. The Altmode transition processor131of the USB PD controller13performs a process for causing the USB TYPE-C source device2to transition to the HDMI Altmode.

The Altmode transition processor131inquires of the USB PD controller21of the USE TYPE-C source device2whether the device conforms to the HDMI Altmode. When the USB PD controller21of the USB TYPE-C source device2receives the inquiry, and further when the device conforms to the HDMI Altmode, the USB PD controller21sends a response indicating that the device conforms to the HDMI Altmode. When the device does not conform to the HDMI Altmode, the USE PD controller21sends a response indicating that the device does not conform to the HDMI Altmode. Thus, the USE PD controller21of the USB TYPE-C source device2of the present embodiment comprises a function for responding to the inquiry concerning whether the device conforms to the HDMI Altmode.

Regarding this inquiry, as described above, the adapter apparatus1inquires of the USB TYPE-C source device2whether the USB TYPE-C source device2supports the HDMI Altmode, and further, the USB TYPE-C source device2sends a response indicating whether the device supports the HDMI Altmode. Instead of this configuration, the adapter apparatus1may request the USB TYPE-C source device2to send a list of support functions (a list of conforming protocols as Altmodes). The USB TYPE-C source device2may send back a list of support functions. In this way, the adapter apparatus1may confirm whether the USB TYPE-C source device2supports the HDMI Altmode, using the support list sent back from the USE TYPE-C source device2.

Alternatively, the adapter apparatus1may transmit, to the USB TYPE-C source device2, a signal for determining whether the USB TYPE-C source device2supports the HDMI Altmode. The adapter apparatus1may determine whether the USB TYPE-C source device2supports the HDMI Altmode (mainly, the adapter apparatus1determines that the USB TYPE-C source device2does not support the HDMI Altmode) by confirming a predetermined operation, for example, by confirming that no response has been sent from the USB TYPE-C source device2for a predetermined period, or that a response has been sent conforming to a different protocol.

When a response indicating that the device conforms to the HDMI Altmode has been sent, the Altmode transition processor131causes the USB TYPE-C source device2to transition to the HDMI Altmode. The Altmode transition processor131notifies the HDMI controller14that the USB TYPE-C source device2conforms to the HDMI Altmode. When this notification has been received, the HDMI controller14connects the video signal line (Tx, Rx) of the USB TYPE-C connector11and the video signal line (TMDS) of the HDMI TYPE-A connector12.

When a response indicating that the device does not conform to the HDMI Altmode has been sent, the Altmode transition processor131notifies the HDMI controller14that the USB TYPE-C source device2does not conform to the HDMI Altmode. When this notification has been received, the HDMI controller14disconnects the video signal line (Tx, Rx) of the USB TYPE-C connector11from the video signal line (TMDS) of the HDMI TYPE-A connector12. At this time, the video signal line (TMDS) of the HDMI TYPE-A connector12is connected to the warning processor141of the HDMI controller14. The video signal of an image indicating that the electronic apparatus connected to the USB TYPE-C connector11does not conform to the HDMI Altmode is output from the warning processor141. This video signal is supplied to the HDMI sink device3. For example, the image shown inFIG. 3is displayed on the HDMI sink device3. In this manner, the user can recognize that the intended image display is not performed because the USB TYPE-C source device2does not conform to the HDMI Altmode.

FIG. 3shows the display screen of the HDMI sink device3by reference number300. Here, the video signal of the image displayed on the display screen300is output from the warning processor141of the HDMI controller14. The text data of the message indicated by reference number301and a command requesting that the text data be displayed may be transmitted to the HDMI sink device3by communication using, for example, DDC (SCL, SDA).

Instead of the display performed by the HDMI sink device3, for example, the adapter apparatus1may comprise a speaker or a light-emitting diode (LED) to indicate that the USB TYPE-C source device2does not conform to the HDMI Altmode by audio output or lamp lighting.

FIG. 4is an exemplary flowchart showing the operation procedure of the adapter apparatus1when the USB TYPE-C source device2is connected according to the first embodiment.

The adapter apparatus1detects the connection of the USB TYPE-C source device2to the USB TYPE-C connector11(block A1). The adapter apparatus1inquires of the USB TYPE-C source device2connected to the USB TYPE-C connector11whether the USB TYPE-C source device2conforms to the HDMI Altmode (block A2).

When a response indicating that the device conforms to the HDMI Altmode has been sent (YES in block A2), the adapter apparatus1causes the USB TYPE-C source device2to transition to the HDMI Altmode (block A3). In this way, authentication can be performed between the USB TYPE-C source device2and the HDMI sink device3in conformity with the HDMI standard. Thus, an appropriate video signal is output from the USB TYPE-C source device2to the HDMI sink device3.

When a response indicating that the device does not conform to the HDMI Altmode has been sent (NO in block A2), in place of the USB TYPE-C source device2, the adapter apparatus1performs authentication with the HDMI sink device3in conformity with the HDMI standard, and outputs, to the HDMI sink device3, the video signal of an image indicating that the USB TYPE-C source device2does not conform to the HDMI Altmode (block A4).

As described above, in the adapter apparatus1of the present embodiment, when the USB TYPE-C source device2which does not conform to the HDMI Altmode is connected to the USB TYPE-C connector11, the user can recognize that the USB TYPE-C source device2connected to the USB TYPE-C connector11does not conform to the HDMI Altmode.

Second Embodiment

A second embodiment is explained below.

FIG. 5is an exemplary view showing the configuration of an adapter apparatus1as well as the connection form of the adapter apparatus1according to the present embodiment. Structural elements equivalent to those of the first embodiment are denoted by the same reference numbers, and detailed explanation is omitted. Although not shown inFIG. 5, a USB PD controller13comprises the Altmode transition processor131explained in the first embodiment, and an HDMI controller14comprises the warning processor141explained in the first embodiment.

As stated in the first embodiment, the adapter apparatus1comprises a function for transferring a CEC signal received from an HDMI sink device3to a USB TYPE-C source device2which has transitioned to the HDMI Altmode. Further, as explained above, when transferring the CEC signal, the CEC signal conforming to the HDMI protocol is converted into a signal suitable for the USB PD protocol because of the restriction on the number of pins usable in a USB TYPE-C connector11.

Here, this specification assumes that the USE TYPE-C source device2connected to the USB TYPE-C connector11of the adapter apparatus1is a DVD player, and the HDMI sink device3connected to an HDMI TYPE-A connector12of the adapter apparatus1is a television receiver, and further, the user has performed an operation for the DVD player as the USB TYPE-C source device2, such as a fast-forward operation, using the remote controller of the television receiver as the HDMI sink device3. In this type of operation such as a fast-forward operation, a predetermined key is held down until the target scene is reached.

With regard to a case where a key is held down, a repeat (press and hold) time is defined in the HDMI CEC. A CEC signal indicating that a key has been pressed is supposed to be transmitted from the HDMI sink device3at intervals of time shorter than the repeat time.

However, when the USB TYPE-C source device2is connected to the HDMI sink device3with the adapter apparatus1interposed, as described above, overhead is produced in the adapter apparatus1to convert a CEC signal. Thus, the time from when the HDMI sink device3transmits a CEC signal to when the HDMI sink device3receives a response to the CEC signal from the USB TYPE-C source device2may exceed the repeat time defined in the HDMI CEC.

In the present embodiment, when a key is held down, the adapter apparatus1relays a CEC signal from the HDMI sink device3to the USB TYPE-C source device2without exceeding the repeat time defined in the HDMI CEC to report that the key is held down. The USB PD controller13of the adapter apparatus1comprises a key operation notification processor132which controls the relay of a CEC signal including the process for converting the CEC signal. The key operation notification processor132functions so as not to exceed the repeat time defined in the HDMI CEC when a key is held down. Here, the relay of a CEC signal refers to transfer of the content indicated by a CEC signal (CEC message). The number of CEC signals received by the adapter apparatus1from the HDMI sink device3does not necessarily conform to the number of CEC signals transmitted by the adapter apparatus1to the USB TYPE-C source device2.

FIG. 6is an exemplary sequence diagram shown for explaining an operation which is performed by the adapter apparatus1(more specifically, the key operation notification processor132of the USB PD controller13) when a key is held down.

When a key is held down on the remote controller of the HDMI sink device3(a1inFIG. 6), the first CEC signal indicating that the key has been pressed is transmitted from the HDMI sink device3(a2-1inFIG. 6). The adapter apparatus1transmits an alternative response to the CEC signal to the HDMI sink device3(a3-1inFIG. 6). The adapter apparatus1stores the CEC signal.

When the key is held down, the second CEC signal indicating that the key has been pressed is transmitted from the HDMI sink device3within the repeat time defined in the HDMI CEC (a2-2inFIG. 6). Since this CEC signal conforms to the stored CEC signal, the adapter apparatus1determines that the key is held down, and transmits, to the USB TYPE-C source device2, a CEC signal indicating that the key is held down in conformity with the USB PD protocol (a4inFIG. 6). The adapter apparatus1transmits, to the HDMI sink device3, an alternative response to the CEC signal received from the HDMI sink device3(a3-2inFIG. 6). The CEC signal indicating that the key is held down is structured so as to, for example, include a repeat code in addition to a key code.

A USB PD controller21provided in the USB TYPE-C source device2of the present embodiment comprises a function for interpreting a CEC signal indicating that a key is held down, as structured above. As a matter of course, when the USB PD controller21of the USB TYPE-C source device2successively receives the same CEC signals indicating that a key has been pressed within the repeat time defined in the HDMI CEC, the USB PD controller21is configured to also recognize that the key is being held down.

Subsequently, every time a CEC signal indicating that the key has been pressed is transmitted from the HDMI sink device3(a2-3, . . . inFIG. 6), the adapter apparatus1transmits, to the HDMI sink device3, an alternative response to the CEC signal (a3-3, . . . inFIG. 6). When the key which is being held down is released (a5inFIG. 6), a CEC signal indicating that the key has been released is transmitted from the HDMI sink device3(a6inFIG. 6). Thus, the adapter apparatus1transmits a CEC signal indicating that the key has been released in conformity with the USB PD protocol to the USB TYPE-C source device2(a8inFIG. 8). The adapter apparatus1transmits, to the HDMI sink device3, an alternative response to the CEC signal received from the HDMI sink device3(a7inFIG. 6).

When a CEC signal indicating that the key has been pressed is not received even beyond the repeat time defined in the HDMI CEC, or when a CEC signal different from the stored CEC signal is received, the adapter apparatus1determines that the key which is being held down has been released, and transmits a CEC signal indicating that the key has been released in conformity with the USB PD protocol to the USB TYPE-C source device2.

The remote controller of the HDMI sink device3may comprise a key which is held down in some cases and is pressed as a one-shot operation in other cases. When this type of key is pressed as a one-shot operation, as shown inFIG. 7, a CEC signal indicating that the key has been pressed is transmitted from the HDMI sink device3(a12inFIG. 7) in connection with the press of the key (a11inFIG. 7). Since the key is immediately released, a CEC signal indicating that the key has been released is transmitted from the HDMI sink device3(a14inFIG. 7) instead of the second CEC signal indicating that the key has been pressed. At this time, the adapter apparatus1determines that the key has been pressed as a one-shot operation. Based on the stored CEC signal, the adapter apparatus1transmits a CEC signal indicating that the key has been pressed in conformity with the USB PD protocol to the USB TYPE-C source device2(a16inFIG. 7). Further, the adapter apparatus1transmits a CEC signal indicating that the key has been released in conformity with the USB PD protocol to the USB TYPE-C source device2(a17inFIG. 7). In a manner similar to that of the above description, the adapter apparatus1transmits, to the HDMI sink device3, alternative responses to the CEC signals received from the HDMI sink device3(a13, a15inFIG. 7).

In the above manner, the adapter apparatus1of the present embodiment is capable of relaying a CEC signal transmitted from the HDMI sink device3to the USB TYPE-C source device2without exceeding the repeat time defined in the HDMI CEC when, for example, a key is held down on the remote controller of the HDMI sink device3.

Third Embodiment

A third embodiment is explained below.

In the present embodiment, when a key is held down on the HDMI sink device3side as an operation for a USB TYPE-C source device2as explained in the second embodiment, an adapter apparatus1relays a CEC signal from the HDMI sink device3to the USB TYPE-C source device2without exceeding the repeat time defined in the HDMI CEC to report that the key is being held down by a method different from that of the second embodiment.

FIG. 8is an exemplary sequence diagram shown for explaining an operation which is performed by the adapter apparatus1(more specifically, a key operation notification processor132provided in a USB PD controller13) when a key is held down according to the present embodiment.

When a key is held down on the remote controller of the HDMI sink device3(b1inFIG. 8), the first CEC signal indicating that the key has been pressed is transmitted from the HDMI sink device3(b2-1inFIG. 8). The adapter apparatus1transmits, to the HDMI sink device3, an alternative response to the CEC signal (b3-1inFIG. 8). The adapter apparatus1stores the CEC signal. Further, the adapter apparatus1of the present embodiment transmits a CEC signal indicating that the key has been pressed in conformity with the USE PD protocol to the USB TYPE-C source device2(b4-1inFIG. 8).

As explained in the second embodiment, when a key is held down, a CEC signal indicating that the key has been pressed is transmitted from the HDMI sink device3at intervals of time shorter than the repeat time defined in the HDMI CEC (b2-2, b2-3, . . . inFIG. 8). After receiving the first CEC signal, the adapter apparatus1of the present embodiment transmits a CEC signal indicating that the key has been pressed in conformity with the USB PD protocol to the USE TYPE-C source device2at predetermined intervals based on the stored CEC signal without waiting for the transmission of the second CEC signal from the HDMI sink device3(b4-1, b4-2, . . . inFIG. 8). These intervals are preferably shorter than the repeat time defined in the HDMI CEC, and longer than the intervals between a CEC signal indicating that the key has been pressed and a CEC signal indicating that the key has been released transmitted from the HDMI sink device3when the key is pressed as a one-shot operation.

Until a CEC signal indicating that the key has been released is transmitted from the HDMI sink device3, the adapter apparatus1transmits, to the USB TYPE-C source device2, a CEC signal indicating that the key has been pressed in conformity with the USB PD protocol at the above intervals based on the stored CEC signal. During this period, the adapter apparatus1transmits, to the HDMI sink device3, an alternative response (b3-2, . . . inFIG. 8) to each CEC signal indicating that the key has been pressed (b2-2, . . . inFIG. 8) and transmitted from the HDMI sink device3.

When the key being held down is released (b5inFIG. 8), a CEC signal indicating that the key has been released is transmitted from the HDMI sink device3(b6inFIG. 8). The adapter apparatus1transmits a CEC signal indicating that the key has been released in conformity with the USB PD protocol to the USB TYPE-C source device2(b8inFIG. 8). The adapter apparatus1transmits, to the HDMI sink device3, an alternative response to the CEC signal received from the HDMI sink device3(b7inFIG. 8).

In the present embodiment, when a CEC signal indicating that the key has been pressed is not received even beyond the repeat time defined in the HDMI CEC, or when a CEC signal different from the stored CEC signal is received, the adapter apparatus1determines that the key being held down has been released, and transmits a CEC signal indicating that the key has been released in conformity with the USB PD protocol to the USB TYPE-C source device2.

In the above manner, the adapter apparatus1of the present embodiment is capable of relaying a CEC signal transmitted from the HDMI sink device3to the USB TYPE-C source device2without exceeding the repeat time defined in the HDMI CEC when, for example, a key is held down on the remote controller of the HDMI sink device3.

Fourth Embodiment

A fourth embodiment is explained below.

In the present embodiment, when a key is held down on the HDMI sink device3side as an operation for a USB TYPE-C source device2as explained in the second and third embodiments, an adapter apparatus1relays a CEC signal from the HDMI sink device3to the USB TYPE-C source device2without exceeding the repeat time defined in the HDMI CEC to report that the key is being held down by a hybrid method in which the methods of the second and third embodiments are combined with each other.

FIG. 9is an exemplary sequence diagram shown for explaining an operation which is performed by the adapter apparatus1(more specifically, a key operation notification processor132provided in a USB PD controller13) when a key is held down according to the present embodiment.

When a key is held down on the remote controller of the HDMI sink device3(c1inFIG. 9), the first CEC signal indicating that the key has been pressed is transmitted from the HDMI sink device3(c2-1inFIG. 9). The adapter apparatus1transmits, to the HDMI sink device3, an alternative response to the CEC signal (c3-1inFIG. 9). The adapter apparatus1stores the CEC signal. Further, the adapter apparatus1transmits a CEC signal indicating that the key has been pressed in conformity with the USB PD protocol to the USB TYPE-C source device2(c4inFIG. 9).

When the key is held down, the second CEC signal indicating that the key has been pressed is transmitted from the HDMI sink device3within the repeat time defined in the HDMI CEC (c2-2inFIG. 9). Since this CEC signal conforms to the stored CEC signal, the adapter apparatus1determines that the key is being held down, and transmits, to the HDMI sink device3, an alternative response to the CEC signal (c3-2inFIG. 9). The adapter apparatus1transmits a CEC signal indicating that the key is being held down in conformity with the USB PD protocol to the USB TYPE-C source device2(c5inFIG. 9).

Subsequently, every time a CEC signal indicating that the key has been pressed is transmitted from the HDMI sink device3(c2-3, . . . inFIG. 9), the adapter apparatus1transmits, to the HDMI sink device3, an alternative response to the CEC signal (c3-3, . . . inFIG. 9). When the key being held down is released (c6inFIG. 9), a CEC signal indicating that the key has been released is transmitted from the HDMI sink device3(c7inFIG. 9). Thus, the adapter apparatus1transmits a CEC signal indicating that the key has been released in conformity with the USB PD protocol to the USB TYPE-C source device2(c9inFIG. 9). The adapter apparatus1transmits, to the HDMI sink device3, an alternative response to the CEC signal received from the HDMI sink device3(c8inFIG. 9).

In the present embodiment, when a CEC signal indicating that the key has been pressed is not received even beyond the repeat time defined in the HDMI CEC, or when a CEC signal different from the stored CEC signal is received, the adapter apparatus1determines that the key being held down has been released. The adapter apparatus1transmits a CEC signal indicating that the key has been released in conformity with the USB PD protocol to the USB TYPE-C source device2.

In the above manner, the adapter apparatus1of the present embodiment is capable of relaying a CEC signal transmitted from the HDMI sink device3to the USB TYPE-C source device2without exceeding the repeat time defined in the HDMI CEC when, for example, a key is held down on the remote controller of the HDMI sink device3.

Fifth Embodiment

A fifth embodiment is explained below.

FIG. 10is an exemplary view showing the configuration of an adapter apparatus1as well as the connection form of the adapter apparatus1according to the present embodiment. Structural elements equivalent to those of the first to fourth embodiments are denoted by the same reference numbers, and detailed explanation is omitted. Although not shown inFIG. 10, a USB PD controller13comprises the Altmode transition processor131explained in the first embodiment, and the key operation notification processor132explained in the second to fourth embodiments. An HDMI controller14comprises the warning processor141explained in the first embodiment.

The adapter apparatus1comprises a USB TYPE-C connector11. A USB TYPE-C source device2connected to the USB TYPE-C connector11is capable of outputting a video signal to an HDMI sink device3by transitioning to the HDMI Altmode. In addition, the USB TYPE-C source device2is capable of operating based on a CEC signal from the HDMI sink device3. In other words, the HDMI sink device3is capable of controlling the USB TYPE-C source device2based on a CEC signal.

Many electronic apparatuses comprise a function for transitioning to a standby state for power saving when, for example, the idle period exceeds a predetermined period. Even if the USB TYPE-C source device2conforms to the HDMI Altmode and has transitioned to the HDMI Altmode, the HDMI Altmode is disabled when transitioning to a standby state. Thus, even if the USB TYPE-C source device2conforms to the HDMI Altmode, for example, a sink device cannot use the function for activating the source device in a standby state defined in the HDMI CEC.

In the present embodiment, even when the USB TYPE-C source device2is in a standby state, and the HDMI Altmode is disabled, the adapter apparatus1is capable of controlling the USB TYPE-C source device2based on a CEC signal from the HDMI sink device3. To realize this function, the HDMI controller14of the adapter apparatus1of the present embodiment comprises a CEC message management processor142.

As explained in the first embodiment, when the USB PD controller13detects the connection of the HDMI sink device3to an HDMI TYPE-A connector12, the EDID of the HDMI sink device3is obtained by the HDMI controller14. The CEC message management processor142obtains and stores the physical address of the HDMI sink device3included in the EDID.

In addition, as stated in the first embodiment, the USB PD controller13which has detected the connection of the USB TYPE-C source device2to the USB TYPE-C connector11causes the USB TYPE-C source device2to transition to the HDMI Altmode when the USB TYPE-C source device2conforms to the HDMI Altmode. The CEC message management processor142monitors a CEC signal transmitted from the HDMI sink device3to the USB TYPE-C source device2which has transitioned to the HDMI Altmode. The CEC message management processor142obtains and stores the logical address of the USB TYPE-C source device2allocated to the stored physical address of the HDMI sink device3. This logical address is included in the CEC signal.

Subsequently, it is assumed that the USB TYPE-C source device2transitions to a standby state, and the HDMI Altmode is disabled. Further, the HDMI sink device3is assumed to transmit a CEC signal to the USB TYPE-C source device2in a standby state with the HDMI Altmode disabled.

The CEC message management processor142monitors each CEC signal transmitted from the HDMI sink device3even while the USB TYPE-C source device2is in a standby state. When the stored logical address of the USB TYPE-C source device2is included in a CEC signal, the CEC signal is stored. The CEC message management processor142requests the USB PD controller13to cause the USB TYPE-C source device2in a standby state to be activated and transition to the HDMI Altmode. Further, the CEC message management processor142requests the USB PD controller13to transmit the stored CEC signal to the USB TYPE-C source device2. As explained in the first embodiment, the Altmode transition processor131of the USB PD controller13is responsible for the transition of the USE, TYPE-C source device2to the HDMI Altmode. As explained in the second to fourth embodiments, the key operation notification processor132of the USB PD controller13is responsible for the transmission of CEC signals to the USB TYPE-C source device2.

In the above manner, in place of the USB TYPE-C source device2in a standby state with the HDMI Altmode disabled, the adapter apparatus1of the present embodiment receives and stores a CEC signal transmitted from the HDMI sink device3to the USB TYPE-C source device2. After the CEC signal is received and stored, the adapter apparatus1causes the USB TYPE-C source device2to be activated and transition to the HDMI Altmode, and transmits the stored CEC signal to the USB TYPE-C source device2.

The adapter apparatus1of the present embodiment allows the HDMI sink device3to transmit a CEC signal to the USB TYPE-C source device2in a standby state with the HDMI Altmode disabled.

In other words, in the present embodiment, a USB PD controller21provided in the USB TYPE-C source device2comprises the following function. After the transition to the HDMI Altmode, the USB PD controller21is configured to receive, from the adapter apparatus1, a CEC signal which was transmitted from the HDMI sink device3to the USB TYPE-C source device2while the USB TYPE-C source device2was not in the HDMI Altmode.

FIG. 11is an exemplary flowchart showing the operation procedure of a process which is performed by the adapter apparatus1of the present embodiment to store the physical address of the HDMI sink device3.

The adapter apparatus1supplies power to the 5 V power line of the HDMI TYPE-A connector12(block B1) and monitors the connection of the HDMI sink device3by an HPD line (block B2). When the connection of the HDMI sink device3is detected (YES in block B2), the adapter apparatus1obtains the EDID of the HDMI sink device3by an SCL/SDA line, and stores the physical address of the HDMI sink device3included in the EDID (block B3).

FIG. 12is an exemplary flowchart showing the operation procedure of a process which is performed by the adapter apparatus1of the present embodiment to store the logical address of the USB TYPE-C source device2.

The adapter apparatus1causes the USB TYPE-C source device2to transition to the HDMI Altmode by a CC line when the USB TYPE-C source device2is connected (block C1). When the transition to the HDMI Altmode has been successful (YES in block C2), the adapter apparatus1causes the HPD line, a CEC line and a DDC (SCL/SDA line) to transition to a pass-through mode (block C3).

The adapter apparatus1monitors each CEC signal transmitted from the HDMI sink device3to the USB TYPE-C source device2which has transitioned to the HDMI Altmode by the CEC line (block C4). The adapter apparatus1detects the logical address of the USB TYPE-C source device2allocated to the stored physical address of the HDMI sink device3(block C5). This logical address is included in a CEC signal. When the logical address of the USB TYPE-C source device2is detected (YES in block C5), the adapter apparatus1stores the detected logical address of the USB TYPE-C source device (block C6).

FIG. 13is an exemplary flowchart showing the operation procedure of a process which is performed by the adapter apparatus1of the present embodiment to disable the HDMI Altmode of the USB TYPE-C source device2.

The adapter apparatus1monitors the CC line to detect the disabling of the HDMI Altmode of the USB TYPE-C source device2(block D1). When a reset signal is detected (YES in block D2), the adapter apparatus1disables the pass-through mode of the HPD line, the CEC line and the DDC (SCL/SDA line) (block D3).

The adapter apparatus1monitors the disconnection of the HDMI sink device3by the HPD line (block D4). When the disconnection of the HDMI sink device3is not detected (NO in block D4), the adapter apparatus1monitors the CEC line to detect the transmission of a CEC signal from the HDMI sink device3to the USB TYPE-C source device2(block D5). When the disconnection of the HDMI sink device3is detected (YES in block D4), the adapter apparatus1executes a system reset (block D6).

FIG. 14is an exemplary flowchart showing the operation procedure of a process which is performed by the adapter apparatus1of the present embodiment to cause the USB TYPE-C source device2to retransition to the HDMI Altmode.

The adapter apparatus1monitors each CEC signal (CEC message) transmitted from the HDMI sink device3(block E1), and determines whether each CEC message transmitted from the HDMI sink device3includes the stored logical address of the USB TYPE-C source device2(block E2). When a CEC message includes the stored logical address of the USB TYPE-C source device2(YES in block E2), the adapter apparatus1receives and stores the CEC message (block E3).

After the CEC message is received and stored, the adapter apparatus1activates the USB TYPE-C source device2which is in a standby state, and causes it to transition to the HDMI Altmode (block E4). The adapter apparatus1transmits the stored CEC message to the USE TYPE-C source device2which has transitioned to the HDMI Altmode (block E5), and causes the HPD line, the CEC line and the DDC (SCL/SDA line) to transition to a pass-through mode (block E6).

Subsequently, the adapter apparatus1monitors each CEC signal (CEC message) transmitted from the HDMI sink device3(block E7), and determines whether the logical address included in each CEC message transmitted from the HDMI sink device3conforms to the stored logical address of the USB TYPE-C source device2(block E8). When the logical addresses conform to each other (YES in block E8), the adapter apparatus1transfers the CEC message to the USE TYPE-C source device2(block E9). When they do not conform to each other (NO in block E8), the adapter apparatus1discards the CEC message (block E10).

As described above, the adapter apparatus1of the present embodiment allows the HDMI sink device3to transmit a CEC signal to the USB TYPE-C source device2which is in a standby state with the HDMI Altmode disabled.

Various functions described in the above embodiments may be implemented by a processing circuit. Examples of the processing circuit include a programmed processor such as a central processing unit (CPU). The processor realizes each of the described functions by executing a program stored in a memory. The processor may be an electronic circuit or a microprocessor. Examples of the processing circuit also include a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a microcontroller, a controller and other electronic circuit components.

Since each process of the above embodiments can be implemented by a computer program, the same advantage as the embodiments can be easily achieved by installing the computer program into a general-purpose computer through a computer-readable storage medium that stores the computer program, and executing the computer program.