Interface circuit, terminal equipment and screen projection system

Abstract

The utility model relates to an interface circuit, terminal equipment and a screen projection system. The circuit comprises a control chip, a change-over switch and a preset interface, the control chip comprises a first identification signal end and a second identification signal end, and the preset interface comprises a first auxiliary signal end and a second auxiliary signal end; the control chip controls the change-over switch to form a first transmission path in a first plugging state and form a second transmission path in a second plugging state; in the first transmission path, the first auxiliary signal end is connected with the first identification signal end, and the second auxiliary signal end is connected with the second identification signal end. In the second transmission path, the first auxiliary signal terminal is connected to the second identification signal terminal and the second auxiliary signal terminal is connected to the first identification signal terminal. Through the arrangement, the first identification signal end and the second identification signal end can form adaptive connection with the first auxiliary signal end and the second auxiliary signal end in different plugging states, so that screen projection scenes in different plugging states can be realized.

Description

Technical Field

[0001] The present disclosure relates to the field of video display technology, and in particular to an interface circuit, a terminal device, and a screen projection system. Background Art

[0002] With the rapid development of video display technology, ultra-high-definition signal experience has also become a focus of attention. In this regard, in terms of image display, the image display interface (DisplayPort, DP) that supports full HD display resolution has also become a common interface for display devices. For example, a terminal device with a Type-C interface is connected to a projection device with an image display interface through a Type-C to DP interface cable to present ultra-high-definition images through projection.

[0003] However, among the existing terminal devices with Type-C interfaces, only a few can support the DP screen projection function, and the screen projection scenarios of terminal devices that support the DP screen projection function are limited. That is, when the Type-C interface of the terminal device is connected to the Type-C interface of the cable, due to the limitation of the internal circuit structure of the terminal device, it can only unilaterally recognize the Type-C interface of the cable for screen projection, such as supporting screen projection in the forward insertion scenario, but not in the reverse insertion scenario. Utility Model Content

[0004] In order to solve the above technical problems or at least partially solve the above technical problems, the present disclosure provides an interface circuit, a terminal device and a screen projection system.

[0005] The present disclosure provides an interface circuit, comprising: a control chip, a switch and a preset interface; the control chip comprises a first identification signal terminal and a second identification signal terminal, and the preset interface comprises a first auxiliary signal terminal and a second auxiliary signal terminal;

[0006] The control chip controls the switching switch to form a first transmission path in a first plug-in state, and to form a second transmission path in a second plug-in state; wherein, in the first transmission path, the first auxiliary signal end is connected to the first identification signal end and the second auxiliary signal end is connected to the second identification signal end; in the second transmission path, the first auxiliary signal end is connected to the second identification signal end and the second auxiliary signal end is connected to the first identification signal end.

[0007] Optionally, the switch includes a first common terminal, a second common terminal, a first switching terminal and a second switching terminal;

[0008] The first switching end is connected to the first identification signal end; the second switching end is connected to the second identification signal end;

[0009] The first common end is connected to the first auxiliary signal end, and the second common end is connected to the second auxiliary signal end; in the first plug-in state, the switching switch connects the first common end to the first switching end, and connects the second common end to the second switching end to form the first transmission path.

[0010] Optionally, the switch further includes a third switch end and a fourth switch end;

[0011] The third switching end is connected to the first auxiliary signal end; the fourth switching end is connected to the second auxiliary signal end;

[0012] In the second plug-in state, the switch connects the first common end to the third switch end, and connects the second common end to the fourth switch end, so as to form the second transmission path.

[0013] Optionally, the switch further includes a first controlled end and a second controlled end; the control chip further includes a control end;

[0014] The first controlled end and the second controlled end are connected to the control end;

[0015] The first controlled terminal and the second controlled terminal are controlled to form a low potential in the first plug-in state to select the first transmission path, or are controlled to form a high potential in the second plug-in state to select the second transmission path.

[0016] Optionally, the switching switch is a dual-channel single-pole double-throw switch.

[0017] Optionally, the first identification signal terminal and the second identification signal terminal are respectively a differential negative signal port and a differential positive signal port of a DP auxiliary channel.

[0018] Optionally, the switch further includes a first enable terminal; the control chip further includes a second enable terminal;

[0019] The first enabling terminal is connected to the second enabling terminal;

[0020] The second enable terminal is used to control the first enable terminal to form a low potential based on the first plugging state or the second plugging state.

[0021] The present disclosure also provides a terminal device, comprising any one of the above-mentioned interface circuits.

[0022] The present disclosure also provides a screen projection system, including an interface conversion cable, a screen projection device and the above-mentioned terminal device;

[0023] The terminal device is connected to the screen projection device via the interface conversion cable.

[0024] Optionally, the interface conversion cable is a Type-C to DP interface cable.

[0025] Compared with the prior art, the technical solution provided by the embodiments of the present disclosure has the following advantages:

[0026] The interface circuit provided by the embodiment of the present disclosure includes a control chip, a switching switch and a preset interface; the control chip includes a first identification signal terminal and a second identification signal terminal, and the preset interface includes a first auxiliary signal terminal and a second auxiliary signal terminal; the control chip controls the switching switch to form a first transmission path in a first plug-in state, and to form a second transmission path in a second plug-in state; wherein, in the first transmission path, the first auxiliary signal terminal is connected to the first identification signal terminal and the second auxiliary signal terminal is connected to the second identification signal terminal; in the second transmission path, the first auxiliary signal terminal is connected to the second identification signal terminal and the second auxiliary signal terminal is connected to the first identification signal terminal. Such a setting ensures that the first identification signal terminal and the second identification signal terminal can form an adaptive connection with the first auxiliary signal terminal and the second auxiliary signal terminal in different plug-in states, thereby facilitating the realization of screen projection scenarios in different plug-in states. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0029] Figure 1 A schematic diagram of the structure of an interface circuit provided by an embodiment of the present disclosure;

[0030] Figure 2 A schematic diagram of the structure of another interface circuit provided by an embodiment of the present disclosure;

[0031] Figure 3 A schematic diagram of the structure of another interface circuit provided in an embodiment of the present disclosure.

[0032] Among them, 110, control chip; 111, first identification signal terminal; 112, second identification signal terminal; 113, control terminal; 114, second enable terminal; 120, switching switch; 121, first common terminal; 122, second common terminal; 123, first switching terminal; 124, second switching terminal; 125, third switching terminal; 126, fourth switching terminal; 127, first controlled terminal; 128, second controlled terminal; 129, first enable terminal; 130, preset interface; 131, first auxiliary signal terminal; 132, second auxiliary signal terminal. DETAILED DESCRIPTION

[0033] In order to more clearly understand the above-mentioned objectives, features and advantages of the present disclosure, the scheme of the present disclosure will be further described below. It should be noted that the embodiments of the present disclosure and the features in the embodiments can be combined with each other without conflict.

[0034] In the following description, many specific details are set forth to facilitate a full understanding of the present disclosure, but the present disclosure may also be implemented in other ways different from those described herein; it is obvious that the embodiments in the specification are only part of the embodiments of the present disclosure, rather than all of the embodiments.

[0035] The interface circuit, terminal device and screen projection system provided in the embodiments of the present disclosure are exemplarily described below in conjunction with the accompanying drawings.

[0036] Figure 1 This is a schematic diagram of the structure of an interface circuit provided by an embodiment of the present disclosure. Figure 1 The interface circuit includes: a control chip 110, a switching switch 120 and a preset interface 130; the control chip 110 includes a first identification signal terminal 111 and a second identification signal terminal 112; the preset interface 130 includes a first auxiliary signal terminal 131 and a second auxiliary signal terminal 132; the control chip 110 controls the switching switch 120 to form a first transmission path in a first plug-in state, and to form a second transmission path in a second plug-in state; wherein, in the first transmission path, the first auxiliary signal terminal 131 is connected to the first identification signal terminal 111 and the second auxiliary signal terminal 132 is connected to the second identification signal terminal 112; in the second transmission path, the first auxiliary signal terminal 131 is connected to the second identification signal terminal 112 and the second auxiliary signal terminal 132 is connected to the first identification signal terminal 111.

[0037] Among them, the first plug-in state and the second plug-in state are states formed when the preset interface 130 is plugged in with other interfaces. It should be noted that the preset interface 130 is connected to the external screen projection device by plugging in other interfaces to further realize screen projection. Exemplarily, preferably, in the embodiment of the present disclosure, the first plug-in state is the forward plug-in state, and the second plug-in state is the reverse plug-in state. In other implementations, the first plug-in state may also be the reverse plug-in state, and the second plug-in state may be the forward plug-in state, which is not limited here.

[0038] Among them, the preset interface 130 is a Type-C interface, and the Type-C interface is provided with pins capable of identifying different plug-in states (a first plug-in state and a second plug-in state), so as to output a first identification signal and a second identification signal based on the confirmed corresponding plug-in state, such as the first plug-in state or the second plug-in state. For example, different plug-in states can be identified through the Configuration Channel (CC) pin in the Type-C interface. For example, 1 represents a high potential and 0 represents a low potential, which is commonly used in digital circuits. When the CC pin identifies a positive plug-in state, the CC pin output may be 1; when the CC pin identifies a reverse plug-in state, the CC pin output may be 0. There is no limitation on the corresponding potential when the CC pin identifies different plug-in states.

[0039] Among them, the preset interface 130 will output the first identification signal and the second identification signal regardless of whether it is in the forward insertion state or the reverse insertion state. Preferably, in the embodiment of the present disclosure, the first auxiliary signal terminal 131 is used to output the second identification signal, and the second auxiliary signal terminal 132 is used to output the first identification signal. On this basis, the first identification signal terminal 111 is used to identify the second identification signal, and the second identification signal terminal 112 is used to identify the first identification signal.

[0040] Among them, the first auxiliary signal terminal 131 and the second auxiliary signal terminal 132 are pins for performing related protocols such as DP protocol identification. For example, taking the preset interface 130 as a Type-C interface, the first auxiliary signal terminal 131 is the SBU2 pin, the second auxiliary signal terminal 132 is the SBU1 pin, and in the first plug-in state, the SBU2 pin outputs the second identification signal, and the SBU1 pin outputs the first identification signal; conversely, in the second plug-in state, the SBU2 pin outputs the first identification signal, and the SBU1 pin outputs the second identification signal.

[0041] In combination with the above example, the first identification signal may be an SBU1 signal, and the second identification signal may be an SBU2 signal. In other embodiments, the first identification signal and the second identification signal may also be signals in other forms. It is only necessary to ensure that the control chip 110 can identify whether the external screen projection device supports screen projection based on the first identification signal and the second identification signal. This is not limited here.

[0042] It should be noted that the first identification signal and the second identification signal are used to transmit the screen projection handshake protocol to the second identification signal terminal 112 and the first identification signal terminal 111 respectively, such as: Digital Living Network Alliance (DLNA) protocol or other screen projection handshake protocols. When the first identification signal terminal 111 and the second identification signal terminal 112 receive the screen projection handshake protocol, they will perform protocol processing operations, for example: the first identification signal terminal 111 and the second identification signal handshake successfully, and the second identification signal terminal 112 and the first identification signal handshake successfully. At this time, the control chip 110 recognizes that the external screen projection device supports screen projection, and further executes subsequent related screen projection operations.

[0043] Exemplarily, in the first plug-in state, the preset interface 130 outputs a first identification signal and a second identification signal to the switching switch 120, and the switching switch 120 constitutes a first transmission path, so that the first identification signal and the second identification signal are transmitted along the first transmission path, and then the first identification signal is transmitted to the second identification signal terminal 112, and the second identification signal is transmitted to the first identification signal terminal 111, and then the second identification signal is identified by the first identification signal terminal 111, and the second identification signal terminal 112 identifies the first identification signal, and it is determined that the external screen projection device supports screen projection, thereby using the external screen projection device for screen projection.

[0044] Similarly, in the second plug-in state, the preset interface 130 outputs the first identification signal and the second identification signal to the switching switch 120, and the switching switch 120 constitutes a second transmission path, so that the first identification signal and the second identification signal are transmitted along the second transmission path, and then the first identification signal is transmitted to the second identification signal terminal 112, and the second identification signal is transmitted to the first identification signal terminal 111, and the second identification signal is identified by the first identification signal terminal 111, and the second identification signal terminal 112 identifies the first identification signal, and it is determined that the screen can be projected using an external screen projection device at present.

[0045] Exemplarily, the control chip 110 may be a port control chip or a system-on-chip (SOC) that supports the DP projection function. In addition, the first identification signal terminal 111 and the second identification signal terminal 112 may be pins with signal identification function in the control chip 110, such as: the first identification signal terminal 111 may be the DP_SOC_M pin, and the second identification signal terminal 112 may be the DP_SOC_P pin. In other embodiments, the first identification signal terminal 111 and the second identification signal terminal 112 may also be pins with other names, as long as they support the signal identification function in the embodiments of the present disclosure, and are not limited here.

[0046] The interface circuit provided by the embodiment of the present disclosure includes: a control chip 110, a switch 120 and a preset interface 130; the control chip 110 includes a first identification signal terminal 111 and a second identification signal terminal 112; the preset interface 130 includes a first auxiliary signal terminal 131 and a second auxiliary signal terminal 132; the control chip 110 controls the switch 120 to form a first transmission path in the first plug-in state, and to form a second transmission path in the second plug-in state; wherein, in the first transmission path, the first auxiliary signal terminal 131 is connected to the first identification signal terminal 111 and the second auxiliary signal terminal 132 is connected to the second identification signal terminal 112; in the second transmission path, the first auxiliary signal terminal 131 is connected to the second identification signal terminal 112 and the second auxiliary signal terminal 132 is connected to the first identification signal terminal 111. In this way, compared with the solution in the prior art that the Type-C interface can only recognize one side for screen projection, the embodiment of the present disclosure ensures that the first identification signal terminal 111 and the second identification signal terminal 112 can respectively recognize the second identification signal and the first identification signal in different plug-in states, which is conducive to realizing screen projection scenarios in different plug-in states.

[0047] In some embodiments, Figure 2 This is a schematic diagram of the structure of another interface circuit provided in an embodiment of the present disclosure, corresponding to a schematic diagram of the structure in a forward plugging scenario. Figure 1 Based on Figure 2 The switching switch 120 includes a first common terminal 121, a second common terminal 122, a first switching terminal 123 and a second switching terminal 124; the first switching terminal 123 is connected to the first identification signal terminal 111; the second switching terminal 124 is connected to the second identification signal terminal 112; the first common terminal 121 is connected to the first auxiliary signal terminal 131, and the second common terminal 122 is connected to the second auxiliary signal terminal 132; in the first plug-in state, the switching switch 120 connects the first common terminal 121 to the first switching terminal 123, and connects the second common terminal 122 to the second switching terminal 124 to form a first transmission path.

[0048] In the first plugging state, the first auxiliary signal terminal 131 outputs the second identification signal, and the second auxiliary signal terminal 132 outputs the first identification signal.

[0049] Exemplarily, in the first plug-in state, the switching switch 120 connects the first common terminal 121 to the first switching terminal 123, and connects the second common terminal 122 to the second switching terminal 124, thereby forming a first transmission path for the first common terminal 121, the second common terminal 122, the first switching terminal 123 and the second switching terminal 124. On this basis, the second identification signal is transmitted to the first identification signal terminal 111 of the control chip 110 via the first common terminal 121 and the first switching terminal 123 in sequence. At the same time, the first identification signal is transmitted to the second identification signal terminal 112 of the control chip 110 via the second common terminal 122 and the second switching terminal 124 in sequence, so as to respectively identify the second identification signal and the first identification signal through the first identification signal terminal 111 and the second identification signal terminal 112.

[0050] In some embodiments, Figure 3 This is a structural diagram of another interface circuit provided by an embodiment of the present disclosure, corresponding to a structural diagram in a reverse insertion scenario. Figure 1 and Figure 2 Based on Figure 3 The switching switch 120 also includes a third switching terminal 125 and a fourth switching terminal 126; the third switching terminal 125 is connected to the first auxiliary signal terminal 131; the fourth switching terminal 126 is connected to the second auxiliary signal terminal 132; in the second plug-in state, the switching switch 120 connects the first common terminal 121 to the third switching terminal 125, and connects the second common terminal 122 to the fourth switching terminal 126 to form a second transmission path.

[0051] In the second plugging state, the first auxiliary signal terminal 131 outputs a first identification signal, and the second auxiliary signal terminal 132 outputs a second identification signal.

[0052] Exemplarily, in the second plug-in state, the switching switch 120 connects the first common terminal 121 to the third switching terminal 125, and the second common terminal 122 to the fourth switching terminal 126, thereby forming a second transmission path for the first common terminal 121, the second common terminal 122, the third switching terminal 125 and the fourth switching terminal 126. On this basis, the first identification signal is transmitted to the second identification signal terminal 112 of the control chip 110 via the first common terminal 121 and the third switching terminal 125 in sequence. At the same time, the second identification signal is transmitted to the first identification signal terminal 111 of the control chip 110 via the second common terminal 122 and the fourth switching terminal 126 in sequence, so as to identify the second identification signal and the first identification signal respectively through the first identification signal terminal 111 and the second identification signal terminal 112.

[0053] For the forward plug-in state and the reverse plug-in state, for example, the prior art solution can only unilaterally identify the Type-C interface for screen projection. Similarly, taking the first identification signal terminal 111 of the control chip 110 being used to identify the second identification signal, and the second identification signal terminal 112 being used to identify the first identification signal as an example, in the prior art, in the forward plug-in state, the second identification signal is usually directly input to the first identification signal terminal 111, and the first identification signal is usually directly input to the second identification signal terminal 112; while in the reverse plug-in state, the first identification signal will be directly input to the first identification signal terminal 111, and the second identification signal will be directly input to the second identification signal terminal 112, so that in the reverse plug-in state, the first identification signal terminal 111 and the second identification signal terminal 112 cannot respectively identify the second identification signal and the first identification signal, resulting in the prior art solution being unable to support screen projection in the reverse plug-in scenario.

[0054] In this regard, the embodiment of the present disclosure transmits the first identification signal and the second identification signal through the first transmission path in the normal plugging state, and transmits the first identification signal and the second identification signal through the second transmission path in the reverse plugging state, thereby ensuring that the first identification signal terminal 111 and the second identification signal terminal 112 can respectively identify the second identification signal and the first identification signal in different plugging states, thereby facilitating the realization of screen projection scenarios in different plugging states, and solving the problem that the existing technical solution cannot support screen projection in reverse plugging scenarios.

[0055] In some embodiments, Figure 1 Based on this, continue to refer to Figure 2 and Figure 3 The switching switch 120 also includes a first controlled terminal 127 and a second controlled terminal 128; the control chip 110 also includes a control terminal 113; the first controlled terminal 127 and the second controlled terminal 128 are connected to the control terminal 113; the first controlled terminal 127 and the second controlled terminal 128 are controlled to form a low potential in the first plug-in state to select the first transmission path, or are controlled to form a high potential in the second plug-in state to select the second transmission path.

[0056] The control terminal 113 is used to control the first controlled terminal 127 and the second controlled terminal 128 to form a low potential or a high potential. For example, taking the first plugging state as the positive plugging state and the second plugging state as the reverse plugging state as an example, in the first plugging state, the first controlled terminal 127 and the second controlled terminal 128 both form a low potential, and then the switch 120 forms a first transmission path, and conversely, in the second plugging state, the first controlled terminal 127 and the second controlled terminal 128 both form a high potential, and then the switch 120 forms a second transmission path.

[0057] It should be noted that the control terminal 113 can further control the potential of the first controlled terminal 127 and the second controlled terminal 128 by sending a level control signal to the first controlled terminal 127 and the second controlled terminal 128. Exemplarily, if the control chip 110 is a SOC chip, the control terminal 113 can be a DP_SEL pin, and accordingly, the DP_SEL pin can send a level control signal such as a DP_SEL signal, specifically: when the DP_SEL signal is a low-level control signal, the first controlled terminal 127 and the second controlled terminal 128 are controlled to form a low potential; when the DP_SEL signal is a high-level control signal, the first controlled terminal 127 and the second controlled terminal 128 are controlled to form a high potential.

[0058] In some embodiments, Figure 1 Based on this, continue to refer to Figure 2 and Figure 3 , the switch 120 is a dual-way single-pole double-throw switch.

[0059] Exemplarily, in combination with the corresponding pins of the switching switch 120 described above, the first common terminal 121 may be a D- pin, the second common terminal 122 may be a D+ pin, the first switching terminal 123 may be a D1- pin, the second switching terminal 124 may be a D1+ pin, the third switching terminal 125 may be a D2- pin, the fourth switching terminal 126 may be a D2+ pin, the first controlled terminal 127 may be a SEL1 pin, and the second controlled terminal 128 may be a SEL2 pin; in addition, the dual-way single-pole double-throw switch may also include other pins, such as a ground pin (GND pin), a power pin (VCC pin), etc., which are not limited here.

[0060] It is not difficult to understand that the two-way single-pole double-throw switch is a switching switch used to provide a first transmission path and a second transmission path to selectively form a first transmission path or a second transmission path based on different plug-in states. Any type of two-way single-pole double-throw switch known to those skilled in the art can be selected and is not limited here.

[0061] In this way, the embodiment of the present disclosure utilizes a dual-way single-pole double-throw switch to form a first transmission path or a second transmission path, which can not only further realize screen projection scenarios in different plug-in states, but also has a simple structure and reduces the overall hardware cost.

[0062] In some embodiments, Figure 1 On the basis of, the first identification signal terminal 111 and the second identification signal terminal 112 are respectively the differential negative signal port and the differential positive signal port of the DP auxiliary channel.

[0063] Among them, the DP auxiliary channel (AUX Channel) is an independent bidirectional transmission auxiliary channel in the DP interface, which usually adopts an AC-coupled differential transmission method, specifically a bidirectional half-duplex transmission channel. It should be noted that the DP auxiliary channel is used to transmit the projection handshake protocol. Preferably, in the embodiment of the present disclosure, the DP auxiliary channel specifically includes a first transmission path and a second transmission path, and the first transmission path and the second transmission path are well coupled.

[0064] Exemplarily, the first identification signal and the second identification signal may be differential signals with the same amplitude but opposite phases. Correspondingly, for differential signal transmission, the differential signal may be received by two ports with opposite polarities, such as: the first identification signal terminal 111 as a differential positive signal port, and the second identification signal terminal 112 as a differential negative signal port.

[0065] In some embodiments, Figure 1 Based on this, continue to refer to Figure 2 and Figure 3 The switch 120 further includes a first enable terminal 129; the control chip 110 further includes a second enable terminal 114; the first enable terminal 129 is connected to the second enable terminal 114; the second enable terminal 114 is used to control the first enable terminal 129 to form a low potential based on the first plug-in state or the second plug-in state.

[0066] The potential of the first enable terminal 129 determines whether the switch 120 can work, specifically including: when the first enable terminal 129 is at a low potential, the switch 120 can work; conversely, when the first enable terminal 129 is at a high potential, the switch 120 cannot work. Exemplarily, the first enable terminal 129 can be an OEB pin, and the second enable terminal 114 can be an ENABLE pin.

[0067] Specifically, when the preset interface 130 is plugged into other interfaces to form a first plug-in state (i.e., a plug-in state), it indicates that the switching switch 120 needs to start working. In response, the second enabling terminal 114 controls the first enabling terminal 129 to form a low potential, and the first controlled terminal 127 and the second controlled terminal 128 are controlled to form a low potential, so that the switching switch 120 forms a first transmission path.

[0068] Correspondingly, when the preset interface 130 is plugged into other interfaces to form a second plug-in state (i.e., a reverse plug-in state), it indicates that the switching switch 120 needs to start working. Similarly, the second enabling terminal 114 controls the first enabling terminal 129 to form a low potential, and the first controlled terminal 127 and the second controlled terminal 128 are controlled to form a high potential, so that the switching switch 120 forms a second transmission path.

[0069] In combination with the corresponding pins of the dual-way single-pole double-throw switch described above, illustratively, Table 1 is a truth table for the dual-way single-pole double-throw switch provided in an embodiment of the present disclosure. As shown in Table 1, the table shows the corresponding relationship between the first enabling terminal 129, the first controlled terminal 127, and the second controlled terminal 128 at the corresponding potential and the transmission path.

[0070] Table 1 Truth table for dual-channel single-pole double-throw switch

[0071] First enable terminal The first controlled terminal The second controlled terminal Transmission Path H - - - L L L D- to D1-, D+ to D1+ L L H D- to D1-, D+ to D2+ L H L D- to D2-, D+ to D1+ L H H D- to D2-, D+ to D2+

[0072] Specifically, in combination with Table 1, H represents a high potential, L represents a low potential, D- represents a first common terminal, D1- represents a first switching terminal, D2- represents a third switching terminal, D+ represents a second common terminal, D1+ represents a second switching terminal, and D2+ represents a fourth switching terminal; when the first enabling terminal, the first controlled terminal, and the second controlled terminal are all at a low potential, the corresponding transmission path is the first transmission path; when the first enabling terminal is at a low potential, and the first controlled terminal and the second controlled terminal are both at a high potential, the corresponding transmission path is the second transmission path, and the relevant contents of the first transmission path and the second transmission path in the above text can be referred to for understanding, which will not be repeated here.

[0073] On the basis of the above implementation manner, the embodiment of the present disclosure further provides a terminal device, comprising any one of the interface circuits provided in the above embodiments.

[0074] Exemplarily, the terminal device includes but is not limited to a mobile phone, a tablet computer, and a laptop computer, and may also be other types of terminal devices known to those skilled in the art, which are not limited here.

[0075] The embodiments of the present disclosure also provide a screen projection system, including an interface conversion cable, a screen projection device, and the terminal device provided in the above embodiments, which has corresponding beneficial effects.

[0076] In some embodiments, the terminal device is connected to the screen projection device via an interface conversion cable.

[0077] It is not difficult to understand that the pre-set interface in the terminal device and the related interface in the projection device are of different types. In this regard, in order to solve the problem of different interface types, it is necessary to use an interface conversion cable with the above two interfaces to connect the terminal device and the projection device respectively. For example: the pre-set interface in the terminal device is plugged into the interface at one end of the interface conversion cable, and the related interface in the projection device is plugged into the interface at the other end of the interface conversion cable, wherein: the interface at one end of the interface conversion cable is the same type as the pre-set interface in the terminal device, and the interface at the other end of the interface conversion cable is the same type as the related interface in the projection device. Such connection ensures that the terminal device can project the screen through the projection device.

[0078] Specifically, when the control chip in the terminal device recognizes that the projection device supports projection, the projection device will receive audio data, video data, etc. transmitted by the terminal device, so that the corresponding data of the terminal device can be projected through the projection device. Exemplarily, the projection device can be a high-definition television, a projector, or other types of devices with projection functions known to those skilled in the art, which are not limited here.

[0079] In some embodiments, the interface conversion cable is a Type-C to DP interface cable.

[0080] Among them, the Type-C to DP interface cable includes a Type-C interface and a DP interface. Specifically, when the pre-set interface in the terminal device is a Type-C interface, and the relevant interface in the projection device is a DP interface, the pre-set interface is plugged into the Type-C interface in the Type-C to DP interface cable, and the relevant interface in the projection device is plugged into the DP interface in the Type-C to DP interface cable, so as to achieve matching plug-in of the above corresponding interfaces.

[0081] It should be noted that, in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0082] The above description is only a specific embodiment of the present disclosure, so that those skilled in the art can understand or implement the present disclosure. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present disclosure. Therefore, the present disclosure will not be limited to the embodiments described herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An interface circuit, characterized in that: include: A control chip, a switch and a preset interface; the control chip includes a first identification signal terminal and a second identification signal terminal, and the preset interface includes a first auxiliary signal terminal and a second auxiliary signal terminal; The control chip controls the switch to form a first transmission path in a first plug-in state and a second transmission path in a second plug-in state; wherein, in the first transmission path, the first auxiliary signal end is connected to the first identification signal end and the second auxiliary signal end is connected to the second identification signal end; In the second transmission path, the first auxiliary signal terminal is connected to the second identification signal terminal and the second auxiliary signal terminal is connected to the first identification signal terminal.

2. The interface circuit according to claim 1, characterized in that: The switch comprises a first common terminal, a second common terminal, a first switching terminal and a second switching terminal; The first switching end is connected to the first identification signal end; the second switching end is connected to the second identification signal end; The first common end is connected to the first auxiliary signal end, and the second common end is connected to the second auxiliary signal end; in the first plug-in state, the switching switch connects the first common end to the first switching end, and connects the second common end to the second switching end to form the first transmission path.

3. The interface circuit according to claim 2, characterized in that: The switch further includes a third switch terminal and a fourth switch terminal; The third switching end is connected to the first auxiliary signal end; the fourth switching end is connected to the second auxiliary signal end; In the second plug-in state, the switch connects the first common end to the third switch end, and connects the second common end to the fourth switch end, so as to form the second transmission path.

4. The interface circuit according to claim 3, characterized in that: The switching switch further includes a first controlled end and a second controlled end; the control chip further includes a control end; The first controlled end and the second controlled end are connected to the control end; The first controlled terminal and the second controlled terminal are controlled to form a low potential in the first plug-in state to select the first transmission path, or are controlled to form a high potential in the second plug-in state to select the second transmission path.

5. The interface circuit according to claim 4, characterized in that: The switching switch is a dual-channel single-pole double-throw switch.

6. The interface circuit according to claim 1, characterized in that: The first identification signal terminal and the second identification signal terminal are respectively a differential negative signal port and a differential positive signal port of the DP auxiliary channel.

7. The interface circuit according to claim 1, characterized in that: The switching switch further includes a first enabling terminal; the control chip further includes a second enabling terminal; The first enabling terminal is connected to the second enabling terminal; The second enable terminal is used to control the first enable terminal to form a low potential based on the first plugging state or the second plugging state.

8. A terminal device, characterized in that: The invention comprises an interface circuit as claimed in any one of claims 1 to 7.

9. A screen projection system, characterized in that: It comprises an interface conversion cable, a screen projection device and the terminal device as claimed in claim 8; The terminal device is connected to the screen projection device via the interface conversion cable.

10. The screen projection system according to claim 9, characterized in that: The interface conversion cable is a Type-C to DP interface cable.

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