Terminal equipment

Abstract

The embodiment of the utility model discloses terminal equipment, a processor comprises a first universal asynchronous receiver / transmitter end, a signal switch control circuit comprises a keyboard in-place state detection end, a first keyboard data transmission end and a second universal asynchronous receiver / transmitter end, and a keyboard connector comprises a keyboard state output end and a second keyboard data transmission end. The keyboard in-place state detection end is connected with the keyboard state output end; the first keyboard data transmission end is connected with the second keyboard data transmission end, and the first universal asynchronous receiver-transmitter end is connected with the second universal asynchronous receiver-transmitter end; wherein the signal switch control circuit is used for connecting or disconnecting the first keyboard data transmission end and the second universal asynchronous transceiver end based on the keyboard in-place state. According to the scheme, the terminal equipment can realize the communication function between the tablet personal computer and the Pogo keyboard without additionally adding related hardware, so that the cost is reduced, and differentiated control production can be more easily carried out.

Description

Technical Field

[0001] The present disclosure relates to the field of electronic technology, and in particular to a terminal device. Background Art

[0002] At present, in order to allow users to use tablet computers with keyboards in various application scenarios, Pogo pin interfaces are generally reserved on the outside of tablet computers and supported by Pogo keyboards. In order to realize the communication function between tablet computers and Pogo keyboards, a corresponding single-chip microcomputer needs to be added to the motherboard of the tablet computer, and the two-way communication and bridge device between the tablet computer and Pogo keyboard are realized mainly through the universal asynchronous receiver and transmitter of the single-chip microcomputer.

[0003] Therefore, regardless of whether the user needs to support the Pogo keyboard, the tablet computer has default hardware such as a microcontroller added to it, increasing the cost of the motherboard patch materials. If the tablet computer is produced based on whether it supports or not the Pogo keyboard, the complexity of the structure of the microcontroller and the peripheral circuits will result in more material changes and greater difficulty. Utility Model Content

[0004] In order to solve the above technical problem or at least partially solve the above technical problem, the present disclosure provides a terminal device.

[0005] In a first aspect, the present application provides a terminal device, including a processor, a signal switch control circuit, and a keyboard connector;

[0006] The processor includes a first universal asynchronous receiver / transmitter terminal, the signal switch control circuit includes a keyboard in-position state detection terminal, a first keyboard data transmission terminal and a second universal asynchronous receiver / transmitter terminal, and the keyboard connector includes a keyboard state output terminal and a second keyboard data transmission terminal;

[0007] The keyboard in-place state detection terminal is connected to the keyboard state output terminal and is used to detect the keyboard in-place state;

[0008] The first keyboard data transmission end is connected to the second keyboard data transmission end for transmitting keyboard data, and the first universal asynchronous receiver and transmitter end is connected to the second universal asynchronous receiver and transmitter end for transmitting the keyboard data;

[0009] Wherein, the signal switch control circuit is used for connecting or disconnecting the first keyboard data transmission terminal and the second universal asynchronous receiver / transmitter terminal based on the keyboard in-position state.

[0010] Optionally, the signal switch control circuit further includes a state detection module and a data transmission control module;

[0011] The control end of the state detection module is connected to the keyboard in-position state detection end, the output end of the state detection module is connected to the control end of the data transmission control module, the first end of the data transmission control module is connected to the first keyboard data transmission end, and the second end of the data transmission control module is connected to the second universal asynchronous receiver and transmitter end;

[0012] The state detection module is used to control the connection or disconnection between the first end and the second end of the data transmission control module based on the keyboard in-place state.

[0013] Optionally, the state detection module includes a first switch tube;

[0014] The control end of the first switch tube serves as the control end of the state detection module, the first end of the first switch tube serves as the output end of the state detection module and is connected to a power supply end, and the second end of the first switch tube is grounded.

[0015] Optionally, the state detection module further includes a first resistor;

[0016] The first resistor is connected between the keyboard presence status detection terminal and the control terminal of the first switch tube.

[0017] Optionally, the state detection module further includes a second resistor;

[0018] The second resistor is connected between the power supply terminal and the first terminal of the first switch tube.

[0019] Optionally, the data transmission control module includes a second switch tube;

[0020] The control end of the second switch tube serves as the control end of the data transmission control module, the first end of the second switch tube serves as the first end of the data transmission control module, and the second end of the second switch tube serves as the second end of the data transmission control module.

[0021] Optionally, the data transmission control module further includes a third resistor and a fourth resistor;

[0022] The third resistor is connected between the first keyboard data transmission end and the first end of the second switch tube;

[0023] The fourth resistor is connected between the second end of the second switch tube and the second universal asynchronous receiver transmitter end.

[0024] Optionally, the first universal asynchronous receiver / transmitter end includes a first signal transmitting end and a first signal receiving end;

[0025] The second universal asynchronous receiver / transmitter terminal comprises a second signal transmitting terminal, a second signal receiving terminal and a first universal input / output terminal;

[0026] The first signal transmitting end is connected to the second signal receiving end, the first signal receiving end is connected to the second signal transmitting end, and the first general input and output end is connected to the first signal transmitting end and the first signal receiving end.

[0027] Optionally, the signal switch control circuit further includes a fifth resistor and a sixth resistor;

[0028] The fifth resistor is connected between the second signal receiving end and the second signal sending end, and the sixth resistor is connected between the first general input and output end and the second signal sending end.

[0029] Optionally, a linear voltage-regulated power supply is also included;

[0030] The processor further includes a second general purpose input and output terminal, and the keyboard connector further includes a power supply terminal;

[0031] One end of the linear regulated power supply is connected to the second universal input and output end, and the other end of the linear regulated power supply is connected to the power supply end of the keyboard connector.

[0032] Compared with the prior art, the technical solution provided by the embodiments of the present application has the following advantages:

[0033] The present solution provides a terminal device, which internally connects the keyboard in-position state detection terminal of the signal switch control circuit with the keyboard status output terminal of the keyboard connector to detect the keyboard in-position state; the first keyboard data transmission terminal of the signal switch control circuit is connected to the second keyboard data transmission terminal of the keyboard connector, and the first universal asynchronous receiver and transmitter terminal of the processor is connected to the second universal asynchronous receiver and transmitter terminal of the signal switch control circuit, so as to transmit keyboard data; wherein, the signal switch control circuit can connect or disconnect the first keyboard data transmission terminal and the second universal asynchronous receiver and transmitter terminal based on the keyboard in-position state. Therefore, the present solution provides a terminal device that can realize the communication function between the tablet computer and the Pogo keyboard without adding additional hardware such as a single-chip microcomputer to the internal motherboard of the tablet computer supporting the Pogo keyboard, thereby reducing the cost of the motherboard patch materials and saving the central processing unit resources; and the structure of the signal switch control circuit proposed in the present application is simple, such as when the production of the corresponding tablet computer is to be differentiated according to whether the Pogo keyboard is supported or not, the materials that need to be changed will be less, and the difficulty will also be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] 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.

[0035] 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.

[0036] Figure 1 A schematic diagram of the structure of a terminal device provided by the prior art;

[0037] Figure 2 A schematic diagram of the structure of a terminal device provided in an embodiment of the present application;

[0038] Figure 3 A schematic diagram of the structure of a signal switch control circuit provided in an embodiment of the present application;

[0039] Figure 4 A circuit diagram of a signal switch control circuit provided in an embodiment of the present application;

[0040] Figure 5 A schematic diagram of the shutdown process of the signal switch control circuit provided in an embodiment of the present application;

[0041] Figure 6 A schematic diagram of the conduction process of the signal switch control circuit provided in an embodiment of the present application. DETAILED DESCRIPTION

[0042] 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.

[0043] 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.

[0044] Currently, in order to allow users to conveniently use a keyboard with a tablet in a variety of application scenarios, a Pogo pin interface is generally reserved on the outside of the tablet and is paired with a Pogo keyboard.

[0045] Before introducing the terminal device proposed in this solution, a method used in the prior art to realize the communication function between a tablet computer and a Pogo keyboard is first introduced so that it is easier to understand this solution later.

[0046] In the prior art, in order to realize the communication function between the tablet computer and the Pogo keyboard, a corresponding single-chip microcomputer needs to be added to the motherboard of the tablet computer, and the two-way communication and the role of the bridge device between the tablet computer and the Pogo keyboard are realized mainly through the universal asynchronous receiver and transmitter of the single-chip microcomputer. The following article will better describe the solution and existing problems of the prior art by analyzing the structural diagram of a terminal device provided by the prior art.

[0047] For example, Figure 1 The following is a schematic diagram of the structure of a terminal device provided by the prior art. Figure 1 As shown, a terminal device provided by the prior art includes a keyboard connector 101 , a linear voltage-regulated power supply 102 , a single-chip microcomputer 103 and a processor 104 .

[0048] The following text will introduce the ports of each module of a terminal device provided by the prior art.

[0049] The single-chip computer 103 includes a general purpose input and output terminal (GPIO), a serial communication bus (I2C), and a universal asynchronous receiver and transmitter terminal (UART); the processor 104 includes a signal transceiver terminal, a serial data line terminal (SDA), and a serial clock line terminal (SCL); the keyboard connector 101 includes a keyboard data transmission terminal and a power supply terminal.

[0050] The following text will introduce the connection relationship and functions between various modules of a terminal device provided by the prior art.

[0051] The general input and output terminals of the single-chip microcomputer 103 are connected to the signal transceiver terminals of the processor 104 for transmitting interrupt requests or other request information; the serial communication buses of the single-chip microcomputer 103 are connected to the serial data line terminals and serial clock line terminals of the processor 104 for transmitting data signals; the general input and output terminals of the single-chip microcomputer 103 are also connected to one end of the linear regulated power supply 102, and the other end of the linear regulated power supply 102 is connected to the power supply terminal of the keyboard connector 101.

[0052] The universal asynchronous receiver and transmitter end of the single-chip microcomputer 103 is connected to the keyboard data transmission end of the keyboard connector 101. When the keyboard connector 101 of the terminal device is connected to the Pogo keyboard, the universal asynchronous receiver and transmitter implemented in the single-chip microcomputer can perform single-line two-way communication. The single-chip microcomputer 103 acts as an intermediate bridge device between the processor 104 and the keyboard connector 101, and realizes two-way communication between the terminal device and the Pogo keyboard. The single-chip microcomputer can determine whether the Pogo keyboard is connected, thereby controlling the connection and disconnection between the processor 104 and the keyboard connector 101.

[0053] Therefore, the problem in the prior art is that when these terminal devices, such as tablet computers, are actually produced, regardless of whether the user needs to support the Pogo keyboard, the microcontroller and other related hardware are added by default, which increases the cost of the motherboard patch materials. If the corresponding tablet computers are produced according to whether they support the Pogo keyboard or not, the structure of the microcontroller and the peripheral circuits is complex, which makes it more difficult to change the materials.

[0054] In order to solve the above technical problems, an embodiment of the present application provides a terminal device, and the terminal device provided by the present application will be introduced in detail below.

[0055] For example, Figure 2 A schematic diagram of the structure of a terminal device provided in an embodiment of the present application. Figure 2 As shown, the terminal device provided in the embodiment of the present application includes a keyboard connector 201, a linear voltage-regulated power supply 202, a signal switch control circuit 203 and a processor 204.

[0056] The ports of each module of a terminal device provided in an embodiment of the present application will be introduced below.

[0057] The keyboard connector 201 includes a keyboard status output terminal, a second keyboard data transmission terminal and a power supply terminal;

[0058] The signal switch control circuit 203 includes a keyboard in-position state detection terminal, a first keyboard data transmission terminal and a second universal asynchronous receiver / transmitter terminal; the processor 204 includes a first universal asynchronous receiver / transmitter terminal and a second universal input / output terminal.

[0059] The following text will introduce the connection relationship and functions between the various modules of a terminal device provided in an embodiment of the present application.

[0060] The keyboard in-position state detection terminal of the signal switch control circuit 203 is connected to the keyboard state output terminal of the keyboard connector 201 for detecting the keyboard in-position state;

[0061] One end of the linear regulated power supply 202 is connected to the second general input / output terminal of the processor 204 , and the other end of the linear regulated power supply 202 is connected to the power supply terminal of the keyboard connector 201 .

[0062] The first keyboard data transmission terminal of the signal switch control circuit 203 is connected to the second keyboard data transmission terminal of the keyboard connector 201 for transmitting keyboard data; the first universal asynchronous receiver and transmitter terminal of the processor 204 is connected to the second universal asynchronous receiver and transmitter terminal of the signal switch control circuit 203 for transmitting keyboard data.

[0063] The signal switch control circuit 203 is used to connect or disconnect the first keyboard data transmission terminal and the second universal asynchronous receiver / transmitter terminal based on the keyboard in-position state.

[0064] The working principle of a terminal device provided in an embodiment of the present application is: when the terminal device is not connected to a keyboard, the keyboard status output end of the keyboard connector 201 of the terminal device will transmit a signal to the keyboard in-place status detection end of the signal switch control circuit 203, so that the detection result of the keyboard in-place status detection end is that there is no keyboard connection. At this time, the signal switch control circuit 203 will disconnect the communication connection between its first keyboard data transmission end and the second universal asynchronous receiver and transmitter end.

[0065] When the terminal device is connected to the keyboard, the keyboard status output end of the keyboard connector 201 of the terminal device will transmit a signal to the keyboard in-place status detection end of the signal switch control circuit 203, so that the detection result of the keyboard in-place status detection end is that there is a keyboard connection. At this time, the signal switch control circuit 203 will connect the communication connection between its first keyboard data transmission end and the second universal asynchronous receiver and transmitter end.

[0066] The present solution provides a terminal device, which internally connects the keyboard in-position state detection end of the signal switch control circuit with the keyboard state output end of the keyboard connector to realize the function of detecting the keyboard in-position state; the first keyboard data transmission end of the signal switch control circuit is connected to the second keyboard data transmission end of the keyboard connector, and the first universal asynchronous receiver and transmitter end of the processor is connected to the second universal asynchronous receiver and transmitter end of the signal switch control circuit, so as to realize the transmission of keyboard data; wherein, the signal switch control circuit can realize the connection or disconnection of the first keyboard data transmission end and the second universal asynchronous receiver and transmitter end based on the keyboard in-position state. Therefore, a terminal device provided by the embodiment of the present application can mainly detect the connection state of the keyboard through the internal signal switch control circuit to control the connection and disconnection between the terminal device and the keyboard; and the communication function between the tablet computer and the Pogo keyboard can be realized without adding related single-chip microcomputer and other hardware on the internal motherboard of the tablet computer supporting the Pogo keyboard, which reduces the cost of the motherboard patch material and saves the central processing unit resources; and the structure of the signal switch control circuit proposed in the present application is simple, such as when the corresponding tablet computer is to be produced according to the support or non-support of the Pogo keyboard to differentiate the control, the materials that need to be changed will be less, and the difficulty will also be reduced.

[0067] In some embodiments, the internal structure of the tablet computer is made into the internal structure of a terminal device provided in the embodiments of this application, and the keyboard can be a Pogo keyboard. Since the metal point of the Pogo keyboard data transmission end on the tablet computer keyboard connector is exposed on the surface of the tablet computer, when the Pogo keyboard is not connected, the internal signal transceiver end of the tablet computer will still present a high level voltage of 1.8V when it is not working, which will cause the Pogo keyboard data transmission end of the tablet computer to have a voltage of 1.8V, which may introduce the risk of electrostatic discharge to damage the internal circuit and generate leakage current.

[0068] By using a terminal device structure provided in an embodiment of the present application, there is no need to add additional hardware such as a single-chip microcomputer, and the risk of introducing electrostatic discharge to damage the internal circuit and generate leakage current can be eliminated; and the communication function between the tablet computer and the Pogo keyboard can be realized, reducing the cost of motherboard patch materials and saving central processing unit resources; and the signal switch control circuit proposed in the present application has a simple structure. If the production of corresponding tablet computers is to be differentiated according to whether the Pogo keyboard is supported or not, fewer materials need to be changed and the difficulty will be reduced.

[0069] The main structure of a terminal device provided in an embodiment of the present application has been introduced above. The core part for realizing its functions is the signal switch control circuit. Therefore, the structure of the signal switch control circuit of this solution will be introduced in detail below.

[0070] For example, Figure 3 This is a schematic diagram of the signal switch control circuit structure provided in the embodiment of the present application. Figure 3 As shown, the signal switch control circuit provided in the embodiment of the present application includes a state detection module 2301 and a data transmission control module 2302.

[0071] The structure of the signal switch control circuit provided in the embodiment of the present application is: the control end of the status detection module 2301 is connected to the keyboard in-position status detection end, the output end of the status detection module 2301 is connected to the control end of the data transmission control module 2302, the first end of the data transmission control module 2302 is connected to the first keyboard data transmission end, and the second end of the data transmission control module 2302 is connected to the second universal asynchronous receiver and transmitter end.

[0072] The working process of the signal switch control circuit provided in the embodiment of the present application is: the keyboard in-place state is detected by the state detection module 2301, so as to control the connection or disconnection between the first end and the second end of the data transmission control module 2302. When the terminal device is not connected to the keyboard, the detection result of the keyboard in-place state detection end is that there is no keyboard connection, and at this time, the communication connection between the first end and the second end of the data transmission control module 2302 is controlled to be disconnected; when the terminal device is connected to the keyboard, the detection result of the keyboard in-place state detection end is that there is a keyboard connection, and at this time, the communication connection between the first end and the second end of the data transmission control module 2302 is controlled to be connected.

[0073] Therefore, the signal switch control circuit provided in the embodiment of the present application can replace the single-chip microcomputer in the prior art, and can realize the communication function between the terminal device and the keyboard without adding additional hardware such as the related single-chip microcomputer, thereby reducing the cost of the motherboard patch materials and saving central processing unit resources.

[0074] The specific circuit structure of the signal switch control circuit provided in the embodiment of the present application will be introduced below.

[0075] For example, Figure 4 Schematic diagram of a signal switch control circuit provided in an embodiment of the present application. Figure 4 As shown, the specific circuit structures of the state detection module 401 and the data transmission control module 402 in the signal switch control circuit provided in the embodiment of the present application will be introduced below.

[0076] The state detection module 401 includes a first switch tube Q1, a control end of the first switch tube Q1 serves as a control end of the state detection module 401, a first end of the first switch tube Q1 serves as an output end of the state detection module 401 and is connected to a power supply end, and a second end of the first switch tube Q1 is grounded.

[0077] In a specific implementation, the first switch tube Q1 is an NPN transistor, and a MOS tube or other electronic devices that can play the same role can also be used; the output end of the state detection module 401 can be the output end of the Hall chip; and its power supply end can be a 3.3V power supply.

[0078] In some embodiments, the state detection module 401 further includes a first resistor R1; the first resistor R1 is connected between the keyboard presence state detection terminal 401 and the control terminal of the first switch tube Q1 to play a role of current limiting.

[0079] In some embodiments, the state detection module 401 further includes a second resistor R2; the second resistor R2 is connected between the power supply terminal and the first end of the first switch tube Q1, and plays a role in pulling up the potential when there is actual need.

[0080] The data transmission control module 402 in the signal switch control circuit provided in the embodiment of the present application further includes a second switch tube Q2. The control end of the second switch tube Q2 serves as the control end of the data transmission control module 402, the first end of the second switch tube Q2 serves as the first end of the data transmission control module 402, and the second end of the second switch tube Q2 serves as the second end of the data transmission control module 402.

[0081] In a specific implementation, the second switch tube Q2 is an NPN transistor, and a MOS tube or other electronic devices that can play the same role can also be used; the first end of the data transmission control module 402 is the Pogo keyboard data transmission end; the second end of the data transmission control module 402 is the universal asynchronous receiver and transmitter transmitting end.

[0082] In some embodiments, the data transmission control module 402 further includes a third resistor R3 and a fourth resistor R4; the third resistor R3 is connected between the first keyboard data transmission terminal and the first terminal of the second switch tube; the fourth resistor R4 is connected between the second terminal of the second switch tube and the second universal asynchronous receiver transmitter terminal. The third resistor R3 and the fourth resistor R4 are used to prevent the risk of electrostatic discharge (ESD) and over-electrical stress (EOS).

[0083] The first universal asynchronous receiver / transmitter end in the signal switch control circuit provided in the embodiment of the present application includes a first signal transmitting end and a first signal receiving end; the second universal asynchronous receiver / transmitter end includes a second signal transmitting end, a second signal receiving end and a first universal input / output end;

[0084] The first signal transmitting end is connected to the second signal receiving end, the first signal receiving end is connected to the second signal transmitting end, and the first universal input and output end is connected to the first signal transmitting end and the first signal receiving end.

[0085] In a specific implementation, the first signal sending end of the first universal asynchronous receiver / transmitter end may be a universal asynchronous receiver / transmitter sending end, and the first signal receiving end of the first universal asynchronous receiver / transmitter end may be a universal asynchronous receiver / transmitter receiving end; the second signal sending end of the second universal asynchronous receiver / transmitter end may be a universal asynchronous receiver / transmitter sending end, and the second signal receiving end of the second universal asynchronous receiver / transmitter end may be a universal asynchronous receiver / transmitter receiving end.

[0086] In some embodiments, the signal switch control circuit further includes a fifth resistor R5 and a sixth resistor R6; the fifth resistor R5 is connected between the second signal receiving terminal and the second signal sending terminal, and the sixth resistor R6 is connected between the first universal input and output terminal and the second signal sending terminal. The fifth resistor R5 and the sixth resistor R6 act as jumper resistors, and resistors with appropriate resistance values ​​can be selected according to actual needs to make the circuit more flexible.

[0087] The above describes the circuit structure of the signal switch control circuit provided in the embodiment of the present application. The following describes the working process and principle of the signal switch control circuit provided in the embodiment of the present application.

[0088] For example, Figure 5 Schematic diagram of the signal switch control circuit shutdown process provided in the embodiment of the present application. Figure 5 As shown, the shutdown process of the signal switch control circuit provided in the embodiment of the present application is: when the terminal device is not connected to the keyboard, the keyboard status detection end in the terminal device is at a high level, so that the first switch tube Q1 is in an on state, and the first end of the first switch tube Q1 is in a low potential state, causing the potential of the control end of the second switch tube Q2 to be pulled low, and the second switch tube Q2 is in a cut-off state, isolating the signal between the first keyboard data transmission end and the second universal asynchronous receiver and transmitter end.

[0089] For example, Figure 6 This is a schematic diagram of the conduction process of the signal switch control circuit provided in the embodiment of the present application. Figure 6 As shown, the conduction process of the signal switch control circuit provided in the embodiment of the present application is: when the terminal device is connected to the keyboard, the keyboard status detection end in the terminal device is at a low level, so that the first switch tube Q1 is in a cut-off state, and the first end of the first switch tube Q1 is in a high potential state, causing the potential of the control end of the second switch tube Q2 to be pulled up, and the second switch tube Q2 is in an on state, connecting the signal between the first keyboard data transmission end and the second universal asynchronous receiver and transmitter end.

[0090] In some embodiments, the first switch tube Q1 and the second switch tube Q2 in the signal switch control circuit are both NPN transistors; the keyboard state detection end is the output end of the Hall chip; its power supply end is a 3.3V power supply; the first keyboard data transmission end is the Pogo keyboard data transmission end; the second signal transmission end is the universal asynchronous receiver transmitter transmission end. The terminal device is a tablet computer, and the keyboard is a Pogo keyboard. Therefore, the potential of the Hall chip output end will be different when the tablet computer is connected to a Pogo keyboard or not. When the tablet computer is not connected to a Pogo keyboard, the Hall chip output end will generate a high potential of 1.8V; when the tablet computer is connected to a Pogo keyboard, the Hall chip output end will become a low potential of 0V.

[0091] Therefore, when the tablet computer is not connected to the Pogo keyboard, the Hall chip output will generate a high potential of 1.8V, which makes the transistor Q1 in the on state and its collector in the low potential state, causing the base potential of the transistor Q2 to be pulled down, and the transistor Q2 is in the cut-off state, isolating the signal between the Pogo data end and the transmitting end of the universal asynchronous receiver and transmitter.

[0092] When the tablet computer is connected to the Pogo keyboard, since the output end of the Hall chip inside is a low level of 0V, the transistor Q1 is in the cut-off state and its collector is in a high potential state, causing the base potential of the transistor Q2 to be pulled up to 3.3V. The transistor Q2 is in the on state, connecting the signal between the Pogo data end and the transmitting end of the universal asynchronous receiver and transmitter.

[0093] In some embodiments, the selection criteria for each device in the signal switch control circuit are:

[0094] When the tablet computer is not connected to the Pogo keyboard, the output of the Hall chip outputs a high level of 1.8V, and the default conduction voltage of transistor Q1 is 0.7V. At this time, transistor Q1 is in the default on state, so the base input current of transistor Q1 is 0.011mA, and the calculation process is Ib=(1.8-0.7)V / 100k=0.011mA. If transistor Q1 is in the amplification state, its amplification factor is 100, then the collector current of transistor Q1 is 1.1mA, and the calculation process is IC=β*Ib=100*0.011=1.1mA.

[0095] The second resistor R2 is 10K, so ICmax = 1.8 / 10 = 0.18mA is much smaller than 1.1mA, so the transistor Q1 works in saturation mode and the output voltage is 0V. The transistor Q2 works in the cut-off state. The first resistor R1 is 100K, which effectively reduces the power consumption caused by the conduction of the transistor Q1 in the idle state.

[0096] When the tablet computer is connected to the Pogo keyboard, the third resistor R3 and the fourth resistor R4 in the signal switch control circuit are mainly used to prevent electrostatic discharge (ESD) from entering the circuit and damaging the components. At the same time, the resistance of the third resistor R3 and the fourth resistor R4 should not be too large, so as not to affect the normal communication between the tablet computer and the Pogo keyboard.

[0097] 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.

[0098] 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. A terminal device, characterized in that: including a processor, a signal switch control circuit, and a keyboard connector; The processor includes a first universal asynchronous receiver / transmitter terminal, the signal switch control circuit includes a keyboard in-position state detection terminal, a first keyboard data transmission terminal and a second universal asynchronous receiver / transmitter terminal, and the keyboard connector includes a keyboard state output terminal and a second keyboard data transmission terminal; The keyboard in-place state detection terminal is connected to the keyboard state output terminal and is used to detect the keyboard in-place state; The first keyboard data transmission end is connected to the second keyboard data transmission end for transmitting keyboard data, and the first universal asynchronous receiver and transmitter end is connected to the second universal asynchronous receiver and transmitter end for transmitting the keyboard data; Wherein, the signal switch control circuit is used for connecting or disconnecting the first keyboard data transmission terminal and the second universal asynchronous receiver / transmitter terminal based on the keyboard in-position state.

2. The terminal device according to claim 1, characterized in that: The signal switch control circuit also includes a state detection module and a data transmission control module; The control end of the state detection module is connected to the keyboard in-position state detection end, the output end of the state detection module is connected to the control end of the data transmission control module, the first end of the data transmission control module is connected to the first keyboard data transmission end, and the second end of the data transmission control module is connected to the second universal asynchronous receiver and transmitter end; The state detection module is used to control the connection or disconnection between the first end and the second end of the data transmission control module based on the keyboard in-place state.

3. The terminal device according to claim 2, characterized in that: The state detection module includes a first switch tube; The control end of the first switch tube serves as the control end of the state detection module, the first end of the first switch tube serves as the output end of the state detection module and is connected to a power supply end, and the second end of the first switch tube is grounded.

4. The terminal device according to claim 3, characterized in that: The state detection module also includes a first resistor; The first resistor is connected between the keyboard presence status detection terminal and the control terminal of the first switch tube.

5. The terminal device according to claim 3, characterized in that: The state detection module also includes a second resistor; The second resistor is connected between the power supply terminal and the first terminal of the first switch tube.

6. The terminal device according to claim 2, characterized in that: The data transmission control module includes a second switch tube; The control end of the second switch tube serves as the control end of the data transmission control module, the first end of the second switch tube serves as the first end of the data transmission control module, and the second end of the second switch tube serves as the second end of the data transmission control module.

7. The terminal device according to claim 6, characterized in that: The data transmission control module also includes a third resistor and a fourth resistor; The third resistor is connected between the first keyboard data transmission end and the first end of the second switch tube; The fourth resistor is connected between the second end of the second switch tube and the second universal asynchronous receiver transmitter end.

8. The terminal device according to claim 1, characterized in that: The first universal asynchronous receiver / transmitter end includes a first signal transmitting end and a first signal receiving end; The second universal asynchronous receiver / transmitter terminal comprises a second signal transmitting terminal, a second signal receiving terminal and a first universal input / output terminal; The first signal transmitting end is connected to the second signal receiving end, the first signal receiving end is connected to the second signal transmitting end, and the first universal input and output end is connected to the first signal transmitting end and the first signal receiving end.

9. The terminal device according to claim 8, characterized in that: The signal switch control circuit further includes a fifth resistor and a sixth resistor; The fifth resistor is connected between the second signal receiving end and the second signal sending end, and the sixth resistor is connected between the first general input and output end and the second signal sending end.

10. The terminal device according to claim 1, characterized in that: Also included is a linear regulated power supply; The processor further includes a second general purpose input and output terminal, and the keyboard connector further includes a power supply terminal; One end of the linear regulated power supply is connected to the second universal input and output end, and the other end of the linear regulated power supply is connected to the power supply end of the keyboard connector.

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