Function expansion circuit, device and computer all-in-one based on TYPE_C interface

Abstract

A function expansion circuit, device and all-in-one computer based on TYPE_C interface, wherein an interface detection circuit detects the access status of an external device to generate a connection detection signal, and transmits a screen projection signal; a control circuit generates a data selection control signal, a data transmission control signal and a selection control signal according to the connection detection signal and the screen projection signal; a data selection circuit selects and outputs original audio and video signals according to the data selection control signal; a signal conversion circuit receives and generates a differential video signal according to the original audio and video signals according to the data transmission control signal; a first signal switching circuit selects and outputs the differential video signal to a display screen for display according to the selection control signal, and a screen projection display can be performed on a computer through a double-headed Type_C line, and the interface of the external device and the computer interface are automatically switched, and the interface of the cloud server is displayed when the external device and the cloud server interact with each other, thereby meeting the user's new application function requirements and improving the practicality of the function expansion circuit.

Description

Technical Field

[0001] The present application belongs to the technical field of computer equipment, and in particular, relates to a function expansion circuit, device and all-in-one computer based on a TYPE_C interface. Background Art

[0002] At present, various all-in-one computers on the market are widely used in entertainment and office due to their features such as few connections, small space, low energy consumption, high integration, and fashionable appearance. Especially in recent years, with the strong support of the state for domestic computers, domestic all-in-one computers have also developed like mushrooms after rain. However, once the design of the all-in-one computer is completed and shipped out of the factory, most of the hardware design and software program design are fixed, and it is impossible to add processors to the all-in-one computer without limit to extend and expand the functions of the all-in-one computer based on cost and volume considerations. As a result, the all-in-one computer often runs slower and its functions do not meet the actual application requirements after a certain period of use and operation, resulting in an increase in maintenance and replacement costs. In addition, smartphone technology is also developing rapidly, with mobile phone products changing with each passing day, more and more powerful performance, and more and more rich functions. Smartphones have become an indispensable part of people's lives. However, based on the convenience of mobile products, the display screen size of mobile phones is usually small, which limits mobile phones in entertainment, office, etc. People usually project their mobile phones onto large-screen displays to obtain a wider field of view, and even achieve convenient office through interactive operations between mobile phones and large-screen devices.

[0003] If you want to project your mobile phone screen onto an all-in-one computer, there are usually two methods, one is wireless projection via WiFi sharing, and the other is wired projection via an expansion dock. Both methods can achieve projection, but in actual use, the former commonly used method requires that both the mobile phone and the all-in-one computer are connected to the same WiFi. When projecting wirelessly, the image clarity, response timeliness, and stability are related to the WiFi signal strength. In addition, WiFi wireless projection requires the support of application software on the mobile phone, usually video playback software, while office software cannot be projected, and this projection method does not support interaction between smartphones and large-screen devices. The latter commonly used method requires the use of an expansion dock with a video output interface to achieve projection, which is currently a more commonly used projection method with relatively good image stability. However, the disadvantage of this method is that it requires the all-in-one computer to support video input, while most computers only support video output.

[0004] Therefore, the traditional technical solution has the problem that the function expandability of the all-in-one computer is poor after the design is completed and leaves the factory, while the convenient office work achieved by projecting the smartphone screen onto the all-in-one computer is limited by the application software design, and the all-in-one computer needs to support video input or require the additional use of expansion hardware. Summary of the invention

[0005] The purpose of this application is to provide a function expansion circuit, device and all-in-one computer based on TYPE_C interface, aiming to solve the problem in traditional technical solutions that the function expansion of the all-in-one computer is poor after the design is completed and shipped out of the factory, and the convenient office work achieved by projecting the screen of a smartphone to the all-in-one computer is limited by the inherent application software design, and the all-in-one computer needs to support video input or require additional expansion tungsten.

[0006] A first aspect of an embodiment of the present application provides a function expansion circuit based on a TYPE_C interface, connected to a main control circuit, the function expansion circuit comprising:

[0007] An interface detection circuit is configured to detect the access status of an external device to generate a connection detection signal, and transmit a screen projection signal sent by the external device;

[0008] A control circuit connected to the interface detection circuit and configured to generate a data selection control signal, a data transmission control signal and a gating control signal according to the connection detection signal and the screen projection signal;

[0009] A data selection circuit, connected to the interface detection circuit and the control circuit, configured to select and output the original audio and video signal sent by the external device according to the data selection control signal;

[0010] a signal conversion circuit connected to the data selection circuit and the control circuit, configured to receive the original audio and video signal according to the data transmission control signal, and generate a differential video signal according to the original audio and video signal;

[0011] The first signal switching circuit is connected to the control circuit, the signal conversion circuit, the main control circuit and the display screen, and is configured to select and output the differential video signal to the display screen for display according to the selection control signal.

[0012] In one embodiment, the interface detection circuit is further configured to transmit a first USB signal sent by the external device; and the function expansion circuit based on the TYPE_C interface further includes:

[0013] A USB interface circuit configured to transmit USB signals;

[0014] A USB hub control circuit is connected to the USB interface circuit and is configured to select and output the USB signal according to an input signal;

[0015] The USB signal switching circuit is connected to the interface detection circuit, the main control circuit, the control circuit and the USB hub control circuit, and is configured to select and output the USB signal to the interface detection circuit according to the selection control signal.

[0016] In one embodiment, the function expansion circuit based on the TYPE_C interface further includes:

[0017] The input component is connected to the USB hub control circuit and is configured to generate the input signal according to user input.

[0018] In one embodiment, the function expansion circuit based on the TYPE_C interface further includes:

[0019] The second signal switching circuit is connected to the control circuit, the signal conversion circuit, the main control circuit and the key component, and is configured to select and output the key control signal output by the user operating the key component to the control circuit according to the selection control signal.

[0020] In one of the embodiments, the signal conversion circuit is further configured to receive the original audio and video signal according to the data transmission control signal, and generate a differential video signal and a backlight control signal according to the original audio and video signal;

[0021] The function expansion circuit based on the TYPE_C interface also includes:

[0022] A third signal switching circuit is connected to the control circuit, the signal conversion circuit and the main control circuit, and is configured to select and output the backlight control signal according to the selection control signal;

[0023] The backlight driving circuit is connected to the third signal switching circuit and the display screen, and is configured to generate a backlight driving signal according to the backlight control signal to drive the display screen to display the differential video signal.

[0024] In one of the embodiments, the signal conversion circuit is further configured to generate a digital audio signal based on the original audio and video signal;

[0025] The function expansion circuit based on the TYPE_C interface also includes:

[0026] an audio conversion circuit, connected to the signal conversion circuit, configured to convert the digital audio signal to generate an analog audio signal;

[0027] an audio power amplifier circuit, connected to the audio conversion circuit, and configured to amplify the analog audio signal to generate a target audio signal;

[0028] The audio signal switching circuit is connected to the audio power amplifier circuit, the control circuit, the main control circuit and the playback component, and is configured to select and output the target audio signal to the playback component for playback according to the selection control signal.

[0029] In one embodiment, the data selection circuit includes: a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a fifth capacitor and a data selection chip;

[0030] The enable terminal of the data selection chip is connected to the first end of the first resistor, the second end of the first resistor is connected to the first DC power supply terminal, the power supply voltage terminal of the data selection chip is connected to the first DC power supply terminal and the first end of the first capacitor, the second end of the first capacitor is connected to the power ground, the selection terminal of the data selection chip is connected to the first end of the sixth resistor and the first end of the seventh resistor, the second end of the sixth resistor is connected to the power ground, the second end of the seventh resistor is connected to the first DC power supply terminal, the configuration terminal of the data selection chip is connected to the first end of the eighth resistor and the first end of the ninth resistor, the second end of the eighth resistor is connected to the power ground, the second end of the ninth resistor is connected to the first DC power supply terminal, the heat dissipation ground terminal of the data selection chip is connected to the power ground, the first positive phase receiving terminal of the data selection chip is connected to the first end of the third resistor, the first negative phase receiving terminal of the data selection chip is connected to the first end of the second resistor, the second positive phase receiving terminal of the data selection chip is connected to the first end of the fifth resistor, and the second negative phase receiving terminal of the data selection chip is connected to the first end of the fourth resistor , the first positive phase transmitting end of the data selection chip is connected to the first end of the third capacitor, the first negative phase transmitting end of the data selection chip is connected to the first end of the second capacitor, the second positive phase transmitting end of the data selection chip is connected to the first end of the fifth capacitor, the second negative phase transmitting end of the data selection chip is connected to the first end of the fourth capacitor, the second end of the second resistor, the second end of the third resistor, the second end of the fourth resistor, the second end of the fifth resistor, the second end of the second capacitor, the second end of the third capacitor, the second end of the fourth capacitor and the second end of the fifth capacitor are connected to the interface detection circuit, the A channel positive phase output end of the data selection chip, the A channel negative phase output end of the data selection chip, the B channel positive phase output end of the data selection chip, the B channel negative phase output end of the data selection chip, the C channel positive phase output end of the data selection chip, the C channel negative phase output end of the data selection chip, the D channel positive phase output end of the data selection chip and the D channel negative phase output end of the data selection chip are connected to the signal conversion circuit, and the configuration end of the data selection chip is also connected to the control circuit.

[0031] In one embodiment, the USB signal switching circuit includes: an analog switch, a tenth resistor and an eleventh resistor;

[0032] The power input terminal of the analog switch is connected to the second DC terminal, the selection input terminal of the analog switch is connected to the first terminal of the tenth resistor, the second terminal of the tenth resistor is connected to the control circuit, the output enable terminal of the analog switch is connected to the first terminal of the eleventh resistor, the second terminal of the eleventh resistor is connected to the power ground, the ground terminal of the analog switch is connected to the power ground, the first data terminal port of the analog switch, the second data terminal port of the analog switch, the third data terminal port of the analog switch and the fourth data terminal port of the analog switch are connected to the interface detection circuit, and the fifth data terminal port of the analog switch and the sixth data terminal port of the analog switch are connected to the USB hub control circuit.

[0033] A second aspect of an embodiment of the present application provides a function expansion device based on a TYPE_C interface, wherein the function expansion device includes a function expansion circuit based on a TYPE_C interface as described in any one of the above items.

[0034] A third aspect of the embodiments of the present application provides an all-in-one computer, the all-in-one computer comprising: a base, a hinge bracket, a display screen, a main control board, and a function expansion circuit based on a TYPE_C interface as described in any one of the above or a function expansion device as described in the above;

[0035] Among them, the main control board is placed in the base, the function expansion circuit based on the TYPE_C interface or the function expansion device is placed behind the display screen, and the hinge bracket is used to connect the base and the display screen.

[0036] Compared with the prior art, the embodiments of the present invention have the following beneficial effects: the above-mentioned function expansion circuit based on the TYPE_C interface detects the access status of the external device through the interface detection circuit to generate a connection detection signal, and transmits the screen projection signal sent by the external device; the control circuit generates a data selection control signal, a data transmission control signal and a selection control signal according to the connection detection signal and the screen projection signal; the data selection circuit selects and outputs the original audio and video signal sent by the external device according to the data selection control signal; the signal conversion circuit receives the original audio and video signal according to the data transmission control signal, and generates a differential video signal according to the original audio and video signal; the first signal switching circuit selects and outputs the differential video signal to the display screen according to the selection control signal Display, realize wired screen projection of external devices (such as mobile phones that support wired screen projection) on a computer all-in-one that does not support video input, and there is no need to use an additional expansion dock. Only a standard double-headed Type-C cable is needed to realize the mobile phone screen projection function. The mobile phone interface and the computer all-in-one display interface are automatically switched, and in the process of two-way information interaction between the mobile phone and the cloud server, the interaction process and results are displayed on the computer all-in-one, thereby realizing functions that cannot be achieved by the inherent hardware design and software design of the computer all-in-one after leaving the factory, meeting the application function requirements of users for upgrading and updating, achieving the purpose of lightweight and convenient office and entertainment, improving the stability, reliability and practicality of wired screen projection, and enhancing the user experience of video display. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 A schematic diagram of a structure of a function expansion circuit based on a TYPE_C interface provided in one embodiment of the present application;

[0038] Figure 2 Another structural schematic diagram of a function expansion circuit based on a TYPE_C interface provided in one embodiment of the present application;

[0039] Figure 3 Another structural schematic diagram of a function expansion circuit based on a TYPE_C interface provided in one embodiment of the present application;

[0040] Figure 4 Another structural schematic diagram of a function expansion circuit based on a TYPE_C interface provided in one embodiment of the present application;

[0041] Figure 5 Another structural schematic diagram of a function expansion circuit based on a TYPE_C interface provided in one embodiment of the present application;

[0042] Figure 6 Another structural schematic diagram of a function expansion circuit based on a TYPE_C interface provided in one embodiment of the present application;

[0043] Figure 7 An example circuit schematic diagram of a data selection circuit in a function expansion circuit based on a TYPE_C interface provided in an embodiment of the present application;

[0044] Figure 8 An example circuit schematic diagram of a USB signal switching circuit in a function expansion circuit based on a TYPE_C interface provided in an embodiment of the present application. DETAILED DESCRIPTION

[0045] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0046] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0047] It should be understood that the orientation or position relationship indicated by terms such as "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0048] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0049] Figure 1 A schematic diagram of the structure of a function expansion circuit based on a TYPE_C interface provided in the first embodiment of the present application is shown. For ease of explanation, only the part related to the present embodiment is shown, which is described in detail as follows:

[0050] A function expansion circuit 10 based on a TYPE_C interface is connected to a main control circuit 102 . The function expansion circuit 10 includes: an interface detection circuit 11 , a control circuit 12 , a data selection circuit 13 , a signal conversion circuit 14 and a first signal switching circuit 15 .

[0051] The interface detection circuit 11 is configured to detect the access status of the external device to generate a connection detection signal, and transmit the screen projection signal sent by the external device; the control circuit 12 is connected to the interface detection circuit 11, and is configured to generate a data selection control signal, a data transmission control signal and a selection control signal according to the connection detection signal and the screen projection signal; the data selection circuit 13 is connected to the interface detection circuit 11 and the control circuit 12, and is configured to select and output the original audio and video signal sent by the external device according to the data selection control signal; the signal conversion circuit 14 is connected to the data selection circuit 13 and the control circuit 12, and is configured to receive the original audio and video signal according to the data transmission control signal, and generate a differential video signal according to the original audio and video signal; the first signal switching circuit 15 is connected to the control circuit 12, the signal conversion circuit 14, the main control circuit 102 and the display screen 101, and is configured to select and output the differential video signal to the display screen 101 for display according to the selection control signal.

[0052] In a specific implementation, the main control board can be a main control board in an all-in-one computer or a main control board in other devices, and the main control circuit 102 is integrated on the main control board. It is based on the Feiteng central processing unit (CPU) and the Kylin operating system, and can output audio and video signals for display and playback, as well as realize other application functions. The function expansion circuit 10 based on the TYPE_C interface is integrated on the TYPE_C printed circuit board. The display screen 101 can be a display screen of an all-in-one computer, such as an LVDS interface display screen of an all-in-one computer. Optionally, the external device is a mobile terminal, such as a mobile phone that supports wired screen projection, and the external device can be connected to a remote cloud server by wireless communication for two-way information exchange. The interface detection circuit 11 is a Type_C interface detection circuit, which includes a Type_C interface, supports double-sided insertion of a USB interface, and both positive and negative insertion are possible. When the Type_C interface in the interface detection circuit 11 is not plugged into an external device (such as a mobile phone that supports wired screen projection), the control ends of each signal switching circuit are in a low-level state, and various signal output paths and signal input paths of the main control circuit 102 are selected by default. When the main control circuit 102 is turned on, various signal sources come from the main control circuit 102 and the input main control circuit 102, and the display screen 101 displays the differential video signal output by the main control circuit 102 and the corresponding system interface.When a mobile phone is connected through the Type_C interface in the interface detection circuit 11, the interface detection circuit 11 generates a connection detection signal when a connection confirmation signal CC is detected, and when the screen projection signal corresponding to the screen projection function of the mobile phone is not detected, the interface detection circuit 11 acts as a power transmission interface circuit, that is, the Type_C interface is used as a charging port, and the mobile phone is charged through the Type_C interface. The control end of the first signal switching circuit 15 is in a low level state, and the first signal switching circuit 15 selects and outputs the differential video signal sent by the main control circuit 102 to the display screen 101 for display; when the connection confirmation signal CC is detected to generate a connection detection signal and the screen projection signal corresponding to the screen projection function of the mobile phone is detected, the interface detection circuit 11 transmits the screen projection signal to the control circuit 12, and at the same time, the interface detection circuit 11 processes the original audio and video output by the mobile phone. The signal is transmitted, the control circuit 12 generates a data selection control signal, a data transmission control signal and a selection control signal according to the connection detection signal and the projection signal, the data selection circuit 13 selects to receive the original audio and video signal and outputs the original audio and video signal according to the data selection control signal; the signal conversion circuit 14 accurately receives the original audio and video signal output by the data selection circuit 13 according to the data transmission control signal, and converts the original audio and video signal to generate an analog differential video signal, wherein the original audio and video signal is a digital signal transmitted by the DP signal line; the first signal switching circuit 15 switches the signal transmission path from the video signal path output by the transmission main control circuit 102 to the differential video signal path output by the transmission signal conversion circuit 14 according to the selection control signal, so as to transmit the differential video signal output by the transmission signal conversion circuit 14 to the display screen 101 for display.

[0053] Optionally, the first signal switching circuit 15 is a signal switching switch, such as a multiplexer or a multiplexing analog switch.

[0054] The implementation of the present application can realize wired screen projection of a mobile terminal on an all-in-one computer that does not support video input, and there is no need to use an additional expansion dock. Only a standard double-headed Type-C cable is needed to realize the mobile terminal screen projection function. The mobile terminal interface and the all-in-one computer display interface are automatically switched, and in the process of two-way information interaction between the mobile terminal and the cloud server, the interaction process and results are displayed on the all-in-one computer, that is, the interface and display content of the cloud server are displayed on the all-in-one computer interface, thereby realizing functions that cannot be realized by the inherent hardware design and software design of the all-in-one computer after leaving the factory, meeting the application function requirements of users for upgrades and updates, achieving the purpose of lightweight and convenient office and entertainment, improving the stability, reliability and practicality of mobile terminal screen projection, and also improving the functional expandability of all-in-one computers and other equipment corresponding to the main control circuit.

[0055] See also Figure 2In one embodiment, the interface detection circuit 11 is also configured to transmit a first USB signal sent by an external device; the function expansion circuit 10 also includes: a USB interface circuit 16, a USB hub control circuit 17 and a USB signal switching circuit 18.

[0056] The USB interface circuit 16 is configured to transmit USB signals; the USB hub control circuit 17 is connected to the USB interface circuit 16 and configured to select and output USB signals according to input signals; the USB signal switching circuit 18 is connected to the interface detection circuit 11, the control circuit 12, the main control circuit 102 and the USB hub control circuit 17, and configured to select and output USB signals to the interface detection circuit 11 according to the selection control signal.

[0057] In a specific implementation, the USB interface circuit 16 includes at least one USB interface, which can be connected to an external mouse, keyboard, U disk, etc., and inputs USB signals to the USB hub control circuit 17 through the USB interface. The USB hub control circuit 17 selects and outputs USB signals to the USB signal switching circuit 18 according to the input signals.

[0058] Optionally, the USB signal switching circuit 18 is a USB signal switching switch, such as a multiplexer or a multiplexed analog switch. When the interface detection circuit 11 is not connected to the mobile phone, the USB signal switching switch turns on the connection between the main control circuit 102 and the line collection control circuit 17, and selects the USB signal output by the line collection control circuit 17 to be output to the main control circuit 102 through the USB signal switching switch, thereby realizing the required control of the main control circuit 102 through the USB interface; when the interface detection circuit 11 is connected to the mobile phone and detects that the screen projection function of the mobile phone is not turned on, that is, when the interface detection circuit 11 detects the connection confirmation signal CC but does not detect the screen projection signal, the interface detection circuit 11 generates a connection detection signal and transmits it to the control circuit 12, the control circuit 12 does not generate a selection control signal, the control end of the USB signal switching switch remains in a low level state, and the USB signal switching switch remains connected to the main control circuit 102 and the line collection control circuit 17. In this case, the power signal provided by the main control board is converted to voltage by the voltage conversion circuit on the TYPE_C printed circuit board. For example, voltage reduction and voltage regulation processing are performed to generate and output a charging voltage signal, and the charging voltage signal is output through the Type_C interface in the interface detection circuit 11 to charge the connected mobile phone, and the Type_C interface is used as a charging port; when the interface detection circuit 11 is connected to a mobile phone and detects that the mobile phone has turned on the screen projection function, the control circuit 12 generates a selection control signal according to the connection detection signal and the screen projection signal, and changes the level state of the control end of the USB signal switching switch, for example, changing the low level state of the control end of the USB signal switching switch to a high level state, thereby controlling the USB signal switching switch to switch to turn on the connection between the interface detection circuit 11 and the line hub control circuit 17, and shutting off the connection between the main control circuit 102 and the line hub control circuit 17, and transmitting the USB signal to the mobile phone through the USB signal switching switch and the interface detection circuit 11, thereby realizing the external connection of a mouse, keyboard or U disk and other peripherals through the USB interface to perform the required control on the mobile phone.

[0059] The embodiment of the present application only needs a standard double-headed Type-C cable to realize the mobile phone screen projection function, automatically switching the mobile phone interface of the small display screen and the computer display interface of the high-definition large display screen, while also supporting the interactive operation between the mobile phone and the computer, and can also connect external USB peripherals such as mouse, keyboard, U disk to perform relevant control on the mobile phone or computer, thereby realizing lightweight and convenient office and entertainment, retaining the characteristics of the all-in-one computer with few external connections, and improving the stability and practicality of mobile phone screen projection.

[0060] See also Figure 3 In one of the embodiments, the function expansion circuit 10 based on the TYPE_C interface also includes: an input component 19.

[0061] The input component 19 is connected to the USB hub control circuit 17 and is configured to generate an input signal according to a user input.

[0062] In a specific implementation, the input component 19 is an electromagnetic screen, a capacitive screen or a touch button, which can generate an input signal according to user input or user operation, and then combine with the USB interface circuit 16, the USB hub control circuit 17 and the USB signal switching circuit 18 to realize corresponding control of the main control circuit 102 or the mobile terminal connected through the TYPE_C interface, such as screen projection control and display control, etc., support electromagnetic pen operation, improve user experience, and improve the practicality of the function expansion circuit.

[0063] See also Figure 4 In one of the embodiments, the function expansion circuit 10 based on the TYPE_C interface further includes: a second signal switching circuit 20 .

[0064] The second signal switching circuit 20 is connected to the control circuit 12, the signal conversion circuit 14, the main control circuit 102 and the key assembly 103, and is configured to select and output the key control signal output by the user operating the key assembly 103 to the control circuit 12 according to the selection control signal.

[0065] In a specific implementation, the button assembly 103 can use a button switch to realize power on / off and backlight adjustment. The second signal switching circuit 20 uses a signal switching switch, such as a multiplexer or a multiplexed analog switch. In the default state, that is, when the interface detection circuit 11 is not connected to an external device (such as a mobile phone that supports wired screen projection), the second signal switching circuit 20 connects the connection between the main control circuit 102 and the button assembly 103. The user operates the key assembly 103 to generate a button control signal and outputs it to the main control circuit 102. The main control circuit 102 performs power on / off control and backlight drive control according to the button control signal to realize backlight brightness adjustment; when the interface detection circuit 11 is connected to an external device and detects that the external device turns on the screen projection function, the control circuit 12 generates a selection control signal according to the connection detection signal and the screen projection signal to control the second signal switching circuit 20 to connect the signal conversion circuit 14 and the button assembly 103. The signal conversion circuit 14 adjusts the backlight brightness according to the button control signal, thereby improving the practicality of the function expansion circuit based on the TYPE_C interface.

[0066] See also Figure 5 In one embodiment, the signal conversion circuit 14 is also configured to receive the original audio and video signal according to the data transmission control signal, and generate a differential video signal and a backlight control signal according to the original audio and video signal; the function expansion circuit 10 based on the TYPE_C interface also includes: a third signal switching circuit 21 and a backlight driving circuit 22.

[0067] The third signal switching circuit 21 is connected to the control circuit 12, the signal conversion circuit 14 and the main control circuit 102, and is configured to output a backlight control signal according to a selection control signal; the backlight driving circuit 22 is connected to the third signal switching circuit 21 and the display screen 101, and is configured to generate a backlight driving signal according to the backlight control signal to drive the display screen 101 to display the differential video signal.

[0068] In a specific implementation, the third signal switching circuit 21 may adopt a signal switching switch, such as a multiplexer or a multiplexed analog switch, etc. The signal conversion circuit 14 may generate a backlight enable signal and a backlight brightness adjustment signal according to the key control signal, wherein the backlight control signal includes a backlight enable signal and a backlight brightness adjustment signal, so as to control the backlight driving circuit 22 to generate a backlight driving signal, so as to drive the backlight lamp in the display screen 101 to start, stop or adjust the brightness, thereby realizing the display of the differential video signal. In the default state, the control end of the third signal switching circuit 21 is in a low level state, so that the third signal switching circuit 21 connects the main control circuit 102 and the backlight driving circuit 22, so that the differential video signal output by the main control circuit 102 is displayed on the display screen 101; when the interface detection circuit 11 is connected to an external device and the external device turns on the screen projection function, the control circuit 12 generates a selection control signal according to the connection detection signal and the screen projection signal to control the third signal switching circuit 21 to connect the signal conversion circuit 14 and the backlight driving circuit 22, so that the differential video signal output by the signal conversion circuit 14 is displayed on the display screen 101. The third signal switching circuit 21 and the backlight driving circuit 22 improve the effect of adjusting the backlight brightness of the display screen 101 to display the video, improve the stability and reliability of the function expansion circuit based on the TYPE_C interface, and improve the user experience of large-screen display.

[0069] See also Figure 6 In one embodiment, the signal conversion circuit 14 is also configured to generate a digital audio signal based on the original audio and video signal; the function expansion circuit 10 based on the TYPE_C interface also includes: an audio conversion circuit 23, an audio power amplifier circuit 24 and an audio signal switching circuit 25.

[0070] The audio conversion circuit 23 is connected to the signal conversion circuit 14 and is configured to convert the digital audio signal to generate an analog audio signal; the audio power amplifier circuit 24 is connected to the audio conversion circuit 23 and is configured to amplify the analog audio signal to generate a target audio signal; the audio signal switching circuit 25 is connected to the audio power amplifier circuit 24, the control circuit 12, the main control circuit 102 and the playback component 104, and is configured to output the target audio signal to the playback component 104 for playback according to the selection control signal.

[0071] In a specific implementation, the audio signal switching circuit 25 may adopt a signal switching switch, such as a multiplexer or a multiplexed analog switch, etc. When an audio signal is needed for playback, the signal conversion circuit 14 generates a digital audio signal according to the original audio and video signal, the audio conversion circuit 23 performs digital-to-analog conversion on the digital audio signal to generate an analog audio signal, the audio power amplifier circuit 24 amplifies the analog audio signal to generate a target audio signal, and then the target audio signal is played through the playback component 104 to meet the application requirements of audio playback.

[0072] In the default state, the control end of the audio signal switching circuit 25 is in a low level state, so that the audio signal switching circuit 25 connects the main control circuit 102 and the playback component 104, so that the analog audio signal output by the main control circuit 102 is played through the playback component 104; when the interface detection circuit 11 is connected to an external device and the external device turns on the screen projection function, the control circuit 12 generates a selection control signal according to the connection detection signal and the screen projection signal to control the audio signal switching circuit 25 to connect the audio power amplifier circuit 24 and the playback component 104, shut down the connection between the main control circuit 102 and the playback component 104, and select the digital audio signal output by the output signal conversion circuit 14 through the audio signal switching circuit 25, so as to play the digital audio signal output by the signal conversion circuit 14. The audio from the main control circuit 102 or the audio from the external device is played through the audio conversion circuit 23, the audio power amplifier circuit 24 and the audio signal switching circuit 25, thereby improving the practicality of the function expansion circuit.

[0073] See also Figure 7In one embodiment, the data selection circuit 13 includes: a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a first capacitor C1, a second capacitor C2, a third capacitor C3, a fourth capacitor C4, a fifth capacitor C5 and a data selection chip U1;Among them, the enable terminal EN of the data selection chip U1 is connected to the first end of the first resistor R1, the second end of the first resistor R1 is connected to the first DC power supply terminal, the power supply voltage terminal VCC of the data selection chip U1 is connected to the first DC power supply terminal and the first end of the first capacitor C1, the second end of the first capacitor C1 is connected to the power ground, the selection terminal AMSEL of the data selection chip U1 is connected to the first end of the sixth resistor R6 and the first end of the seventh resistor R7, the second end of the sixth resistor R6 is connected to the power ground, the second end of the seventh resistor R7 is connected to the first DC power supply terminal, the configuration terminal POL of the data selection chip U1 is connected to the first end of the eighth resistor R8 and the ninth resistor R9. The first end of the eighth resistor R9 is connected to the power supply ground, the second end of the ninth resistor R9 is connected to the first DC power supply end, the heat dissipation ground end EPAD of the data selection chip U1 is connected to the power supply ground, the first positive phase receiving end CRX2p of the data selection chip U1 is connected to the first end of the third resistor R3, the first negative phase receiving end CRX2n of the data selection chip U1 is connected to the first end of the second resistor R2, the second positive phase receiving end CRX1p of the data selection chip U1 is connected to the first end of the fifth resistor R5, the second negative phase receiving end CRX1n of the data selection chip U1 is connected to the first end of the fourth resistor R4, and the first positive phase receiving end CRX2n of the data selection chip U1 is connected to the first end of the fifth resistor R5. The positive phase transmitting terminal CTX2p is connected to the first end of the third capacitor C3, the first negative phase transmitting terminal CTX2n of the data selection chip U1 is connected to the first end of the second capacitor C2, the second positive phase transmitting terminal CTX1p of the data selection chip U1 is connected to the first end of the fifth capacitor C5, the second negative phase transmitting terminal CTX1n of the data selection chip U1 is connected to the first end of the fourth capacitor C4, the second end of the second resistor R2, the second end of the third resistor R3, the second end of the fourth resistor R4, the second end of the fifth resistor R5, the second end of the second capacitor C2, the second end of the third capacitor C3, the second end of the fourth capacitor C4 and the second end of the fifth capacitor C5 are connected to the interface The detection circuit 11, the A channel positive phase output terminal LnAp of the data selection chip U1, the A channel negative phase output terminal LnAn of the data selection chip U1, the B channel positive phase output terminal LnBp of the data selection chip U1, the B channel negative phase output terminal LnBn of the data selection chip U1, the C channel positive phase output terminal LnCp of the data selection chip U1, the C channel negative phase output terminal LnCn of the data selection chip U1, the D channel positive phase output terminal LnDp of the data selection chip U1 and the D channel negative phase output terminal LnDn of the data selection chip U1 are connected to the signal conversion circuit 1414, and the configuration terminal POL of the data selection chip U1 is also connected to the control circuit 12.;

[0074] In a specific implementation, the first DC power supply terminal outputs a first DC power, and the voltage of the first DC power can be selected as +V3P3A. The data selection chip U1 can adopt a data selection chip of model VL170, which has a low-voltage buck regulator integrated inside, and can effectively select and receive the original audio and video signal sent by the external device according to the digital selection control signal and output it to the signal conversion circuit 14.

[0075] See also Figure 8 In one embodiment, the USB signal switching circuit 18 includes: an analog switch U2, a tenth resistor R10 and an eleventh resistor R11; wherein, the power input terminal V+ of the analog switch U2 is connected to the second DC terminal, the selection input terminal SEL of the analog switch U2 is connected to the first end of the tenth resistor R10, the second end of the tenth resistor R10 is connected to the control circuit 12, the output enable terminal / OE of the analog switch U2 is connected to the first end of the eleventh resistor R11, the second end of the eleventh resistor R11 is connected to the power ground, the ground terminal GND of the analog switch U2 is connected to the power ground, the first data terminal port HSD1+ of the analog switch U2, the second data terminal port HSD1- of the analog switch U2, the third data terminal port HSD2+ of the analog switch U2 and the fourth data terminal port HSD2- of the analog switch U2 are connected to the interface detection circuit 11, and the fifth data terminal port D+ of the analog switch U2 and the sixth data terminal port D- of the analog switch U2 are connected to the USB hub control circuit 17.

[0076] In a specific implementation, the analog switch U2 may be an analog switch of the SGM series, such as SGM7222. The output enable terminal / OE of the analog switch U2 is effective at a low level, and the output enable terminal / OE of the analog switch U2 is kept at a low level through the eleventh resistor R11, so that the fifth data terminal port D+ of the analog switch U2 and the sixth data terminal port D- of the analog switch U2 are kept in a connected state. The selection input terminal SEL pin of the analog switch U2 is a switch control pin. When the selection input terminal SEL pin of the analog switch U2 is at a low level, the fifth data terminal port D+ of the analog switch U2 and the sixth data terminal port D- of the analog switch U2 are respectively connected to the first data terminal port HSD1+ of the analog switch U2 and the second data terminal port HSD1- of the analog switch U2; when the selection input terminal SEL pin of the analog switch U2 is at a high level, the fifth data terminal port D+ of the analog switch U2 and the sixth data terminal port D- of the analog switch U2 are respectively connected to the third data terminal port HSD2+ of the analog switch U2 and the fourth data terminal port HSD2- of the analog switch U2. When the Type_C interface of the interface detection circuit 11 is connected to an external device and detects the external device and turns on the screen projection function, the selection control signal output by the control circuit 12 pulls up the level of the selection input pin SEL of the analog switch U2, and transmits the USB signal output by the USB hub control circuit 17 according to the input signal selection to the external device connected to the TYPE_C interface (for example, a mobile phone that supports wired screen projection), thereby enabling relevant control of the mobile phone connected to the Type_C interface through the USB interface.

[0077] In a specific implementation, the first signal switching circuit 15, the second signal switching circuit 20, the third signal switching circuit 21 and the audio signal switching circuit 25 can all adopt SGM series analog switches, and refer to the working principle of the above-mentioned analog switch U2 to perform the selection output of differential video signals, key control signals, backlight control signals and analog audio signals.

[0078] In one embodiment, the control circuit 12 adopts a PD3.0 controller of model VL103R, which can generate a selection control signal according to the connection detection signal and the screen projection signal to control the switching of the signal transmission path of each signal switching circuit, and generate a data selection signal to control the data selection circuit 12 to select to receive data from an external device to obtain and output the original audio and video signal, and generate a data transmission control signal to ensure that the signal conversion circuit 14 can accurately read the DP signal (that is, the digital original audio and video signal) output from the data selection circuit 13, and convert the digital original audio and video signal to generate a differential video signal (that is, LVDS signal), so that the mobile phone screen projection function can be realized through only a standard double-headed Type_C line, and the mobile phone interface and the computer all-in-one display interface are automatically switched. When the mobile phone interacts with the remote cloud server, the interface and display content of the cloud server can be projected and displayed on the display interface of the computer all-in-one, so as to realize lightweight and convenient office and entertainment, improve the user experience, and expand the functions of devices such as computers all-in-one.

[0079] A second aspect of an embodiment of the present application provides a function expansion device based on a TYPE_C interface, and the function expansion device includes a function expansion circuit 10 based on a TYPE_C interface as described in any one of the above items.

[0080] In a specific implementation, a function expansion device based on a TYPE_C interface is connected to a main control circuit 102 and a display screen 101, and can access external devices such as mobile phones that support wired screen projection through the TYPE_C interface of the function expansion device, automatically switch the interface of the mobile phone and the display interface of the all-in-one computer, and project the interface and display content of the mobile phone onto the large-size display screen of the all-in-one computer for display. When the mobile phone interacts with the cloud server, the interface of the mobile phone displays the interface and display content of the cloud server, thereby projecting the interface and display content on the cloud server onto the large-size display screen of the all-in-one computer for display, so as to obtain a wider field of view, so that users can enjoy the convenience of the mobile phone and the clarity and comfort of the large screen, thereby improving the user experience of video display. At the same time, the interactive operation between the mobile phone and the large-screen device can achieve the purpose of convenient office work, effectively overcome the functional limitations caused by the design of the all-in-one computer and the inherent software design and hardware design after leaving the factory, and can meet the new application function requirements of users without updating the inherent software and hardware design of the all-in-one computer or developing new software and hardware designs.

[0081] A third aspect of an embodiment of the present application provides an all-in-one computer, which includes: a base, a hinge bracket, a display screen, a main control board, and a function expansion circuit as described above or a function expansion device as described above; wherein the main control board is placed in the base, the function expansion device or the function expansion circuit is placed behind the display screen, and the hinge bracket is used to connect the base and the display screen.

[0082] In a specific implementation, the computer all-in-one is a domestic computer all-in-one. Optionally, the main control circuit, button components, and playback components are integrated on the main control board. The display screen is a display screen of a domestic computer all-in-one. The function expansion circuit 10 or function expansion device based on the TYPE_C interface is placed behind the display screen, wherein the function expansion circuit 10 or function expansion device based on the TYPE_C interface can be integrated on a TYPE_C printed circuit board. Feature-rich smartphones are based on the convenience of mobile products, and the display screen size is usually small, but the software is updated and upgraded quickly, and can be connected to a remote cloud server wirelessly for two-way information interaction, while the display screen of a domestic computer all-in-one is relatively much larger in size, and is widely used in entertainment and office. Therefore, through the function expansion circuit 10 or function expansion device based on the TYPE_C interface, it is possible to realize the projection of the smartphone screen with only one standard double-headed Type_C cable, wherein the smartphone is a mobile phone that supports wired projection. Through the function expansion circuit 10 or function expansion device based on the TYPE_C interface, the mobile phone interface and the computer interface can be automatically switched, and the interface and display content of the mobile phone can be projected onto the large-size display screen of the all-in-one computer for display. Therefore, when the mobile phone interacts with the cloud server, the interface and display content on the cloud server are projected onto the large-size display screen of the all-in-one computer for display, thereby eliminating the need for excessive software design and hardware development on the all-in-one computer and updating the inherent software and hardware design of the all-in-one computer, so as to meet the user's updated and upgraded office or entertainment application function requirements, reduce the burden on the all-in-one computer, ensure the operating speed of the hardware (such as the processor) of the all-in-one computer, and reduce the maintenance and replacement costs caused by the backward software and hardware functions of the all-in-one computer after leaving the factory.

[0083] At the same time, the all-in-one computer can also connect to USB peripherals such as mouse, keyboard, U disk, etc. to control the computer or mobile phone. In this way, the all-in-one computer can be used as a computer and as a display for mobile phone projection. It is a dual-purpose machine, which makes office and entertainment lightweight and convenient, and also improves the stability, practicality and functional expandability of the all-in-one computer.

[0084] Those skilled in the art can clearly understand that, for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In practical applications, the above-mentioned function allocation can be completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments can be integrated in a processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. In the above embodiments, the description of each embodiment has its own emphasis. For the part that is not described or recorded in detail in a certain embodiment, refer to the relevant description of other embodiments.

[0085] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A function expansion circuit based on TYPE_C interface, connected to a main control circuit, characterized in that: The function expansion circuit comprises: An interface detection circuit, configured to detect the access status of an external device to generate a connection detection signal, and transmit a screen projection signal sent by the external device, and serve as a power transmission interface circuit when no screen projection signal is detected; A control circuit connected to the interface detection circuit and configured to generate a data selection control signal, a data transmission control signal and a gating control signal according to the connection detection signal and the screen projection signal; A data selection circuit, connected to the interface detection circuit and the control circuit, configured to select and output the original audio and video signal sent by the external device according to the data selection control signal; a signal conversion circuit connected to the data selection circuit and the control circuit, configured to receive the original audio and video signal according to the data transmission control signal, and generate a differential video signal according to the original audio and video signal; The first signal switching circuit is connected to the control circuit, the signal conversion circuit, the main control circuit and the display screen, and is configured to select and output the differential video signal to the display screen for display according to the selection control signal.

2. The function expansion circuit based on TYPE_C interface according to claim 1, characterized in that: The interface detection circuit is further configured to transmit a first USB signal sent by the external device; the function expansion circuit based on the TYPE_C interface further includes: A USB interface circuit configured to transmit USB signals; A USB hub control circuit is connected to the USB interface circuit and is configured to select and output the USB signal according to an input signal; The USB signal switching circuit is connected to the interface detection circuit, the control circuit, the main control circuit and the USB hub control circuit, and is configured to select and output the USB signal to the interface detection circuit according to the selection control signal.

3. The function expansion circuit based on TYPE_C interface as claimed in claim 2, characterized in that: The function expansion circuit based on the TYPE_C interface also includes: The input component is connected to the USB hub control circuit and is configured to generate the input signal according to user input.

4. The function expansion circuit based on TYPE_C interface according to claim 1, characterized in that: The function expansion circuit based on the TYPE_C interface also includes: The second signal switching circuit is connected to the control circuit, the signal conversion circuit, the main control circuit and the key component, and is configured to select and output the key control signal output by the user operating the key component to the control circuit according to the selection control signal.

5. The function expansion circuit based on TYPE_C interface according to claim 1, characterized in that: The signal conversion circuit is further configured to receive the original audio and video signal according to the data transmission control signal, and generate a differential video signal and a backlight control signal according to the original audio and video signal; The function expansion circuit based on the TYPE_C interface also includes: A third signal switching circuit is connected to the control circuit, the signal conversion circuit and the main control circuit, and is configured to select and output the backlight control signal according to the selection control signal; The backlight driving circuit is connected to the third signal switching circuit and the display screen, and is configured to generate a backlight driving signal according to the backlight control signal to drive the display screen to display the differential video signal.

6. The function expansion circuit based on TYPE_C interface according to claim 1, characterized in that: The signal conversion circuit is also configured to generate a digital audio signal based on the original audio and video signal; The function expansion circuit based on the TYPE_C interface also includes: an audio conversion circuit, connected to the signal conversion circuit, configured to convert the digital audio signal to generate an analog audio signal; an audio power amplifier circuit, connected to the audio conversion circuit, and configured to amplify the analog audio signal to generate a target audio signal; The audio signal switching circuit is connected to the audio power amplifier circuit, the control circuit, the main control circuit and the playback component, and is configured to select and output the target audio signal to the playback component for playback according to the selection control signal.

7. The function expansion circuit based on TYPE_C interface according to claim 1, characterized in that: The data selection circuit includes: a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a fifth capacitor and a data selection chip; The enable terminal of the data selection chip is connected to the first end of the first resistor, the second end of the first resistor is connected to the first DC power supply terminal, the power supply voltage terminal of the data selection chip is connected to the first DC power supply terminal and the first end of the first capacitor, the second end of the first capacitor is connected to the power ground, the selection terminal of the data selection chip is connected to the first end of the sixth resistor and the first end of the seventh resistor, the second end of the sixth resistor is connected to the power ground, the second end of the seventh resistor is connected to the first DC power supply terminal, the configuration terminal of the data selection chip is connected to the first end of the eighth resistor and the first end of the ninth resistor, the second end of the eighth resistor is connected to the power ground, the second end of the ninth resistor is connected to the first DC power supply terminal, the heat dissipation ground terminal of the data selection chip is connected to the power ground, the first positive phase receiving terminal of the data selection chip is connected to the first end of the third resistor, the first negative phase receiving terminal of the data selection chip is connected to the first end of the second resistor, the second positive phase receiving terminal of the data selection chip is connected to the first end of the fifth resistor, and the second negative phase receiving terminal of the data selection chip is connected to the first end of the fourth resistor , the first positive phase transmitting end of the data selection chip is connected to the first end of the third capacitor, the first negative phase transmitting end of the data selection chip is connected to the first end of the second capacitor, the second positive phase transmitting end of the data selection chip is connected to the first end of the fifth capacitor, the second negative phase transmitting end of the data selection chip is connected to the first end of the fourth capacitor, the second end of the second resistor, the second end of the third resistor, the second end of the fourth resistor, the second end of the fifth resistor, the second end of the second capacitor, the second end of the third capacitor, the second end of the fourth capacitor and the second end of the fifth capacitor are connected to the interface detection circuit, the A channel positive phase output end of the data selection chip, the A channel negative phase output end of the data selection chip, the B channel positive phase output end of the data selection chip, the B channel negative phase output end of the data selection chip, the C channel positive phase output end of the data selection chip, the C channel negative phase output end of the data selection chip, the D channel positive phase output end of the data selection chip and the D channel negative phase output end of the data selection chip are connected to the signal conversion circuit, and the configuration end of the data selection chip is also connected to the control circuit.

8. The function expansion circuit based on TYPE_C interface according to claim 2, characterized in that: The USB signal switching circuit comprises: an analog switch, a tenth resistor and an eleventh resistor; The power input terminal of the analog switch is connected to the second DC terminal, the selection input terminal of the analog switch is connected to the first terminal of the tenth resistor, the second terminal of the tenth resistor is connected to the control circuit, the output enable terminal of the analog switch is connected to the first terminal of the eleventh resistor, the second terminal of the eleventh resistor is connected to the power ground, the ground terminal of the analog switch is connected to the power ground, the first data terminal port of the analog switch, the second data terminal port of the analog switch, the third data terminal port of the analog switch and the fourth data terminal port of the analog switch are connected to the interface detection circuit, and the fifth data terminal port of the analog switch and the sixth data terminal port of the analog switch are connected to the USB hub control circuit.

9. A function expansion device based on TYPE_C interface, characterized in that: The function expansion device comprises: a function expansion circuit based on a TYPE_C interface as described in any one of claims 1 to 8.

10. An all-in-one computer, characterized in that: The all-in-one computer comprises: a base, a hinge bracket, a display screen, a main control board, and a function expansion circuit based on a TYPE_C interface as described in any one of claims 1 to 8 or a function expansion device as described in claim 9; Among them, the main control board is placed in the base, the function expansion circuit based on the TYPE_C interface or the function expansion device is placed behind the display screen, and the hinge bracket is used to connect the base and the display screen.

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