Direct connection multi-screen interface expansion circuit and industrial computer

Abstract

The utility model discloses a kind of direct connection multi-screen interface expansion circuit and industrial computer, direct connection multi-screen interface expansion circuit includes: interface unit, including multiple different types of connectors, connector is used to access display screen;Upstream conversion unit, connect one type of connector, for converting input signal into the interface signal matched with the type of connected connector corresponding communication protocol;Downstream conversion unit, connect upstream conversion unit and the connector of remaining type, for converting the interface signal of upstream conversion unit into the interface signal matched with the type of connected connector corresponding communication protocol;Control unit, connect upstream conversion unit, downstream conversion unit and the connector of all types, for identifying display screen access connector, control upstream conversion unit and downstream conversion unit corresponding interface signal is output to the connector of access display screen after.The present application can be flexibly compatible with multiple different types of display screen, satisfy the connection use demand of different types of display screen.

Description

Technical Field

[0001] This utility model relates to the field of industrial control computer technology, and in particular to a direct-connect multi-screen interface expansion circuit and an industrial control computer. Background Technology

[0002] Industrial PCs, also known as "industrial control computers," are computers specifically designed for industrial control and automation. As a crucial component of industrial control and automation, they have found widespread and profound applications across various industries. As key equipment in industrial automation, industrial PCs typically have a reserved display interface for connecting to a monitor. Currently, the industry mainly uses three types of display interfaces: eDP, LVDS, and MIPI. To avoid wasting hardware resources by consuming multiple graphics card video resources, existing industrial PCs usually reserve one of these interfaces, typically the eDP interface. However, if the on-site display environment uses an LVDS or MIPI monitor, the reserved interface on the industrial PC will be incompatible, causing significant inconvenience. Utility Model Content

[0003] This utility model provides a direct-connect multi-screen interface expansion circuit and an industrial control computer, which solves the problem that the reserved interfaces of existing industrial control computers cannot adapt to various display screens with different interface types.

[0004] In a first aspect, this utility model provides a direct-connect multi-screen interface expansion circuit, comprising: an interface unit including multiple connectors of different types for connecting to a display screen; an upstream conversion unit connected to one type of connector for converting input signals into interface signals matching the communication protocol corresponding to the type of the connected connector; a downstream conversion unit connected to the upstream conversion unit and the other types of connectors for converting the interface signals of the upstream conversion unit into interface signals matching the communication protocol corresponding to the type of the connected connector; and a control unit connected to the upstream conversion unit, the downstream conversion unit, and all types of connectors for recognizing that after the display screen is connected to the connector, controlling the upstream conversion unit and the downstream conversion unit to output corresponding interface signals to the connector connected to the display screen.

[0005] Furthermore, the upstream conversion unit is provided with a first upstream output terminal, a second upstream output terminal, and an upstream control terminal. One type of connector is connected to the first upstream output terminal, the downstream conversion unit is connected to the second upstream output terminal, and the control unit is connected to the upstream control terminal. The control unit controls the upstream conversion unit to select the first upstream output terminal or the second upstream output terminal to output interface signals by outputting control signals to the upstream control terminal.

[0006] Furthermore, the downstream conversion unit is provided with a downstream output terminal and a downstream control terminal. The downstream output terminal is connected to the other types of connectors respectively, and the control unit is connected to the downstream control terminal. The control unit controls the downstream conversion unit to select one type of interface signal to be output through the downstream output terminal by outputting a control signal to the downstream control terminal.

[0007] Furthermore, the plurality of different types of connectors include a first connector, a second connector, and a third connector, wherein the first connector is connected to the first upstream output terminal, and the second connector and the third connector are both connected to the downstream output terminal.

[0008] Furthermore, the first connector is an eDP connector, the second connector is an LVDS connector, and the third connector is a MIPI connector.

[0009] Furthermore, the first connector has a first pin, the second connector has a second pin, and the third connector has a third pin. The control unit is connected to the first pin, the second pin, and the third pin. The control unit determines whether the first connector, the second connector, and the third connector are connected to the display screen by identifying the level signals of the first pin, the second pin, and the third pin.

[0010] Furthermore, the direct-connect multi-screen interface expansion circuit also includes a first level inverting unit and a second level inverting unit. The control unit is connected to the second pin through the first level inverting unit and to the third pin through the second level inverting unit. The first level inverting unit is used to invert the level signal of the second pin and output it to the control unit, and the second level inverting unit is used to invert the level signal of the second pin and output it to the control unit.

[0011] Furthermore, the first level inverting unit includes a first MOSFET, a first resistor, and a second resistor. The gate of the first MOSFET is connected to the second pin and is connected to the power supply through the first resistor. The drain of the first MOSFET is connected to the power supply through the second resistor, and the source of the first MOSFET is grounded.

[0012] Furthermore, the first level inverting unit includes a second MOSFET, a third resistor, and a fourth resistor. The gate of the second MOSFET is connected to the third pin and connected to the power supply through the third resistor. The drain of the second MOSFET is connected to the power supply through the fourth resistor. The source of the second MOSFET is grounded.

[0013] Secondly, this utility model provides an industrial control computer, which includes a CPU unit and the direct-connect multi-screen interface expansion circuit described in the first aspect, wherein the direct-connect multi-screen interface expansion circuit is connected to the CPU unit.

[0014] This utility model provides a direct-connect multi-screen interface expansion circuit and an industrial control computer. The direct-connect multi-screen interface expansion circuit is configured with an interface unit including multiple different types of connectors for connecting to a display screen. An upstream conversion unit connects to one type of connector to convert the input signal into an interface signal that matches the communication protocol corresponding to the type of the connected connector. A downstream conversion unit connects the upstream conversion unit and the other types of connectors to convert the interface signal of the upstream conversion unit into an interface signal that matches the communication protocol corresponding to the type of the connected connector. A control unit connects the upstream conversion unit, the downstream conversion unit, and all types of connectors to identify when a display screen is connected to a connector and control the upstream and downstream conversion units to output the corresponding interface signal to the connector connected to the display screen. This allows for the matching of connection requirements for various types of display screens, which is very convenient. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 A schematic diagram of the direct-connect multi-screen interface expansion circuit provided in this embodiment of the utility model;

[0017] Figure 2 A circuit diagram of the upstream conversion unit provided for an embodiment of this utility model;

[0018] Figure 3 A circuit diagram of the downstream conversion unit provided for an embodiment of this utility model;

[0019] Figure 4 A circuit diagram of the first connector provided in an embodiment of this utility model;

[0020] Figure 5 A circuit diagram of the second connector provided in an embodiment of this utility model;

[0021] Figure 6 Circuit diagram of the third connector provided in this embodiment of the utility model;

[0022] Figure 7 Circuit diagram of the control unit provided in the embodiment of this utility model;

[0023] Figure 8 A partial structural diagram of the industrial control computer provided in an embodiment of this utility model.

[0024] The labels for the attached figures are as follows:

[0025] 10. Interface unit; 11. First connector; 12. Second connector; 13. Third connector; 20. Upstream conversion unit; 21. First upstream output terminal; 22. Second upstream output terminal; 23. Upstream control terminal; 30. Downstream conversion unit; 31. Downstream output terminal; 32. Downstream control terminal; 40. Control unit; 50. First level inverting unit; 60. Second level inverting unit; 200. Industrial computer; 210. CPU unit; 220. Direct connection multi-screen interface expansion circuit. Detailed Implementation

[0026] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0027] The directional terms used in this invention, such as "up," "down," "front," "back," "left," "right," "inner," "outer," and "side," are merely for reference to the accompanying drawings. Therefore, the directional terms used are for explanation and understanding of this invention, and not for limiting it. Furthermore, in the accompanying drawings, structures that are similar or identical are indicated by the same reference numerals.

[0028] Reference Figure 1This utility model provides a direct-connect multi-screen interface expansion circuit. The structure and working principle of the direct-connect multi-screen interface expansion circuit are described in detail below with reference to the accompanying drawings. The direct-connect multi-screen interface expansion circuit includes: an interface unit 10, comprising multiple connectors of different types for connecting to a display screen; an upstream conversion unit 20, connected to one type of connector, for converting input signals into interface signals matching the communication protocol corresponding to the type of the connected connector; a downstream conversion unit 30, connected to the upstream conversion unit 20 and the other types of connectors, for converting the interface signals of the upstream conversion unit 20 into interface signals matching the communication protocol corresponding to the type of the connected connector; and a control unit 40, connected to the upstream conversion unit 20, the downstream conversion unit 30, and all types of connectors, for recognizing that the display screen is connected to the connector, and controlling the upstream conversion unit 20 and the downstream conversion unit 30 to output the corresponding interface signals to the connector connected to the display screen.

[0029] In practical implementation, the direct-connect multi-screen interface expansion circuit can be used in industrial control computers for interface expansion, meeting the access needs of various types of interface displays, and can also be used in other machines and equipment with display requirements for interface expansion. For example... Figure 1As shown, the direct-connect multi-screen interface expansion circuit mainly consists of an interface unit 10, an upstream conversion unit 20, a downstream conversion unit 30, and a control unit 40. The interface unit 10 is composed of multiple connectors of different types, including but not limited to eDP connectors, LVDS connectors, and MIPI connectors. Each type of connector is used to connect to a matching display screen. The upstream conversion unit 20 connects to one type of connector, such as an eDP connector. The upstream conversion unit 20 can convert the input signals provided by the host computer or host chip into interface signals that match the communication protocol of the connected connector type. For example, if the upstream conversion unit 20 connects to an eDP connector, it can convert the input signals into interface signals of the eDP communication protocol. When the eDP display screen is connected to the eDP connector, signal communication can be performed, such as video display and touch control. The downstream conversion unit 30 connects to the upstream conversion unit 20 and other types of connectors in the interface unit 10, such as LVDS connectors and MIPI connectors. The downstream conversion unit 30 can convert the interface signal of the upstream conversion unit 20 into an interface signal that matches the communication protocol of the connected connector type. For example, when the downstream conversion unit 30 connects to LVDS connectors and MIPI connectors, when the upstream conversion unit 20 outputs an eDP signal, the downstream conversion unit 30 can convert the eDP signal into interface signals of LVDS communication protocol and MIPI communication protocol respectively. When the LVDS display is connected to the LVDS connector, signal communication can be performed. When the MIPI display is connected to the MIPI connector, signal communication can also be performed.The control unit 40 is connected to the upstream conversion unit 20 and the downstream conversion unit 30, and also connects to all types of connectors in the interface unit 10. The control unit 40 is the core of the circuit and can be designed using a microcontroller. The control unit 40 is used to identify whether a connector is connected to the display screen. After identifying that the display screen is connected to the connector, the control unit 40 will control the upstream conversion unit 20 or the downstream conversion unit 30 to output the corresponding interface signal to the connector connected to the display screen, enabling the display screen connected to that connector to perform normal signal communication. For example, when the upstream conversion unit 20 is connected to an eDP connector and the downstream conversion unit 30 is connected to both an LVDS connector and a MIPI connector, when the eDP connector is connected to the display screen, the control unit 40 will control the upstream conversion unit 20 to output the eDP protocol interface signal, thereby enabling the connection to the eDP connector to perform normal signal communication. The P-connector display can perform signal communication. When the LVDS connector is connected to the display, the control unit 40 first controls the upstream conversion unit 20 to output the eDP protocol interface signal to the downstream conversion unit 30. The downstream conversion unit 30 then converts the eDP protocol to the LVDS protocol and outputs the LVDS protocol interface signal, enabling the display connected to the LVDS connector to perform signal communication. Similarly, when the MIPI connector is connected to the display, the control unit 40 first controls the upstream conversion unit 20 to output the eDP protocol interface signal to the downstream conversion unit 30. The downstream conversion unit 30 then converts the eDP protocol to the MIPI protocol and outputs the MIPI protocol interface signal, enabling the display connected to the MIPI connector to perform signal communication. Thus, the input signal provided by the host computer or chip can be expanded and converted into interface signals with different protocols for various interfaces. After being connected to different displays, it can be automatically identified and directly displayed, providing flexible compatibility with various displays and meeting the usage requirements of different displays.

[0030] Furthermore, referring to Figure 1The upstream conversion unit 20 is provided with a first upstream output terminal 21, a second upstream output terminal 22, and an upstream control terminal 23. One type of connector is connected to the first upstream output terminal 21. The downstream conversion unit 30 is connected to the second upstream output terminal 22. The control unit 40 is connected to the upstream control terminal 23. The control unit 40 controls the upstream conversion unit 20 to select either the first upstream output terminal 21 or the second upstream output terminal 22 to output interface signals by outputting a control signal to the upstream control terminal 23. In specific implementation, the first upstream output terminal 21 and the second upstream output terminal 22 serve as two signal output channels of the upstream conversion unit 20. The control unit 40 outputs a control signal to the upstream control terminal 23, and the control signal determines whether the upstream conversion unit 20 selects the first upstream output terminal 21 or the second upstream output terminal 22 to output interface signals. When the upstream conversion unit 20 selects to output the interface signal through the first upstream output terminal 21, the corresponding type of connector communication signal connected to the first upstream output terminal is turned on; when the upstream conversion unit 20 selects to output the interface signal through the second upstream output terminal 22, the downstream conversion unit 30 has an interface signal input. At this time, the downstream conversion unit 30 can convert the interface signal into a communication protocol that matches the communication protocol of the other multiple different types of connectors, thereby turning on the communication signal of the connector connected to the downstream conversion unit 30.

[0031] By way of example, refer to Figure 2 The upstream conversion unit 20 uses the DS160PR412 chip. The SEL pin serves as the upstream control terminal 23, and the TX_A channel serves as the first upstream output terminal 21, including pins 28, 29, 33, 34, 37, and 38 of the chip. The TX_A channel connects to the eDP connector. The TX_B channel serves as the second upstream output terminal 22, including pins 26, 27, 31, 32, 35, and 36 of the chip. The TX_B channel connects to the downstream conversion unit 30, which is connected to both an LVDS connector and a MIPI connector. When the control unit 40 outputs a low level as a control signal to the SEL pin, the TX_A channel of the DS160PR412 chip is active, and the TX_A channel outputs an eDP signal to the eDP connector, which can be connected to an eDP display screen. When the control unit 40 outputs a high level as a control signal to the SEL pin of the DS160PR412 chip, the TX_B channel of the DS160PR412 chip is active, and the TX_B channel outputs an eDP signal to the downstream conversion unit 30. After communication protocol conversion by the downstream conversion unit 30, an LVDS or MIPI signal can be output, which can be connected to an LVDS or MIPI display screen.

[0032] Furthermore, referring to Figure 1The downstream conversion unit 30 is provided with a downstream output terminal and a downstream control terminal 32. The downstream output terminal 31 is connected to the other types of connectors respectively. The control unit 40 is connected to the downstream control terminal 32. The control unit 40 controls the downstream conversion unit 30 to select one type of interface signal to be output through the downstream output terminal 31 by outputting a control signal to the downstream control terminal 32. In specific implementation, the downstream output terminal 31 serves as a multi-select signal output channel for the downstream conversion unit 30. The control unit 40 outputs a control signal to the downstream control terminal 32, which determines which type of interface signal the downstream output terminal 31 of the downstream conversion unit 30 outputs, i.e., controls the downstream conversion unit 30 to perform multi-select output. When the downstream conversion unit 30 selects to output a certain type of interface signal through the downstream output terminal 31, among the other types of connectors connected to the downstream output terminal, only the connector whose interface signal type matches that output by the downstream output terminal 31 will have its communication signal connected. At this time, the display screen connected to that connector can perform normal signal communication.

[0033] By way of example, refer to Figure 3 The downstream conversion unit 30 uses the LT7911D chip. The LT7911D chip can realize the function of eDP protocol to LVDS or MIPI protocol. The interface signals of the two communication protocols are output using the same pins. Therefore, pins 35-44 and 49-58 of the LT7911D chip are used as downstream output terminals 31, which are connected to both LVDS and MIPI connectors. Pin 26 of the LT7911D chip, CTRL / GPIO5, is used as the downstream control terminal 32, which can control pins 35-44 and 49-58 to perform a two-way output of LVDS and MIPI signals. When the control unit 40 outputs a low level as a control signal to pin 26 CTRL / GPIO5 of the LT7911D chip, pins 35-44 and 49-58 of the LT7911D chip output LVDS signals to the LVDS connector, which can be connected to an LVDS display screen; when the control unit 40 outputs a high level as a control signal to pin 26 CTRL / GPIO5 of the LT7911D chip, pins 35-44 and 49-58 of the LT7911D chip output MIPI signals to the MIPI connector, which can be connected to a MIPI display screen.

[0034] Furthermore, referring to Figure 1The plurality of connectors of different types include a first connector 11, a second connector 12, and a third connector 13. The first connector 11 is connected to the first upstream output terminal 21, and the second connector 12 and the third connector 13 are both connected to the downstream output terminal 31. In specific implementation, the first connector 11, the second connector 12, and the third connector 13 are three different types of connectors. In specific applications, when the control unit 40 controls the upstream conversion unit 20 to output an interface signal through the first upstream output terminal 21, the first connector 11 has an interface signal input, the communication signal of the first connector 11 is connected, and the display screen connected to the first connector 11 can perform signal communication normally. When the control unit 40 controls the upstream conversion unit 20 to output an interface signal through the second upstream output terminal 22, and controls the downstream conversion unit 30 to output an interface signal that matches the communication protocol of the second connector 12 through the downstream output terminal 31, the second connector 12 has a corresponding interface signal input, and the second connector 12 can perform signal communication normally when connected to the display screen. When the control unit 40 controls the downstream conversion unit 30 to output an interface signal that matches the communication protocol of the third connector 13 through the downstream output terminal 31, the third connector 13 has a corresponding interface signal input, and the third connector 13 can perform signal communication normally when connected to the display screen.

[0035] Furthermore, referring to Figure 1 The first connector 11 is an eDP connector, the second connector 12 is an LVDS connector, and the third connector 13 is a MIPI connector. Specifically, the first connector 11 is an eDP connector, which can be connected to an eDP display screen; the second connector 12 is an LVDS connector, which can be connected to an LVDS display screen; and the third connector 13 is a MIPI connector, which can be connected to a MIPI display screen. In specific applications, when the upstream conversion unit 20 selects to output an eDP signal through the first upstream output terminal 21, the eDP connector receives an eDP signal input, and the eDP display screen performs normal signal communication. When the upstream conversion unit 20 selects to output an eDP signal through the second upstream output terminal 22, the downstream conversion unit 30 receives an eDP signal input. If the control unit 40 controls the downstream conversion unit 30 to convert to an LVDS signal output, then the downstream output terminal 31 outputs an LVDS signal, the LVDS connector receives an LVDS signal input, and the LVDS display screen can perform normal signal communication. If the control unit 40 controls the downstream conversion unit 30 to convert to a MIPI signal output, then the downstream output terminal 31 outputs a MIPI signal, the MIPI connector receives a MIPI signal input, and the MIPI display screen can perform normal signal communication.

[0036] Furthermore, referring to Figures 4 to 6The first connector 11 has a first pin, the second connector 12 has a second pin, and the third connector 13 has a third pin. The control unit 40 is connected to the first pin, the second pin, and the third pin. The control unit 40 determines whether the first connector 11, the second connector 12, and the third connector 13 are connected to the display screen by identifying the level signals of the first pin, the second pin, and the third pin. In specific implementation, when the first connector 11, the second connector 12, and the third connector are inserted into their respective matching displays, according to the protocol specifications of the eDP interface, LVDS interface, and MIPI interface, pin 15 of the eDP connector outputs a high level, while pin 18 of the LVDS connector and pin 19 of the MIPI connector are grounded, both at a low level. Therefore, pin 15 of the first connector 11 (i.e., the eDP connector) can be used as the first pin, pin 18 of the second connector 12 (i.e., the LVDS connector) can be used as the second pin, and pin 19 of the third connector 13 (i.e., the MIPI connector) can be used as the third pin. The control unit 40 can determine whether the first connector 11, the second connector 12, and the third connector 13 are connected to the corresponding display by identifying the level signals output by the first, second, and third pins.

[0037] By way of example, refer to Figure 7The control unit 40 uses an M054LDN microcontroller. Pin 15 of the first connector 11 (eDP connector) serves as the first pin, pin 18 of the second connector 12 (LVDS connector) serves as the second pin, and pin 19 of the third connector 13 (MIPI connector) serves as the third pin. Pin 32 of the M054LDN microcontroller connects to pin 15 of the eDP connector, pin 33 connects to pin 18 of the LVDS connector, and pin 34 connects to pin 19 of the MIPI connector. When the M054LDN microcontroller detects that pin 15 of the eDP connector is high, it outputs a low level to the upstream control terminal 23 of the upstream conversion unit 20, controlling the first upstream output terminal 21 of the upstream conversion unit 20 to output an eDP signal. When pin 33 of the M054LDN microcontroller is high, it outputs a high level to the upstream control terminal 23 of the upstream conversion unit 20, controlling the second upstream output terminal 22 of the upstream conversion unit 20 to output an eDP signal, and simultaneously outputs a signal to the downstream conversion unit 30. The downstream control terminal 32 outputs a low level, controlling the downstream output terminal 31 of the downstream conversion unit 30 to output an LVDS signal; when pin 34 of the M054LDN microcontroller is high, the M054LDN microcontroller outputs a high level to the upstream control terminal 23 of the upstream conversion unit 20, controlling the second upstream output terminal 22 of the upstream conversion unit 20 to output an eDP signal, and simultaneously outputs a high level to the downstream control terminal 32 of the downstream conversion unit 30, controlling the downstream output terminal 31 of the downstream conversion unit 30 to output a MIPI signal.

[0038] Furthermore, referring to Figure 5 and Figure 6The direct-connect multi-screen interface expansion circuit further includes a first level inverting unit 50 and a second level inverting unit 60. The control unit 40 is connected to a second pin through the first level inverting unit 50 and to a third pin through the second level inverting unit 60. The first level inverting unit 50 inverts the level signal of the second pin and outputs it to the control unit 40, and the second level inverting unit 60 inverts the level signal of the second pin and outputs it to the control unit 40. In a specific implementation, the control unit 40 is connected to the upstream control terminal 23 of the upstream conversion unit 20 and the downstream control terminal 32 of the downstream conversion unit 30, respectively. By controlling the level signals of the upstream control terminal 23 of the upstream conversion unit 20 and the downstream control terminal 32 of the downstream conversion unit 30, the upstream conversion unit 20 and the downstream conversion unit 30 output corresponding interface signals. Since the first pin of the first connector 11 is at a high level when connected to the display screen, and the corresponding second and third pins of the second connector 12 and the third connector 13 are at a low level when connected to the display screen, in order to facilitate the control unit 40 to uniformly identify the connection status of the display screen and unify the signal, the control unit 40 connects the second pin through the first level inverting unit 50 and the third pin through the second level inverting unit 60. Both the first level inverting unit 50 and the second level inverting unit 60 can realize level flipping, which can flip the low level to a high level and the high level to a low level. In this way, when any of the first connector 11, the second connector 12, and the third connector 13 is connected to the corresponding display screen, the control unit 40 can receive a high level, thereby enabling better control of the upstream conversion unit 20 and the downstream conversion unit 30.

[0039] Furthermore, referring to Figure 5 and Figure 6The first level inverting unit 50 includes a first MOSFET Q1, a first resistor R1, and a second resistor R2. The gate of the first MOSFET Q1 is connected to the second pin and connected to the power supply through the first resistor R1. The drain of the first MOSFET Q1 is connected to the power supply through the second resistor R2, and the source of the first MOSFET Q1 is grounded. The first level inverting unit 50 also includes a second MOSFET Q2, a third resistor R3, and a fourth resistor R4. The gate of the second MOSFET Q2 is connected to the third pin and connected to the power supply through the third resistor R3. The drain of the second MOSFET Q2 is connected to the power supply through the fourth resistor R4, and the source of the second MOSFET Q2 is grounded. In specific implementations, the first level inverting unit 50 and the second level inverting unit 60 have the same structure, both using a switching transistor and a resistor to invert the level signal. When the display screen is not connected, the second pin of the second connector 12 and the third pin of the third connector 13 are both at a high level. The gates of the first MOSFET Q1 and the second MOSFET Q2 are both at a high level, causing the first MOSFET Q1 to conduct, grounding its drain, and the second MOSFET Q2 to conduct, grounding its drain. The control unit 40 receives a low-level signal. When the second connector 12 is connected to the display screen, the second pin of the second connector 12 is at a low level, the first MOSFET Q1 is off, and the second resistor R2 pulls the drain of the first MOSFET Q1 up to the power supply VCC3_3. At this time, the control unit 40 receives a high-level signal. Similarly, when the third connector 13 is connected to the display screen, the third pin of the third connector 13 is at a low level, the second MOSFET Q2 is off, and the fourth resistor R4 pulls the drain of the second MOSFET Q2 up to the power supply VCC3_3. At this time, the control unit 40 receives a high-level signal.

[0040] In summary, the direct-connect multi-screen interface expansion circuit of this utility model expands one input signal into multiple interface signals with different interfaces and communication protocols, and outputs them to the corresponding type of connector. After the connector is connected to the corresponding display screen, it can be automatically recognized and directly displayed. It can flexibly accommodate multiple different types of display screens and meet the connection and usage needs of different types of display screens.

[0041] Reference Figure 8 This utility model also provides an industrial control computer 200. Figure 8The diagram shows a partial structural block diagram of the industrial control computer 200. The industrial control computer 200 can be used in industrial control, automated production, and other scenarios. The industrial control computer 200 includes a CPU unit 210 and a direct-connect multi-screen interface expansion circuit 220 provided in the above embodiment. The direct-connect multi-screen interface expansion circuit 220 is connected to the CPU unit 210. The CPU unit 210 acts as the upper-level control unit of the direct-connect multi-screen interface expansion circuit 220. The CPU unit 210 inputs signals to the direct-connect multi-screen interface expansion circuit 220, which then performs interface expansion output. Different types of displays can interact with the CPU unit 210 by connecting to the direct-connect multi-screen interface expansion circuit 220. Directly connected displays can include commonly used eDP displays, LVDS displays, MIPI displays, etc. It does not require occupying multiple graphics card video resources and can be compatible with various types of displays in the industry, enabling direct connection display of multiple screens and meeting the direct connection display needs of various displays on site. Since the previous manual has already described in detail the specific structure and working principle of the direct connection multi-screen interface expansion circuit 220, it will not be repeated here for the sake of brevity.

[0042] The industrial control computer in this embodiment, by adopting the direct-connect multi-screen interface expansion circuit provided in this utility model embodiment, can adapt to various types of displays on site, meet the direct-connect display requirements of the on site displays, has good applicability, and is more convenient to use.

[0043] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this utility model, and these modifications or substitutions should all be covered within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope of the claims.

Claims

1. A direct-connect multi-screen interface expansion circuit, characterized in that, include: The interface unit includes multiple connectors of different types, which are used to connect to the display screen; An upstream conversion unit, connected to one type of connector, is used to convert an input signal into an interface signal that matches the communication protocol corresponding to the type of the connected connector; A downstream conversion unit, connecting the upstream conversion unit and other types of connectors, is used to convert the interface signal of the upstream conversion unit into an interface signal that matches the communication protocol corresponding to the type of the connected connector; The control unit, which connects the upstream conversion unit, the downstream conversion unit, and all types of connectors, is used to identify when the display screen is connected to the connector and control the upstream conversion unit and the downstream conversion unit to output the corresponding interface signals to the connector connected to the display screen.

2. The direct-connect multi-screen interface expansion circuit according to claim 1, characterized in that, The upstream conversion unit is provided with a first upstream output terminal, a second upstream output terminal, and an upstream control terminal. One type of connector is connected to the first upstream output terminal, the downstream conversion unit is connected to the second upstream output terminal, and the control unit is connected to the upstream control terminal. The control unit controls the upstream conversion unit to select the first upstream output terminal or the second upstream output terminal to output interface signals by outputting control signals to the upstream control terminal.

3. The direct-connect multi-screen interface expansion circuit according to claim 2, characterized in that, The downstream conversion unit has a downstream output terminal and a downstream control terminal. The downstream output terminal is connected to the other types of connectors respectively. The control unit is connected to the downstream control terminal. The control unit controls the downstream conversion unit to select one type of interface signal to be output through the downstream output terminal by outputting a control signal to the downstream control terminal.

4. The direct-connect multi-screen interface expansion circuit according to claim 3, characterized in that, The plurality of connectors of different types include a first connector, a second connector, and a third connector, wherein the first connector is connected to the first upstream output terminal, and the second connector and the third connector are both connected to the downstream output terminal.

5. The direct-connect multi-screen interface expansion circuit according to claim 4, characterized in that, The first connector is an eDP connector, the second connector is an LVDS connector, and the third connector is a MIPI connector.

6. The direct-connect multi-screen interface expansion circuit according to claim 5, characterized in that, The first connector has a first pin, the second connector has a second pin, and the third connector has a third pin. The control unit is connected to the first pin, the second pin, and the third pin. The control unit determines whether the first connector, the second connector, and the third connector are connected to the display screen by identifying the level signals of the first pin, the second pin, and the third pin.

7. The direct-connect multi-screen interface expansion circuit according to claim 6, characterized in that, The direct-connect multi-screen interface expansion circuit further includes a first level inverting unit and a second level inverting unit. The control unit is connected to a second pin through the first level inverting unit and to a third pin through the second level inverting unit. The first level inverting unit is used to invert the level signal of the second pin and output it to the control unit, and the second level inverting unit is used to invert the level signal of the second pin and output it to the control unit.

8. The direct-connect multi-screen interface expansion circuit according to claim 7, characterized in that, The first level inverting unit includes a first MOSFET, a first resistor, and a second resistor. The gate of the first MOSFET is connected to the second pin and is connected to the power supply through the first resistor. The drain of the first MOSFET is connected to the power supply through the second resistor. The source of the first MOSFET is grounded.

9. The direct-connect multi-screen interface expansion circuit according to claim 8, characterized in that, The first level inverting unit includes a second MOSFET, a third resistor, and a fourth resistor. The gate of the second MOSFET is connected to the third pin and connected to the power supply through the third resistor. The drain of the second MOSFET is connected to the power supply through the fourth resistor. The source of the second MOSFET is grounded.

10. An industrial control computer, characterized in that, It includes a CPU unit and a direct-connect multi-screen interface expansion circuit as described in any one of claims 1-9, wherein the direct-connect multi-screen interface expansion circuit is connected to the CPU unit.

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