Display switching circuit of double-display mainboard

Abstract

The utility model relates to a display switching circuit of a double-display mainboard, which comprises an information source expansion switcher, a mainboard display output interface, an external display signal input interface, a switching display output interface and a first resistor, the input end of the information source expansion switcher comprises a first information source access channel, a second information source access channel and a gating access port; the first information source access channel is connected with the mainboard display output interface, the external display signal input interface is respectively connected with the second information source access channel and the gating access port, and the output end of the information source expansion switcher is connected with the switching display output interface; one end of the first resistor is connected with the gating access port, and the other end of the first resistor is grounded; according to the utility model, after an external display signal is accessed into the external display signal input interface, the signal source expansion switcher can output the external display signal, thereby realizing automatic selection and output of the external display signal.

Description

Technical Field

[0001] This utility model relates to the field of computer motherboard technology, specifically to a display switching circuit for a dual-display motherboard. Background Technology

[0002] Computer motherboards typically only output their own display data and cannot connect to external displays. While some laptops do have external display capabilities, this data is only displayed on the local monitor. When using a laptop for PowerPoint presentations, external data needs to be inserted into the laptop via a removable storage device, and the document opened on the laptop for display. For highly confidential files that are unsuitable for data transfer, confidentiality is compromised when presenting the content.

[0003] It is evident that existing computer motherboards lack the functionality of an intermediate display data transmission interface, resulting in cumbersome data display or file content presentation. Utility Model Content

[0004] To address the technical problem that existing computer motherboards lack an intermediate display data transmission interface, resulting in cumbersome data display or file content presentation, this utility model provides a display switching circuit for a dual-display motherboard.

[0005] The technical solution of this utility model to solve the above-mentioned technical problems is as follows:

[0006] A display switching circuit for a dual-display motherboard includes a source expansion switcher, a motherboard display output interface, an external display signal input interface, a switching display output interface, and a first resistor. The input terminal of the source expansion switcher includes a first source access channel, a second source access channel, and a gating access port. The first source access channel is connected to the motherboard display output interface, and the external display signal input interface is connected to the second source access channel and the gating access port, respectively. The output terminal of the source expansion switcher is connected to the switching display output interface. One end of the first resistor is connected to the gating access port, and the other end of the first resistor is grounded. The motherboard display output interface is used to connect to the display output interface of a computer motherboard.

[0007] The beneficial effects of this invention are as follows: By setting up a dual-input, single-output source expansion switch, and connecting the computer motherboard's display output port and the external display signal input interface to the two input ports of the source expansion switch respectively, and the external display signal input interface also connected to the selection access port of the source expansion switch, when an external display input signal is connected to the external display signal input interface, the selection access port of the source expansion switch is at a high level, and the source expansion switch outputs the display signal from the external display signal input interface; when no display signal is connected to the external display signal input interface, the selection access port is at a low level, and the source expansion switch outputs the display signal output by the motherboard. Therefore, this invention enables the source expansion switch to output an external display signal after an external display signal is connected to the external display signal input interface, achieving automatic selection and output of the external display signal. When a computer equipped with this invention connects to an external display signal, the computer motherboard can automatically output the external display signal from the computer's display output port, giving the computer the function of an intermediate display data transmission interface, and realizing convenient display of data or file content.

[0008] Based on the above technical solution, the present invention can be further improved as follows.

[0009] Furthermore, the motherboard display output interface, the external display signal input interface, and the switching display output interface are all high-definition multimedia interfaces.

[0010] Furthermore, it also includes an OR gate, which has two input terminals. One input terminal of the OR gate is electrically connected to the AC voltage transmission pin of the external display signal input interface, and the other input terminal of the OR gate is grounded. The output terminal of the OR gate is electrically connected to the gating access port.

[0011] The beneficial effect of adopting the above-mentioned further solution is that by setting an OR gate, it is possible to determine whether the external input signal is at a high level, and drive the gating access port through the OR gate, thereby improving the high-level driving performance of the gating access port.

[0012] Furthermore, it also includes a signal amplification unit, the signal input terminal of which is electrically connected to the output terminal of the OR gate, and the output terminal of which is electrically connected to the gating access port.

[0013] The beneficial effect of adopting the above-mentioned further solution is that, by setting up an amplification unit, the driving capability of the external display signal to the gating access port can be improved.

[0014] Furthermore, the signal amplification unit includes a second resistor, a third resistor, a fourth resistor, and an operational amplifier. One end of the second resistor is electrically connected to the inverting input terminal of the operational amplifier, and the other end of the second resistor is electrically connected to the output terminal of the operational amplifier. One end of the third resistor is electrically connected to the inverting input terminal of the operational amplifier, and the other end of the third resistor is grounded. The non-inverting input terminal of the operational amplifier is electrically connected to the output terminal of the OR gate through the fourth resistor in series.

[0015] The beneficial effect of adopting the above-mentioned further scheme is that by using an operational amplifier, a second resistor, and a third resistor to form a non-inverting amplifier, the output voltage of the OR gate is amplified to improve the driving capability.

[0016] Furthermore, the source expansion switcher is specifically a source expansion switch chip of model ASE3642. A fifth resistor is connected to the enable pin of the source expansion switch chip. One end of the fifth resistor is electrically connected to the enable pin of the source expansion switch chip, and the other end of the fifth resistor is grounded.

[0017] The advantage of adopting the above-mentioned further solution is that by connecting a fifth resistor to the enable pin and using the fifth resistor as a pull-down resistor, the voltage on the enable pin is prevented from being too high, which would affect the normal use of the source expansion switching chip.

[0018] Furthermore, it also includes a first switch, one end of which is electrically connected to the selected access port, and the other end of which is grounded.

[0019] The beneficial effect of adopting the above-mentioned further solution is that, by setting a first switch, when it is necessary for the motherboard to force the output of the motherboard's display signal, the first switch can be directly turned on, so that the selected access port is directly grounded and continuously kept at a low level, thereby forcing the output of the motherboard's display signal and preventing accidental connection of external display signals.

[0020] Furthermore, it also includes a second switch, one end of which is electrically connected to the selected access port, and the other end of which is connected to the power supply voltage.

[0021] The beneficial effect of adopting the above-mentioned further solution is that by setting a second switch to connect the power supply voltage, when the second switch is turned on, the selected access port remains in a high-level state, and the signal source expansion switching chip will continue to output external display signals.

[0022] To solve the above-mentioned technical problems, a computer motherboard is also provided, the specific technical details of which are as follows:

[0023] A computer motherboard includes a display switching circuit for the aforementioned dual-display motherboard.

[0024] To solve the above-mentioned technical problems, a computer motherboard is also provided, the specific technical details of which are as follows:

[0025] A computer includes a computer host, wherein a computer motherboard is disposed within the computer host, and the computer motherboard includes the display switching circuit of the aforementioned dual-display motherboard. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the display switching circuit of a dual-display motherboard in an embodiment of the present invention. Figure 1 ;

[0027] Figure 2 This is a schematic diagram of the display switching circuit of a dual-display motherboard in an embodiment of the present invention. Figure 2 ;

[0028] Figure 3 This is a circuit diagram of the signal amplification unit in an embodiment of this utility model. Detailed Implementation

[0029] The principles and features of this utility model are described below with reference to the accompanying drawings. The examples given are only for explaining this utility model and are not intended to limit the scope of this utility model.

[0030] like Figure 1 As shown, this embodiment provides a display switching circuit for a dual-display motherboard, including a source expansion switcher, a motherboard display output interface, an external display signal input interface, a switching display output interface, and a first resistor R1. The input terminal of the source expansion switcher includes a first source access channel, a second source access channel, and a gating access port. The first source access channel is connected to the motherboard display output interface, and the external display signal input interface is connected to the second source access channel and the gating access port, respectively. The output terminal of the source expansion switcher is connected to the switching display output interface. One end of the first resistor R1 is connected to the gating access port, and the other end of the first resistor R1 is grounded. The motherboard display output interface is used to connect to the display output interface of the computer motherboard, the external display signal input interface is used to access external display signals, and the gating access port SEL is an enable gating port. When the gating access port SEL is low, the output channel C of the source expansion switcher outputs the signal of the first source access channel A; when the gating access port SEL is high, the output channel C of the source expansion switcher outputs the signal of the second source access channel B.

[0031] The first signal source access channel A and the second signal source access channel B are two input signals of the signal source expansion switcher. The output channel C of the signal source expansion switcher is directly connected to the switching display output interface to output the motherboard's display output signal or the external display signal through the switching display output interface.

[0032] like Figure 2 As shown, in some embodiments, the motherboard display output interface, the external display signal input interface, and the switching display output interface are all High Definition Multimedia Interfaces (HDMI) interfaces. HDMI interfaces can transmit audio and video signals, I2C and other control signals, and +5V power signals. Besides providing audio and video signals to external display devices, they can also provide +5V power. HDMI is a fully digital video and audio transmission interface that can send uncompressed audio and video signals. HDMI can be used in set-top boxes, DVD players, personal computers, televisions, game consoles, integrated amplifiers, digital audio systems, and televisions. HDMI can transmit audio and video signals simultaneously, greatly simplifying system wiring installation because audio and video signals use the same cable. Here, HDMI interface mainly refers to a communication connector with an HDMI interface type.

[0033] exist Figure 2 In this design, the source expansion switcher is specifically a source expansion switch chip U1, model ASE3642. A fifth resistor R5 is connected to the enable pin of the source expansion switch chip. One end of the fifth resistor R5 is electrically connected to the enable pin of the source expansion switch chip, and the other end is grounded. The power input terminal VCC of the source expansion switch chip U1 is connected to a positive 5V power supply voltage. The power input terminal VCC of the source expansion switch chip U1 is electrically connected to one end of a first capacitor C1, and the other end of the first capacitor C1 is grounded, using the first capacitor C1 to filter the power supply voltage. Specifically, the first capacitor C1 is a variable capacitor. By connecting the fifth resistor R5 to the enable pin nOE, the fifth resistor R5 acts as a pull-down resistor to prevent excessive voltage on the enable pin, which could affect the normal operation of the source expansion switch chip.

[0034] In some embodiments, the display switching circuit further includes an OR gate U2, which has two input terminals. One input terminal of the OR gate U2 is electrically connected to the AC voltage transmission pin of the external display signal input interface, and the other input terminal of the OR gate U2 is grounded. The output terminal of the OR gate U2 is electrically connected to the gating access port. Since the two input terminals of the OR gate U2 are respectively connected to the +5V AC voltage pin of the external display signal input interface and ground, when an external display signal passes through the external display signal input interface, the +5V AC voltage pin of the external display signal input interface carries a high-level voltage of +5V. The OR gate U2 directly outputs a high level to drive the gating access port SEL of the signal source extension switching chip U1.

[0035] By setting OR gate U2, it is possible to determine whether the external input signal is at a high level, and drive the gating access port through the OR gate, thereby improving the high-level driving performance of the gating access port.

[0036] In some embodiments, the display switching circuit further includes a signal amplification unit, the signal input terminal of which is electrically connected to the output terminal of the OR gate U2, and the output terminal of which is electrically connected to the gating access port. By providing the amplification unit, the driving capability of the external display signal on the gating access port can be improved.

[0037] like Figure 3 As shown, the signal amplification unit includes a second resistor R2, a third resistor R3, a fourth resistor R4, and an operational amplifier U3. One end of the second resistor R2 is electrically connected to the inverting input terminal of the operational amplifier U3, and the other end of the second resistor R2 is electrically connected to the output terminal of the operational amplifier U3. One end of the third resistor R3 is electrically connected to the inverting input terminal of the operational amplifier U3, and the other end of the third resistor R3 is grounded. The non-inverting input terminal of the operational amplifier U3 is electrically connected to the output terminal of the OR gate U2 through the fourth resistor R4 in series. The operational amplifier U3 requires a 3.3V power supply during operation, which is common knowledge for operational amplifier U3 applications. Therefore, the operational amplifier U3 can be powered by the 3.3V power supply on the motherboard. The amplification factor formula for the signal amplification unit is: Vo = Vp(1 + R4 / R3); Vo is the output voltage of the signal amplification unit, Vp is the input voltage of the signal amplification unit (i.e., the output voltage of the OR gate U2), R4 is the resistance value of the fourth resistor R4, and R3 is the resistance value of the third resistor R3. By using operational amplifier U3, second resistor R2, and third resistor R3 to construct a non-inverting amplifier, the output voltage of the OR gate is amplified to improve the driving capability.

[0038] In some embodiments, the display switching circuit further includes a first switch S1, one end of which is electrically connected to the selection access port, and the other end of which is grounded. The first switch S1 can preferably be a position-switching slider switch with two positions, representing the first switch S1 being on and off respectively. By setting the first switch S1, when it is necessary to force the motherboard to output its display signal, the first switch S1 can be directly turned on, causing the selection access port to be directly grounded and continuously maintained at a low level, thereby forcing the output of the motherboard's display signal and preventing accidental connection of external display signals.

[0039] In some embodiments, the display switching circuit further includes a second switch S2, one end of which is electrically connected to the selection access port, and the other end of which is connected to a power supply voltage. By setting the second switch S2 to connect the power supply voltage, when the second switch S2 is turned on, the selection access port remains at a high level, and the signal source expansion switching chip will continue to output external display signals.

[0040] This embodiment of the invention uses a dual-input, single-output source expansion switch. The display output port of the computer motherboard and the external display signal input interface are connected to the two input ports of the source expansion switch, respectively. The external display signal input interface is also connected to the selection access port of the source expansion switch. When an external display input signal is connected to the external display signal input interface, the selection access port of the source expansion switch is at a high level, and the source expansion switch outputs the display signal from the external display signal input interface. When no display signal is connected to the external display signal input interface, the selection access port is at a low level, and the source expansion switch outputs the display signal from the motherboard. Therefore, this invention enables the source expansion switch to output an external display signal after an external display signal is connected to the external display signal input interface, achieving automatic selection and output of the external display signal. When a computer equipped with this invention connects to an external display signal, the computer motherboard can automatically output the external display signal from the computer's display output port, giving the computer the function of an intermediate display data transmission interface, enabling convenient display of data or file content.

[0041] In other embodiments, a computer motherboard is also provided, including the display switching circuit of the aforementioned dual-display motherboard. In this embodiment, the computer motherboard can be a functional circuit board with display output, the motherboard inside the computer host, or a graphics card circuit board, i.e., configuring the switching circuit of this utility model on the existing graphics card to realize the switching output of external display signals.

[0042] In other embodiments, a computer is also provided, including a computer host, wherein a computer motherboard is disposed within the computer host, and the computer motherboard includes the display switching circuit of the aforementioned dual-display motherboard. In this embodiment, the computer motherboard is a motherboard with display output function, i.e., a computer motherboard integrating a display chip.

[0043] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the concept and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A display switching circuit for a dual-display motherboard, characterized in that: The device includes a source expansion switcher, a motherboard display output interface, an external display signal input interface, a switching display output interface, and a first resistor (R1). The input terminal of the source expansion switcher includes a first source access channel, a second source access channel, and a gating access port. The first source access channel is connected to the motherboard display output interface, and the external display signal input interface is connected to the second source access channel and the gating access port, respectively. The output terminal of the source expansion switcher is connected to the switching display output interface. One end of the first resistor (R1) is connected to the gating access port, and the other end of the first resistor (R1) is grounded. The motherboard display output interface is used to connect to the display output interface of the computer motherboard.

2. The display switching circuit of the dual-display motherboard according to claim 1, characterized in that: The motherboard display output interface, the external display signal input interface, and the switching display output interface are all high-definition multimedia interfaces.

3. The display switching circuit of the dual-display motherboard according to claim 2, characterized in that: It also includes an OR gate (U2), which has two input terminals. One input terminal of the OR gate (U2) is electrically connected to the AC voltage transmission pin of the external display signal input interface, and the other input terminal of the OR gate (U2) is grounded. The output terminal of the OR gate (U2) is electrically connected to the gating access port.

4. The display switching circuit of the dual-display motherboard according to claim 3, characterized in that: It also includes a signal amplification unit, the signal input terminal of which is electrically connected to the output terminal of the OR gate (U2), and the output terminal of which is electrically connected to the gating access port.

5. The display switching circuit of the dual-display motherboard according to claim 4, characterized in that: The signal amplification unit includes a second resistor (R2), a third resistor (R3), a fourth resistor (R4), and an operational amplifier (U3). One end of the second resistor (R2) is electrically connected to the inverting input terminal of the operational amplifier (U3), and the other end of the second resistor (R2) is electrically connected to the output terminal of the operational amplifier (U3). One end of the third resistor (R3) is electrically connected to the inverting input terminal of the operational amplifier (U3), and the other end of the third resistor (R3) is grounded. The non-inverting input terminal of the operational amplifier (U3) is electrically connected to the output terminal of the OR gate (U2) through the fourth resistor (R4) in series.

6. The display switching circuit of the dual-display motherboard according to claim 1, characterized in that: The source expansion switcher is specifically a source expansion switch chip with model number ASE3642. A fifth resistor (R5) is connected to the enable pin of the source expansion switch chip. One end of the fifth resistor (R5) is electrically connected to the enable pin of the source expansion switch chip, and the other end of the fifth resistor (R5) is grounded.

7. The display switching circuit of the dual-display motherboard according to claim 1, characterized in that: It also includes a first switch (S1), one end of which is electrically connected to the selected access port, and the other end of which is grounded.

8. The display switching circuit of the dual-display motherboard according to claim 7, characterized in that: It also includes a second switch (S2), one end of which is electrically connected to the selected access port, and the other end of which is connected to the power supply voltage.

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