Keyboard and all-in-one machine equipment

Abstract

The utility model provides a key board and all-in-one machine equipment. The key board comprises an interface module, a voltage conversion module, a key module, a first grounding end and a second grounding end, the input end of the voltage conversion module is used for connecting a power supply anode end of a mainboard, the first output end of the voltage conversion module is connected with the first end of the key module, the second end of the key module is used for connecting a signal detection end of the mainboard, and the third end of the key module is connected with a first grounding end which is used for connecting a power supply cathode end of the mainboard through a first connecting line. The second output end of the voltage conversion module is connected with the power supply end of the interface module, the interface module is further connected with the first end of an external load, and the second grounding end is connected with the second end of the external load and connected with the power supply cathode end through a second connecting line; through the arrangement, the first current loop and the second current loop are independent from each other, so that a partial pressure signal output by the key module is prevented from being influenced when the interface module outputs power to the load, and the accuracy and the reliability of key detection are improved.

Description

Technical Field

[0001] The embodiments of the utility model relate to the field of circuit technology, and in particular to a keypad and an all-in-one device. Background Art

[0002] All-in-one products usually have the characteristics of strong integration, small space occupation, simple and beautiful appearance, etc. In all-in-one products, buttons are an indispensable way of interaction. Usually a separate keypad is designed, on which buttons and interfaces corresponding to specific functions are set, such as Figure 1 As shown, the keypad 1 may include a Universal Serial Bus (USB) interface module 11 and a keypad module 12. When the USB interface module 11 is externally connected to a load 3, the keypad 11 and the load 12 are both connected to the mainboard 2 via the same connection line. For example, the negative electrodes of the keypad 12 and the load 3 are both connected to the ground GND of the mainboard 2 via a cable containing a resistor Rp1. The resistor Rp1 is the equivalent resistance of the connection line between the negative terminal of the keypad 1 and the negative terminal of the mainboard 2. In this circuit, the mainboard 2 typically uses a preset fixed value to compare with the voltage amplitude at position A to determine which key is pressed. It is understandable that the current flowing through the load 3 will flow through the resistor Rp1, generating a certain voltage drop across the resistor Rp1. When the current flowing through the load 3 increases, the voltage amplitude at position B will change, causing the voltage divider value at position A to change when a key in the keypad 12 is pressed. This will affect the mainboard's recognition accuracy of the key and result in inaccurate key recognition. Utility Model Content

[0003] The embodiment of the utility model provides a keypad and an all-in-one device, which makes the current loop of the key module independent of the current loop of the interface module, thereby preventing the interface module from affecting the voltage division signal output by the key module when outputting power to the load, and improving the accuracy of key detection.

[0004] In the first aspect, the utility model provides a keypad, which includes: an interface module, a voltage conversion module, a keypad module, a first grounding terminal, and a second grounding terminal. The input terminal of the voltage conversion module is used to connect to the positive power terminal of the mainboard, the first output terminal of the voltage conversion module is connected to the first end of the keypad module, the second end of the keypad module is used to connect to the signal detection terminal of the mainboard, the third end of the keypad module is connected to the first grounding terminal, the first grounding terminal is used to connect to the negative power terminal of the mainboard through a first connecting line, the second output terminal of the voltage conversion module is connected to the power supply terminal of the interface module, the interface module is also used to connect to the first end of an external load, the second grounding terminal is used to connect to the second end of the external load and to the negative power terminal through a second connecting line; wherein, the voltage conversion module is configured to perform voltage conversion on the input voltage; when the input terminal of the voltage conversion module is connected to the positive power terminal, the first grounding terminal is connected to the negative power terminal of the mainboard, and the second grounding terminal is connected to the negative power terminal of the mainboard. When the ground end is connected to the negative end of the power supply through the first connecting line, the positive end of the power supply, the voltage conversion module, the first end of the button module, the third end of the button module, the first ground end and the negative end of the power supply form a first current loop, and the button module is configured to output a voltage division signal to the mainboard based on the first current loop when triggered; when the input end of the voltage conversion module is connected to the positive end of the power supply, the interface module is connected to the first end of the external load, the second end of the external load is connected to the second ground end, and the second ground end is connected to the negative end of the power supply through the second connecting line, the positive end of the power supply, the voltage conversion module, the interface module, the external load, the first ground end and the negative end of the power supply form a second current loop.

[0005] In this embodiment, the third end of the key module is connected to the negative end of the power supply through a first connecting line, and the second ground end is connected to the negative end of the power supply through a second connecting line, so that the first current loop and the second current loop are independent return paths and do not interfere with each other, thereby avoiding the interface module from affecting the voltage divider signal output by the key module when outputting power to the load, thereby improving the accuracy and reliability of key detection.

[0006] In some embodiments, the voltage conversion module includes a first voltage conversion unit and a second voltage conversion unit; the input end of the first voltage conversion unit and the input end of the second voltage conversion unit are both used to connect to the positive terminal of the power supply, the output end of the first voltage conversion unit is connected to the first terminal of the key module, and the output end of the second voltage conversion unit is connected to the power supply end of the interface module. The first voltage conversion unit is configured to perform voltage conversion on the input voltage and output the converted voltage to the key module; the second voltage conversion unit is configured to perform voltage conversion on the input voltage and output the converted voltage to the interface module.

[0007] In this embodiment, by providing a first voltage conversion unit and a second voltage conversion unit, the input power can be converted into different voltages and output to different modules to meet the input voltage required by each module.

[0008] In some embodiments, the first voltage conversion unit includes one of a DC-to-DC converter and a low-voltage dropout linear regulator; the second voltage conversion unit includes one of a DC-to-DC converter and a low-voltage dropout linear regulator.

[0009] In this embodiment, a DC-DC converter or a low voltage dropout linear regulator can be selected as the voltage conversion unit according to actual needs, which can improve the flexibility of design.

[0010] In some embodiments, the interface module includes a universal serial bus interface, a power supply terminal of the universal serial bus interface is connected to the second output terminal of the voltage conversion module, and the universal serial bus interface is further configured to connect to a first terminal of an external load.

[0011] In this embodiment, by setting a universal serial bus interface on the keypad, external devices such as a USB flash drive, keyboard, mouse or other peripheral devices can be easily connected. Subsequently, the keypad is applied to all-in-one products to expand the functions and compatibility of the all-in-one product.

[0012] In some embodiments, the data transmission end of the interface module is used to connect to the data transmission end of the mainboard.

[0013] In this embodiment, by connecting the data transmission end of the interface module with the data transmission end of the mainboard, subsequent external loads can achieve bidirectional communication with the mainboard through the interface module after being connected to the interface module, thereby improving user experience.

[0014] In some embodiments, the key module includes a first resistor, at least one key unit, and at least one voltage divider unit. The key units correspond to the voltage divider units one by one, the first end of the first resistor is connected to the first output end of the voltage conversion module, the second end of the first resistor is respectively connected to the first end of each key unit and the signal detection end of the mainboard, the second end of each key unit is connected to the first end of the corresponding voltage divider unit, and the second end of each voltage divider unit is connected to the first ground end. The key unit is configured to conduct the connection between the corresponding voltage divider unit and the first resistor when triggered, so that the second end of the first resistor outputs the voltage divider signal.

[0015] In this embodiment, the above structure is used as a button module. When different buttons are pressed, the second end of the first resistor can output voltage-divided signals of different sizes to the mainboard, allowing the mainboard to identify which button unit is pressed, thereby saving the interface resources of the mainboard.

[0016] In some embodiments, the voltage dividing unit includes a second resistor, a first end of the second resistor is connected to the second end of the corresponding button unit, and a second end of the second resistor is connected to the first ground end.

[0017] In this embodiment, by setting a second resistor, the voltage dividing unit can be used to divide the voltage. During the design process, the resistance value of the second resistor in each voltage dividing unit is made different, so that when each key unit is pressed, the voltage dividing signal output from the second end of the first resistor is different, which enables the motherboard to accurately identify the pressing status of different key units, thereby realizing multi-function key operation.

[0018] In a second aspect, an embodiment of the present invention further provides an all-in-one device, comprising a mainboard, a cable, and a keypad as described in any one of the first aspects. The cable comprises a first connecting line, a second connecting line, a third connecting line, and a fourth connecting line, wherein the first grounding terminal in the keypad is connected to the negative power supply terminal of the mainboard via the first connecting line, the second grounding terminal in the keypad is connected to the negative power supply terminal of the mainboard via the second connecting line, the input terminal of the voltage conversion module in the keypad is connected to the positive power supply terminal of the mainboard via the third connecting line, and the second terminal of the key module in the keypad is connected to the signal detection terminal of the mainboard via the fourth connecting line.

[0019] In this embodiment, the third end of the key module is connected to the negative end of the power supply through a first connecting line, and the second ground end is connected to the negative end of the power supply through a second connecting line, so that the first current loop and the second current loop are independent return paths and do not interfere with each other, thereby avoiding the interface module from affecting the voltage divider signal output by the key module when outputting power to the load, thereby improving the accuracy and reliability of key detection.

[0020] In some embodiments, the mainboard includes a main control chip; the main control chip is connected to the signal detection end, and the main control chip is configured to determine the key information based on the voltage division signal output by the key module.

[0021] In this embodiment, a main control chip integrating multiple functional modules is used as a controller in the mainboard, which can not only realize the function of identifying keys, but also control the operation of other modules, which can greatly reduce the size of the device and improve the overall performance.

[0022] In some embodiments, the all-in-one device further includes a display device; the display device is connected to the mainboard.

[0023] In this embodiment, by providing a display device, information can be presented intuitively, human-computer interaction can be facilitated, and user experience can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] One or more embodiments are exemplarily described by pictures in the corresponding drawings. These exemplified descriptions do not constitute limitations on the embodiments. Elements / modules and steps with the same reference numerals in the drawings are represented as similar elements / modules and steps. Unless otherwise stated, the figures in the drawings do not constitute a scale limitation.

[0025] Figure 1 This is a structural diagram of a keypad provided by the prior art;

[0026] Figure 2 This is a partial structural diagram of an all-in-one device provided by an embodiment of the present utility model;

[0027] Figure 3 It is a partial structural diagram of another all-in-one device provided by an embodiment of the present utility model. DETAILED DESCRIPTION

[0028] The present invention will be described in detail below with reference to specific embodiments. The following embodiments will help those skilled in the art further understand the present invention, but are not intended to limit the present invention in any way. It should be noted that a person skilled in the art may make various modifications and improvements without departing from the scope of the present invention. These modifications and improvements are all within the scope of protection of the present invention.

[0029] For ease of understanding of the present application, the present application will be described in more detail below in conjunction with the accompanying drawings and specific embodiments. Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as those generally understood by those skilled in the art in the field of the present application. The terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit the present application. The term "and / or" used in this specification includes any and all combinations of one or more related listed items.

[0030] It should be noted that, unless they conflict, the various features of the embodiments of the present invention may be combined with each other and are all within the scope of protection of this application. Furthermore, although the functional modules are divided in the device schematic, in some cases, the module division may be different from that in the device. Furthermore, the terms "first," "second," and the like used herein do not limit the order of data or execution; they are merely used to distinguish between identical or similar items with substantially the same functions and effects.

[0031] At present, the keypad of an all-in-one product is usually provided with an interface module and a keypad module. When identifying the pressed key in the keypad module, an analog method is often used, that is, the voltage change on a pin of the control unit is compared with several preset fixed voltage values to identify the pressed key, such as Figure 1 As shown, due to the different resistance values of the resistors Rp3 and Rp4, when one of the buttons SW1 and SW2 is pressed, different voltage values will be generated at point A. However, when the interface module 11 is externally connected to a load 3, since the negative electrodes of the load 3 and the button module 12 are both connected to the ground GND of the motherboard 2 through the cable where the resistor Rp1 is located, when the USB interface module 11 outputs power to the load 3, that is, when the USB interface module 11 outputs current to the load 3, the current flowing through the load 3 will flow back to the ground GND of the motherboard 2 through the cable where the resistor Rp1 is located, and a certain voltage drop will be generated on the resistor Rp1, that is, the voltage divider signal U output by the button module 12 to the motherboard 2 A (That is, the voltage at position A) is:

[0032]

[0033] Among them, V2 is the voltage at one end of the resistor Rp2, that is, the voltage at position C, R p3 is the resistance value of resistor Rp3, R p2 is the resistance of resistor Rp2, I Rp1 is the current flowing through the resistor Rp1 , that is, the total current flowing from the keypad 1 to the mainboard 2 .

[0034] The resistor Rp1 is the equivalent resistance of the connection line between the negative terminal of the keypad 1 and the negative terminal of the mainboard 2. The resistance value of this resistor is generally in the milliohm level. When the power output of the keypad 1 to the load 3 is small, the return current of the keypad 1 is relatively small, so that I Rp1 *R p1 Much smaller than V2, at this time:

[0035]

[0036] That is U A It is only related to the voltage output by the mainboard 2 and the resistance value set in the key module. When the power output by the key board 1 to the load 3 is large, I Rp1 will become larger, thus affecting U A For example, when the output voltage V1 of the mainboard 2 is 12V and the power required by the keypad 1 is 12.5W, then I Rp1The load is 2.5A. When the resistance value of resistor Rp1 is 80 milliohms, the voltage drop at position B is 200mV. At this time, when the button SW1 is pressed, the voltage-dividing signal output by the button module 12 obtained by the mainboard 2 will be 200mV higher than the original set value, and the system will make an incorrect judgment. It can be understood that when the load is greater and the connecting cable between the negative pole of the key board 1 and the negative pole of the mainboard 2 is longer, the additional voltage drop will be greater, and the error will also be greater, resulting in a larger error in the voltage-dividing value output by the button module, the button detection will become inaccurate, and the reliability of the button recognition work will be seriously reduced.

[0037] In order to solve the above technical problems, the present application provides a keypad and an all-in-one device, in which the key module is connected to the negative power supply terminal of the mainboard through a first connecting line, and the interface module is connected to the negative power supply terminal of the mainboard through a second connecting line, so that the current loop of the key module and the current loop of the interface module are independent, thereby avoiding the interface module affecting the voltage divider signal output by the key module when outputting power to the load, thereby improving the accuracy and reliability of key detection.

[0038] In the first aspect, the present invention provides a keypad 100. Figure 2 The keypad 100 includes an interface module 110 , a voltage conversion module 120 , a keypad module 130 , a first ground terminal GND1 , and a second ground terminal GND2 .

[0039] The input end of the voltage conversion module 120 is used to connect to the positive power terminal VOUT of the mainboard 200, the first output end of the voltage conversion module 120 is connected to the first end of the key module 130, the second end of the key module 130 is used to connect to the signal detection end Detect of the mainboard 200, the third end of the key module 130 is connected to the first ground terminal GND1, the first ground terminal GND1 is used to connect to the negative power terminal GND3 of the mainboard 200 through the first connecting line 310, the second output end of the voltage conversion module 120 is connected to the power supply end of the interface module 110, the interface module 110 is also used to connect to the first end of the external load 400, the second ground terminal GND2 is used to connect to the second end of the external load 400 and to the negative power terminal GND3 through the second connecting line 320.

[0040] The voltage conversion module 120 is configured to convert an input voltage. When the input terminal of the voltage conversion module 120 is connected to the positive power supply terminal VOUT and the first ground terminal GND1 is connected to the negative power supply terminal GND3 via the first connection line 310, the positive power supply terminal VOUT, the voltage conversion module 120, the first terminal of the button module 130, the third terminal of the button module 130, the first ground terminal GND1, and the negative power supply terminal GND3 form a first current loop. The button module 130 is configured to output a voltage-divided signal based on the first current loop to the signal detection terminal Detect of the mainboard 200 when triggered. When the input end of the voltage conversion module 120 is connected to the positive power supply terminal VOUT, the interface module 110 is connected to the first end of the external load 400, the second end of the external load 400 is connected to the second ground terminal GND2, and the second ground terminal GND2 is connected to the negative power supply terminal GND3 through the second connecting line 320, the positive power supply terminal VOUT, the voltage conversion module 120, the interface module 110, the external load 400, the first ground terminal GND1 and the negative power supply terminal GND3 form a second current loop.

[0041] The external load 400 refers to a device that consumes power, such as a USB flash drive, keyboard, mouse, or other peripheral devices.

[0042] The voltage conversion module 120 can be used to convert the input voltage into the required voltage and output it. The voltage conversion module 120 can adopt different circuit structures to achieve voltage boost output or voltage buck output. Its circuit structure can refer to the existing technology and is not limited here.

[0043] In the key module 130 , when the user presses different keys in the key module 130 , the voltage values outputted from the second end of the key module 130 are not equal. Thus, the mainboard 200 can determine the state of the key by detecting the voltage value outputted from the second end of the key module 130 .

[0044] The positive power terminal VOUT refers to the positive terminal of the power module on the motherboard 200 that provides power to the keypad 100, and the negative power terminal GND3 refers to the negative terminal of the power module on the motherboard 200. Usually, the negative power terminal GND3 is the ground terminal, that is, the voltage of the negative power terminal GND3 can be 0V.

[0045] In actual applications, the input end of the voltage conversion module 120 can be connected to the positive power supply terminal VOUT of the mainboard 200 through the third connecting line 330, and the third end of the key module 130 can be connected to the signal detection end Detect of the mainboard 200 through the fourth connecting line 340. The first connecting line 310, the second connecting line 320, the third connecting line 330 and the fourth connecting line 340 can be uniformly packaged inside the cable 300. In this way, when the key panel 100 is used in an all-in-one device or other device, it is convenient to store the lines and improve the neatness of the line layout.

[0046] On the keypad 100 provided in this embodiment, the negative terminals of the modules other than the key module 130 are all connected to the second ground terminal GND2. When the input terminal of the voltage conversion module 120 is connected to the positive power terminal VOUT, the interface module 110 is connected to the first terminal of the external load 400, the second terminal of the external load 400 is connected to the second ground terminal GND2, and the second ground terminal GND2 is connected to the negative power terminal GND3 via the second connection line 320, the positive power terminal VOUT, the voltage conversion module 120, the first terminal of the key module 130, the third terminal of the key module 130, the first ground terminal GND1, and the negative power terminal GND3 form a first current loop. The positive power terminal VOUT, the voltage conversion module 120, The interface module 110, the external load 400, the first ground terminal GND1 and the negative power terminal GND3 form a second current loop. It can be seen that the third terminal of the key module is connected to the negative power terminal through the first connecting line, and the second ground terminal is connected to the negative power terminal through the second connecting line, so that the first current loop and the second current loop are independent return paths from each other, and the two do not interfere with each other. It can be ensured that when the key board 100 outputs power to the external load 400, the current on the second current loop will not affect the voltage value of the third terminal of the key module 130, that is, it will not affect the size of the voltage divider signal output by the key module 130 to the signal detection terminal Detect of the main board 200, thereby improving the accuracy and reliability of key recognition.

[0047] In some of these embodiments, see Figure 3 The voltage conversion module 120 includes a first voltage conversion unit 121 and a second voltage conversion unit 122. The input end of the first voltage conversion unit 121 and the input end of the second voltage conversion unit 122 are both used to connect to the positive power supply terminal VOUT. The output end of the first voltage conversion unit 121 is connected to the first end of the key module 130, and the output end of the second voltage conversion unit 122 is connected to the power supply end of the interface module 110. The first voltage conversion unit 121 is configured to perform voltage conversion on the input voltage and output the converted voltage to the key module 130; the second voltage conversion unit 122 is configured to perform voltage conversion on the input voltage and output the converted voltage to the interface module 110.

[0048] The first voltage conversion unit 121 can be used to convert the input voltage into the voltage required by the key module 130 and output it. Different circuit structures can be used to achieve a boosted or bucked output of the voltage. The second voltage conversion unit 122 can be used to convert the input voltage into the voltage required by the interface module 110 and output it. Different circuit structures can also be used to achieve a boosted or bucked output of the voltage.

[0049] Specifically, the first voltage conversion unit 121 and the second voltage conversion unit 122 are both step-down circuits, and the input end of the first voltage conversion unit 121 and the input end of the second voltage conversion unit 122 are both 12V. The first voltage conversion unit 121 can be used to convert the 12V voltage into a 1.8V voltage and output it to the first end of the key module 130. The second voltage conversion unit 122 can be used to convert the 12V voltage into a 5V voltage and output it to the power supply end of the interface module 110, that is, the output end of the first voltage conversion unit 121 is 1.8V, and the output end of the second voltage conversion unit 122 is 5V.

[0050] In this embodiment, by providing the first voltage conversion unit 121 and the second voltage conversion unit 122 , the input power can be converted into different voltages and output to different modules to meet the input voltage required by each module.

[0051] In some embodiments, the first voltage conversion unit 121 includes one of a DC-DC converter and a low-dropout linear regulator; the second voltage conversion unit 122 includes one of a DC-DC converter and a low-dropout linear regulator.

[0052] A DC-to-DC converter is a device used to convert one DC voltage to another, capable of either stepping up or stepping down the output voltage to provide a stable output voltage for varying power requirements. A low-dropout linear regulator (LDO) is a voltage stabilizing device that can provide a stable output voltage even when the input voltage is only slightly higher than the desired output voltage. The specific circuit structures of DC-to-DC converters and LDOs can be found in existing technology and are not limited here.

[0053] In practical applications, a DC-to-DC converter or a low-dropout linear regulator can be selected as the voltage conversion unit according to actual needs, which can improve the flexibility of the design.

[0054] In some embodiments, the interface module 110 includes a universal serial bus (USB) interface. The power supply terminal of the USB interface is connected to the second output terminal of the voltage conversion module 120. The USB interface is also used to connect to a first terminal of the external load 400. The USB interface may include at least one of a USB 2.0 interface, a USB 3.0 interface, and a Type-C interface.

[0055] In this embodiment, by setting a universal serial bus interface on the keypad 100, external devices such as a USB flash drive, keyboard, mouse or other peripheral devices can be easily connected. Subsequently, the keypad 100 is applied to an all-in-one product to expand the functions and compatibility of the all-in-one product.

[0056] In some of these embodiments, see Figure 3 The data transmission terminal of the interface module 110 is used to connect to the data transmission terminal Data of the mainboard 200.

[0057] Specifically, the data transmission terminal of the interface module 110 is connected to the data transmission terminal Data of the mainboard 200 via a fifth connection line 350. For example, if the interface module 110 includes a universal serial bus interface, the data transmission terminal of the interface module 110 and the data transmission terminal Data of the mainboard 200 can be connected using the USB protocol. By connecting the data transmission terminal of the interface module 110 to the data transmission terminal of the mainboard 200, when the interface module 110 is connected to an external load 400, the external load 400 can exchange data with the mainboard 200 through the interface module 110. For example, the external load 400 can receive instructions from the mainboard 200 and simultaneously transmit data to the mainboard 200, allowing the interface module 110 to implement data transmission between the external load 400 and the mainboard 200.

[0058] In this embodiment, by connecting the data transmission end of the interface module 110 with the data transmission end of the mainboard 200, the external load 400 can achieve two-way communication with the mainboard 200 through the interface module 110 after being connected to the interface module 110, thereby improving the user experience.

[0059] In some of these embodiments, see Figure 3The key module 130 includes a first resistor R1, at least one key unit (may include K1, K2, K3, K4) and at least one voltage divider unit (may include 131, 132, 133, 134); the key unit (may include K1, K2, K3, K4) and the voltage divider unit (may include 131, 132, 133, 134) correspond one to one, the first end of the first resistor R1 is connected to the first output end of the voltage conversion module 120, and the second end of the first resistor R1 is respectively connected to the first end of each key unit (may include K1, K2, K3, K4) and the signal detection end of the mainboard 200. Detect, each button unit may include (may include K1, K2, K3, K4) a second end connected to the first end of the corresponding voltage divider unit (may include 131, 132, 133, 134), and the second end of each voltage divider unit (may include 131, 132, 133, 134) is connected to the first ground end GND1; wherein, the button unit (may include K1, K2, K3, K4) is configured to turn on the connection between the corresponding voltage divider unit (may include 131, 132, 133, 134) and the first resistor R1 when triggered, so that the second end of the first resistor R1 outputs a voltage divider signal.

[0060] The key unit (which may include K1, K2, K3, K4) refers to a button that can be used to input instructions. It can be a suitable key type such as a mechanical key, a touch key, or a membrane key. After receiving the user's input, if it is pressed by the user, it can establish a connection between the corresponding voltage divider unit (which may include 131, 132, 133, 134) and the first resistor R1, so that the first current loop can be turned on, so that the second end of the first resistor R1 outputs a voltage divider signal.

[0061] The voltage dividing unit (may include 131 , 132 , 133 , 134 ) refers to a device that can be used to divide the voltage, such as a resistor or other device.

[0062] exist Figure 3 In the illustrated embodiment, it includes four key units and four voltage divider units, namely key unit K1, key unit K2, key unit K3, key unit K4, voltage divider unit 131, voltage divider unit 132, voltage divider unit 133, and voltage divider unit 134. For example, when key unit K1 is pressed, the connection between the first resistor R1 and the voltage divider unit 131 will be conductive, that is, the first current loop will be conductive, and the first resistor R1 and the voltage divider unit 131 will divide the voltage output by the first voltage conversion unit 121 and output it to the mainboard 200 for detection. It should be noted that different voltage divider units, after working together with the first resistor R1 to divide the voltage, output different voltage divider signals to the mainboard 200, so that the mainboard 200 can detect the status of each key unit based on the voltage divider signal.

[0063] In this embodiment, the above structure is used as the button module 130. When different buttons are pressed, the second end of the first resistor R1 can output voltage-divided signals of different sizes to the mainboard 200, allowing the mainboard 200 to identify which button unit is pressed, thereby saving interface resources of the mainboard 200.

[0064] In some embodiments, the voltage dividing unit includes a second resistor; a first end of the second resistor is connected to the second end of the corresponding key unit, and a second end of the second resistor is connected to the first ground terminal GND1.

[0065] It should be noted that the resistance values of the second resistors in different voltage dividing units should be different. Figure 3 In the embodiment shown, the voltage divider unit 131 includes a second resistor R21, the voltage divider unit 132 includes a second resistor R22, the voltage divider unit 133 includes a second resistor R23, and the voltage divider unit 134 includes a second resistor R24. The resistance values of the second resistors R21, R22, R23, and R24 are not equal. Thus, when different keys are pressed, the second end of the first resistor R1 can output voltage divider signals of different magnitudes to the motherboard 200, allowing the motherboard 200 to identify which key unit is pressed. For example, when the key unit K1 is pressed, the voltage divider signal U outputted from the second end of the first resistor R1 is ADC for:

[0066]

[0067] Wherein, VDD is the voltage of the output terminal of the first voltage conversion unit 121, R1 is the resistance value of the first resistor R1, R w1 is the cable resistance of the first connecting line, R 21 is the resistance value of the second resistor R21. It can be seen that the voltage-dividing signal outputted by the second end of the first resistor R1 is independent of the current in the second current loop. In practical applications, the number and resistance values of the resistors in the voltage-dividing unit can be set according to actual needs and are not limited here.

[0068] In this embodiment, by setting a second resistor, the voltage dividing unit can be used to divide the voltage. During the design process, the resistance value of the second resistor in each voltage dividing unit is made different, so that when each key unit is pressed, the voltage dividing signal output from the second end of the first resistor R1 is different, which enables the motherboard 200 to accurately identify the pressing status of different key units, thereby realizing multi-function key operation.

[0069] In the second aspect, the present invention provides an all-in-one device. Figure 2The all-in-one device includes a motherboard 200, a cable 300, and a keypad 100 as described in any one of the first aspects. The cable 300 includes a first connecting line 310, a second connecting line 320, a third connecting line 330, and a fourth connecting line 340. The first ground terminal GND1 in the keypad 100 is connected to the negative power supply terminal GND3 of the motherboard 200 through the first connecting line 310, the second ground terminal GND2 in the keypad 100 is connected to the negative power supply terminal GND3 of the motherboard 200 through the second connecting line 320, the input terminal of the voltage conversion module 120 in the keypad 100 is connected to the positive power supply terminal VOUT of the motherboard 200 through the third connecting line 330, and the second terminal of the key module 130 in the keypad 100 is connected to the signal detection terminal Detect of the motherboard 200 through the fourth connecting line 340.

[0070] The all-in-one device can be a light emitting diode (LED) all-in-one device. In this embodiment, the key module 130 is connected to the negative power supply terminal GND3 of the mainboard 200 via an independent first connection line 310, and the second ground terminal GND2 is connected to the negative power supply terminal GND3 via a second connection line. This makes the current loop of the key module 130 independent of the current loop of the interface module 110. This prevents the interface module 110 from affecting the voltage-divided signal output by the key module 130 when outputting power to the external load 400, thereby improving the accuracy and reliability of key detection.

[0071] In some of these embodiments, see Figure 3 The main board 200 includes a main control chip 210 ; the main control chip 210 is connected to the signal detection terminal Detect, and the main control chip 210 is configured to determine the key information based on the voltage division signal output by the key module 130 .

[0072] The main control chip 210 can be an integrated circuit chip that integrates functional modules such as processor core, memory, input / output interface, timer, counter, analog interface circuit, digital interface circuit, peripheral controller, memory, controller, etc. Its specific structure can refer to the existing technology and is not limited here.

[0073] In this embodiment, the main control chip 210 integrated with multiple functional modules is used as the controller in the mainboard 200, which can not only realize the function of identifying keys, but also control the operation of other modules, which can greatly reduce the size of the device and improve the overall performance.

[0074] In some embodiments, the all-in-one device further includes a display device connected to the mainboard 200. Specifically, the display device can be a display device such as an LED display, which can be connected to the main control chip 210, so that the main control chip 210 can control the operation of the display device.

[0075] In this embodiment, by providing a display device, information can be presented intuitively, human-computer interaction can be facilitated, and user experience can be improved.

[0076] It should be noted that the device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of the modules may be selected based on actual needs to achieve the objectives of this embodiment.

[0077] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Under the idea of the present invention, the technical features in the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations in different aspects of the present invention as described above. For the sake of simplicity, they are not provided in detail. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the above embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A keypad, characterized in that: include: An interface module, a voltage conversion module, a key module, a first ground terminal and a second ground terminal; The input end of the voltage conversion module is used to connect to the positive power terminal of the mainboard, the first output end of the voltage conversion module is connected to the first end of the key module, the second end of the key module is used to connect to the signal detection end of the mainboard, the third end of the key module is connected to the first ground end, the first ground end is used to connect to the negative power terminal of the mainboard via a first connecting line, the second output end of the voltage conversion module is connected to the power supply end of the interface module, the interface module is also used to connect to the first end of an external load, the second ground end is used to connect to the second end of the external load and to the negative power terminal via a second connecting line; Wherein, the voltage conversion module is configured to perform voltage conversion on the input voltage; When the input end of the voltage conversion module is connected to the positive power supply end and the first ground end is connected to the negative power supply end through the first connecting line, the positive power supply end, the voltage conversion module, the first end of the key module, the third end of the key module, the first ground end, and the negative power supply end form a first current loop, and the key module is configured to output a voltage-divided signal to the mainboard based on the first current loop when triggered; When the input end of the voltage conversion module is connected to the positive end of the power supply, the interface module is connected to the first end of the external load, the second end of the external load is connected to the second ground end, and the second ground end is connected to the negative end of the power supply through the second connecting line, the positive end of the power supply, the voltage conversion module, the interface module, the external load, the first ground end and the negative end of the power supply form a second current loop.

2. The keypad according to claim 1, wherein: The voltage conversion module includes a first voltage conversion unit and a second voltage conversion unit; The input end of the first voltage conversion unit and the input end of the second voltage conversion unit are both used to connect to the positive terminal of the power supply, the output end of the first voltage conversion unit is connected to the first end of the key module, and the output end of the second voltage conversion unit is connected to the power supply end of the interface module; Wherein, the first voltage conversion unit is configured to perform voltage conversion on the input voltage and output the converted voltage to the key module; The second voltage conversion unit is configured to perform voltage conversion on an input voltage and output the converted voltage to the interface module.

3. The keypad according to claim 2, wherein: The first voltage conversion unit includes one of a DC-to-DC converter and a low-dropout linear regulator; The second voltage conversion unit includes one of a DC-to-DC converter and a low voltage dropout linear regulator.

4. The keypad according to any one of claims 1 to 3, wherein: The interface module includes a universal serial bus interface; The power supply end of the universal serial bus interface is connected to the second output end of the voltage conversion module, and the universal serial bus interface is also used to connect to the first end of an external load.

5. The keypad according to any one of claims 1 to 3, wherein: The data transmission end of the interface module is used to connect to the data transmission end of the mainboard.

6. The keypad according to any one of claims 1 to 3, wherein: The key module includes a first resistor, at least one key unit and at least one voltage dividing unit; The button units correspond to the voltage divider units one by one, the first end of the first resistor is connected to the first output end of the voltage conversion module, the second end of the first resistor is respectively connected to the first end of each button unit and the signal detection end of the mainboard, the second end of each button unit is connected to the first end of the corresponding voltage divider unit, and the second end of each voltage divider unit is connected to the first ground end; The button unit is configured to conduct the connection between the corresponding voltage dividing unit and the first resistor when triggered, so that the second end of the first resistor outputs the voltage dividing signal.

7. The keypad according to claim 6, wherein: The voltage dividing unit includes a second resistor; A first end of the second resistor is connected to the second end of the corresponding button unit, and a second end of the second resistor is connected to the first ground end.

8. An all-in-one device, characterized in that: It includes a main board, a cable, and a key board according to any one of claims 1 to 7; The cable includes a first connecting line, a second connecting line, a third connecting line and a fourth connecting line. The first grounding end in the key panel is connected to the negative power supply end of the mainboard through the first connecting line, the second grounding end in the key panel is connected to the negative power supply end of the mainboard through the second connecting line, the input end of the voltage conversion module in the key panel is connected to the positive power supply end of the mainboard through the third connecting line, and the second end of the key module in the key panel is connected to the signal detection end of the mainboard through the fourth connecting line.

9. The all-in-one device according to claim 8, characterized in that: The mainboard includes a main control chip; The main control chip is connected to the signal detection end, and the main control chip is configured to determine key information based on the voltage division signal output by the key module.

10. The all-in-one device according to claim 8 or 9, characterized in that: The all-in-one device further includes a display device; The display device is connected to the main board.

Images