A key whose output is linearly related to the pressing stroke

Abstract

The utility model provides a key whose output is linearly related to the pressing stroke. The key comprises: a non-magnetic end cap, a magnet, a pressing spring, a magnetic sensor and a PCB board. The bottom of the end cap has a magnet sleeve portion, the magnet is installed in the magnet sleeve portion, and its magnetization direction is upward and downward; the PCB is arranged below the end cap, and the magnetic sensor is arranged on the PCB. By reasonably setting the relative position of the magnet with respect to the sensing point of the magnetic sensor when the key is pressed, and coordinating with the setting of the sensing direction of the magnetic sensor, the output of the key is linearly related to the pressing stroke. The key provided by the utility model has a simple structure and a clever design. It can conveniently determine various details of the pressing process based on the output signal, providing expansion space for the interactive mode of the key.

Description

Technical Field

[0001] The utility model relates to the field of input components of human-computer interaction equipment, in particular to a key whose output is in a linear relationship with a pressing stroke. Background Art

[0002] Physical buttons are a very important type of input and output device, which are widely used in electronic devices such as mobile phones and computers, as well as various electrical appliances. Among physical buttons, magnetic axis buttons use magnetic sensors to sense the movement of the magnetic axis to output the pressing signal.

[0003] Existing magnetic axis buttons usually include a magnetic axis made of permanent magnets and a Hall sensor, where the Hall sensor is placed on the PCB board below the magnetic axis to detect whether the button is pressed based on the magnetic field and the Hall effect. When the button is not pressed, the magnetic axis maintains a certain distance from the Hall sensor; when the button is pressed, the magnetic axis approaches the Hall sensor below it as the button cap is pressed down, and the Hall sensor senses the change in the vertical magnetic field and generates a corresponding sensing output (i.e., Hall voltage). When the Hall voltage exceeds a certain threshold, it is considered that the key action is detected and the corresponding function is executed.

[0004] During the pressing process of the existing magnetic axis button, the output of the magnetic sensor changes nonlinearly with the pressing stroke. For application scenarios that require accurate knowledge of the pressing process (for example, safety verification through the pressing process), it is necessary to mark the relationship between the sensing output and each pressing stroke position, and make a "sensing output-pressing stroke" reference table so that the corresponding pressing stroke position can be obtained by subsequent table lookup based on the sensing output. Obviously, this not only requires storage space to save the corresponding "sensing output-pressing stroke", but also in order to accurately grasp the position of the button at each moment during the pressing process, the frequent table lookup process will also affect the response speed of the system. Summary of the invention

[0005] The purpose of the utility model is to provide a key with a simple structure and an output in a linear relationship with the pressing stroke, so as to meet the actual needs of some application scenarios for quickly and accurately locating the position changes of the key during the pressing process, while reducing the storage space occupied by related program files and providing more possibilities for key-based interactions.

[0006] To achieve the above purpose, the present invention provides the following technical solutions:

[0007] A button whose output is linearly related to the pressing stroke, comprising: a non-magnetic end cap, a magnet and a magnetic sensor. The end cap has a magnet sleeve portion at the bottom. The magnet is installed in the magnet sleeve portion, and its magnetization direction is upward and downward. The magnetization direction of the magnet is the Z-axis direction, the sensing direction of the magnetic sensor is the X-axis direction, and the horizontal projection line between the magnet and the magnetic sensor is parallel to the X-axis. When the button is in an initial state without being pressed, the sensing point of the magnetic sensor is not lower than the lowermost end surface of the magnet; when the button is pressed to a limited lowest position, the sensing point of the magnetic sensor is not higher than the uppermost end surface of the magnet. Preferably, the magnet is a bar magnet.

[0008] Furthermore, the button also includes a PCB board; the PCB is arranged below the end cap, and the magnetic sensor is arranged on the PCB.

[0009] In one embodiment, the PCB board has a hole at a position corresponding to the bottom of the end cap, and a support plate is also provided on the other side of the PCB board relative to the end cap. The button also includes a pressing spring passing through the hole and installed between the bottom of the end cap and the support plate. When the button is pressed, the spring is compressed so that at least a portion of the magnet is embedded in or passes through the hole. In order to limit the maximum stroke of the button press, a bump is provided on the end cap at a position higher than the upper end surface of the magnet, which cooperates with the PCB hole to limit the button press stroke.

[0010] Furthermore, a lower convex portion is provided at the bottom of the end cap, and the lower convex portion is embedded in the ring of the compression spring to fix the compression spring. Preferably, the lower convex portion is in the shape of a cylinder.

[0011] Preferably, the magnet is a rectangular parallelepiped magnet with a length of 2 mm, a width of 1.3 mm, and a height of 3.5 mm, and the distance between the sensing point of the magnetic sensor and the center axis of the magnet in the Z-axis direction is 2.5 mm. The pressing stroke of the button is set to a maximum of no more than 3.3 mm.

[0012] Furthermore, the magnetic sensor is implemented based on a HALL induction element or an XMR magnetoresistance, and the XMR includes TMR, AMR, and GMR.

[0013] The key provided by the utility model is based on the position setting of the magnetic pole of the magnet relative to the magnetic sensor, and combined with the selection of the sensor sensing direction, and only uses a relatively simple structure to achieve a linear relationship between the pressing stroke (full stroke) of the key and the sensing output of the key. The key structure provided by the utility model is novel, simple, and low-cost, and provides a good physical basis for quickly and accurately determining the real-time position of the key during the pressing process, and provides convenience for expanding more key interaction methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a front schematic diagram of a key provided by the utility model in a first embodiment.

[0015] Figure 2 for Figure 1 Bottom view of the key in the embodiment shown.

[0016] Figure 3 for Figure 1 In the embodiment shown, the pressing simulation result is shown when the sensing point is set at 2.5 mm from the center of the magnet (Z axis).

[0017] Figure 4 A schematic structural diagram of a key provided by the utility model in another embodiment. DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only some embodiments of the utility model, not all embodiments. Generally, the components of the embodiments of the utility model described and shown in the drawings here can be arranged and designed in various different configurations.

[0019] Therefore, the following detailed description of the embodiments of the utility model provided in the accompanying drawings is not intended to limit the scope of the utility model claimed for protection, but merely represents selected embodiments of the utility model. Based on the embodiments of the utility model, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the utility model.

[0020] like Figure 1 As shown, in one embodiment, the button provided by the utility model includes: a non-magnetic end cap 1, a magnet 2, a magnetic sensor 3 and a PCB board 4.

[0021] The end cap 1 has a magnet sleeve 11 and a lower convex shaft 12 at the bottom. The lower convex shaft 12 is used to be inserted into the coil of the pressing spring (not shown in the figure) to fix the position of the pressing spring. The magnet 2 is installed in the magnet sleeve 11, and its magnetization direction is upward and downward. Figure 1 , Figure 2 As shown, in this embodiment, the magnet 2 is a rectangular parallelepiped magnet, and its dimensions are 2 mm in length, 1.3 mm in width, and 3.5 mm in height. Obviously, the magnet 2 can also be a magnet of other regular shapes, such as a bar magnet.

[0022] The PCB board 4 is arranged below the end cap 1 , and the magnetic sensor 3 is arranged on the PCB.

[0023] like Figure 2 As shown, the sensing direction of the magnetic sensor 3 is in the direction of the projection line of the magnet 2 and the magnetic sensor 3 on the horizontal plane. The magnetization direction of the magnet 2 is the Z-axis direction, the sensing direction of the magnetic sensor 3 is the X-axis direction, and the horizontal projection line of the magnet 2 and the magnetic sensor 3 is parallel to the X-axis.

[0024] In order to ensure that the output of the magnetic sensor 3 is linearly related to the pressing stroke throughout the pressing process, when the button is in an initial state without being pressed, the sensing point of the magnetic sensor 3 is not lower than the lowermost end surface of the magnet 2. When the button is pressed to a specified lowest position, the sensing point of the magnetic sensor 3 is not higher than the uppermost end surface of the magnet 2.

[0025] As can be seen from the magnetic field distribution of magnet 2, the farther the sensing point is from the center of magnet 2, during the pressing process, the magnetic sensor 3 can detect a larger pressing range, and the horizontal magnetic field change (small change rate) is linearly related to the pressing stroke, and the larger the maximum pressing stroke of the key can be set; the closer the sensing point is to the surface of magnet 2, the horizontal magnetic field change (large change rate) detected by the magnetic sensor 3 is linearly related to the pressing stroke, the smaller the corresponding pressing range becomes, and the smaller the maximum pressing stroke of the key becomes. Preferably, as Figure 3 As shown, in Figure 1 , Figure 2 In the embodiment shown, the size of the magnet 2 is small. When the sensing point is set 2.5 mm away from the center axis (Z-axis direction) of the magnet 2, it can be ensured that the output of the magnetic sensor 3 has a good linear relationship with the pressing stroke within a range of 3.3 mm. At the same time, the horizontal magnetic field generated by the magnet 2 at the position of the magnetic sensor has a good rate of change with the pressing stroke.

[0026] Furthermore, in order to simplify the arrangement of the magnetic sensor 3 on the PCB board, the volume of the button is compressed to meet the requirements of the miniaturization of the button in specific application scenarios; Figure 4 As shown, an opening 41 can be provided at a position of the PCB board 4 directly opposite to the bottom of the end cap 1, and a support plate (not shown) can be provided on the other side of the PCB board relative to the end cap 1. The pressing spring passes through the opening 41 and is installed between the bottom of the end cap 1 and the support plate. That is, one end of the pressing spring is fixed by the lower convex shaft body 12, and the other end contacts the support plate and is fixed by a corresponding component on the support plate (for example, the shaft body into which the pressing spring is inserted).

[0027] like Figure 4As shown, in order to limit the maximum stroke of the button, a bump 13 is provided on the end cap 1 at a position higher than the upper end surface of the magnet, which cooperates with the PCB opening to limit the button pressing stroke. When the button is pressed, the spring is compressed, so that at least a part of the magnet is embedded in or passes through the opening. When the button is released after being pressed, due to the elastic force of the pressing spring, the end cap 1 will return to its initial state when it is not pressed.

[0028] Furthermore, the magnetic sensor is implemented based on a HALL induction element or an XMR magnetoresistance, and the XMR includes TMR, AMR, and GMR.

[0029] The above description is only an embodiment of the present invention and is not intended to limit the present application. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A key whose output is linearly related to the pressing stroke, characterized in that: The button includes: a non-magnetic end cap, a magnet and a magnetic sensor; The end cap has a magnet sleeve portion at the bottom, the magnet is installed in the magnet sleeve portion, and its magnetization direction is upward and downward magnetization; the magnetization direction of the magnet is the Z-axis direction, the sensing direction of the magnetic sensor is the X-axis direction, and the horizontal projection line of the magnet and the magnetic sensor is parallel to the X-axis; When the button is in an initial unpressed state, the sensing point of the magnetic sensor is not lower than the lowermost end surface of the magnet; when the button is pressed to a limited lowest position, the sensing point of the magnetic sensor is not higher than the uppermost end surface of the magnet.

2. The key according to claim 1, characterized in that The button also includes a PCB board; the PCB is arranged below the end cap, and the magnetic sensor is arranged on the PCB.

3. The key according to claim 2, characterized in that: The PCB board has a hole at a position corresponding to the bottom of the end cap, and a support plate is also provided on the other side of the PCB board relative to the end cap; the button also includes a pressing spring that passes through the hole and is installed between the bottom of the end cap and the support plate; when the button is pressed, the spring is compressed, so that at least a portion of the magnet is embedded in or passes through the opening.

4. The key according to claim 3, characterized in that: A protrusion is also provided on the end cap at a position higher than the upper end surface of the magnet, which cooperates with the PCB opening to limit the key pressing stroke.

5. The key according to claim 4, characterized in that: The bottom of the end cap is also provided with a lower convex portion, and the lower convex portion is embedded in the ring of the pressing spring to fix the pressing spring.

6. The key according to any one of claims 1 to 5, characterized in that: The magnet is a bar magnet.

7. The key according to claim 6, characterized in that: The magnet is a rectangular parallelepiped magnet with a length of 2 mm, a width of 1.3 mm, and a height of 3.5 mm. The distance between the sensing point of the magnetic sensor and the central axis of the magnet in the Z-axis direction is 2.5 mm.

8. The key according to claim 7, characterized in that: The pressing stroke of the button is set to be no more than 3.3 mm at most.

9. The key according to any one of claims 1 to 5, characterized in that: The magnetic sensor is implemented based on a HALL inductive element or an XMR magnetoresistance, and the XMR includes TMR, AMR, and GMR.

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