Key structure with TMR chip and keyboard structure
By using magnets and TMR chips in the keyboard key structure to simulate voltage sensing with a linear proportional relationship, the problem of key wear leading to malfunction in traditional keyboards has been solved, achieving a high-sensitivity and low-cost key design.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- DONGGUAN HEATMOVING ELECTRONIC TECH CO LTD
- Filing Date
- 2025-05-22
- Publication Date
- 2026-05-15
AI Technical Summary
Traditional keyboards are prone to malfunctioning of frequently used keys after a period of use. This is mainly due to excessive wear on the internal key shaft and the deformation switch on the circuit board, which causes the key to fail to reset or fail to trigger the circuit in a timely and effective manner. Moreover, it is difficult to reduce production costs.
Magnets and TMR chips are respectively mounted on a relatively sliding shaft and base. By simulating a linear proportional relationship between the output voltage and the external magnetic field, precise key press depth sensing is achieved, avoiding direct contact between the key and the circuit board, thereby reducing wear. A reset spring is used to ensure high key sensitivity and good tactile feel.
This allows the buttons to maintain high sensitivity for extended periods, reducing wear and tear, lowering production costs, and improving button lifespan and tactile feel.
Smart Images
Figure CN224248519U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of keyboard technology, and in particular to a key structure with a TMR chip and a keyboard structure. Background Technology
[0002] Traditional keyboards are prone to key malfunctions after a period of use. This is mainly due to excessive wear on the key's internal spindle and the deformation switches on the circuit board caused by frequent key presses. This can lead to the spindle failing to reset or the deformed switches failing to trigger the circuit effectively. Therefore, current improvements to keyboard performance primarily focus on refining key structure and circuit board sensitivity. However, both approaches require high precision in the installation of the circuit board and keys, as well as in the shape and position of the support plates that support all or many keys and the base plate that supports the circuit board. This makes it difficult to reduce keyboard production costs. Utility Model Content
[0003] To address the problems existing in the prior art, this utility model provides a key structure with a TMR chip and a keyboard structure. By mounting the magnet and the TMR chip on a relatively sliding shaft and base respectively, the linear proportional relationship between the output voltage and the external magnetic field can be simulated, thereby achieving precise key press depth sensing. During the pressing process, the key does not need to directly contact the deformation switch on the circuit board, and there will be no wear between the two. The key can maintain a high sensitivity state for a long time, and the return spring can ensure that the key has a good pressing feel.
[0004] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:
[0005] A key structure with a TMR chip includes a keycap, a spindle, and a support base. The support base is detachably fixed to a circuit board. The spindle can slide on the support base under external force to move closer to or away from the circuit board. The key structure also includes a magnet and a TMR chip. The magnet is detachably fixed to the spindle, and the TMR chip is detachably fixed to the support base and positioned above the circuit board. The TMR chip can detect the displacement of the magnet and is signal-connected to the circuit board.
[0006] As a further explanation of the above technical solution:
[0007] In the above technical solution, the shaft core includes a first hole post and a limiting part provided on its outer wall. The two ends of the limiting part extend symmetrically to the radially outer side of the first hole post, and an axially extending first slide is formed on each of its two ends.
[0008] In the above technical solution, the support base includes a matching and snap-fitting upper cover and a base, both of which are frame structures open at both ends:
[0009] On the inner wall of the upper cover, an axially extending second slide is formed on the radially outer side of each first slide, and a plurality of second positioning buckles are formed on its outer wall.
[0010] The base has two third slides, several legs, a limiting plate, and a second post. The two third slides extend axially and are symmetrically arranged on the ends of the base facing the top cover. The inner wall of each third slide is adapted to a first slide, and its outer wall is adapted to a second slide. Several legs are arranged on the ends of the base facing the circuit board, and their bottom surfaces can abut against the upper surface of the circuit board. The limiting plate is arranged on the inner wall of the base, and a second post is arranged coaxially with the first post. Both ends of the second post extend to the outside of the limiting plate, and one end extends to the inside of the two third slides. Its inner wall is adapted to the outer wall of the first post, and a return spring is sleeved on the outer wall. The other end of the second post extends between the limiting plate and several legs, and the TMR chip is embedded on its bottom end and its inner wall.
[0011] In the above technical solution, arc-shaped grooves for avoiding the reset spring are formed on the opposing inner walls of the two first slides and the opposing inner walls of the upper cover.
[0012] One technical solution adopted by this utility model is as follows:
[0013] A keyboard structure includes a base plate, a circuit board, a support plate, and several keys. The circuit board is detachably mounted on the inner wall of the base plate, and the support plate is detachably fixed above the circuit board. Several keys are provided on the support plate. Several slots are formed on the support plate to fit each key. Each key has the key structure described in the above technical solution. Each support base has a positioning protrusion extending radially outward from its contour. Each positioning protrusion is matched to the outside of a slot and presses against the end face of the support plate away from the circuit board.
[0014] Compared with the prior art, the beneficial effects of this utility model are as follows: by mounting the magnet and the TMR chip on the relatively sliding shaft and base respectively, the linear proportional relationship between the output voltage and the external magnetic field can be simulated, thereby achieving precise key press depth sensing. During the pressing process, the key does not need to directly contact the deformation switch on the circuit board, and there will be no wear between the two. The key can maintain a high sensitivity state for a long time, and the reset spring can ensure that the key has a good pressing feel. Attached Figure Description
[0015] Figure 1 This is an exploded structural diagram of this embodiment (keycaps are not shown);
[0016] Figure 2 This is a cross-sectional structural diagram of this embodiment (keycaps are not shown);
[0017] Figure 3 This is a schematic diagram of the shaft core in this embodiment;
[0018] Figure 4 This is a schematic diagram of the upper cover structure in this embodiment;
[0019] Figure 5 This is a schematic diagram of the base structure in this embodiment;
[0020] Figure 6 This is a cross-sectional view of part of the disk in this embodiment (keycaps are not shown). Detailed Implementation
[0021] The present invention will now be described in further detail with reference to the accompanying drawings.
[0022] The embodiments described with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application. In the description of this application, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "several" or "more than" means two or more, unless otherwise explicitly specified. In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances. In this application, unless otherwise expressly specified and limited, "above" or "below" a second feature can include direct contact between the first and second features, or it can include contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of a second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" of a second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.
[0023] like Figure 1-2 As shown, the key structure with a TMR chip includes a keycap, a spindle 20, and a support base 30. The support base 30 is detachably fixed to a circuit board. The spindle 20 can slide on the support base 30 under the action of external force to move closer to or away from the circuit board. It also includes a magnet 40 and a TMR chip 50. The magnet 40 is detachably fixed to the spindle 20. The TMR chip 50 is detachably fixed to the support base 30 and located above the circuit board. The TMR chip 50 can detect the displacement of the magnet 40 and is connected to the circuit board signal.
[0024] like Figure 3 As shown, the shaft core 20 includes a first hole post 21 and a limiting part 22 provided on its outer wall. The two ends of the limiting part 22 extend symmetrically to the radial outer side of the first hole post 21, and each end of the limiting part 22 forms an axially extending first slide rail 1.
[0025] like Figure 4-5 As shown, the support base 30 includes a matching and snap-fit upper cover 31 and a base 32, both of which are frame-shaped structures open at both ends.
[0026] like Figure 4 As shown, an axially extending second slide 2 is formed on the radially outer side of each first slide 1 on the inner wall of the upper cover 31, and a plurality of second positioning buckles 3 are formed on its outer wall.
[0027] like Figure 5 As shown, the base 32 has two third slides 4, several legs 5, a limiting plate 6, and a second post 7. The two third slides 4 extend axially and are symmetrically arranged on the ends of the base 32 facing the upper cover 31. The inner wall of each third slide 4 is adapted to a first slide 1, and its outer wall is adapted to a second slide 2. Several legs 5 are arranged on the ends of the base 32 facing the circuit board, and their bottom surfaces can match and abut against the upper surface of the circuit board. The limiting plate 6 is arranged on the inner wall of the base 30, and a second post 7 is arranged on it coaxially with the first post 21. Both ends of the second post 7 extend to the outside of the limiting plate 6, one end extends to the inside of the two third slides 4, and its inner wall is adapted to the outer wall of the first post 21. A reset spring 60 is sleeved on the outer wall. The other end of the second post 7 extends between the limiting plate 6 and several legs 5, and a TMR chip 50 is embedded on its bottom end and its inner wall.
[0028] like Figure 3-4 As shown, arc-shaped grooves 8 for avoiding the return spring 60 are formed on the inner walls of the two first slides 1 and the inner walls of the upper cover 31.
[0029] The upper end of the switch core 20 is generally a cross-shaped structure and is embedded in the inner wall of the keycap. To clearly demonstrate the key structure, see attached... Figure 1 and 2 Keycaps are not shown.
[0030] During use, since the support base 30 is fixed to the circuit board, when the keycap is pressed, it will simultaneously push the switch core 20 to slide inside the upper cover 31. The inner wall of its limiting part 22 presses against and squeezes the return spring 60. The first slide rail 1 slides on the inner wall of the third slide rail 4, and the first hole post 21 slides on the inner wall of the second hole post 7, causing the magnet 40 to approach the TMR chip 50. The TMR chip 50 detects / senses the displacement of the magnet 40 and sends a signal to the control chip on the circuit board 300. After receiving the signal, the control chip will issue a corresponding command. At the same time, the return spring 60 will limit the downward movement distance of the switch core 20 to prevent the first hole post 21 and the magnet 40 from damaging the TMR chip 50. When there is no pressure on the keycap, the switch core 20 drives the keycap to reset under the action of the rebound force of the return spring 60.
[0031] The TMR chip 50 is existing technology, integrating a tunnel magnetoresistive sensor (TMR), operational amplifier, and DAC circuit. In this invention, through its cooperation with the magnet 40, the output voltage and the external magnetic field can be simulated to satisfy a linear proportional relationship, thereby achieving precise key press depth sensing. During the pressing process, the key 100 does not need to directly contact the deformation switch on the circuit board 300, and there will be no wear between them. The key can maintain a high sensitivity state for a long time, and the reset spring 60 can ensure that the key has a good pressing feel.
[0032] This utility model also discloses a specific application embodiment of the above embodiments:
[0033] like Figure 6 As shown, a keyboard structure includes a base plate 200, a circuit board 300, a support plate 400, and several keys 100. The circuit board 300 is detachably mounted on the inner wall of the base plate 200, and the support plate 400 is detachably fixed above the circuit board 300. Several keys 100 are mounted on the support plate 400. Several slots that are adapted to each key 100 are formed on the support plate 400. Each key 100 has the key structure described in the above embodiment, and each support base 30 is provided with a positioning protrusion 9 extending radially outward from its contour. Each positioning protrusion 9 is matched to the outside of a slot and presses against the end face of the support plate 400 away from the circuit board 300.
[0034] During assembly, magnets 40 are fixed one by one in the first hole post 21, TMR chips 50 are fixed one by one in the second hole post 7, and the shaft core 20, upper cover 31, return spring 60 and base 32 are assembled to form a button 100. After completion, the buttons 100 are matched and installed into the slots of the support plate 400, and the protrusions 9 of the base 32 on each button are pressed against the support plate 400. The circuit board 300 and the support plate 400 are locked together with the locking screws. Finally, the circuit board 300 is fixed to the inner wall of the base plate 200.
[0035] The above does not limit the technical scope of this utility model. Any modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of this utility model shall still fall within the scope of the technical solution of this utility model.
Claims
1. A key structure with a TMR chip, the key comprising a keycap, a spindle, and a support base, wherein the support base is detachably fixed to a circuit board, and the spindle can slide on the support base under external force to move closer to or further away from the circuit board; characterized in that, It also includes a magnet and a TMR chip. The magnet is detachably fixed to the shaft shown, and the TMR chip is detachably fixed to the support and located above the circuit board. The TMR chip can detect the displacement of the magnet and is connected to the circuit board for signal transmission.
2. The button structure with a TMR chip according to claim 1, characterized in that, The shaft core includes a first bore post and a limiting part provided on its outer wall. The two ends of the limiting part extend symmetrically to the radially outer side of the first bore post, and an axially extending first slide is formed on each of its two ends.
3. The button structure with a TMR chip according to claim 2, characterized in that, The support base includes a matching and snap-fitting upper cover and a base, both of which are frame structures open at both ends: On the inner wall of the upper cover, an axially extending second slide is formed on the radially outer side of each first slide, and a plurality of second positioning buckles are formed on its outer wall. The base has two third slides, several legs, a limiting plate, and a second post. The two third slides extend axially and are symmetrically arranged on the ends of the base facing the top cover. The inner wall of each third slide is adapted to a first slide, and its outer wall is adapted to a second slide. Several legs are arranged on the ends of the base facing the circuit board, and their bottom surfaces can abut against the upper surface of the circuit board. The limiting plate is arranged on the inner wall of the base, and a second post is arranged coaxially with the first post. Both ends of the second post extend to the outside of the limiting plate, and one end extends to the inside of the two third slides. Its inner wall is adapted to the outer wall of the first post, and a return spring is sleeved on the outer wall. The other end of the second post extends between the limiting plate and the several legs, and the TMR chip is embedded on its inner wall.
4. The button structure with a TMR chip according to claim 3, characterized in that, Arc-shaped grooves for avoiding the return spring are formed on the opposing inner walls of the two first slides and the opposing inner walls of the upper cover.
5. A keyboard structure, wherein the keyboard comprises a base plate, a circuit board, a support plate, and a plurality of keys, the circuit board is detachably mounted on the inner wall of the base plate, the support plate is detachably fixed above the circuit board, and the support plate comprises a plurality of keys; characterized in that, The support plate has a plurality of slots that are adapted to each of the buttons. Each button has a button structure as described in any one of claims 1-4. Each support base has a positioning protrusion extending radially outward from its outline. Each positioning protrusion is matched to the outside of a slot and presses against the end face of the support plate away from the circuit board.