Capacitive pressure detection mechanism and handwriting pen

Abstract

The utility model provides a capacitive pressure detection mechanism and a stylus, the capacitive pressure detection mechanism comprises a conductive column, a conductive elastomer, a dielectric medium and a substrate, the conductive elastomer, the dielectric medium and the substrate are arranged in sequence, the dielectric medium comprises a first through hole, a first surface and a second surface, the first surface and the second surface are opposite, and the first through hole extends from the first surface to the second surface; the substrate comprises a second through hole, a third surface and a fourth surface which are opposite, the second through hole extends from the third surface to the fourth surface, the second surface is provided with an electrode surface which is communicated with the substrate, the conductive column is inserted into the first through hole and the second through hole and comprises a first end and a second end which are opposite, and the fourth surface is provided with a second conductive part which is communicated with the second end. The conductive elastomer is arranged close to the first surface and the first end and elastically deforms under external force to change the contact area with the first surface, so that the capacitance value between the conductive elastomer and the electrode surface is changed accordingly. The capacitive pressure detection mechanism is simple and compact in structure and good in stability.

Description

Technical Field

[0001] The utility model relates to the technical field of computer peripheral equipment, in particular to a capacitive pressure detection mechanism and a stylus. Background Art

[0002] A stylus is a handwriting input device that senses the writing pressure of the user and provides feedback on the weight changes of the handwriting. The prior art patent US20110241703A1 discloses a variable capacitor and a position indicator, which determines the weight changes of the user's writing based on the change in capacitance value of the variable capacitor caused by pressure. For details, please refer to Figure 1 , is a cross-sectional view of a variable capacitor disclosed in the prior art. The variable capacitor comprises a dielectric 1, a first electrode 2, a second electrode 3, a gasket 4, an elastomer 5, a shell 6, a pressing body 7, a terminal 8 and a terminal 9. The shell 6 is composed of a first shell member 61 and a second shell member 62, and the first electrode 2, the dielectric 1, the gasket 4, the second electrode 3, and the elastomer 5 are sequentially accommodated in the first shell member 61. The pressing body 7 is composed of a core 71 and a cover 72, and the terminals 8 and 9 are inserted into the first shell member 61 from the upper part of the first shell member 61. The terminal 8 is electrically connected to the first electrode 2, and the second electrode 3 is configured to pass through the gasket 4 and contact the dielectric 1 when the second electrode 3 is subjected to the pressure of the pressing body 7, and the end of the second electrode 3 is electrically connected to the terminal 9.

[0003] Thus, the first electrode 2 and the second electrode 3 are arranged on both sides of the dielectric 1 and the spacer 4, and the dielectric 1, the spacer 4, the first electrode 2 and the second electrode 3 form a capacitor. Moreover, the second electrode 3 is arranged to be able to contact the dielectric 1 through the spacer 4. Therefore, the contact area between the dielectric 1 and the second electrode 3 changes with the pressing force applied by the pressing body 7, thereby realizing variable capacitance.

[0004] The variable capacitor provided by the prior art needs to be connected to an external terminal 9 outside the radial range of the dielectric 1, which occupies external space, has a complex structure, increases a lot of uncertainty, and has poor stability. Utility Model Content

[0005] In order to solve the technical problems of the existing variable capacitor having a complex structure and poor stability, the utility model provides a capacitive pressure detection mechanism and a stylus pen with a simple and compact structure and good stability.

[0006] The first aspect of the utility model provides a capacitive pressure detection mechanism, including a conductive column, a conductive elastomer arranged in sequence, a dielectric and a substrate, wherein the dielectric includes a first through hole, a first surface and a second surface arranged oppositely, and the first through hole extends from the first surface to the second surface; the substrate includes a second through hole, a third surface and a fourth surface arranged oppositely, and the second through hole extends from the third surface to the fourth surface, and an electrode surface is arranged on the second surface, and the electrode surface is conductively connected to the substrate; the conductive column is inserted into the first through hole and the second through hole, and includes a first end and a second end arranged oppositely, and a second conductive part is arranged on the fourth surface, which is conductively connected to the second end; the conductive elastomer is arranged adjacent to the first surface and the first end, and is used to undergo elastic deformation under external force to change the contact area with the opposite surface, so that the capacitance value between the conductive elastomer and the electrode surface changes accordingly, wherein the opposite surface is composed of the surface of the first surface opposite to the conductive elastomer and the surface of the first end opposite to the conductive elastomer.

[0007] In some embodiments, a first conductive portion is disposed on the third surface, and the electrode surface is electrically connected to the first conductive portion.

[0008] In some embodiments, the first conductive portion and the electrode surface are in contact and conductive.

[0009] In some embodiments, a main board is further included, and the substrate further includes a first connecting portion and a second connecting portion on a side surface, the electrode surface is electrically connected to the main board via the first connecting portion, and the second conductive portion is electrically connected to the main board via the second connecting portion.

[0010] In some embodiments, the first connection portion and the second connection portion are protruding structures, which are used to match and fix with the notch of the shell covering the substrate.

[0011] In some embodiments, the conductive column includes a first column and a second column connected to each other, the diameter of the second column is larger than the diameter of the first column, the first column is disposed in the first through hole, and the second column is disposed in the second through hole.

[0012] In some embodiments, the first end is substantially flush with the first surface.

[0013] In some embodiments, the conductive elastomer includes a body and an elastic protrusion, and the elastic protrusion is formed by extending from the body toward the dielectric.

[0014] In some embodiments, an inductor component is further included, and the inductor component is electrically connected to the capacitor to form an oscillation circuit.

[0015] The utility model provides a stylus pen in a first aspect, including a pen core and a capacitive pressure detection mechanism, wherein the capacitive pressure detection mechanism includes a conductive column, a conductive elastomer, a dielectric and a substrate arranged in sequence, wherein the dielectric includes a first through hole, a first surface and a second surface arranged oppositely, and the first through hole extends from the first surface to the second surface; the substrate includes a second through hole, a third surface and a fourth surface arranged oppositely, the second through hole extends from the third surface to the fourth surface, an electrode surface is arranged on the second surface, and the electrode surface is conductively connected to the substrate; the conductive column is inserted into the first through hole and the second through hole, and includes a second through hole arranged oppositely. one end and a second end, the fourth surface is provided with a second conductive part, which is conductive with the second end; the conductive elastomer is arranged adjacent to the first surface and the first end, and is used for being elastically deformed by an external force to change the contact area with the opposite surface, so that the capacitance value between the conductive elastomer and the electrode surface changes accordingly, wherein the opposite surface is composed of the surface of the first surface relative to the conductive elastomer and the surface of the first end relative to the conductive elastomer, the pen core is arranged on the side of the conductive elastomer away from the first surface, and transmits pressure to the conductive elastomer, so that the conductive elastomer is elastically deformed, and the capacitance value between the conductive elastomer and the electrode surface changes.

[0016] In some embodiments, a bracket and a seat chamber are further included, the capacitive pressure detection mechanism and the seat chamber are fixed to the bracket, the conductive elastomer is accommodated in the seat chamber, and the pen core passes through the seat chamber and abuts against the conductive elastomer.

[0017] Compared with the prior art, in the capacitive pressure detection mechanism of the utility model, the dielectric is provided with the first through hole, the first surface and the second surface, the substrate is provided with the second through hole, the third surface and the fourth surface, the conductive column passes through the first through hole and the second through hole in sequence, the second end of the conductive column is connected with the second conductive part provided on the fourth surface, as a first electrode, the conductive elastomer is arranged adjacent to the first surface and the first end, the electrode surface provided on the second surface is connected with the first conductive part provided on the third surface, as a second electrode, the first electrode and the second electrode are arranged within the radial range of the dielectric through the conductive column and the substrate, and do not occupy the space outside the radial range, the structure is simple, compact and small in size, and at the same time, the conductive column and the substrate are used as lead-out electrodes, the reliability is better, the conduction function can be reliably played, and better stability is maintained. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a cross-sectional view of a stylus pen in the prior art;

[0019] Figure 2 It is a cross-sectional view of a stylus provided by the utility model;

[0020] Figure 3 yes Figure 2 The three-dimensional exploded schematic diagram of the capacitive pressure detection mechanism shown. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] In the present utility model, the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like to indicate the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present utility model and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as a limitation on the present utility model. The terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features.

[0023] Please refer to Figure 2 and Figure 3 ,in, Figure 2 This is a cross-sectional view of a stylus provided by the utility model. Figure 3 yes Figure 2 The stylus 100 comprises a refill 10, a housing 20, a bracket 30, a seat 40 and a capacitive pressure detection mechanism 50. The refill 10 is partially exposed from the housing 20 for writing, and the bracket 30, the seat 40 and the capacitive pressure detection mechanism 50 are accommodated in the housing 20. The capacitive pressure detection mechanism 50 and the seat 40 are fixed to the bracket 30.

[0024] The capacitive pressure detection mechanism 50 includes a conductive elastic body 51, a dielectric 52, a substrate 53 and a conductive column 54. The pen core 10, the housing 40, the conductive elastic body 51, the dielectric 52 and the substrate 53 are arranged in sequence, the conductive elastic body 51 is accommodated in the housing 40, and the pen core 10 passes through the housing 40 and abuts against the conductive elastic body 51.

[0025] The conductive elastic body 51 includes a body 511 and an elastic protrusion 513, wherein the elastic protrusion 513 extends from the body 511 toward the dielectric 52. The diameter of the body 511 is larger than the diameter of the elastic protrusion 513, forming a step, and the body 511 is accommodated in the seat 40, and the step abuts against the side wall of the seat 40. The pen core 10 passes through the seat 40 and abuts against the body 511.

[0026] The dielectric 52 includes a first through hole 520, a first surface 521 and a second surface 522 that are oppositely arranged, wherein the first through hole 520 extends from the first surface 521 to the second surface 522, the first surface 521 is an insulating surface facing the elastic protrusion 513, and the second surface 522 is provided with an electrode surface facing the substrate 53.

[0027] The substrate 53 includes a second through hole 530, a third surface 533 and a fourth surface 534 arranged opposite to each other, the second through hole 530 extends from the third surface 533 to the fourth surface 534, the electrode surface is conductively connected to the substrate 53, and in the present embodiment, a first conductive portion is arranged on the third surface 533, and the electrode surface is in contact and conductively connected with the first conductive portion.

[0028] The conductive column 54 passes through the first through hole 520 and the second through hole 530 in sequence, is insulated from the electrode surface and the first conductive part, and includes a first end 541 and a second end 542 that are arranged opposite to each other. The fourth surface 534 is provided with a second conductive part that is in electrical communication with the second end 542, and the first end 541 is inserted into the first through hole 520. The conductive elastic body 51 is arranged adjacent to the first surface 521 and the first end 541, and is used to undergo elastic deformation under external force to change the contact area with the opposite surface, so that the capacitance value of the conductive elastic body 51 and the electrode surface changes accordingly. The opposite surface is composed of the surface of the first surface 521 opposite to the conductive elastic body 51 and the surface of the first end 541 opposite to the conductive elastic body 51.

[0029] Specifically, the capacitance determination formula is C=εS / (4πkd), where ε is the dielectric constant, each material has a fixed dielectric constant, S is the area facing the two electrodes of the capacitor, d is the distance between the two plates of the capacitor, and k is the electrostatic force constant. Therefore, the capacitance value of the capacitor is related to the area facing the two electrodes.

[0030] In this embodiment, the first surface 521 is an insulating surface, the conductive column 54 is inserted into the first through hole 520 and the second through hole 530, the first end 541 is arranged adjacent to the first surface 521, and the second end 542 is connected to the second conductive part, serving as a first electrode; the electrode surface arranged on the second surface 522 is connected to the first conductive part, serving as a second electrode, and the first electrode, the second electrode and the dielectric 52 constitute a capacitor. When the conductive elastic body 51 is connected to the first end 541, the elastic protrusion 513 also serves as the first electrode. When the elastic protrusion 513 is subjected to the pressure transmitted by the pen core 10, it undergoes elastic deformation, changing the contact area between the elastic protrusion 513 and the first surface 521, which is equivalent to changing the area of ​​the first electrode, thereby changing the facing area of ​​the first electrode and the second electrode, and the capacitance value between the first electrode and the second electrode changes. The change in the capacitance value between the first electrode and the second electrode is used to feedback the change in the pressure on the pen core 10.

[0031] The elastic protrusion 513 may be a curved surface, a conical surface, or a combination of various geometric surfaces. It only needs to abut against the first surface 521 under force to change the contact area with the first surface 521, and no specific limitation is made here.

[0032] It can be understood that the conductive column 54 is used to connect the elastic protrusion 513 with the second conductive part of the substrate 53, and the area of ​​the first electrode is the contact area between the elastic protrusion 513 and the first surface 521; the first conductive part of the substrate 53 is in direct contact and conduction with the electrode surface, and the area of ​​the second electrode can be the area of ​​the electrode surface, and the electrode surface completely overlaps with the first conductive part, and can be the area of ​​the electrode surface and the first conductive part relative to the second surface 522, and the electrode surface partially overlaps with the first conductive part. Further, the electrode surface and the first conductive part can be integrated into a conductive element.

[0033] It can also be understood that the capacitance value between the first electrode and the second electrode depends on the facing area of ​​the first electrode and the second electrode. The electrode surface can completely cover the second surface 522 or partially cover the second surface 522 to limit the range of variation of the facing area of ​​the first electrode and the second electrode. Those skilled in the art can set it as needed.

[0034] It can also be understood that, when the conductive elastic body 51 is disposed adjacent to the first surface 521 and the first end 541, “adjacent” includes two situations: abutting and maintaining a gap, specifically including:

[0035] When the conductive elastic body 51 initially directly contacts the first surface 521 and the first end 541, there is an initial capacitance value, and the elastic protrusion 513 is elastically deformed by pressure, thus changing the capacitance value between the first electrode and the second electrode;

[0036] When the conductive elastic body 51 initially maintains a gap with the first surface 521 and the first end 541, the elastic protrusion 513 is subjected to pressure and moves toward the first surface 521, abuts against the first surface 521, and abuts against the first end 541 to be conductive, thereby changing the contact area with the first surface 521 and changing the capacitance value between the first electrode and the second electrode;

[0037] The conductive elastomer 51 initially directly abuts the first end 541 and maintains a gap with the first surface 521. The conductive elastomer 51 and the first end 541 are initially connected, and the elastic protrusion 513 is subjected to pressure, which changes the contact area with the first surface 521 and changes the capacitance value between the first electrode and the second electrode.

[0038] When the conductive elastomer 51 initially directly abuts against the first surface 521 and maintains a gap with the first end 541, the elastic protrusion 513 is elastically deformed by pressure and conducts with the first end 541, thereby changing the contact area with the first surface 521 and changing the capacitance value between the first electrode and the second electrode.

[0039] It can also be understood that, along the direction from the second surface 522 to the first surface 521 of the dielectric 52, the first end 541 may be flush with the first surface 521, may protrude from the first surface 521, or may be lower than the first surface 521. Specifically,

[0040] 1) The first end 541 is flush with the first surface 521 , and when the conductive elastic body 51 abuts against the first surface 521 , it also abuts against and conducts with the first end 541 ;

[0041] The first end 541 is flush with the first surface 521, and the elastic protrusion 513 can be provided with a depression corresponding to the first end 541. When the conductive elastic body 51 is subjected to force, it first abuts against the first surface 521, and when elastic deformation occurs, it abuts against the first end 541 to conduct;

[0042] The first end 541 is flush with the first surface 521, and the elastic protrusion 513 can be set to a step structure corresponding to the first end 541. When the conductive elastic body 51 is subjected to force, it first abuts against the first end 541 to be connected, and then abuts against the first surface 521;

[0043] 2) The first end 541 protrudes from the first surface 521 , and the conductive elastic body 51 can be first connected to the first end 541 and then abut against the first surface 521 ;

[0044] The first end 541 protrudes from the first surface 521 and pre-compresses the conductive elastic body 51, so that the conductive elastic body 51 initially directly abuts against the first surface 521 and the first end 541;

[0045] The first end 541 protrudes from the first surface 521, and the elastic protrusion 513 is provided with a depression corresponding to the portion of the first end 541 protruding from the first surface 521. Based on different sizes of the depression, when the conductive elastic body 51 abuts against the first surface 521, it can also abut and conduct with the first end 541 at the same time, or when the conductive elastic body 51 is subjected to force, it first abuts against the first surface 521, and then abuts and conducts with the first end 541 when elastic deformation occurs;

[0046] 3) The first end 541 is lower than the first surface 521, and the elastic protrusion 513 can be provided with a protrusion corresponding to the first end 541, and the protrusion can extend into the first through hole 520, and abut and conduct with the first end 541. Based on the size of the protrusion, when the conductive elastomer 51 abuts against the first surface 521, it can also abut and conduct with the first end 541 at the same time, or the conductive elastomer 51 can be firstly conducted with the first end 541 and then abut against the first surface 521.

[0047] The conductive column 54 includes a first column 543 and a second column 544 which are connected to each other. The diameter of the second column 544 is greater than that of the first column 543 . The first column 543 passes through the first through hole 520 , and the second column 544 passes through the second through hole 530 .

[0048] In some embodiments, the first column is fixed to the first through hole of the dielectric, and specifically, can be bonded to the first through hole by glue.

[0049] The capacitive pressure detection mechanism 50 further includes a main board 55, and the main board 55 is connected to the substrate 53. The substrate 53 further includes a plate body 535, a first connection portion 536, and a second connection portion 537. The third surface 533 and the fourth surface 534 are two opposite surfaces of the plate body 535. The second through hole 530 is provided on the plate body 535. The first connection portion 536 and the second connection portion 537 are formed by extending outward from the center of the plate body 535 on the side of the plate body 535 different from the third surface 533 and the fourth surface 534. The first conductive portion is connected to the main board 55 through the first connection portion 536, and the second conductive portion is connected to the main board 55 through the second connection portion 537. Specifically, the first connection portion 536 is connected to the main board 55 by welding, and the second connection portion 537 is connected to the main board 55 by welding.

[0050] It is understandable that the diameter of the substrate 53 can be set to be smaller than or approximately equal to the diameter of the dielectric 52. In this case, the first conductive portion may not be set on the third surface 533, and the electrode surface is directly electrically connected to the first connecting portion on the side of the substrate 53.

[0051] In some embodiments, the first connection portion and the second connection portion are protruding structures that are matched and fixed with the notches of the shell covering the substrate.

[0052] In some embodiments, the body is fixedly matched with the notch of the main board, and the first connecting portion and the second connecting portion are protruding structures that abut against the main board to facilitate welding and conduction with the main board.

[0053] In some embodiments, the substrate and the main board are integrated into one component.

[0054] The capacitive pressure detection mechanism 50 also includes an inductor component 56, which is electrically connected to the capacitor formed by the first electrode, the second electrode and the dielectric 52 to form an LC oscillation circuit. The inductor component 56 includes a hollow magnetic core 561 and a coil 563. The pen core 10 movably passes through the magnetic core 561. The induction coil 563 is fixedly wound around the outer surface of the magnetic core 561 and is electrically connected to the main board 55. When the capacitance value between the first electrode and the second electrode changes, the oscillation frequency of the LC oscillation circuit changes accordingly, and the pressure change on the pen core 10 is fed back through the change in the oscillation frequency.

[0055] Compared with the prior art, in the capacitive pressure detection mechanism 50 of the utility model, the dielectric 52 is provided with the first through hole 520, the first surface 521 and the second surface 522, the substrate 53 is provided with the second through hole 530, the third surface 533 and the fourth surface 534, the conductive column 54 passes through the first through hole 520 and the second through hole 530 in sequence, the second end 542 of the conductive column 54 is connected to the second conductive part provided on the fourth surface 534, serving as the first electrode, the conductive elastomer 51 is arranged adjacent to the first surface 521 and the first end 541, the electrode surface provided on the second surface 522 is connected to the first conductive part provided on the third surface 533, serving as the second electrode. The first electrode and the second electrode are arranged within the radial range of the dielectric 52 through the conductive column 54 and the substrate 53, and do not occupy the space outside the radial range. The structure is simple, compact and small in size. At the same time, the conductive column 54 and the substrate 53 are used as lead-out electrodes, and the reliability is better. The conductive column 54 and the substrate 53 are easier to fix and have better strength. They can reliably play a conductive role and maintain better stability.

[0056] The above description is only an embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A capacitive pressure detection mechanism, characterized in that: It includes a conductive column, a conductive elastic body, a dielectric and a substrate arranged in sequence, wherein: The dielectric includes a first through hole, a first surface and a second surface that are oppositely disposed, and the first through hole extends from the first surface to the second surface; The substrate comprises a second through hole, a third surface and a fourth surface which are arranged opposite to each other, the second through hole extends from the third surface to the fourth surface, an electrode surface is arranged on the second surface, and the electrode surface is electrically connected to the substrate; The conductive column is inserted into the first through hole and the second through hole, and includes a first end and a second end that are oppositely arranged, and a second conductive part is arranged on the fourth surface, and is in electrical communication with the second end; The conductive elastomer is arranged near the first surface and the first end, and is used to undergo elastic deformation when subjected to external force to change the contact area with the opposite surface, so that the capacitance value between the conductive elastomer and the electrode surface changes accordingly, wherein the opposite surface is composed of the surface of the first surface relative to the conductive elastomer and the surface of the first end relative to the conductive elastomer.

2. The capacitive pressure detection mechanism according to claim 1, characterized in that: The third surface is provided with a first conductive portion, and the first conductive portion is in contact and conductive with the electrode surface.

3. The capacitive pressure detection mechanism according to claim 1, characterized in that: It also includes a main board, and the substrate also includes a first connecting portion and a second connecting portion on a side surface, the electrode surface is connected to the main board through the first connecting portion, and the second conductive portion is connected to the main board through the second connecting portion.

4. The capacitive pressure detection mechanism according to claim 3, characterized in that: The first connection portion and the second connection portion are protruding structures, and are used to match and fix with the notch of the shell covering the substrate.

5. The capacitive pressure detection mechanism according to claim 3, characterized in that: The first connection portion is connected to the main board by welding, and the second connection portion is connected to the main board by welding.

6. The capacitive pressure detection mechanism according to claim 1, characterized in that: The conductive column includes a first column and a second column which are connected to each other. The diameter of the second column is larger than the diameter of the first column. The first column is disposed in the first through hole, and the second column is disposed in the second through hole.

7. The capacitive pressure detection mechanism according to claim 1, characterized in that: The first end is substantially flush with the first surface.

8. The capacitive pressure detection mechanism according to claim 1, characterized in that: The conductive elastic body includes a body and an elastic protrusion, and the elastic protrusion is formed by extending from the body toward the dielectric.

9. A stylus pen, comprising a pen core and a capacitive pressure detection mechanism, characterized in that: The capacitive pressure detection mechanism is a capacitive pressure detection mechanism as described in any one of claims 1-8, and the pen core is arranged on the side of the conductive elastomer away from the first surface, and transmits pressure to the conductive elastomer, so that the conductive elastomer undergoes elastic deformation, thereby changing the capacitance value between the conductive elastomer and the electrode surface.

10. The stylus pen according to claim 9, characterized in that: It also includes a bracket and a seat chamber, the capacitive pressure detection mechanism and the seat chamber are fixed to the bracket, the conductive elastomer is accommodated in the seat chamber, and the pen core passes through the seat chamber and abuts against the conductive elastomer.

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