Pressure sensor, refill and electronic pen

Abstract

The present disclosure relates to a pressure sensor, a refill and an electronic pen, the pressure sensor comprising a capacitor and a flexible conductive member, the flexible conductive member comprising a contact portion, the flexible conductive member and the capacitor being arranged along an axial direction of the contact portion, a capacitance value output by the capacitor being changed with a change in a contact area between the capacitor and the contact portion, the contact area being changed with a change in a pressure applied to the contact portion; the contact portion having an end surface facing the capacitor, the end surface being convex in the axial direction toward the capacitor, the contact portion sequentially comprising a first section and a second section along the axial direction, a change in the capacitance value of the first section being smaller than a change in the capacitance value of the second section in a case where the pressure applied to the contact portion is changed by the same amount. In the present disclosure, the pressure sensor is sensitive to the pressure when a light pressure is applied, and the sensitivity to the pressure is reduced when a heavy pressure is applied, so as to adapt to different feelings of a user when the light pressure and the heavy pressure are applied.

Description

Technical Field

[0001] This disclosure relates to the field of electronic devices, and more particularly to a pressure sensor, a pen refill, and an electronic pen. Background Technology

[0002] An electronic pen is a device used in conjunction with electronic devices to interact and control them via touch. With the development of touch technology and electronic devices, the application scenarios for electronic pens are becoming increasingly diverse, such as using them for touchscreen drawing. This places increasingly higher demands on the touch functionality of electronic pens. In particular, adjusting the mapping relationship between touch pressure and pen stroke effect under different touch pressures to adapt to the user's varying control precision and achieve better writing and drawing results has become a challenge for electronic pens. Utility Model Content

[0003] To overcome the problems existing in related technologies, this disclosure provides a pressure sensor, a pen refill, and an electronic pen.

[0004] According to some embodiments of this disclosure, a pressure sensor is provided, comprising:

[0005] capacitance;

[0006] A flexible conductive element includes a contact portion, wherein the flexible conductive element and the capacitor are arranged along the axial direction of the contact portion, and the capacitance value output by the capacitor changes with the change of the contact area between the capacitor and the contact portion, and the contact area changes with the change of the pressure applied to the contact portion.

[0007] The contact portion has an end face facing the capacitor, the end face protruding towards the capacitor along the axial direction, and the contact portion is sequentially formed into a first segment and a second segment along the axial direction. When the pressure on the contact portion changes by the same amount, the change in capacitance value of the first segment is less than the change in capacitance value of the second segment.

[0008] In some embodiments, the end face has a cross-sectional line segment in the axial section of the contact portion, and the extension direction of each point on the cross-sectional line segment is at an angle to the central axis of the contact portion. The angle corresponding to each point in the first segment is smaller than the angle corresponding to each point in the second segment.

[0009] In some embodiments, the end face includes an end face edge and a vertex, the end face edge circumferentially engaging with the outer peripheral sidewall of the contact portion, and the vertex being the highest point of the end face protruding from the capacitor.

[0010] The end face edge extends and closes along the circumference of the contact portion, and the end face edge also extends reciprocally along the axial direction of the contact portion. The end face edge includes a first edge point and a second edge point. In the axial direction, the first edge point and the vertex are respectively located on both sides of the second edge point.

[0011] The contact portion has a first normal section, a second normal section, and a third normal section. The first normal section, the second normal section, and the third normal section are all perpendicular to the axial direction. The first normal section passes through the first edge point, the second normal section passes through the second edge point, and the third normal section passes through the vertex. The first segment is located between the first normal section and the second normal section, and the second segment is located between the second normal section and the third normal section.

[0012] In some embodiments, the contact portion has a first axial section and a second axial section, both the first axial section and the second axial section passing through the central axis of the contact portion, and the first axial section passing through the first edge point, and the second axial section passing through the second edge point;

[0013] In the first axial section, the cross-sectional line segment of the end face is an arc with a radius of R1;

[0014] In the second axial section, the cross-sectional line segment of the end face is an arc with a radius of R2;

[0015] Where R1 < R2.

[0016] In some embodiments, the radius R2 is greater than or equal to 2R1.

[0017] In some embodiments, the first segment includes a first spherical surface, and the end of the contact portion protrudes in the direction of the capacitor to form the first spherical surface;

[0018] The second section includes a second spherical surface, which protrudes from the first spherical surface in the direction of the capacitor to form the second spherical surface, and the second spherical surface is partially stacked on the first spherical surface;

[0019] The radius of the first sphere is R1, and the radius of the second sphere is R2, where R1 < R2.

[0020] In some embodiments, the first segment includes a conical surface, and the second segment includes a plane formed at the end of the conical surface.

[0021] In some embodiments, the end face is provided with a texture, and the texture has a concave-convex structure.

[0022] According to some embodiments of this disclosure, a pen refill is provided, including any of the pressure sensors disclosed herein.

[0023] According to some embodiments of this disclosure, an electronic pen is provided, and the pen refill of this disclosure is provided.

[0024] The technical solutions provided by the embodiments of this disclosure can include the following beneficial effects: When lightly pressing the electronic pen, the user's control over the force is relatively accurate. However, as the touch pressure gradually increases, from light pressure to heavy pressure, the accuracy of the user's control over the touch pressure also decreases. Unexpected fluctuations in touch pressure may occur, and in extreme cases, jitter or other issues may occur, causing jumps in touch pressure and affecting the stability of the touch pressure applied by the user. In the pressure sensor of this disclosure, the contact portion of the flexible conductive element has a first section and a second section. When the pressure on the contact portion changes by the same amount, the change in capacitance value of the first section is smaller than the change in capacitance value of the second section, so that the output capacitance value and touch pressure of the pressure sensor have different mapping relationships under light and heavy pressure. By applying the pressure sensor disclosed herein to pen refills and electronic pens, different tactile sensations can be achieved through changes in the aforementioned mapping relationship when the user applies light and heavy pressure. Specifically, during the light pressure phase where the user's touch pressure control is precise, the pressure sensor's capacitance value based on touch pressure feedback becomes more sensitive, thus exhibiting more levels of pressure sensitivity. This results in smoother and faster pen strokes displayed on the electronic device. Conversely, during the heavy pressure phase where the user's touch pressure control accuracy decreases, the sensitivity of the pressure sensor's capacitance value based on touch pressure feedback decreases. This prevents significant fluctuations in the capacitance value output by the pressure sensor when the user applies unexpected touch pressure fluctuations, improving the stability of the capacitance value feedback from the pressure sensor during the heavy pressure phase. This leads to more stable pen strokes displayed on the electronic device and enhances the user experience.

[0025] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Attached Figure Description

[0026] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure.

[0027] Figure 1 This is a cross-sectional view of a pressure sensor according to some embodiments of the present disclosure.

[0028] Figure 2 This is a schematic diagram of the structure of a flexible conductive element according to some embodiments of the present disclosure.

[0029] Figure 3This is a schematic diagram of the structure of a flexible conductive element from another perspective, according to some embodiments of the present disclosure.

[0030] Figure 4 This is a schematic diagram of the structure of a flexible conductive element from another perspective, according to some embodiments of the present disclosure.

[0031] Figure 5 This is a schematic diagram of another flexible conductive element according to some embodiments of the present disclosure.

[0032] Figure 6 This is a schematic diagram of the structure of another flexible conductive element shown according to some embodiments of the present disclosure.

[0033] Figure 7 This is a schematic diagram showing the position of a flexible conductive element and a capacitor according to some embodiments of the present disclosure.

[0034] Figure 8 This is a schematic diagram showing the position of another flexible conductive element and capacitor according to some embodiments of this disclosure.

[0035] Figure 9 This is a cross-sectional view of a pressure sensor according to some embodiments of the present disclosure.

[0036] Figure 10 This is a capacitance-pressure curve of a pressure sensor shown according to some embodiments of the present disclosure.

[0037] Figure 11 This is a capacitance-pressure curve of another pressure sensor shown according to some embodiments of the present disclosure.

[0038] Figure 12 This is a schematic diagram of the appearance structure of an electronic pen according to some embodiments of the present disclosure.

[0039] Figure label:

[0040] 1. Capacitor; 2. Flexible conductive component; 21. Contact portion; 211. End face; 212. First section; 213. Second section; 214. End face edge; 214-a. First edge point; 214-b. Second edge point; 215. Vertex; 216. First spherical surface; 217. Second spherical surface; 218. Plane; 219. Conical surface; 22. Fixing post; 23. Support surface; 3. Piston; 4. Conductive elastic component; 5. First mounting base; 6. Second mounting base; 7. First electrode; 8. Second electrode; 10. Electronic pen. Detailed Implementation

[0041] Some embodiments of this disclosure will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. Various changes, modifications, and equivalents of the methods, apparatus, and / or systems described herein will become apparent upon understanding this disclosure. For example, the order of operations described herein is merely illustrative and is not limited to those orders set forth herein, but can be changed as will become apparent upon understanding this disclosure, except for operations that must be performed in a particular order. Furthermore, for clarity and brevity, descriptions of features known in the art may be omitted.

[0042] The embodiments described in the following examples of this disclosure are not representative of all embodiments consistent with this disclosure. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this disclosure as detailed in the appended claims.

[0043] This disclosure provides a pressure sensor, pen refill, and electronic pen in some embodiments. The pressure sensor can be applied to the pen refill and electronic pen, which are used to work with electronic devices and interact with them via touch to achieve various touch-based functions, such as drawing and writing.

[0044] In related technologies, electronic pens incorporate a pen core with a pressure sensor to collect the touch pressure applied by the user. The pressure sensor converts the touch pressure into an electrical signal, and the electronic device simulates the pen's stroke force based on this signal. However, the user's control over touch pressure differs depending on whether the pressure is light or heavy. Generally, when applying light pressure, the user can control the changes in pressure more precisely. The electronic pen needs to sensitively output the user's precise touch pressure as corresponding stroke lines, so that the pen's stroke lines accurately reflect the user's input requirements. When the user applies heavy pressure, the precision of the touch pressure control decreases, and the output touch pressure fluctuates unexpectedly. The electronic pen needs to mitigate these unexpected touch pressure fluctuations to ensure stable stroke lines. The pressure sensor in the electronic pen and pen refill in the related technology has a constant mapping relationship between the capacitance value output by the capacitor and the touch pressure when applying light and heavy pressure. This means that the electronic pen and pen refill in the related technology cannot simultaneously meet the different switching needs of users for touch pressure and pen stroke lines when applying light and heavy pressure, thus reducing the user experience.

[0045] In view of this, some embodiments of the present disclosure provide a pressure sensor.

[0046] Figure 1This is a cross-sectional view of a pressure sensor according to some embodiments of this disclosure. Figure 1 As shown, the pressure sensor includes a capacitor 1 and a flexible conductive element 2. The flexible conductive element 2 includes a contact portion 21. The flexible conductive element 2 and the capacitor 1 are arranged axially along the contact portion 21. The capacitance value output by the capacitor 1 changes with the contact area between the capacitor 1 and the contact portion 21. The contact area changes with the pressure applied to the contact portion 21. The contact portion 21 has an end face 211 facing the capacitor 1, and the end face 211 protrudes axially toward the capacitor 1. The contact portion 21 is sequentially formed into a first segment 212 and a second segment 213 along the axial direction. When the pressure applied to the contact portion 21 changes by the same amount, the change in capacitance value of the first segment 212 is less than the change in capacitance value of the second segment 213.

[0047] In some embodiments of this disclosure, the contact portion 21 has a first section 212 and a second section 213 distributed along the axial direction. When lightly pressed, the second section 213 contacts the capacitor 1, and the contact area increases with the increase of touch pressure. When heavily pressed, the second section 213 is fully in contact with the capacitor 1, the first section 212 is in contact with the capacitor 1, and the contact area increases with the increase of touch pressure. That is, the second segment 213 corresponds to light pressure, and the first segment 212 corresponds to heavy pressure. By setting the first segment 212 and the second segment 213 such that, when the pressure on the contact portion 21 changes by the same amount, the change in capacitance value of the first segment 212 is less than the change in capacitance value of the second segment 213 (i.e., the rate of change of capacitance value of the first segment 212 based on touch pressure is less than the rate of change of capacitance value of the second segment 213 based on touch pressure), the pressure sensor can be made more sensitive to changes in touch pressure under light pressure, while its sensitivity to touch pressure is reduced under heavy pressure. This allows the same pressure sensor to have two different capacitance output characteristics under light and heavy pressure. Applying the pressure sensor of this disclosure to pen refills and electronic pens allows them to output more varied strokes based on changes in the user's applied touch pressure under light pressure, and to weaken fluctuations in the user's touch pressure under heavy pressure, making the pen's strokes more stable and improving the user experience.

[0048] In some embodiments of this disclosure, a rectangular coordinate system is established with touch pressure as the abscissa and capacitance value as the ordinate, and a corresponding capacitance value-pressure change curve is plotted. The "capacitance value change rate" is the slope of this curve. It should be noted that this is only an exemplary way of understanding "capacitance value change rate," but it is not limited thereto.

[0049] After the pressure sensor is subjected to a touch pressure, the flexible conductive member 2 contacts the capacitor 1 under the action of the touch pressure, forming the other pole of the capacitor 1. Based on this, the capacitance value output by the capacitor 1 will increase correspondingly as the touch pressure increases, and the mapping relationship between the touch pressure it receives and the output capacitance value can be called the pressure-sensing curve. For ease of description, the following text uses the pressure-sensing curve to describe the characteristic that the capacitance value of the pressure sensor changes with pressure.

[0050] The calculation formula for the capacitance value C is:

[0051] C = ε * S * π / d

[0052] Where, ε is the dielectric constant of the capacitor 1, S is the contact area between the flexible conductive member 2 and the capacitor 1, and d is the dielectric thickness of the capacitor 1.

[0053] In some embodiments of the present disclosure, the capacitor 1 includes a ceramic chip and an electrode chip sintered together. Among them, the ceramic chip serves as the dielectric, and d is the thickness of the ceramic chip.

[0054] In some embodiments of the present disclosure, if the end face 211 of the contact portion 21 has a shape such as a cylinder, a cone, or a sphere with a circular normal cross-section, the calculation formula for S is:

[0055] S = (D / 2) 2 *π

[0056] Where, D is the radius of the contact surface between the end face 211 and the capacitor 1.

[0057] In some embodiments of the present disclosure, such as Figure 1 The first section 212 and the second section 213 marked only serve as a schematic illustration of their positions, and do not limit the specific shapes, lengths, and proportions of the first section 212 and the second section 213.

[0058] In some embodiments of the present disclosure, "axial direction" in Figure 1 is reflected as the up and down direction, and can also be expressed as the longitudinal direction.

[0059] In some embodiments of the present disclosure, the flexible conductive member 2 can be made of a material with conductivity and elasticity, such as silicone, but is not limited thereto. To increase the conductivity of the flexible conductive member 2, conductive particles can be doped in the flexible conductive member 2.

[0060] In some embodiments of the present disclosure, the volume resistance of the flexible conductive member 2 is less than 5Ω·cm.

[0061] In some embodiments of the present disclosure, "the same change in pressure" can refer to the same difference in pressure change, or can refer to the same ratio of pressure change, and is not limited thereto. Those skilled in the art can select appropriate indicators according to needs.

[0062] In some embodiments of this disclosure, the contact portion 21 may also include portions other than the first segment 212 and the second segment 213, and this disclosure does not limit this. The first segment 212 and the second segment 213 are merely divisions of the contact portion 21 at different locations for ease of description, and do not imply that the first segment 212 and the second segment 213 are two independent structures. For example, the first segment 212 and the second segment 213 may be partial structures or partial regions of an integral contact portion 21.

[0063] The pressure sensor of this disclosure can be applied to an electronic pen or a pen refill, but is not limited thereto.

[0064] In some embodiments of this disclosure, the end face 211 has a cross-sectional line segment in the axial section of the contact portion 21, and the extension direction of each point on the cross-sectional line segment is at an angle to the central axis of the contact portion 21. The angle corresponding to each point in the first section 212 is smaller than the angle corresponding to each point in the second section 213.

[0065] In some embodiments of this disclosure, the smaller the angle between the extension direction of each point on the axial section and the central axis of the contact portion 21, the slower the area of ​​the normal section of the contact portion 21 changes when the flexible conductive member 2 is subjected to pressure. That is, when the pressure changes by the same amount, the contact area between the contact portion 21 and the capacitor 1 changes less, thereby achieving different pressure sensitivity curves between the first section 212 and the second section 213. The rate of change of capacitance value of the first section 212 based on touch pressure is smaller than that of the second section 213.

[0066] In some embodiments of this disclosure, the shapes of the first segment 212 and the second segment 213 can be varied. For example, the first segment 212 and the second segment 213 can be partially spherical. In this case, the cross-sectional line segments of the first segment 212 and the second segment 213 on the axial section are arc-shaped, and the extension direction of each point on the cross-sectional line segment is the tangent direction of that point. As another example, the first segment 212 and the second segment 213 can be frustum-shaped. In this case, the cross-sectional line segments of the first segment 212 and the second segment 213 on the axial section are straight line segments, and the extension direction of each point on the cross-sectional line segment is the direction of the straight line segment.

[0067] Figure 2 This is a schematic diagram illustrating the structure of a flexible conductive element according to some embodiments of the present disclosure. Figure 3 This is a schematic diagram of a flexible conductive element from another perspective, illustrating some embodiments of the present disclosure. Figure 4 This is a schematic diagram of a flexible conductive element from another perspective, illustrating some embodiments of the present disclosure. Figure 3 This is a front view. Figure 4This is a side view, i.e. Figure 3 and Figure 4 The viewing angles differ by 90°. Figure 2 This is a perspective between the front view and the side view. For example... Figure 2 , Figure 3 and Figure 4 As shown, the end face 211 includes an end face edge 214 and a vertex 215. The end face edge 214 is circumferentially engaged with the outer peripheral sidewall of the contact portion 21, and the vertex 215 is the highest point of the end face 211 protruding towards the capacitor 1. The end face edge 214 extends and closes circumferentially along the contact portion 21, and also extends reciprocally along the axial direction of the contact portion 21. The end face edge 214 includes a first edge point 214-a and a second edge point 214-b. In the axial direction, the first edge point 214-a and the vertex 215 are located on both sides of the second edge point 214-b, respectively. The contact portion 21 has a first normal section, a second normal section, and a third normal section, all of which are perpendicular to the axial direction. The first normal section passes through the first edge point 214-a, the second normal section passes through the second edge point 214-b, the third normal section passes through the vertex 215, the first segment 212 is located between the first normal section and the second normal section, and the second segment 213 is located between the second normal section and the third normal section.

[0068] In some embodiments of this disclosure, the end face edge 214 is configured to extend and close circumferentially along the contact portion 21, and also extend axially along the contact portion 21 to form a corrugated end face edge 214. The corrugated end face edge 214 has a second edge point 214-b relatively close to the vertex 215 in the axial direction and a first edge point 214-a relatively far from the vertex 215. Between the first normal section where the first edge point 214-a is located and the second normal section where the second edge point 214-b is located, the end face 211 and the outer peripheral sidewall of the contact portion 21 are distributed circumferentially. When the pressure changes, the portion between the first normal section and the second normal section has a significantly slower rate of change in contact area with the capacitor 1 than the portion between the second normal section and the third normal section. This achieves the beneficial effect that the pressure sensitivity curve of the first segment 212 is different from the pressure sensitivity curve of the second segment 213.

[0069] In some embodiments of this disclosure, such as Figure 2 , Figure 3 and Figure 4As shown, the contact portion 21 has a first axial section and a second axial section. Both the first axial section and the second axial section pass through the central axis of the contact portion 21. The first axial section passes through the first edge point 214-a, and the second axial section passes through the second edge point 214-b. In the first axial section, the cross-sectional line segment of the end face 211 is an arc with a radius of R1. In the second axial section, the cross-sectional line segment of the end face 211 is an arc with a radius of R2, where R1 < R2.

[0070] In some embodiments of this disclosure, the end face 211 of the contact portion 21 is configured as a sphere with different radii in the first and second axial sections, wherein the sphere with the smaller radius extends longer in the axial direction, and the sphere with the larger radius extends shorter in the axial direction, wherein the portion of the smaller sphere that extends beyond the larger sphere in the axial direction forms the first segment 212. Using a spherical shape as the shape of the end face 211 of the contact portion 21 allows the rate of increase in the contact area between the spherical end face 211 and the capacitor 1 to gradually slow down as pressure increases, thus adapting to changes in the user's control capability under both light and heavy pressure conditions. Furthermore, the pressure sensitivity change curve at the transition between the first segment 212 and the second segment 213 of the spherical end face 211 transitions more smoothly, facilitating a more natural change in touch effect.

[0071] In some embodiments of this disclosure, R2 is greater than or equal to 2R1 to obtain a more ideal pressure sensitivity curve.

[0072] In some embodiments of this disclosure, the first edge point 214-a is the point on the end face edge 214 that is furthest from the vertex 215 in the axial direction, and the second edge point 214-b is the point on the end face edge 214 that is closest to the vertex 215 in the axial direction. This allows the first segment 212 to have a longer distance, enabling a longer deformation stroke under heavy pressure.

[0073] In some embodiments of this disclosure, the first axial section and the second axial section are perpendicular to each other, so that the spherical end face 211 has a relatively smooth transition.

[0074] In some embodiments of this disclosure, the end face edge 214 may also include other edge points besides the first edge point 214-a and the second edge point 214-b, and the contact portion 21 may also have other axial sections passing through these edge points respectively. This disclosure does not limit this.

[0075] Figure 10 This is a capacitance-pressure curve of a pressure sensor shown according to some embodiments of the present disclosure, such as... Figure 10 As shown, capacitance and pressure data of the pressure sensor disclosed herein are acquired and curves are plotted. Figure 10As can be seen, the slope of the pressure sensitivity curve (i.e., the rate of change of capacitance value based on touch pressure) slows down significantly as pressure increases. Applying the pressure sensor of this embodiment to pen refills and electronic pens allows them to have high touch pressure sensitivity under light pressure and reduced sensitivity under heavy pressure, making the output characteristics of pen refills and electronic pens in converting touch pressure and pen strokes more consistent with the user's force application characteristics. Figure 10 The horizontal axis represents pressure, measured in grams per force (gf), and the vertical axis represents capacitance, measured in picofarads (pf). A gram-force (gf) is a unit used to express the magnitude of force, defined as the force applied under standard gravitational acceleration (g = 9.80665 m / s²). 2 Under these conditions, the magnitude of the gravitational force experienced by a mass of 1 gram.

[0076] In some embodiments of this disclosure, pressure below 100 grams can be considered a light pressure range, and pressure above 100 grams can be considered a heavy pressure range. Figure 10 It is evident that the slope of the pressure sensor curve in this embodiment is significantly greater than the slope of the pressure sensor curve above 100 grams of force. Of course, using 100 grams as the boundary between light and heavy pressure is merely an illustrative example, and this disclosure is not limited thereto. Light and heavy pressure can have a definite dividing line in grams, or they can have a transitional range in grams; this disclosure is not limiting in this regard either.

[0077] Figure 5 This is a schematic diagram illustrating the structure of another flexible conductive element according to some embodiments of the present disclosure, such as... Figure 5 As shown, the first segment 212 includes a first spherical surface 216, with the end of the contact portion 21 protruding towards the capacitor 1 to form the first spherical surface 216; the second segment 213 may include a second spherical surface 217, which protrudes from the first spherical surface 216 towards the capacitor 1 to form the second spherical surface 217, and the second spherical surface 217 is partially stacked with the first spherical surface 216. The radius of the first spherical surface 216 is R1, and the radius of the second spherical surface 217 is R2, where R1 < R2.

[0078] In some embodiments of this disclosure, the pressure sensitivity curves differ depending on the diameter of the sphere. The smaller the diameter of the sphere, the flatter the corresponding pressure sensitivity curve. By setting the first segment 212 and the second segment 213 as a stacked sphere, the pressure sensitivity curves of the first segment 212 and the second segment 213 can be set as two different parts by setting the radius of the sphere, which is simpler and more direct in terms of principle and specific parameter design.

[0079] In some embodiments of this disclosure, such as Figure 5 As shown, Figure 5The arc-shaped dashed line in the diagram represents the extension of the arc surface of the first sphere 216 in the front view, for comparison with the second sphere 217, to facilitate observation of the difference in radius between the first sphere 216 and the second sphere 217.

[0080] In some embodiments of this disclosure, the first spherical surface 216 and the second spherical surface 217 are coaxially arranged so that the contact portion 21 becomes a symmetrical body of rotation, simplifying the structure of the contact portion 21 and making its pressure-sensitive characteristics simpler and more uniform.

[0081] In some embodiments of this disclosure, the maximum normal cross-sectional radius of the second sphere 217 is one-third of the maximum normal cross-sectional radius of the first sphere 216. By setting this ratio, a more ideal pressure sensitivity curve can be obtained.

[0082] Figure 6 This is a schematic diagram illustrating the structure of another flexible conductive element according to some embodiments of the present disclosure, such as... Figure 6 As shown, the first section 212 includes a conical surface 219, and the second section 213 includes a plane 218, which is formed at the end of the conical surface 219.

[0083] In some embodiments of this disclosure, the second segment 213 is set as a plane 218, which can make the second segment 213 have a larger base capacitance value when it contacts the capacitor 1, so as to make it easier to clearly identify whether the end face 211 of the contact portion 21 is in contact with the capacitor 1.

[0084] In some embodiments of this disclosure, the diameter of the plane 218 may be set to 1.9 mm.

[0085] Figure 7 This is a schematic diagram showing the position of a flexible conductive element and a capacitor according to some embodiments of this disclosure. Figure 8 This is a schematic diagram illustrating the position of another flexible conductive element and capacitor according to some embodiments of this disclosure, such as... Figure 7 and Figure 8 As shown, in some embodiments of this disclosure, the pressure sensor has a pressurized state and an unpressurized state. Figure 7 The diagram shows the unpressurized state, in which the contact portion 21 of the flexible conductive element 2 is detached from the capacitor 1. Figure 8 The diagram shows the pressure state, in which the contact portion 21 of the flexible conductive element 2 abuts against the capacitor 1. When the second section 213 includes the plane 218, the capacitance value output by the capacitor 1 will jump at the instant the end face 211 of the contact portion 21 contacts the capacitor 1. Figure 11 This is a capacitance-pressure curve of another pressure sensor shown according to some embodiments of the present disclosure, such as... Figure 11As shown, the touch pressure corresponding to C0 is 0, and the corresponding capacitance value is less than 1 picofarad. At this time, the pressure sensor is in a non-pressurized state, and the end face 211 of the contact portion 21 is detached from capacitor 1. The capacitance value output by capacitor 1 is 0. When the touch pressure reaches the pressure value corresponding to C1, the capacitance value output by capacitor 1 jumps to the capacitance value corresponding to C1. From... Figure 11 As can be seen, the capacitance value changes significantly from C0 to C1, which can be used to accurately determine whether the state is under pressure or not. Applying the pressure sensor of this embodiment to pen refills and electronic pens enables them to accurately determine the pressure applied when the pen is put down, lifted, and the handwriting pressure, which is beneficial for handwriting identification and is well-suited for electronic signature handwriting recognition applications.

[0086] In some embodiments of this disclosure, the end face 211 is provided with a texture, which has a concave-convex structure.

[0087] In some embodiments of this disclosure, a textured surface with an uneven structure is provided on the end face 211 to prevent the end face 211 from sticking to the capacitor 1. This allows the end face 211 of the contact portion 21 to quickly recover its deformation and change the capacitance value output by the capacitor 1 when the touch pressure decreases, thereby improving the sensitivity of the pressure sensor. Applying the pressure sensor of this disclosure to electronic pens and pen refills can shorten the response time for pen tip lift-off detection in writing scenarios and avoid signal trailing during light pressure operations in drawing scenarios.

[0088] In some embodiments of this disclosure, the texture of the end face 211 can be formed in various ways. For example, the flexible conductive element 2 can be directly processed, or the flexible conductive element 2 can be manufactured using a mold, and the texture can be pre-processed directly on the mold, but it is not limited to this.

[0089] Figure 9 This is a cross-sectional view of a pressure sensor shown according to some embodiments of the present disclosure, such as... Figure 9 As shown, the pressure sensor also includes a piston 3 with a hollow structure. The flexible conductive element 2 includes a fixing post 22 connected to the contact portion 21. The fixing post 22 is inserted into the hollow structure of the piston 3 to fix the piston 3 to the flexible conductive element 2, and the piston 3 receives external pressure. The contact portion 21 also includes a support surface 23 protruding from the fixing post 22. The support surface 23 abuts against the edge of the hollow structure of the piston 3 to make the support of the piston 3 on the flexible conductive element 2 more stable.

[0090] In some embodiments of this disclosure, such as Figure 9 As shown, the pressure sensor also includes a conductive elastic element 4 and a first mounting base 5. The capacitor 1 is disposed in the first mounting base 5. One end of the conductive elastic element 4 is sleeved on a portion of the piston 3, and the other end abuts against the first mounting base 5.

[0091] In some embodiments of this disclosure, the conductive elastic element 4 is used to help the flexible conductive element 2 return to its original position after compression.

[0092] In some embodiments of this disclosure, the conductive elastic element 4 is a spring.

[0093] In some embodiments of this disclosure, such as Figure 9 As shown, the pressure sensor also includes a first electrode 7 and a second electrode 8. The first electrode 7 is electrically connected to a conductive elastic element 4, which in turn is electrically connected to a flexible conductive element 2, to conduct the charge generated at one pole of capacitor 1 through the flexible conductive element 2, the conductive elastic element 4 (which may be a spring), and the first electrode 7. The second electrode 8 is connected to capacitor 1 to conduct the charge generated at the other pole of capacitor 1 through the second electrode 8. By connecting the first electrode 7 and the second electrode 8 to relevant control components, the capacitance value output by capacitor 1 can be detected.

[0094] In some embodiments of this disclosure, such as Figure 9 As shown, the pressure sensor also includes a second mounting base 6, and the piston 3 is disposed within the second mounting base 6. The first mounting base 5 and the second mounting base 6 are connected to form the housing of the pressure sensor.

[0095] In some embodiments of this disclosure, the connection method between the first mounting base 5 and the second mounting base 6 can be various, such as plug-in, snap-in, screw-in and adhesive, but is not limited to these.

[0096] This disclosure also proposes a pen refill that includes a pressure sensor according to any embodiment of this disclosure. Accordingly, the advantages of the pressure sensor described above are also present in the pen refill, which will not be repeated here.

[0097] Figure 12 This is a schematic diagram of the appearance structure of an electronic pen according to some embodiments of the present disclosure, such as... Figure 12 As shown, this disclosure also proposes an electronic pen 10, including the pen refill in the embodiments of this disclosure. Accordingly, the electronic pen 10 including such a pen refill also has the same advantages as the aforementioned pen refill, which will not be repeated here.

[0098] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the utility model disclosed herein. This application is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein.

[0099] It should be understood that this disclosure is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this disclosure is limited only by the appended claims.

Claims

1. A pressure sensor, characterized in that, include: Capacitor (1); A flexible conductive element (2) includes a contact portion (21). The flexible conductive element (2) and the capacitor (1) are arranged along the axial direction of the contact portion (21). The capacitance value output by the capacitor (1) changes with the change of the contact area between the capacitor (1) and the contact portion (21). The contact area changes with the change of the pressure on the contact portion (21). The contact portion (21) has an end face (211) facing the capacitor (1), the end face (211) protruding towards the capacitor (1) along the axial direction, and the contact portion (21) is sequentially formed into a first section (212) and a second section (213) along the axial direction. When the pressure on the contact portion (21) changes by the same amount, the change in capacitance value of the first section (212) is less than the change in capacitance value of the second section (213).

2. The pressure sensor according to claim 1, characterized in that, The end face (211) has a cross-sectional line segment in the axial section of the contact portion (21). The extension direction of each point on the cross-sectional line segment is at an angle to the central axis of the contact portion (21). The angle corresponding to each point in the first section (212) is smaller than the angle corresponding to each point in the second section (213).

3. The pressure sensor according to claim 2, characterized in that, The end face (211) includes an end face edge (214) and a vertex (215). The end face edge (214) is circumferentially joined to the outer peripheral sidewall of the contact portion (21). The vertex (215) is the highest point of the end face (211) protruding toward the capacitor (1). The end face edge (214) extends and closes along the circumference of the contact portion (21), and the end face edge (214) also extends back and forth along the axial direction of the contact portion (21). The end face edge (214) includes a first edge point (214-a) and a second edge point (214-b). In the axial direction, the first edge point (214-a) and the vertex (215) are located on both sides of the second edge point (214-b). The contact portion (21) has a first normal section, a second normal section and a third normal section. The first normal section, the second normal section and the third normal section are all perpendicular to the axial direction. The first normal section passes through the first edge point (214-a), the second normal section passes through the second edge point (214-b), and the third normal section passes through the vertex (215). The first segment (212) is located between the first normal section and the second normal section, and the second segment (213) is located between the second normal section and the third normal section.

4. The pressure sensor according to claim 3, characterized in that, The contact portion (21) has a first axial section and a second axial section. Both the first axial section and the second axial section pass through the central axis of the contact portion (21), and the first axial section passes through the first edge point (214-a), while the second axial section passes through the second edge point (214-b). In the first axial section, the cross-sectional line segment of the end face (211) is a circular arc with a radius of R1; In the second axial section, the cross-sectional line segment of the end face (211) is a circular arc with a radius of R2; Where R1 < R2.

5. The pressure sensor according to claim 4, characterized in that, The radius R2 is greater than or equal to 2R1.

6. The pressure sensor according to claim 2, characterized in that, The first section (212) includes a first spherical surface (216), and the end of the contact portion (21) protrudes in the direction of the capacitor (1) to form the first spherical surface (216); The second section (213) includes a second spherical surface (217), which protrudes from the first spherical surface (216) toward the capacitor (1) to form the second spherical surface (217), and the second spherical surface (217) is partially stacked on the first spherical surface (216); The radius of the first sphere (216) is R1, and the radius of the second sphere (217) is R2, where R1 < R2.

7. The pressure sensor according to claim 2, characterized in that, The first section (212) includes a conical surface (219), and the second section (213) includes a plane (218) formed at the end of the conical surface (219).

8. The pressure sensor according to any one of claims 1-7, characterized in that, The end face (211) is provided with a texture, which has a concave-convex structure.

9. A pen refill, characterized in that, Includes the pressure sensor as described in any one of claims 1-8.

10. An electronic pen, characterized in that, Includes the pen refill as described in claim 9.

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