Pressure sensor, cartridge and electronic pen
By designing the section structure of the flexible conductive parts in the pressure sensor of the electronic pen, so that they have different capacitance value change rates during light pressure and heavy pressure, the problem of constant mapping relationship in the prior art is solved, and sensitive and stable feedback under different pressures is achieved, which improves the user experience.
Patent Information
- Application Number
- CN202510913451.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-02
- Publication Date
- 2025-08-29
AI Technical Summary
The existing electronic pen pressure sensor has a constant mapping relationship between the capacitance value and touch pressure when the pressure sensor of the capacitance is light and heavy, and cannot meet the different conversion needs of the user for touch pressure and stroke lines during light and heavy pressure, resulting in a decline in user experience.
A pressure sensor is designed. The contact part of the flexible conductive member is divided into the first section and the second section along the axial direction. The capacitance value change rate is different. It is sensitive when the pressure is light, and the sensitivity is reduced when the pressure is heavy. Through the structural design of the flexible conductive member, the difference in the capacitance value change rate at different pressure stages is achieved, adapting to the changes in the user's control ability under light and heavy pressure.
Improve the sensitivity of touch pressure changes during light pressure, stabilize the output of capacitance value during heavy pressure, improve user experience, ensure the smoothness and stability of stroke lines, and improve writing and painting effects.
Smart Images
Figure CN120558438A_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to the field of electronic equipment, and in particular to a pressure sensor, a pen core, and an electronic pen. Background Art
[0002] An electronic pen is a device used with electronic devices to interact with them through touch control. With the advancement of touch technology and electronic devices, the application scenarios for electronic pens are becoming increasingly diverse, such as using them for drawing on touchscreens. This places increasingly stringent demands on the pen's touch control capabilities. A particular challenge with electronic pens is adjusting the mapping between touch pressure and pen stroke effects to accommodate the user's varying levels of touch pressure, thereby achieving optimal writing and drawing results. Summary of the Invention
[0003] In order to overcome the problems existing in the related art, the present disclosure provides a pressure sensor, a pen core and an electronic pen.
[0004] According to some embodiments of the present disclosure, a pressure sensor is provided, comprising:
[0005] capacitance;
[0006] a flexible conductive member comprising a contact portion, wherein the flexible conductive member and the capacitor are arranged along an axial direction of the contact portion, wherein a capacitance value output by the capacitor changes with a change in a contact area between the capacitor and the contact portion, and wherein the contact area changes with a change in a pressure applied to the contact portion;
[0007] The contact portion has an end face facing the capacitor, and the end face protrudes toward the capacitor along the axial direction. The contact portion forms a first section and a second section in sequence along the axial direction. When the pressure applied to the contact portion changes in the same manner, the change in the capacitance value of the first section is smaller than the change in the capacitance value of the second section.
[0008] In some embodiments, the end face has a cross-sectional line segment in the axial cross-section of the contact portion, and the extension direction of each point on the cross-sectional line segment has an angle with the central axis of the contact portion, and 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 surface includes an end surface edge and a vertex, the end surface edge is circumferentially engaged with the outer peripheral side wall of the contact portion, and the vertex is the highest point of the end surface protruding from the capacitor;
[0010] The end surface edge extends along the circumference of the contact portion and is closed, and the end surface edge also extends reciprocatingly along the axial direction of the contact portion, and the end surface edge includes a first edge point and a second edge point, and 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, the third normal section passes through the vertex, the first section is located between the first normal section and the second normal section, and the second section is located between the second normal section and the third normal section.
[0012] In some embodiments, the contact portion has a first axial cross-section and a second axial cross-section, both of which pass through the central axis of the contact portion, and the first axial cross-section passes through the first edge point, and the second axial cross-section passes through the second edge point;
[0013] In the first axial section, the cross-sectional line segment of the end face is an arc line with a radius of R1;
[0014] In the second axial section, the cross-sectional line segment of the end face is an arc line with a radius of R2;
[0015] Among them, R1<R2.
[0016] In some embodiments, radius R2 is greater than or equal to 2R1.
[0017] In some embodiments, the first section includes a first spherical surface, and the end of the contact portion protrudes toward the capacitor to form the first spherical surface;
[0018] The second section includes a second spherical surface, which is protruded from the first spherical surface in the direction of the capacitor, and the second spherical surface is partially stacked on the first spherical surface;
[0019] The radius of the first spherical surface is R1, and the radius of the second spherical surface is R2, where R1<R2.
[0020] In some embodiments, the first section includes a conical surface, and the second section includes a flat surface, wherein the flat surface is formed at an end of the conical surface.
[0021] In some embodiments, the end surface is provided with textures, and the textures have a concave-convex structure.
[0022] According to some embodiments of the present disclosure, a pen refill is provided, comprising any one of the pressure sensors disclosed herein.
[0023] According to some embodiments of the present disclosure, an electronic pen and a pen refill of the present disclosure are provided.
[0024] The technical solution provided by the embodiments of the present disclosure may include the following beneficial effects: when lightly pressing the electronic pen, the user's control over the force is relatively accurate, and as the touch pressure gradually increases and turns from light pressure to heavy pressure, the user's control accuracy over the touch pressure also decreases. Touch pressure fluctuations unexpected by the user may occur. In extreme cases, jitter and other conditions may occur, causing the touch pressure to jump, affecting the stability of the touch pressure applied by the user. In the pressure sensor disclosed in the present disclosure, the contact portion of the flexible conductive part has a first section and a second section. When the pressure on the contact portion changes in the same manner, the capacitance value of the first section changes less than the capacitance value of the second section, so that the pressure sensor has different mapping relationships between the output capacitance value and the touch pressure when light pressure and heavy pressure are applied. The pen core and electronic pen using the pressure sensor disclosed herein can reflect different hand feels through the changes in the above-mentioned mapping relationship when the user presses lightly and heavily. In the light-pressing stage where the user accurately controls the touch pressure, the capacitance value change of the pressure sensor based on the touch pressure feedback is more sensitive, thereby reflecting more pressure-sensitive levels, so that the pen stroke lines ultimately reflected on the electronic device change more smoothly and quickly; in the heavy-pressing stage where the user's touch pressure control accuracy decreases, the sensitivity of the capacitance value change of the pressure sensor based on the touch pressure feedback decreases, avoiding obvious fluctuations in the capacitance value output by the pressure sensor when the touch pressure applied by the user fluctuates unexpectedly by the user, thereby improving the stability of the capacitance value feedbacked by the pressure sensor in the heavy-pressing stage, making the pen stroke lines ultimately reflected on the electronic device more stable, and improving the user experience.
[0025] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure. BRIEF DESCRIPTION OF THE DRAWINGS
[0026] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and, together with the description, serve to explain the principles of the present disclosure.
[0027] Figure 1 is a cross-sectional view of a pressure sensor according to some embodiments of the present disclosure.
[0028] Figure 2 1 is a schematic structural diagram of a flexible conductive member according to some embodiments of the present disclosure.
[0029] Figure 3This is a structural schematic diagram of a flexible conductive member from another perspective according to some embodiments of the present disclosure.
[0030] Figure 4 This is a structural schematic diagram of a flexible conductive member from another perspective according to some embodiments of the present disclosure.
[0031] Figure 5 is a schematic structural diagram of another flexible conductive member according to some embodiments of the present disclosure.
[0032] Figure 6 is a schematic structural diagram of another flexible conductive member according to some embodiments of the present disclosure.
[0033] Figure 7 This is a schematic diagram showing the position of a flexible conductive member and a capacitor according to some embodiments of the present disclosure.
[0034] Figure 8 Schematic diagram of another flexible conductive member and capacitor position according to some embodiments of the present disclosure.
[0035] Figure 9 is a cross-sectional view of a pressure sensor according to some embodiments of the present disclosure.
[0036] Figure 10 FIG. 4 is a capacitance-pressure curve diagram of a pressure sensor according to some embodiments of the present disclosure.
[0037] Figure 11 FIG. 4 is a capacitance-pressure curve diagram of another pressure sensor according to some embodiments of the present disclosure.
[0038] Figure 12 The figure shows the appearance structure of an electronic pen according to some embodiments of the present disclosure.
[0039] Reference numerals:
[0040] 1. Capacitor; 2. Flexible conductive member; 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. Fixed column; 23. Support surface; 3. Piston; 4. Conductive elastic member; 5. First mounting seat; 6. Second mounting seat; 7. First electrode; 8. Second electrode; 10. Electronic pen. DETAILED DESCRIPTION
[0041] Some embodiments of the present disclosure will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. Various changes, modifications and equivalents of the methods, devices and / or systems described herein will become apparent after understanding the present disclosure. For example, the order of operations described herein is merely an example and is not limited to those orders set forth herein, but may be changed as becomes apparent after understanding the present disclosure, except for operations that must be performed in a specific order. In addition, for the sake of clarity and brevity, descriptions of features known in the art may be omitted.
[0042] The embodiments described in the following examples of the present disclosure do not represent all embodiments consistent with the present disclosure. Instead, they are merely examples of devices and methods consistent with some aspects of the present disclosure as detailed in the appended claims.
[0043] Some embodiments of the present disclosure provide pressure sensors, pen refills, and electronic pens. The pressure sensors can be applied to pen refills and electronic pens. The pen refills and electronic pens are used to cooperate with electronic devices and interact with electronic devices through touch to achieve various touch-based functions, such as drawing, writing, etc.
[0044] In related art, an electronic pen is equipped with a refill containing 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 stroke force based on the electrical signal from the electronic pen. However, the user's ability to control touch pressure varies between light and heavy pressure. Generally speaking, when the user applies less touch pressure (i.e., the light pressure stage), the change in touch pressure can be controlled more accurately. The electronic pen needs to sensitively output the user's precise touch pressure as a stroke line with corresponding changes. In this way, the stroke line of the electronic pen can more accurately reflect the user's input requirements. When the user applies more touch pressure (i.e., the heavy pressure stage), the user's control accuracy of touch pressure decreases, and the output touch pressure will fluctuate unexpectedly. The electronic pen needs to weaken these unexpected touch pressure fluctuations so that the stroke line output by the electronic pen can be stable. However, the pressure sensors of the electronic pens and refills in the related art have a constant mapping relationship between the capacitance value output by the capacitor and the touch pressure when light pressure and heavy pressure are applied. As a result, the electronic pens and refills in the related art cannot simultaneously meet the user's different conversion requirements between touch pressure and pen stroke lines when light pressure and heavy pressure are applied, thereby reducing the user experience.
[0045] In view of this, some embodiments of the present disclosure provide a pressure sensor.
[0046] Figure 1FIG is a cross-sectional view of a pressure sensor according to some embodiments of the present disclosure. Figure 1 As shown, the pressure sensor includes a capacitor 1 and a flexible conductive member 2. The flexible conductive member 2 includes a contact portion 21. The flexible conductive member 2 and the capacitor 1 are arranged axially along the contact portion 21. The capacitance output by the capacitor 1 changes with the contact area between the capacitor 1 and the contact portion 21, and 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. The end face 211 protrudes axially toward the capacitor 1. The contact portion 21 is sequentially formed along the axial direction into a first section 212 and a second section 213. When the pressure applied to the contact portion 21 changes by the same amount, the capacitance value of the first section 212 changes less than the capacitance value of the second section 213.
[0047] In some embodiments of the present disclosure, the contact portion 21 has a first section 212 and a second section 213 distributed along the axial direction. When light pressure is applied, the second section 213 contacts the capacitor 1, and the contact area increases with increasing touch pressure; when heavy pressure is applied, the second section 213 completely contacts the capacitor 1, the first section 212 contacts the capacitor 1, and the contact area increases with increasing touch pressure. That is, the second section 213 corresponds to light pressure, and the first section 212 corresponds to heavy pressure. The first section 212 and the second section 213 are set so that when the pressure on the contact portion 21 changes by the same amount, the change in the capacitance value of the first section 212 is less than the change in the capacitance value of the second section 213 (that is, the rate of change of the capacitance value of the first section 212 based on the touch pressure is less than the rate of change of the capacitance value of the second section 213 based on the touch pressure). This can make the pressure sensor more sensitive to changes in touch pressure in a light pressure state, while reducing the sensitivity of the pressure sensor to touch pressure in a heavy pressure state, so that the same pressure sensor has two different capacitance output characteristics under light and heavy pressure. Applying the pressure sensor disclosed in the present invention to a pen refill and an electronic pen can enable the pen refill and the electronic pen to output strokes with richer light and heavy variations based on changes in the touch pressure applied by the user when light pressure is applied, and weaken the fluctuation of the touch pressure output by the user when heavy pressure is applied, making the strokes output by the electronic pen more stable, thereby improving the user experience.
[0048] In some embodiments of the present disclosure, a rectangular coordinate system is established with touch pressure as the horizontal axis and capacitance as the vertical axis, and a corresponding capacitance-pressure change curve is plotted. The "capacitance change rate" is the slope of the curve. It should be noted that this is merely an exemplary understanding of the "capacitance change rate" and is not intended to be limiting.
[0049] When the pressure sensor is subjected to touch pressure, flexible conductive member 2 contacts capacitor 1 under the action of the touch pressure, forming the other electrode of capacitor 1. As a result, the capacitance output by capacitor 1 increases accordingly with increasing touch pressure. The mapping between the touch pressure and the output capacitance is called a pressure sensitivity curve. For ease of description, the pressure sensitivity curve will be used below to describe the characteristic of a pressure sensor's capacitance changing with pressure.
[0050] The calculation formula for the capacitance value C is:
[0051] C=ε*S*π / d
[0052] Wherein, ε is the dielectric field number of capacitor 1, S is the contact area between the flexible conductive member 2 and capacitor 1, and d is the dielectric thickness of capacitor 1.
[0053] In some embodiments of the present disclosure, the capacitor 1 includes a ceramic sheet and an electrode sheet sintered together, wherein the ceramic sheet serves as a dielectric and d is the thickness of the ceramic sheet.
[0054] In some embodiments of the present disclosure, if the end surface 211 of the contact portion 21 is a cylindrical, conical, or spherical shape with a circular normal cross-section, the calculation formula for S is:
[0055] S=(D / 2) 2 *π
[0056] Wherein, D is the radius of the contact surface between the end surface 211 and the capacitor 1 .
[0057] In some embodiments of the present disclosure, Figure 1 The first section 212 and the second section 213 indicated in the figure are merely schematic illustrations 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, the "axial direction" is Figure 1 The middle direction can be expressed as the up and down direction, or as the longitudinal direction.
[0059] In some embodiments of the present disclosure, the flexible conductive member 2 can be made of a conductive and elastic material, such as silicone, but is not limited thereto. To increase the conductivity of the flexible conductive member 2, conductive particles can be doped into the flexible conductive member 2.
[0060] In some embodiments of the present disclosure, the body 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" may refer to the same difference in pressure change, or the same ratio of pressure change, and is not limited thereto. Those skilled in the art may select a suitable indicator as needed.
[0062] In some embodiments of the present disclosure, the contact portion 21 may include portions other than the first section 212 and the second section 213, but this disclosure does not limit this. The first section 212 and the second section 213 are merely for ease of description. The division of the contact portion 21 into different locations does not imply that the first section 212 and the second section 213 are two independent structures. For example, the first section 212 and the second section 213 may be partial structures or regions of a single, integrated contact portion 21.
[0063] The pressure sensor of the embodiment of the present disclosure can be applied to an electronic pen or a pen refill, but is not limited thereto.
[0064] In some embodiments of the present disclosure, the end face 211 has a cross-sectional line segment in the axial cross-section of the contact portion 21, and the extension direction of each point on the cross-sectional line segment has an angle with the central axis of the contact portion 21, and 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 the present disclosure, the smaller the angle between the extension direction of each point on the axial cross-section and the central axis of the contact portion 21, the slower the area of the normal cross-section of the contact portion 21 changes when the flexible conductive member 2 is subjected to pressure, that is, when the pressure applied thereto changes by the same amount, the smaller the change in the contact area between the contact portion 21 and the capacitor 1, thereby achieving different pressure sensitivity curves between the first segment 212 and the second segment 213, and a smaller rate of change of the capacitance value of the first segment 212 based on touch pressure relative to the second segment 213.
[0066] In some embodiments of the present disclosure, the first segment 212 and the second segment 213 may have various shapes. For example, the first segment 212 and the second segment 213 may be partially spherical. In this case, the cross-sectional line segments of the first segment 212 and the second segment 213 on the axial cross section are arc-shaped, and the extension direction of each point on the cross-sectional line segment is the tangent direction of that point. For another example, the first segment 212 and the second segment 213 may be truncated cone-shaped. In this case, the cross-sectional line segments of the first segment 212 and the second segment 213 on the axial cross 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 is a schematic structural diagram of a flexible conductive member according to some embodiments of the present disclosure. Figure 3 is a structural schematic diagram of a flexible conductive member from another perspective according to some embodiments of the present disclosure. Figure 4 is a structural schematic diagram of a flexible conductive member from another perspective according to some embodiments of the present disclosure, wherein: Figure 3 is the front view, Figure 4is a side view, i.e. Figure 3 and Figure 4 The viewing angles differ by 90°. Figure 2 It is a perspective between the front view and the side view. Figure 2 、 Figure 3 and Figure 4 As shown, end face 211 includes an end face edge 214 and a vertex 215. End face edge 214 is circumferentially joined to the outer peripheral sidewall of contact portion 21, and vertex 215 is the highest point of end face 211 protruding toward capacitor 1. End face edge 214 extends and closes along the circumference of contact portion 21. End face edge 214 also extends back and forth along the axial direction of contact portion 21. End face edge 214 includes a first edge point 214-a and a second edge point 214-b. In the axial direction, first edge point 214-a and vertex 215 are respectively located on either side of second edge point 214-b. Contact portion 21 has a first normal cross section, a second normal cross section, and a third normal cross section, all of which are perpendicular to the axial direction. Among them, 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 section 212 is located between the first normal section and the second normal section, and the second section 213 is located between the second normal section and the third normal section.
[0068] In some embodiments of the present disclosure, the end face edge 214 is configured to extend and close along the circumference of the contact portion 21, and also to extend back and forth 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 in the circumferential direction. When the pressure applied changes, the contact area between the first and second normal sections and the capacitor 1 changes significantly more slowly than the section between the second and third normal sections. This achieves the beneficial effect of having a pressure sensitivity curve for the first section 212 that is different from that for the second section 213.
[0069] In some embodiments of the present disclosure, Figure 2 、 Figure 3 and Figure 4As shown, the contact portion 21 has a first axial section and a second axial section, both of which pass through the central axis of the contact portion 21, and 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 a circular arc line with a radius of R1; in the second axial section, the cross-sectional line segment of the end face 211 is a circular arc line with a radius of R2, wherein R1<R2.
[0070] In some embodiments of the present disclosure, the end face 211 of the contact portion 21 is set to a spherical surface with different radii in the first axial section and the second axial section, wherein the spherical surface with a smaller radius extends longer in the axial direction, and the spherical surface with a larger radius extends shorter in the axial direction, wherein the portion of the small spherical surface that extends axially beyond the large spherical surface forms a first section 212. Using a spherical shape as the shape of the end face 211 of the contact portion 21, as the pressure increases, the rate of increase of the contact area between the spherical end face 211 and the capacitor 1 will gradually slow down to adapt to the change in the user's control ability under light pressure and heavy pressure. In addition, the pressure change curve of the spherical end face 211 at the transition between the first section 212 and the second section 213 will also transition more smoothly, so as to facilitate a more natural change in the touch effect.
[0071] In some embodiments of the present disclosure, R2 is greater than or equal to 2R1 to obtain a more ideal pressure sensitivity curve.
[0072] In some embodiments of the present disclosure, the first edge point 214-a is the point on the end surface edge 214 that is farthest from the vertex 215 in the axial direction, and the second edge point 214-b is the point on the end surface edge 214 that is closest to the vertex 215 in the axial direction. This allows the first section 212 to have a longer distance, thereby allowing for a longer deformation stroke when subjected to heavy pressure.
[0073] In some embodiments of the present disclosure, the first axial cross section and the second axial cross section are perpendicular to each other, so that the spherical end surface 211 has a relatively smooth transition.
[0074] In some embodiments of the present disclosure, the end face edge 214 may also include other edge points in addition to 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, which is not limited in the present disclosure.
[0075] Figure 10 is a capacitance-pressure curve diagram of a pressure sensor according to some embodiments of the present disclosure, such as Figure 10 As shown, the capacitance and pressure data of the pressure sensor disclosed in the present invention are collected and a curve is drawn. Figure 10As can be seen in the figure, as the pressure increases, the slope of the pressure curve (i.e., the rate of change of the capacitance value based on the touch pressure) slows down significantly. Applying the pressure sensor of the embodiment of the present disclosure to the pen core and the electronic pen can make the pen core and the electronic pen have a higher touch pressure sensitivity when light pressure is applied, and reduce the sensitivity to touch pressure when heavy pressure is applied, so that the conversion output characteristics of the pen core and the electronic pen to touch pressure and stroke lines are more in line with the user's force characteristics. Among them, Figure 10 The horizontal axis is pressure, the unit is gram-force (gf), and the vertical axis is capacitance, the unit is picofarad (pf). Gram-force (gf) is a unit used to express the magnitude of force, which is defined as the acceleration due to gravity (g = 9.80665m / s 2 ) under the condition of gravity acting on 1 gram of mass.
[0076] In some embodiments of the present disclosure, a force below 100 grams can be considered as a light pressure range, and a force above 100 grams can be considered as a heavy pressure range. Figure 10 It can be clearly seen that the slope of the pressure sensitivity curve of the pressure sensor in the embodiment of the present disclosure within 100 g-force is significantly greater than the slope of the pressure sensitivity curve above 100 g-force. Of course, using 100 g-force as the boundary between light pressure and heavy pressure is merely an example, and the present disclosure is not limited to this. Light pressure and heavy pressure can have a clear g-force value as the boundary, or they can have a transitional g-force value range, and the present disclosure is also not limited to this.
[0077] Figure 5 is a schematic structural diagram of another flexible conductive member according to some embodiments of the present disclosure, such as Figure 5 As shown, the first section 212 includes a first spherical surface 216, formed by the end of the contact portion 21 protruding toward the capacitor 1. The second section 213 may include a second spherical surface 217, which protrudes from the first spherical surface 216 toward the capacitor 1. 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 the present disclosure, the pressure sensitivity curve varies depending on the diameter of the sphere. The smaller the sphere diameter, the flatter the corresponding pressure sensitivity curve. By configuring the first section 212 and the second section 213 as stacked spheres, the first section 212 and the second section 213 can be configured as two sections with different pressure sensitivity curves by setting the sphere radius, which is simpler and more direct in principle and specific parameter design.
[0079] In some embodiments of the present disclosure, Figure 5 As shown, Figure 5The arc dotted line in FIG. 2 represents the arc extension line of the first spherical surface 216 in the front view, which is used for comparison with the second spherical surface 217 to facilitate observation of the radius difference between the first spherical surface 216 and the second spherical surface 217 .
[0080] In some embodiments of the present disclosure, the first spherical surface 216 and the second spherical surface 217 are coaxially arranged to make the contact portion 21 a symmetrical body of revolution, simplifying the structure of the contact portion 21 and making its pressure sensing characteristics simpler and more uniform.
[0081] In some embodiments of the present disclosure, the maximum normal cross-sectional radius of the second spherical surface 217 is one-third of the maximum normal cross-sectional radius of the first spherical surface 216. According to this ratio setting, a relatively ideal pressure sensitivity curve can be obtained.
[0082] Figure 6 is a structural diagram of another flexible conductive member 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 flat surface 218 . The flat surface 218 is formed at the end of the conical surface 219 .
[0083] In some embodiments of the present disclosure, the second section 213 is set as a plane 218, so that when the second section 213 contacts the capacitor 1, it has a larger basic capacitance value, which is conducive to clearly identifying whether the end surface 211 of the contact portion 21 contacts the capacitor 1.
[0084] In some embodiments of the present disclosure, the diameter of the plane 218 may be set to 1.9 mm.
[0085] Figure 7 is a schematic diagram showing the position of a flexible conductive member and a capacitor according to some embodiments of the present disclosure. Figure 8 is another schematic diagram of the position of a flexible conductive member and a capacitor according to some embodiments of the present disclosure, such as Figure 7 and Figure 8 As shown, in some embodiments of the present disclosure, the pressure sensor has a pressurized state and a non-pressurized state. Figure 7 The figure shows a non-pressurized state, in which the contact portion 21 of the flexible conductive member 2 is separated from the capacitor 1 . Figure 8 The diagram shows a compressed state, in which the contact portion 21 of the flexible conductive member 2 contacts the capacitor 1. When the second section 213 includes a flat surface 218, the capacitance output by the capacitor 1 will jump when the end surface 211 of the contact portion 21 contacts the capacitor 1. Figure 11 is a capacitance-pressure curve diagram of another pressure sensor 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 pF. At this time, the pressure sensor is in a non-pressurized state, the end surface 211 of the contact portion 21 is disconnected from the capacitor 1, and the capacitance value output by the capacitor 1 is 0. When the touch pressure reaches the pressure value corresponding to C1, the capacitance value output by the capacitor 1 jumps to the capacitance value corresponding to C1. Figure 11 As can be seen in the figure, the capacitance change from C0 to C1 is quite significant, allowing accurate determination of pressurized and unpressurized states. Applying the pressure sensor of the disclosed embodiment to a pen refill and electronic pen allows them to accurately determine the pressure of pen placement, pen lift, and handwriting, facilitating handwriting identification and making them well-suited for applications such as electronic signature handwriting recognition.
[0086] In some embodiments of the present disclosure, the end surface 211 is provided with textures, and the textures have a concave-convex structure.
[0087] In some embodiments of the present disclosure, a concave-convex pattern is provided on end surface 211 to prevent adhesion between end surface 211 and capacitor 1. When the touch pressure decreases, end surface 211 of contact portion 21 can quickly recover its deformation, changing the capacitance output by capacitor 1 and improving the sensitivity of the pressure sensor. Applying the pressure sensor of the present disclosure embodiment to an electronic pen and refill can shorten the response time of pen tip lift-off detection in writing scenarios and avoid signal smearing during light pressure operations in drawing scenarios.
[0088] In some embodiments of the present disclosure, the texture of the end surface 211 can be formed in a variety of ways. For example, the flexible conductive part 2 can be directly processed, or the flexible conductive part 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 is a cross-sectional view of a pressure sensor according to some embodiments of the present disclosure, such as Figure 9 As shown, the pressure sensor also includes a piston 3 having a hollow structure. The flexible conductive member 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 member 2, thereby receiving external pressure through the piston 3. The contact portion 21 also includes a support surface 23 protruding from the fixing post 22. The support surface 23 abuts the edge of the hollow structure of the piston 3, thereby ensuring that the piston 3 supports the flexible conductive member 2 more stably.
[0090] In some embodiments of the present disclosure, Figure 9 As shown, the pressure sensor further includes a conductive elastic member 4 and a first mounting seat 5 , the capacitor 1 is disposed in the first mounting seat 5 , one end of the conductive elastic member 4 is sleeved on a portion of the piston 3 , and the other end abuts against the first mounting seat 5 .
[0091] In some embodiments of the present disclosure, the conductive elastic member 4 is used to help the flexible conductive member 2 to return to its original position after being compressed.
[0092] In some embodiments of the present disclosure, the conductive elastic member 4 is a spring.
[0093] In some embodiments of the present disclosure, 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 the conductive elastic member 4, and the conductive elastic member 4 is electrically connected to the flexible conductive member 2 to conduct the charge generated by one electrode of the capacitor 1 through the flexible conductive member 2, the conductive elastic member 4 (which can be a spring), and the first electrode 7. The second electrode 8 is electrically connected to the capacitor 1 to conduct the charge generated by the other electrode of the capacitor 1 through the second electrode 8. By connecting the first electrode 7 and the second electrode 8 to the relevant control components, the capacitance value output by the capacitor 1 can be detected.
[0094] In some embodiments of the present disclosure, Figure 9 As shown, the pressure sensor further includes a second mounting seat 6, and the piston 3 is disposed in the second mounting seat 6. The first mounting seat 5 and the second mounting seat 6 are connected to form a housing of the pressure sensor.
[0095] In some embodiments of the present disclosure, there may be various connection methods between the first mounting seat 5 and the second mounting seat 6, such as plug-in connection, snap-on connection, screw connection, and adhesive connection, but not limited thereto.
[0096] The present disclosure also provides a pen refill including the pressure sensor of any embodiment of the present disclosure. Accordingly, the advantages of the pressure sensor mentioned above are also possessed by the pen refill including such a pressure sensor, which will not be elaborated here.
[0097] Figure 12 FIG. 1 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, the present disclosure also provides an electronic pen 10, including the refill in the embodiment of the present disclosure. Accordingly, the advantages of the refill mentioned above are also possessed by the electronic pen 10 including the refill, which will not be elaborated here.
[0098] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the invention disclosed herein. This disclosure is intended to cover any variations, uses, or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or customary techniques in the art not disclosed herein.
[0099] It should be understood that the present disclosure is not limited to the exact structures described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure is limited only by the scope of the appended claims.
Claims
1. A pressure sensor, characterized in that: include: Capacitor (1); A flexible conductive member (2) comprising a contact portion (21), wherein the flexible conductive member (2) and the capacitor (1) are arranged along the axial direction of the contact portion (21), and the capacitance value output by the capacitor (1) changes with a change in a contact area between the capacitor (1) and the contact portion (21), and the contact area changes with a change in a pressure applied to the contact portion (21); The contact portion (21) has an end surface (211) facing the capacitor (1), and the end surface (211) protrudes along the axial direction toward the capacitor (1). The contact portion (21) forms a first section (212) and a second section (213) in sequence along the axial direction. When the pressure applied to the contact portion (21) changes in the same manner, the change in the capacitance value of the first section (212) is smaller than the change in the capacitance value of the second section (213).
2. The pressure sensor according to claim 1, wherein The end surface (211) has a cross-sectional line segment in the axial cross-section of the contact portion (21), and the extension direction of each point on the cross-sectional line segment has an angle with the central axis of the contact portion (21), and 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, wherein: The end surface (211) includes an end surface edge (214) and a vertex (215), the end surface edge (214) is circumferentially engaged with the outer peripheral side wall of the contact portion (21), and the vertex (215) is the highest point of the end surface (211) protruding toward the capacitor (1); The end surface edge (214) extends along the circumference of the contact portion (21) and is closed. The end surface edge (214) also extends back and forth along the axial direction of the contact portion (21). The end surface 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 respectively 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), the third normal section passes through the vertex (215), the first section (212) is located between the first normal section and the second normal section, and the second section (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 cross section and a second axial cross section, both of which pass through the central axis of the contact portion (21), and the first axial cross section passes through the first edge point (214-a), and the second axial cross section passes through the second edge point (214-b); In the first axial section, the cross-sectional line segment of the end surface (211) is an arc line with a radius of R1; In the second axial section, the cross-sectional line segment of the end surface (211) is an arc line with a radius of R2; Among them, 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, wherein: The first section (212) includes a first spherical surface (216), and the end of the contact portion (21) protrudes toward the capacitor (1) to form the first spherical surface (216); The second section (213) includes a second spherical surface (217), which is convex 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 spherical surface (216) is R1, and the radius of the second spherical surface (217) is R2, wherein R1<R2.
7. The pressure sensor according to claim 2, wherein: The first section (212) includes a conical surface (219), and the second section (213) includes a plane (218), wherein the plane (218) is formed at the end of the conical surface (219).
8. The pressure sensor according to any one of claims 1 to 7, characterized in that: The end surface (211) is provided with lines, and the lines have a concave-convex structure.
9. A pen refill, characterized in that: The device comprises the pressure sensor according to any one of claims 1 to 8.
10. An electronic pen, characterized in that: The invention comprises the pen core as claimed in claim 9.