Pressure overload protection strain gauge and electronic pen

Abstract

The embodiment of the application discloses a pressure overload protection strain pressure sensing mechanism and an electronic pen, the strain pressure sensing mechanism comprises a pen tip module, a strain sensor, a fixing base, and an overload limiting sleeve, a strain part is arranged on the fixing base, an intermediate piece for transmitting the writing pressure of the pen tip module is arranged on the strain part, the strain sensor is correspondingly attached to the strain part, and the overload limiting sleeve is arranged on the pen tip module and is spaced apart from the front end of the fixing base by a gap. The strain sensor is adopted to detect the writing pressure, the structure is simple, assembly is convenient, detection is more sensitive, power consumption is obviously reduced, and the endurance is prolonged. The overload limiting sleeve is used for limiting, overpressure is prevented, the strain part is prevented from being damaged, the overload resistance of the strain part is stronger than that of a traditional pressure sensor, and the service life is long.

Description

Technical Field

[0001] This invention relates to the field of electronic pen technology, and more particularly to a pressure overload protection strain-sensitive mechanism and an electronic pen. Background Technology

[0002] Most existing electronic pens use pressure sensors to detect writing pressure. The pressure-sensing mechanism of these sensors is bulky and loose; the mechanism and sensor only make contact without a physical connection, leading to pen tip wobbling during writing and a poor writing feel. Furthermore, the writing sensitivity is insufficient, failing to respond to small changes in pressure, resulting in stiff handwriting and a distorted writing experience. If strain gauges and strain sensors are used for detection, the strain gauges are prone to plastic strain under excessive pressure. Summary of the Invention

[0003] The technical problem to be solved by the embodiments of the present invention is to provide a pressure overload protection strain-sensitive mechanism and an electronic pen, so as to simplify the structure, improve the writing feel, and prevent overpressure.

[0004] To address the aforementioned technical problems, this invention provides a pressure overload protection strain-sensitive mechanism, including a pen tip module, a strain sensor, a fixed base, and an overload limiting sleeve. The fixed base is provided with a strain section, and the strain section is provided with an intermediate component for transmitting the writing pressure of the pen tip module. The strain sensor is correspondingly attached to the strain section, and the overload limiting sleeve is provided on the pen tip module. There is a gap between the overload limiting sleeve and the front end of the fixed base.

[0005] Furthermore, the pen tip module is equipped with an overload spring, one end of which acts on the pen tip module and the other end of which acts on the intermediate component.

[0006] Furthermore, it also includes a signal board, which is in contact with the overload spring for conduction, and the pen tip module is connected to the signal board through the overload spring.

[0007] Furthermore, the pen tip module is provided with a centering bushing, and the fixing seat includes an outer sleeve portion; the outer sleeve portion is fitted over the centering bushing and serves as a guide for the centering bushing.

[0008] Furthermore, the intermediate component includes an inner sleeve portion, and a corresponding guide portion protrudes from the pen tip module. The inner sleeve portion is fitted over the guide portion to guide the pen tip module.

[0009] Furthermore, the end of the intermediate component facing the strain section is tapered.

[0010] Furthermore, the strain gauge is strip-shaped, with both ends connected to the fixed base and the middle part connected to the intermediate component.

[0011] Furthermore, the overload limit sleeve and the pen tip module are connected by threads, and the gap between the overload limit sleeve and the front end of the fixed seat can be adjusted by rotating the overload limit sleeve.

[0012] Furthermore, the outer periphery of the fixing base is provided with buckles for fixing.

[0013] Accordingly, embodiments of the present invention also provide an electronic pen, including the aforementioned pressure overload protection strain-sensitive mechanism.

[0014] The beneficial effects of this invention are as follows: This invention uses a strain gauge sensor to detect writing pressure, which has a simple structure, is easy to assemble, is more sensitive to detection, significantly reduces power consumption, and extends battery life; This invention uses an overload limiting sleeve to limit the pressure, prevent overpressure, avoid damage to the strain gauge, and the strain gauge has a stronger overload resistance and a longer service life compared to traditional pressure sensors. Attached Figure Description

[0015] Figure 1 This is a three-dimensional structural diagram of a pressure overload protection strain-sensing mechanism according to an embodiment of the present invention.

[0016] Figure 2 This is an exploded view of a pressure overload protection strain gauge mechanism according to an embodiment of the present invention.

[0017] Figure 3 This is an exploded view of a pressure overload protection strain-sensing mechanism according to an embodiment of the present invention from another angle.

[0018] Figure 4 This is an internal structural diagram of an electronic pen according to an embodiment of the present invention.

[0019] Figure 5 This is a three-dimensional structural diagram of a pressure overload protection strain-sensing mechanism according to another embodiment of the present invention.

[0020] Figure 6 This is an exploded view of a pressure overload protection strain gauge mechanism according to another embodiment of the present invention.

[0021] Figure 7 This is an exploded view from another angle of the pressure overload protection strain gauge mechanism of another embodiment of the present invention.

[0022] Figure 8 This is a three-dimensional structural diagram of the fixing base according to another embodiment of the present invention.

[0023] Figure 9 This is an internal structural diagram of an electronic pen according to another embodiment of the present invention.

[0024] Figure 10 This is a front view of the internal structure of the electronic pen according to another embodiment of the present invention.

[0025] Figure 11 yes Figure 10 Sectional view at point AA.

[0026] Figure 12 yes Figure 11 Enlarged view of point B in the middle.

[0027] Explanation of icon numbers 10. Pen tip module; 11. Overload limit sleeve; 12. Overload spring; 13. Centering bushing; 14. Guide part; 15. Anti-rotation part; 16. TX02 tube; 20. Fixing base; 21. Strain gauge; 22. Intermediate component; 23. Outer sleeve part; 24. Inner sleeve part; 25. Buckle; 26. Locking pin; 30. Strain gauge sensor; 40. Signal board; 50. Inner cylinder; 60. Gap. Detailed Implementation

[0028] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0029] In this embodiment of the invention, directional indicators (such as up, down, left, right, front, back, etc.) are only used to explain the relative positional relationship and movement of each component in a specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0030] Furthermore, in this invention, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features.

[0031] Please refer to Figures 1-12 The pressure overload protection strain-sensitive mechanism of this invention includes a pen tip module, a strain sensor, a fixed base, and an overload limit sleeve.

[0032] A strain gauge is mounted on the mounting base, and an intermediate component is mounted on the strain gauge to transmit the writing pressure from the pen tip module. A strain gauge sensor is correspondingly attached to the strain gauge. An overload spring (in practice, other elastic components such as spring sheets can also be used) is mounted on the pen tip module. One end of the overload spring acts on the pen tip module, and the other end acts on the intermediate component. The preload of the overload spring is typically set between 400g and 500g. During writing, the pen tip module deforms the strain gauge via the intermediate component, and the strain gauge sensor converts the deformation of the strain gauge into an electrical signal to detect the pressure. This invention can achieve a very low operating current for the strain gauge sensor by employing a high-impedance design (e.g., a single-grid resistance of 5KΩ).

[0033] An overload limiting sleeve is installed on the pen tip module, with a gap between the overload limiting sleeve and the front end of the fixing seat (i.e., the front end of the outer sleeve). The gap width ranges from 0.08 mm to 0.5 mm. When the pen tip module is overloaded, the overload limiting sleeve contacts the front end of the fixing seat to prevent the strained part from continuing to deform, keeping the strained part within the elastic strain range and preventing plastic strain from occurring.

[0034] The pen tip module is equipped with a centering bushing, and the fixing base includes an outer sleeve portion. The outer sleeve portion fits over the centering bushing and guides the axial movement of the centering bushing and the pen tip module. The intermediate component includes an inner sleeve portion, on which the pen tip module has a corresponding protruding guide portion. The inner sleeve portion fits over the guide portion and guides the axial movement of the pen tip module. This invention employs dual guidance from the outer sleeve portion and the inner sleeve portion to prevent the pen tip module from loosening and improve the stability of the pen tip module's movement and writing.

[0035] Preferably, the mounting base, strain gauge, and intermediate components are integrally molded. For example, they can be integrally molded from plastic (the strain gauge can also have a structure with an inner steel sheet and an outer plastic coating), resulting in a long lifespan and strong overload resistance. This solves the problem that traditional sensor elastomers are prone to fatigue and aging due to repeated stress, leading to decreased sensitivity and shortened lifespan.

[0036] In one implementation, the pressure overload protection strain gauge mechanism also includes a signal board (usually a flexible board that outputs a TX01 signal). The signal board is in contact with the overload spring and conducts through it. The pen tip module is connected to the signal board via the overload spring, thus achieving conduction at the TX01 end. The main body of the pen tip module is fully connected to the front writing end of the pen tip (pen tip cap). Preferably, the pen tip module is fitted with a TX02 tube.

[0037] In one implementation, the end of the intermediate component facing the strain section is tapered. The tapered tip acts on the strain section, resulting in greater deformation of the strain section under writing pressure and more sensitive pressure detection. The strain section is strip-shaped, with both ends connected to the fixed base and the middle part connected to the intermediate component.

[0038] In one implementation, the overload limit sleeve and the pen tip module are connected by threads, and the gap between the overload limit sleeve and the front end of the fixed seat can be adjusted by rotating the overload limit sleeve.

[0039] In one implementation, the mounting base has clips on its outer periphery for securing it. During installation, the mounting base is directly inserted into the pen holder or inner cylinder of the electronic pen via the clips.

[0040] As one implementation method, the intermediate component is provided with a locking pin, and the pen tip module is provided with a corresponding anti-rotation part. The locking pin is embedded in the anti-rotation part to prevent the pen tip module from rotating, thereby improving writing stability and writing feel.

[0041] Please refer to Figure 4 and Figure 9The electronic pen of this invention includes a pressure overload protection strain-sensitive mechanism. During assembly, the pressure overload protection strain-sensitive mechanism is directly installed in the pen barrel or inner cylinder of the electronic pen.

[0042] During writing, the pen tip module compresses the overload spring, which in turn squeezes the intermediate component, causing the strain gauge to deform. The strain gauge sensor then converts this deformation into an electrical signal to detect the pressure.

[0043] The overall structure of this invention can be made smaller, freeing up the internal space of the electronic pen to accommodate more functional modules (such as Bluetooth, gyroscope, haptic feedback motor), or making the pen body thinner and lighter.

[0044] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A pressure overload protection strain gauge mechanism, comprising a pen tip module, characterized in that, It also includes a strain gauge sensor, a mounting base, and an overload limiting sleeve. The mounting base is equipped with a strain gauge, and the strain gauge is equipped with an intermediate component for transmitting the writing pressure of the pen tip module. The strain gauge sensor is attached to the strain gauge and the overload limiting sleeve is mounted on the pen tip module. There is a gap between the overload limiting sleeve and the front end of the mounting base.

2. The pressure overload protection strain gauge pressure-sensitive mechanism as described in claim 1, characterized in that, An overload spring is provided on the pen tip module. One end of the overload spring acts on the pen tip module, and the other end acts on the intermediate component.

3. The pressure overload protection strain gauge pressure-sensitive mechanism as described in claim 2, characterized in that, It also includes a signal board, which is in contact with the overload spring for conduction, and the pen tip module is connected to the signal board through the overload spring.

4. The pressure overload protection strain gauge pressure-sensitive mechanism as described in claim 1, characterized in that, The pen tip module is equipped with a centering bushing, and the fixing seat includes an outer sleeve portion; the outer sleeve portion is fitted over the centering bushing and serves as a guide for the centering bushing.

5. The pressure overload protection strain gauge pressure-sensitive mechanism as described in claim 4, characterized in that, The intermediate component includes an inner sleeve portion, and a corresponding guide portion protrudes from the pen tip module. The inner sleeve portion is fitted over the guide portion to guide the pen tip module.

6. The pressure overload protection strain gauge pressure-sensitive mechanism as described in claim 1, characterized in that, The end of the intermediate component facing the strain section is tapered.

7. The pressure overload protection strain gauge pressure-sensitive mechanism as described in claim 6, characterized in that, The strain gauge is strip-shaped, with both ends connected to the fixed base and the middle part connected to the intermediate component.

8. The pressure overload protection strain gauge mechanism as described in claim 1, characterized in that, The overload limit sleeve and the pen tip module are connected by threads. The gap between the overload limit sleeve and the front end of the fixed seat can be adjusted by rotating the overload limit sleeve.

9. The pressure overload protection strain gauge pressure-sensitive mechanism as described in claim 1, characterized in that, The outer periphery of the mounting base is provided with clips for fixing.

10. An electronic pen, characterized in that, Includes a pressure overload protection strain gauge pressure-sensitive mechanism as described in any one of claims 1 to 9.

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