Handwriting elimination apparatus and method for touch screen, and electronic stylus and stylus cap thereof

Abstract

Provided in the present application are a handwriting elimination apparatus and method for a touch screen, and an electronic stylus and a stylus cap thereof. The handwriting elimination apparatus comprises a trigger component and a strain component, and thus can be applied to an electronic stylus. During using the handwriting elimination apparatus to perform an elimination action on an image on a touch screen, a pressing portion transmits to a strain sensing assembly a force which is borne by a trigger portion in contact with the touch screen, and the strain sensing assembly is deformed according to a pressing force to generate an erasing signal corresponding to deformation; when the force which is borne by the trigger portion in contact with the touch screen changes, the deformation degree of the strain sensing assembly also correspondingly changes, and a corresponding erasing signal is generated; and when contact forces between the trigger portion and the touch screen are different, the strain sensing assembly can generate different erasing signals, such that a user can achieve graded erasing of the image on the touch screen by means of adjusting the magnitude of the contact force between the trigger portion and the touch screen, thereby achieving different degrees of erasing effects.

Description

Touch screen handwriting erasing device and method, electronic handwriting pen and pen cap thereof

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on June 28, 2023, with application number: 202310776953.6 and application name: "Device and method for erasing handwriting on a touch screen, electronic stylus and its pen cap", all contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of electronic technology, and in particular to a device and method for erasing handwriting from a touch screen, an electronic stylus pen, and a pen cap thereof. Background Art

[0003] A touch screen, also known as a "touch screen" or "touch panel", is an inductive liquid crystal display device that can receive input signals such as contacts. When the graphic buttons on the screen are touched, vivid audio and video effects are produced through the liquid crystal display. It is mainly used in public information query, leadership office, industrial control, military command, electronic games, song and food ordering, multimedia teaching, real estate pre-sale, etc.

[0004] With the continuous development of electronic technology, touch screens have become the most common image forming devices in people's lives. However, in actual use, users may draw erroneous audio and video images due to some unexpected situations such as accidental touches. In this case, a handwriting erasure device is needed to erase the erroneous audio and video images.

[0005] In the prior art, there are several erasing methods:

[0006] 1. Turn the stylus 180 degrees and press the end of the stylus on the screen to erase. Pressing the end of the stylus will make the contacts inside touch, realizing action recognition and triggering the program to call the eraser function to erase.

[0007] 2. By tapping or pressing a specific touch area of ​​the electronic stylus, the stylus can detect the capacitance change caused by the touch input sensor over a period of time and interpret this as the user's gesture to trigger the eraser function.

[0008] In the first erasing method mentioned above, the same erasing mark will appear under different erasing forces, and the erasing effect is poor; in the second erasing method mentioned above, the same erasing mark will appear under different erasing forces, and the erasing effect is poor; its trigger position is generally placed within a distance from the front end of the stylus close to the pen tip, and the interactive program is recognized by regular tapping of the finger. The probability of accidental touch is high, and the eraser function is accidentally switched to during writing with the electronic stylus.

[0009] Therefore, the handwriting erasing device in the prior art has the problem of poor performance.

[0010] Summary of the Invention

[0011] The embodiments of the present application provide a handwriting erasing device and method for a touch screen, an electronic stylus and a pen cap thereof, which solve the problem of poor performance of handwriting erasing devices in the prior art.

[0012] In a first aspect, an embodiment of the present application provides a handwriting erasing device for a touch screen, the handwriting erasing device comprising a trigger component and a strain component; wherein

[0013] The trigger component includes a trigger portion in contact with the touch screen and a pressing portion arranged inside the trigger portion;

[0014] The strain component includes a strain sensing component disposed opposite to the pressing portion; and

[0015] The trigger part contacts the touch screen and is subjected to force, and presses the strain sensing component through the pressing part. The strain sensing component deforms according to the pressing force applied by the pressing part and generates an erasing signal corresponding to the deformation. The erasing signal is used to eliminate the handwriting displayed on the touch screen.

[0016] By adopting the above technical solution, when a handwriting erasing device is used to erase an image on a touch screen, the pressing portion transmits the force exerted by the trigger portion on the touch screen to the strain sensing component, and the strain sensing component deforms according to the pressing force to generate an erasing signal corresponding to the deformation; when the force exerted by the trigger portion on the touch screen changes, the degree of deformation of the strain sensing component also changes accordingly and generates a corresponding erasing signal; in this process, the contact force between the trigger portion and the touch screen is different, and the strain sensing component can generate different erasing signals. The user can achieve graded erasing of the image on the touch screen by adjusting the contact force between the trigger portion and the touch screen, thereby achieving erasing effects of different degrees, which is beneficial to improving the performance of the handwriting erasing device.

[0017] In some embodiments, the strain sensing assembly includes a strain substrate and a plurality of strain sensing elements, wherein the plurality of strain sensing elements are disposed on the strain substrate; wherein,

[0018] The multiple strain sensing elements are located in the same plane, and a plane parallel to the plane where the multiple strain sensing elements are located is used as a projection plane. The multiple strain sensing elements are evenly distributed in an array in the projection plane; and

[0019] The projection of the pressing portion on the projection surface is located within the projection outer contours of the plurality of strain sensing elements on the projection surface.

[0020] By adopting the above technical solution, the pressing part can apply the squeezing force to the strain sensing component regardless of its position when it is subjected to the squeezing force of the trigger part. This can ensure that when any position of the trigger part contacts the touch screen, the strain sensing component can generate a corresponding erasing signal and be used to perform a corresponding erasing action on the handwriting displayed on the touch screen.

[0021] In addition, by configuring the strain sensing component to include multiple strain sensing elements, each strain sensing element can deform independently when subjected to force. This can reduce the probability that when a certain position of the strain sensing component is deformed due to force, other positions are affected and deformed, generating an erroneous erase signal.

[0022] Therefore, the structure can not only ensure that the handwriting erasing device has a larger sensing range, but also improve the accuracy of the handwriting erasing device in performing the erasing action, which is conducive to further improving the performance of the handwriting erasing device.

[0023] In some embodiments, the strained substrate has a centrally symmetrical structure as a whole; and

[0024] The pressing portion is configured as a protruding structure protruding from the inner side of the trigger portion, the protruding direction of the protruding structure is perpendicular to the strain substrate, and the projection point of the geometric center of the end of the protruding structure on the projection surface coincides with the geometric center point of the strain substrate.

[0025] By adopting the above technical solution, by setting multiple strain sensing elements on the strain substrate, the strain substrate as a whole has a centrally symmetrical structure, so that multiple strain sensing elements can be arranged at various angles, so that when the trigger part is linked to the pressing part to squeeze the strain sensing component at any angle, the corresponding strain sensing element in the strain sensing component can be deformed and generate a corresponding erasure signal. The user can use the handwriting erasure device to perform the handwriting erasure action at any angle.

[0026] In addition, the pressing portion is configured as a protruding structure protruding from the inner side of the trigger portion, and the projection point of the geometric center of the end of the protruding structure on the projection surface coincides with the geometric center point of the strain substrate. In this way, when the pressing portion applies pressing force to the corresponding strain sensing element at different angles, the magnitude of the pressing force applied to the corresponding strain sensing element will not be affected by the change in the pressing angle, thereby affecting the erasing effect of the handwriting erasing device.

[0027] In some embodiments, the strained substrate includes a plurality of substrate members arranged in pairs, and the plurality of substrate members are evenly arranged around a geometric center point of the strained substrate;

[0028] Every two strain sensing elements in the plurality of strain sensing elements constitute a pair of strain sensing elements, wherein at least one pair of strain sensing elements is attached to each substrate component in the plurality of substrate components.

[0029] By adopting the above technical solution, when the trigger part and the pressing part apply pressing force to the corresponding strain sensing element at different angles, the deformation of each strain sensing element is the same, thereby reducing the probability that the deformation difference of the strain sensing element is large when the trigger part is pressed at different angles, which affects the erasure signal of the handwriting erasure device, and is beneficial to improving the erasure accuracy of the handwriting erasure device.

[0030] In some embodiments, each of the multiple strain sensing elements is configured as a resistance strain gauge, a pair of resistance strain gauges is attached to each of the multiple substrate components, and the pair of resistance strain gauges on each substrate component is electrically connected to the corresponding pair of auxiliary resistors to form a Wheatstone bridge circuit.

[0031] By adopting the above technical solution, by electrically connecting the resistance strain gauge to the corresponding pair of auxiliary resistors, each resistance strain gauge and the corresponding auxiliary resistor can form a half-bridge circuit of the Wheatstone bridge circuit, and the interference between the half-bridge circuits is relatively small.

[0032] In addition, when the resistance value of the resistance strain gauge changes due to the deformation of the strain steel sheet, since the auxiliary resistor is located outside the strain substrate, it is not disturbed and does not produce resistance changes, and can be used as a reference resistor.

[0033] In some embodiments, each of the plurality of strain sensing elements is configured as a resistance strain gauge, and each of the plurality of substrate components is provided with two pairs of the resistance strain gauges, the two pairs of the resistance strain gauges being electrically connected to form a Wheatstone bridge circuit; and

[0034] The two pairs of resistance strain gauges in each Wheatstone bridge are arranged in a ring or side by side.

[0035] By adopting the above technical solution, the resistance strain gauges are arranged in a ring or side by side. In this way, when the strain steel sheet is deformed at any angle, the resistance strain gauge can adapt to the deformation of the strain steel sheet so that its resistance value changes, which is beneficial to improving the sensitivity of the strain component.

[0036] In some embodiments, the strain substrate is configured as a strained steel sheet.

[0037] By adopting the above technical solution, since the flexible circuit board has a flexible structure and the internal integrated circuit structure may be damaged after multiple squeezing, and may also affect the circuit, this structure can effectively protect the flexible circuit board and reduce the probability of damage and failure of the flexible circuit board after multiple uses.

[0038] In addition, when the strain steel sheet is subjected to impact force, the transmission loss of the impact force is small, and the conversion rate of the impact force into deformation is high. Even when the strain steel sheet is subjected to a small impact force, the resistance strain gauge can convert its deformation into an electrical signal, thereby generating an erasure signal for the handwriting erasure device, which is beneficial to improving the sensitivity of the strain component.

[0039] In some embodiments, the strain sensing component further includes a flexible circuit board, which includes a first portion and a second portion. The first portion is stacked with the strain substrate and attached to a side of the strain substrate facing away from the pressing portion. Each of the multiple strain sensing elements is attached to a surface of the first portion facing away from the strain substrate, so that the multiple strain sensing elements are disposed on the strain substrate through the first portion of the flexible circuit board, and the second portion is bent and extended toward one side of the first portion and is located outside the strain substrate.

[0040] In some embodiments, when the handwriting erasing device is formed with a Wheatstone bridge circuit, an auxiliary resistor of the Wheatstone bridge circuit is disposed on the second portion of the flexible circuit board.

[0041] In some embodiments, the handwriting erasing device further includes a signal transmitting component configured to transmit an erasure signal to an electronic device using a touch screen.

[0042] In some embodiments, the handwriting erasing device further includes a sensing electrode, the sensing electrode constitutes the pressing portion, and the sensing electrode is electrically connected to the second portion of the flexible circuit board.

[0043] By adopting the above technical solution, since there are many conductors inside the touch screen and sensing electrodes are used, capacitance can be generated between the handwriting erasure device in this application and the touch screen when the device is close to the touch screen. No other operations are required in this process, and the handwriting erasure device can interact with the touch screen, turning on the pen eraser function of the electronic device using the touch screen, making it more convenient to use.

[0044] In some embodiments, the handwriting erasing device further includes an insulating member disposed between the sensing electrode and the strain sensing component. The end of the sensing electrode fits within a groove at the corresponding end of the insulating member. The end of the insulating member away from the sensing electrode also forms a protruding structure aligned with the geometric center point of the strain substrate of the strain sensing component. When the trigger portion is subjected to force, the protruding structure of the insulating member presses the strain substrate of the strain sensing component.

[0045] In some embodiments, a bracket is further included, the bracket having a hollow area or a sunken area, one end of each of the multiple substrate components away from the geometric center point is fixed to the bracket, and the other ends are connected to each other and suspended in the hollow area or the sunken area of ​​the bracket to form an end-fixed beam structure.

[0046] In some embodiments, the outer surface of the trigger portion has a soft protective layer.

[0047] In some embodiments, the device further includes a housing, wherein the trigger component and the strain component are fixed in the housing, and the trigger portion is partially exposed from the housing.

[0048] In some embodiments, the portion of the trigger portion exposed from the housing is in the shape of a truncated spherical structure, and the cross-sectional center angle of the truncated spherical structure is in the range of 90° to 150°.

[0049] By adopting the above technical solution, by setting the trigger part to a truncated spherical structure, and the cross-sectional center angle of the truncated spherical structure is in the range of 90° to 150°, the handwriting erasing device in this application can have a larger erasing range.

[0050] In a second aspect, an embodiment of the present application further provides a pen cap for an electronic stylus, which is arranged at the end of the electronic stylus and is used to perform the eraser function of the electronic stylus; the pen cap includes the handwriting erasing device of the above-mentioned touch screen structure.

[0051] By adopting the above technical solution, by integrating the handwriting erasing device of the above structure into the pen cap of the electronic stylus, the handwriting erasing device of the above structure can realize the handwriting erasing function, not only achieving different degrees of erasing effects based on the size of the pressing force, but also realizing multi-angle recognition and erasing. The pen cap of the electronic stylus adopts this structure, which not only improves the functional diversification of the electronic stylus pen cap, but also improves the performance of the electronic stylus.

[0052] In a third aspect, an embodiment of the present application further provides an electronic stylus, comprising a pen body and a pen tip arranged at one end of the pen body, and a pen cap of the above structure, which can be plugged and connected to the other end of the pen body.

[0053] By adopting the above technical solution, the pen cap of the above structure can realize different degrees and multi-angle recognition based on the size of the pressing force to eliminate the handwriting on the touch screen, thereby improving the performance of the electronic stylus.

[0054] In addition, by plugging and detaching the pen cap to the other end of the pen barrel, the pen cap can be used independently when the handwriting erasing function is used, which makes it more convenient to use.

[0055] In a fourth aspect, embodiments of the present application further provide a method for erasing handwriting on a touch screen, which is applied to an electronic stylus. The electronic stylus with the above structure is used to perform a pen eraser function. The method for erasing handwriting on a touch screen includes:

[0056] Receiving a feedback signal from an electronic device using a touch screen to trigger a pen eraser function of the pen cap;

[0057] Detecting and sending electrical signal information indicating the force applied to the trigger portion;

[0058] The target pressure information of the pen cap is determined according to the electrical signal information, and the target pressure information is sent to the electronic device so that the electronic device determines the degree of erasure of the handwriting displayed on the touch screen according to the target pressure information; wherein the target pressure information includes the pressure size information of the pen cap.

[0059] By adopting the above technical solution, the handwriting erasing method can determine the degree of erasure of handwriting displayed on the touch screen based on the pressure information of the pen cap. When the handwriting erasing function is performed using the pen cap, different erasing effects can be achieved under different erasing force sizes.

[0060] In some embodiments, the strain sensing component includes a strain substrate and multiple strain sensing elements, and the multiple strain sensing elements are arranged on the strain substrate; the multiple strain sensing elements generate multiple electrical signal information according to the pressing force applied by the pressing part, and determine the target pressure information of the pen cap based on the multiple electrical signal information, and send the target pressure information to the electronic device, so that the electronic device determines the degree of erasure based on the target pressure information.

[0061] The above technical solution determines the target pressure information of the pen cap through multiple electrical signal information, thus ensuring the accuracy of the target pressure information. Even if an error occurs in one of the electrical signal information, the method can reduce the degree of impact on the target pressure information.

[0062] In some embodiments, the plurality of strain sensing elements correspond to N Wheatstone bridge circuits, each Wheatstone bridge circuit outputs a bridge voltage, and the plurality of electrical signal information are N bridge voltages output by the N Wheatstone bridge circuits.

[0063] In some embodiments, determining the pressure information of the electronic stylus pen cap based on the plurality of electrical signal information includes:

[0064] The current angle of the pen cap is determined based on the N bridge voltages. The current angle is calculated using the following formula:

[0065] Where θ represents the angle between the current force direction of the pen cap and the axis of the pen cap; V2i-1 and V2i represent the current bridge voltages output by the two opposing Wheatstone bridge circuits, 1≤i≤N; K is the correction coefficient;

[0066] Determine current voltage information based on N bridge voltages and current angle information;

[0067] The pressure magnitude information is determined based on the current voltage information and the calibration information; wherein the calibration information represents a one-to-one correspondence between different voltage information and different pressure information when the pen cap is subjected to force at a calibration angle; the calibration angle is configured as: the angle when the force direction of the pen cap coincides with the axis of the pen cap.

[0068] Using this technical solution, the current angle of the pen cap is determined based on N bridge voltages. The current voltage is then determined using these N bridge voltages and the current angle. Pressure is then determined based on the current voltage and calibration information. This allows for compensation of the erasing effect based on the varying cap tilt angles (or, more accurately, the purpose of calculating the tilt angle is to provide compensation for the algorithm). This avoids the need for greater erasing force due to weak signals from the cap edge, allowing for consistent erasing results at varying tilt angles with the same pressing force. This improves the accuracy of erasing on a touch screen.

[0069] In some embodiments, before receiving the feedback signal of the electronic device triggering the pen eraser function, it also includes: sending a trigger signal to enable the pen eraser function.

[0070] The beneficial effects of this application are:

[0071] Provided is a handwriting erasing device for a touch screen, comprising a trigger component and a strain component; the trigger component comprising a trigger portion in contact with the touch screen and a pressing portion arranged inside the trigger portion; the strain component comprising a strain sensing component arranged opposite to the pressing portion; the trigger portion is in contact with the touch screen and receives force, and presses the strain sensing component through the pressing portion; the strain sensing component deforms according to the pressing force applied by the pressing portion and generates an erasing signal corresponding to the deformation, and the erasing signal is used to erase handwriting displayed on the touch screen.

[0072] When the handwriting erasing device is used to erase an image on the touch screen, the pressing part transmits the force exerted by the trigger part on the touch screen to the strain sensing component, and the strain sensing component deforms according to the pressing force to generate an erasing signal corresponding to the deformation; when the force exerted by the trigger part on the touch screen changes, the degree of deformation of the strain sensing component also changes accordingly and generates a corresponding erasing signal; in this process, the contact force between the trigger part and the touch screen is different, and the strain sensing component can generate different erasing signals. The user can achieve graded erasing of the image on the touch screen by adjusting the contact force between the trigger part and the touch screen, thereby achieving erasing effects of different degrees, which is beneficial to improving the performance of the handwriting erasing device. BRIEF DESCRIPTION OF THE DRAWINGS

[0073] FIG1a is a schematic diagram of an electronic stylus pen writing on a touch screen;

[0074] FIG1b is a schematic diagram of an electronic stylus pen in an erasing state on a touch screen;

[0075] Fig. 2 is the erasing effect diagram of physical eraser;

[0076] FIG3a is a schematic diagram of an exploded structure of a handwriting erasing device provided in one embodiment of the present application;

[0077] FIG3 b is a schematic cross-sectional view of a handwriting erasing device and a touch screen according to an embodiment of the present application;

[0078] FIG3c is a schematic diagram showing the principle of the handwriting erasing device provided by an embodiment of the present application in a non-pressed state;

[0079] FIG3 d is a schematic diagram showing the principle of a handwriting erasing device in a pressed state according to an embodiment of the present application;

[0080] FIG4 a is a schematic structural diagram of a strain sensing assembly according to an embodiment of the present application;

[0081] FIG4 b is a schematic structural diagram of a strain component and a pressing portion in an embodiment of the present application;

[0082] FIG5 a is a schematic top view of a first embodiment of a strained substrate provided in an embodiment of the present application;

[0083] FIG5 b is a schematic top view of a second embodiment of a strained substrate provided in an embodiment of the present application;

[0084] FIG5 c is a schematic top view of a third embodiment of a strained substrate provided in an embodiment of the present application;

[0085] FIG5 d is a schematic top view of a fourth embodiment of a strained substrate provided in an embodiment of the present application;

[0086] FIG6 a is a schematic structural diagram of a strain substrate and a resistance strain gauge provided in an embodiment of the present application;

[0087] FIG6 b is a schematic structural diagram of a flexible circuit board provided in an embodiment of the present application;

[0088] FIG7 a is a schematic diagram of the connection structure between the strain substrate and the auxiliary resistor provided in an embodiment of the present application;

[0089] FIG7 b is a circuit diagram of a Wheatstone bridge circuit;

[0090] FIG7c is a schematic diagram of a circuit provided in an embodiment of the present application;

[0091] FIG8a is a schematic structural diagram of a strained substrate provided in an embodiment of the present application;

[0092] FIG8 b is another structural schematic diagram of a strained substrate provided in an embodiment of the present application;

[0093] FIG8c is a schematic diagram of a circuit provided by another embodiment of the present application;

[0094] FIG9 a is a schematic structural diagram of a resistance strain gauge provided in one embodiment of the present application;

[0095] FIG9 b is a schematic structural diagram of a resistance strain gauge provided in another embodiment of the present application;

[0096] FIG9 c is a strain diagram of a resistance strain gauge provided in an embodiment of the present application;

[0097] FIG10 is a schematic diagram of the connection structure between the sensing electrode and the flexible circuit board in an embodiment of the present application;

[0098] Figure 11 is a schematic diagram of the capacitive sensing principle;

[0099] FIG12a is a schematic diagram of an exploded structure of a handwriting erasing device provided in an embodiment of the present application;

[0100] FIG12b is a schematic cross-sectional view of a handwriting erasing device according to an embodiment of the present application;

[0101] FIG12c is a schematic diagram of a top view of the handwriting erasing device provided in an embodiment of the present application;

[0102] FIG12d is a schematic structural diagram of a strain component provided in an embodiment of the present application;

[0103] FIG12e is a schematic diagram of the isometric structure of a handwriting erasing device provided in an embodiment of the present application;

[0104] FIG12f is a diagram showing the use status of the handwriting erasing device provided in an embodiment of the present application;

[0105] FIG13 is a partial cross-sectional structural diagram of a handwriting erasing device provided in an embodiment of the present application;

[0106] FIG14a is a schematic diagram of the assembly structure of a pen cap provided in an embodiment of the present application;

[0107] FIG14 b is a schematic cross-sectional view of a pen cap according to an embodiment of the present application;

[0108] FIG15 a is a schematic diagram of the assembly structure of the electronic stylus provided in an embodiment of the present application;

[0109] FIG15 b is a schematic cross-sectional view of the electronic stylus provided in an embodiment of the present application;

[0110] FIG16a is a block diagram showing the principle of a handwriting elimination method according to an embodiment of the present application;

[0111] FIG16a′ is another principle block diagram of a handwriting removal method provided by an embodiment of the present application;

[0112] FIG16 b is a flow chart of a handwriting elimination method provided in an embodiment of the present application;

[0113] FIG16c is a schematic diagram of a use scenario of a handwriting removal method provided in an embodiment of the present application;

[0114] FIG16d is a schematic diagram of another scenario in which the handwriting removal method provided by an embodiment of the present application is used;

[0115] FIG17 a is a schematic diagram of a bridge circuit in an embodiment of the present application;

[0116] FIG17 b is a diagram of a pen cap model in an embodiment of the present application;

[0117] FIG17 c is a schematic diagram of force analysis of a certain point of the pen cap in an embodiment of the present application.

[0118] Description of reference numerals:

[0119] Description of prior art reference numerals:

[0120] 10', electronic stylus; 10A', pen tip; 10B', pen barrel; 10C', pen cap; 20', touch screen;

[0121] Description of the accompanying drawings in this application:

[0122] 10. Electronic stylus; 10A. Pen tip; 10B. Pen holder; 10D. Processor; 10E. Wireless module;

[0123] 10C, pen cap; 101D, processor; 101E, wireless module;

[0124] 100. Handwriting erasing device; 110. Trigger component; 111. Trigger portion; 112. Pressing portion; 1121. Protruding structure;

[0125] 120, strain component; 121, strain sensing assembly; 1211, strain sensing element; 1211A, resistance strain gauge;

[0126] 122. strain substrate; 1221. substrate component; 1222. strain steel sheet;

[0127] 1223, flexible circuit board; 1223A, first part; 1223B, second part;

[0128] 1224, auxiliary resistor; 122A, conductive foam; 123, bracket;

[0129] 130A, sensing electrode; 140, insulating member; 141, groove; 142, protruding structure; 150, soft protective layer; 160, housing;

[0130] 20. Touch screen; 30. Electronic device; 30A. Processor; 30B. Erasing module; 30C. Wireless interface; 30D. Display. DETAILED DESCRIPTION

[0131] The handwriting erasing device for a touch screen in the present application is used to erase handwriting or images on a touch screen. The touch screen is applied to electronic devices, such as mobile phones, tablet computers, wearable devices, vehicle-mounted devices, augmented reality (AR) / virtual reality (VR) devices, laptop computers, ultra-mobile personal computers (UMPCs), netbooks, personal digital assistants (PDAs), and other electronic devices. A touch screen may also be referred to as a touch panel, and a touch screen may perform a variety of operations, such as sending signals, receiving signals, and the like. It should be understood that the interactive device may also include other units or modules. For example, if the interactive device is a smart phone, it may also include modules such as a speaker, a microphone, and a light sensor.

[0132] The handwriting erasing device may be integrated into an electronic stylus used in conjunction with a touch screen. The electronic stylus may be an active capacitive stylus, but this application does not impose any restrictions on this.

[0133] First, the usage scenario of the electronic stylus is described with reference to FIG. 1 a and FIG. 1 b .

[0134] FIG. 1 a is a schematic diagram of an electronic stylus pen in a writing state on a touch screen, and FIG. 1 b is a schematic diagram of an electronic stylus pen in an erasing state on a touch screen.

[0135] As shown in FIG. 1a-FIG . 1b , the electronic stylus 10 ′ includes a pen body 10B′, a pen tip 10A′ and a pen cap 10C′ respectively disposed at both ends of the pen body 10B′. The writing end is the portion of the pen tip 10A′ used for writing or drawing graphics on the touch screen 20 ′.

[0136] In the state shown in FIG1a , the electronic stylus 10 ′ uses the pen tip 10A′ to write on the touch screen 20 ′. During this process, the user may draw an erroneous audio or video image due to some unexpected circumstances such as accidental touch. In this case, a handwriting erasing device is required to erase the erroneous audio or video image.

[0137] At this time, the electronic stylus 10 ′ can be rotated 180° to the state shown in FIG. 1 b , and the erroneous audio and video images can be eliminated using the pen cap 10C at the end of the electronic stylus 10 .

[0138] As further shown in FIG1b , when using the cap 10C at the end of the electronic stylus 10′ to erase erroneous audio and video images, the user may, based on their previous eraser usage habits, use a physical eraser as shown in FIG2 . FIG2 illustrates the erasing effect of a physical eraser. During the erasing process, a real pencil will produce different erased marks under different erasing forces. Similarly, the user can achieve the desired erasing effect by controlling the pressing force F on the cap 10C′.

[0139] However, the handwriting erasing device of the touch screen or the pen cap 10C' at the end of the electronic stylus 10' in the prior art cannot achieve this function, cannot meet the user's needs, and has the problem of poor usability.

[0140] Based on this problem, the embodiments of the present application provide a handwriting erasing device and method for a touch screen, an electronic stylus and a pen cap thereof. When the handwriting erasing device is used to erase an image on the touch screen, the pressing portion transmits the force exerted by the trigger portion on the touch screen to the strain sensing component. The strain sensing component deforms according to the pressing force and generates an erasing signal corresponding to the deformation. When the force exerted by the trigger portion on the touch screen changes, the degree of deformation of the strain sensing component also changes accordingly and generates a corresponding erasing signal. In this process, the contact force between the trigger portion and the touch screen is different, and the strain sensing component can generate different erasing signals. The user can achieve graded erasing of the image on the touch screen by adjusting the contact force between the trigger portion and the touch screen, thereby achieving erasing effects of different degrees, which is beneficial to improving the performance of the handwriting erasing device.

[0141] The structure and working principle of the handwriting erasing device provided in the embodiment of the present application are described in detail below with reference to the accompanying drawings.

[0142] Please refer to Figures 3a-3d, Figure 3a is a schematic diagram of the exploded structure of the handwriting erasure device provided in an embodiment of the present application; Figure 3b is a schematic diagram of the cross-sectional structure of the handwriting erasure device and the touch screen provided in an embodiment of the present application; Figure 3c is a schematic diagram of the handwriting erasure device provided in an embodiment of the present application in a non-pressed state; Figure 3d is a schematic diagram of the handwriting erasure device provided in an embodiment of the present application in a pressed state.

[0143] As shown in Figures 3a and 3b, an embodiment of the present application provides a handwriting erasing device 100, which includes a trigger component 110 and a strain component 120. The trigger component 110 includes a trigger portion 111 that contacts the touch screen 20, and a pressing portion 112 arranged inside the trigger portion 111; the strain component 120 includes a strain sensing component 121 arranged opposite to the pressing portion 112.

[0144] As shown in Figures 3c-3d, when in use, the pressing portion 112 presses the strain sensing component 121, and the strain sensing component 121 deforms according to the pressing force applied by the pressing portion 112 (as shown in the state of Figure 3d) and generates an erasing signal corresponding to the deformation, and uses the erasing signal to erase the handwriting displayed on the touch screen 20. When the pressing portion 112 does not press the strain sensing component 121, the strain sensing component 121 returns to its initial state (as shown in the transition state of Figure 3c).

[0145] It should be noted that, as shown in Figures 3a and 3b, when the handwriting erasing device 100 is used to erase an image on the touch screen 20, the pressing portion 112 transmits the force exerted by the trigger portion 111 in contact with the touch screen 20 to the strain sensing component 121. The strain sensing component 121 deforms according to the pressing force and generates an erasing signal corresponding to the deformation. When the force exerted by the trigger portion 111 in contact with the touch screen 20 changes, the degree of deformation of the strain sensing component 121 also changes accordingly and generates a corresponding erasing signal. In this process, when the contact force between the trigger portion 111 and the touch screen 20 is different, the strain sensing component 121 can generate different erasing signals according to different pressing forces. The user can achieve graded erasing of the image on the touch screen 20 by adjusting the contact force between the trigger portion 111 and the touch screen 20, thereby achieving different degrees of erasing effects, such as the pencil-like erasing effect shown in Figure 2. This is conducive to improving the performance of the handwriting erasing device 100.

[0146] It should be understood that the erase signal represents the magnitude of the pressing force applied by the pressing portion 112 to the touch screen 20 , and may be specifically sent as voltage information in a circuit.

[0147] Please refer to Figures 4a and 4b. Figure 4a is a structural schematic diagram of the strain sensing component in an embodiment of the present application; Figure 4b is a structural schematic diagram of the strain sensing component and the pressing part in an embodiment of the present application.

[0148] As shown in FIG. 4 a , the strain sensing assembly 121 includes a plurality of strain sensing elements 1211 , and all the strain sensing elements 1211 are located in the same plane.

[0149] Furthermore, the strain sensing assembly 121 further includes a strain substrate 122, on which all strain sensing elements 1211 are disposed. The strain substrate 122 is a centrosymmetric structure. It should be noted that the strain substrate 122 may also have other structural forms, for example, a non-centrosymmetric structure.

[0150] Furthermore, the strain substrate 122 includes substrate components 1221 arranged in pairs, and the substrate components 1221 arranged in pairs are evenly arranged around the geometric center point of the strain substrate 122 .

[0151] As further shown in FIG. 4b , with a plane parallel to the plane on which all strain-sensing elements 1211 lie as a projection plane (the plane indicated by A in the figure), all strain-sensing elements 1211 are evenly distributed within the projection plane. The projection of the pressing portion 112 on the projection plane (the area indicated by B in the figure) lies within the outer contour of the projections of all strain-sensing elements 1211 on the projection plane.

[0152] The pressing portion 112 is configured as a protruding structure 1121 protruding from the inner side of the trigger portion 111. The protruding direction of the protruding structure 1121 is perpendicular to the strain substrate 122, and the projection point of the geometric center of the end of the protruding structure 1121 on the projection plane coincides with the geometric center point of the strain substrate 122.

[0153] It should be noted that, based on the above technical solution, the pressing part 112 can apply the squeezing force to the strain sensing component 121 regardless of the position thereof when it is subjected to the squeezing force of the trigger part 111. This enables the strain sensing component 121 to generate a corresponding erasing signal regardless of the position of the trigger part 111 in contact with the touch screen 20, and to perform a corresponding erasing action on the handwriting displayed on the touch screen 20.

[0154] Furthermore, because each strain sensing element 1211 can deform independently when subjected to force, this reduces the probability that deformation at one location on the strain sensing component 121 will affect deformation at other locations, leading to erroneous erasure signals. This structure not only ensures a larger sensing range for the handwriting eraser 100 but also improves the accuracy of the erasure action performed by the handwriting eraser 100, further enhancing the performance of the handwriting eraser 100.

[0155] Furthermore, the present application arranges the projection point of the geometric center of the end of the protruding structure 1121 on the projection surface to coincide with the geometric center point of the strain substrate 122, so that when the pressing portion 112 applies pressing force to the corresponding strain sensing element 1211 at different angles, the size of the pressing force applied to the corresponding strain sensing element 1211 will not be affected by the change in the pressing angle, thereby affecting the erasing effect of the handwriting erasing device 100.

[0156] Furthermore, the present application sets all strain sensing elements 1211 on the strain substrate 122, and the strain substrate 122 as a whole has a centrally symmetrical structure. In this way, multiple strain sensing elements 1211 can be arranged at various angles, so that when the trigger part 111 and the pressing part 112 squeeze the strain sensing component 121 at any angle, the corresponding strain sensing element 1211 in the strain sensing component 121 can be deformed and generate a corresponding erasure signal. The user can perform a handwriting erasure action at any angle using the handwriting erasure device 100.

[0157] It should be further noted that the number of strain sensing elements 1211 included in the strain sensing assembly 121 in the embodiments of the present application is not limited. As shown in FIG4a , in one embodiment, the strain sensing assembly 121 includes eight strain sensing elements 1211. In other alternative embodiments, the strain sensing assembly 121 may include 16 strain sensing elements 1211, 24 strain sensing elements 1211, or other number, depending on actual design and usage requirements.

[0158] To be further explained, the number of the strain sensing elements 1211 is an even multiple of the number of the substrate components 1221 ; for example, when the number of the substrate components 1221 is n, the number of the strain sensing elements 1211 may be 2n, 4n, or 6n.

[0159] It should be noted that the number of substrate components 1221 is not limited, for example, it can be set to 4, 6, 8, etc.

[0160] Exemplarily, when the number of substrate members 1221 is four, the number of strain sensing elements 1211 should be eight, sixteen, or twenty-four.

[0161] When the number of substrate components 1221 is 6, the number of strain sensing elements 1211 should be 12, 24 or 36.

[0162] When the number of the substrate components 1221 is 8, the number of the strain sensing elements 1211 should be 16, 34 or 48.

[0163] It should be noted that the embodiment of the present application only shows a partial setting example of the substrate component 1221 and the strain sensing element 1211. Specifically, they can also be set to other numbers, which is not limited in the embodiment of the present application.

[0164] The above examples are described below with reference to the accompanying drawings.

[0165] FIG5 a is a schematic top view of a first embodiment of a strain substrate according to an embodiment of the present application. As shown in FIG5 a , the strain substrate 122 includes five pairs (ten) of substrate members 1221 , each of which is provided with two strain sensing elements 1211 , for a total of 20 strain sensing elements 1211 .

[0166] FIG5 b is a schematic top view of a second embodiment of a strain substrate according to an embodiment of the present application. As shown in FIG5 b , the strain substrate 122 includes five pairs (ten) of substrate members 1221 , each of which is provided with four strain sensing elements 1211 , for a total of 40 strain sensing elements 1211 .

[0167] FIG5 c is a schematic top view of a third embodiment of a strained substrate provided in an embodiment of the present application;

[0168] As shown in FIG. 5 c , the strain substrate 122 includes three pairs (six) of substrate components 1221 . Each substrate component 1221 is provided with four strain sensing elements 1211 , and a total of 24 strain sensing elements 1211 are provided.

[0169] FIG5 d is a schematic top view of a fourth embodiment of a strain substrate according to an embodiment of the present application. As shown in FIG5 d , the strain substrate 122 includes two pairs (four) of substrate members 1221 , each of which is provided with two strain sensing elements 1211 , for a total of eight strain sensing elements 1211 .

[0170] It should be noted that the specific structure of the strain substrate 122 is not limited and can be made of an elastically deformable material, such as metal, alloy, or ceramic. When the trigger component 110 deforms under pressure, the strain substrate 122 also deforms under the force of the trigger component 110 and exhibits an elastic restoring force. This elastic restoring force can react on the trigger component 110, helping it return to its original position.

[0171] Furthermore, the specific type of strain sensing element 1211 is not limited and may be a sensing element whose resistance changes with applied force. It can convert strain, such as pressure, tension, gravity, and other physical quantities, into changes in resistance, thereby measuring these physical quantities. The strain sensing element 1211 is a sensing element that can convert strain or strain difference signals into electrical signals and can measure static compressive force. Within the compressive force range, the signal output by the strain sensing element 1211 is proportional to the compressive force applied to the strain substrate 122. In one example, the strain sensing element 1211 may be a resistance strain gauge 1211A.

[0172] Furthermore, in some embodiments of the present application, Figure 6a is a schematic diagram of the structure of a strain substrate and a resistance strain gauge provided in embodiments of the present application; Figure 6b is a schematic diagram of the structure of a flexible circuit board provided in embodiments of the present application. As shown in Figure 6a, the strain substrate 122 is configured as a strain steel sheet 1222, and the strain sensing assembly 121 also includes a flexible circuit board 1223. The strain steel sheet 1222 and the flexible circuit board 1223 are stacked together, and the strain sensing element is configured as a resistance strain gauge 1211A attached to the side of the flexible circuit board 1223 away from the strain steel sheet 1222. The strain steel sheet 1222 is closer to the pressing portion 112 than the flexible circuit board 1223.

[0173] Furthermore, the resistance strain gauge 1211A may also be disposed between the strain steel sheet 1222 and the flexible circuit board 1223 , or may be directly attached to the strain steel sheet 1222 , which is not limited in this application.

[0174] It should be noted that the specific structure of the strain steel sheet 1222 is not limited. By setting the strain steel sheet 1222, the flexible circuit board 1223 can be supported. Since the flexible circuit board 1223 is a flexible structure and the internal integrated circuit structure may be damaged after multiple squeezing, and may affect the circuit on the other hand. This structure can effectively protect the flexible circuit board 1223 and reduce the probability of the flexible circuit board 1223 being damaged and failing after multiple uses.

[0175] During use, when the strain steel sheet 1222 is subjected to impact force, the conduction loss of the impact force is small, and the conversion rate of the impact force into deformation is high. Even when the strain steel sheet 1222 is subjected to a small impact force, the resistance strain gauge 1211A can convert its deformation into an electrical signal, thereby generating an erasure signal for the handwriting erasure device 100, which is beneficial to improving the sensitivity of the strain component 120.

[0176] Furthermore, as shown in Figures 6a and 6b, the flexible circuit board 1223 includes a first portion 1223A and a second portion 1223B. The first portion 1223A is stacked with the strain substrate 122 and attached to the side of the strain substrate 122 facing away from the pressing portion 112. All strain sensing elements 1211 are attached to the surface of the first portion 1223A facing away from the strain substrate 122. The second portion 1223B bends and extends toward the side of the first portion 1223A and is located outside the strain substrate 122.

[0177] As shown in Figure 7a, Figure 7a is a schematic diagram of the connection structure of the strain substrate and auxiliary resistors provided in one embodiment of the present application. In some embodiments of the present application, each substrate member 1221 is provided with a pair of resistance strain gauges 1211A, and the resistance strain gauges 1211A on each substrate member 1221 are also electrically connected to the corresponding pair of auxiliary resistors 1224 to form a Wheatstone bridge circuit.

[0178] It should be noted that by setting each pair of resistance strain gauges 1211A to be electrically connected to the corresponding pair of auxiliary resistors 1224, each pair of auxiliary resistors 1224 can be a resistor integrated in the second part 1223B of the flexible circuit board 1223, or can be set at other positions on the flexible circuit board 1223, or can not be set on the flexible circuit board 1223. Each pair of auxiliary resistors 1224 can be electrically connected to the corresponding resistance strain gauge 1211A. This application does not make a unique requirement for its setting method.

[0179] With the above configuration, each resistance strain gauge 1211A and the corresponding auxiliary resistor 1224 can form a half-bridge circuit of the Wheatstone bridge circuit, and interference between the half-bridge circuits is relatively small.

[0180] It should be further explained that the Wheatstone bridge circuit (English: Wheatstone bridge, also known as Wheatstone bridge, Wheatstone bridge) is used to accurately measure the resistance value of an unknown resistor.

[0181] Figure 7b shows the circuit diagram of a Wheatstone bridge circuit. As shown in Figure 7b, R1, R2, R3, and Rx are the resistors in the four arms of the bridge. Rx is the resistor to be measured, and G is the galvanometer. The four resistors are connected to form a quadrilateral, known as the four arms of the bridge. The galvanometer is connected to one diagonal of the quadrilateral, known as the "bridge." The DC power supply is connected to the other diagonal of the quadrilateral.

[0182] When the power is on, current flows through each branch of the bridge circuit. When the potentials at points BD are unequal, the bridge current Ig ≠ 0, and the galvanometer pointer deflects. When the potentials between points BD are equal, the bridge current Ig = 0, and the galvanometer pointer points to zero (the galvanometer's zero point is in the center of the scale), indicating the bridge is balanced. Using the circuit, given that R1, R2, and R3 are known, the resistance to be measured, Rx, can be calculated.

[0183] Please refer to Figure 7c. Figure 7c is a circuit schematic diagram provided in an embodiment of the present application, which should be understood in conjunction with Figures 7a and 7c. When the substrate member 1221 of the strain substrate 122 is subjected to pressure, it will deform, thereby causing the resistance strain gauge 1211A provided on the substrate member 1221 to also produce corresponding deformation, causing its resistance to change. That is, when the resistance values ​​of the resistors R1 and R3 (corresponding to the two resistance strain gauges 1211A on the same substrate member 1221) change due to the deformation of the resistance strain gauge 1211A, since each pair of auxiliary resistors 1224 is located outside the substrate member 1221 of the strain substrate 122, its resistance does not change. That is, the resistors R2 and R4 are not disturbed and do not produce resistance changes, and can be used as reference resistors.

[0184] In the examples of Figures 7a and 7c, four full-bridge circuits are designed, with one half-bridge circuit placed on each arm (i.e., each substrate component 1221), for a total of four half-bridges; at the same time, the corresponding other four half-bridges are placed on the back-end circuit (for example, on the second part 1223B of the flexible circuit board 1223).

[0185] Please refer to Figures 8a to 8c. Figure 8a is a structural diagram of a strain substrate provided in an embodiment of the present application, Figure 8b is another structural diagram of a strain substrate provided in an embodiment of the present application, and Figure 8c is a circuit diagram provided in another embodiment of the present application.

[0186] As shown in FIG8 a , two pairs of resistance strain gauges 1211A are attached to each substrate member 1221 . Each two pairs of resistance strain gauges 1211A are electrically connected to form a Wheatstone bridge circuit. The two pairs of resistance strain gauges 1211A in each Wheatstone bridge are arranged in a ring shape.

[0187] As shown in FIG8 b , two pairs of strain gauges 1211A are attached to each substrate member 1221 . Each two pairs of strain gauges 1211A are electrically connected to form a Wheatstone bridge circuit. The two pairs of strain gauges 1211A in each Wheatstone bridge are arranged side by side.

[0188] In the example of FIG. 8 a and FIG. 8 b , four full-bridge circuits are designed, with one full-bridge circuit being placed in each arm (ie, each substrate member 1221 ).

[0189] As shown in Figures 8a to 8c, when an external force acts on the pen cap, when the resistance strain gauge 1211A changes its resistance due to the deformation of the substrate component 1221, the resistances R1, R2, R3, and R4 corresponding to the resistance strain gauge 1211A on the cross bridge arm also change due to the strain.

[0190] It should be noted that the resistance strain gauges 1211A are arranged in a ring or side by side. In this way, when the substrate component 1221 is deformed at any angle, the resistance value of the resistance strain gauge 1211A can change due to the deformation of the substrate component 1221, which is beneficial to improving the sensitivity of the strain component.

[0191] It should be further explained that, in the embodiment of the present application, the number of resistance strain gauges 1211A is not limited to two pairs, but can also be 3 pairs, 4 pairs, etc., which can be set according to actual design and usage requirements.

[0192] It should be noted that a resistance strain gauge is a component used to measure strain, converting changes in strain on a mechanical component into changes in resistance. In this application, the specific structure of the resistance strain gauge is not limited. The structure and operating principle of the resistance strain gauge provided in the embodiments of this application are explained below with reference to the accompanying drawings.

[0193] Please refer to Figures 9a to 9c. Figure 9a is a structural schematic diagram of a resistance strain gauge provided in one embodiment of the present application, Figure 9b is a structural schematic diagram of a resistance strain gauge provided in another embodiment of the present application, and Figure 9c is a strain principle diagram of the resistance strain gauge provided in an embodiment of the present application.

[0194] As shown in Figure 9a, the resistance strain gauge 1211A is formed by winding a constantan or nickel-chromium wire with a diameter of 0.02-0.05 mm into a grid-like sensitive grid 12A. Sensitive grid 12A is fixed to a substrate 12B, and the constantan or nickel-chromium wire is connected to the external circuit via a wire 12C. Wire 12C is connected to the strain gauge grid using silver-plated copper wire.

[0195] As shown in FIG9b, the resistance strain gauge 1211A is formed by etching a thin metal foil 12D into a grid shape and formed on a substrate 12B. The metal foil 12D is connected to the external circuit through a wire 12C. The wire 12C is connected to the metal foil 12D using a silver-plated copper wire.

[0196] It should be noted that the resistance strain gauges of the above two structures are both sandwiched between two layers of insulating sheets after being formed into a grid shape.

[0197] Furthermore, as shown in Figure 9c, resistance strain gauges are based on the principle that a material's resistance changes when subjected to mechanical stress. Specifically, the measurement principle of a resistance strain gauge is as follows: the resistance of a metal wire is related not only to the properties of the material but also to its length and cross-sectional area. When the wire is attached to a component, when the component is deformed by force, the length and cross-sectional area of ​​the wire also change along with the component, causing a change in resistance. The resistance change rate ΔR / R of the resistance gauge is converted into a voltage output, which is then amplified and measured by an amplifier circuit.

[0198] dR / R=Ks*ε;

[0199] Ks is the material's sensitivity coefficient, which physically translates to the rate of change in resistance per unit strain and indicates whether the wire-like resistance strain gauge effect is significant. ε is the strain at the measuring point. While dimensionless, it is often expressed in microstrain units, often represented by the symbol με.

[0200] From this we can see that when the metal wire produces a strain effect, the strain ε is linearly related to the resistance change rate dR / R. This is the theoretical basis for using metal strain gauges to measure component strain.

[0201] Furthermore, the deformation capacity of a resistance strain gauge is related to its elastic modulus. Specifically, the elastic modulus is a mathematical description of the tendency of an object to deform elastically (non-permanently) when an external force is applied. The elastic modulus can be considered an indicator of how easily a material can deform elastically. The larger its value, the greater the stress required to produce a certain elastic deformation. In other words, the greater the material's stiffness, the less elastic deformation it undergoes under a given stress.

[0202] It should be further explained that, in the embodiment of the present application, the following steps may be adopted when the resistance strain gauge 1211A is attached to the substrate member 1221:

[0203] Before mounting, visually inspect and measure the resistance of the strain gauges to be used. Visual inspection can be performed visually or with the aid of a magnifying glass. The purpose is to observe whether the sensitive grids are free of rust or defects, whether they are neatly arranged, whether the base and cover are damaged, and whether the leads are intact. Resistance measurement is performed using the JM3840 quarter-bridge resistor. This is to check for open or short circuits in the sensitive grids and to sort the resistance values. For a group of strain gauges sharing temperature compensation, the resistance value difference must not exceed ±0.5. Strain gauges used in the same measurement must have the same sensitivity coefficient.

[0204] For metal components such as steel, the first step is to remove surface paint, oxide layers, and dirt; then, grind or file the surface flat and polish with fine sandpaper. This process is commonly referred to as "sanding." The polished finish should be approximately ▽5. For very smooth components, fine sandpaper should be used to create cross-cutting grooves at 45° to enhance adhesion. The polished area is approximately five times the area of ​​the resistance strain gauge. After sanding, use a stylus to gently mark the precise location of the patch. The final step in surface treatment is cleaning. This involves repeatedly scrubbing the patch area with clean cotton yarn or a cotton ball dipped in acetone or another volatile solvent until no dirt is visible on the cotton ball.

[0205] The patching process varies depending on the adhesive used. For patching with 502 adhesive, after the cleaning agent evaporates, a small amount of 502 adhesive is first applied to the patch location. The adhesive is evenly spread on the back of the strain gauge. Tweezers are then used to manipulate the gauge to adjust its position and angle. Once positioned, a layer of polyethylene or tetrafluoroethylene film is placed over the gauge. Use your fingers to gently squeeze out any excess adhesive and air bubbles. Once the adhesive has initially solidified, the adhesive can be released.

[0206] After the adhesive has initially cured, wire bonding can begin. For static measurements at room temperature, use a two-core, multi-strand copper-plastic cable. For dynamic measurements, use a three-core or four-core shielded cable. The strain gauges and wires are connected via terminal blocks, ensuring no cold solder joints.

[0207] Observe the correct patch orientation, any damage to the gauge, and ensure the adhesive is secure and free of bubbles. Measuring resistance can help check for open circuits and loops. Insulation resistance is the most important parameter to inspect. The quality of the insulation depends on the base of the strain gauge. Strain gauges that are poorly bonded or insufficiently cured often have low insulation resistance.

[0208] Finally, moisture in the strain gauge can reduce insulation resistance and bond strength, and in severe cases, can cause corrosion of the sensitive grid. Acid, alkali, and oil infiltration can even change the physical properties of the substrate and adhesive. To prevent the infiltration of free moisture in the atmosphere, rainwater, and dew, and in special environments to prevent the intrusion of impurities such as acids, alkalis, and oils, a protective layer should be applied to the fully dried, cured, and wire-soldered resistance strain gauge.

[0209] The protective layer uses protective agents such as vaseline, lime, gun oil, rosin mixture, epoxy resin, etc.

[0210] It should be further explained that, as shown in FIG. 7 a and FIG. 7 c , the principle by which the resistance strain gauge 1211A generates electrical signal information when subjected to a pressing force in the embodiment of the present application is as follows:

[0211] Where VO represents the detection voltage; VS represents the given circuit excitation voltage, which is a constant; GF represents the sensitivity coefficient of the relationship between the resistance change rate and strain, which is a constant; ε1 and ε2 represent the strain within the strain region on the lower surface of substrate member 1221 (i.e., a single arm); ε3 and ε4 represent the strain of the reference resistor on the rear strain gauge, which should be zero. When strain gauge 1211A is deformed by force, the corresponding voltage change can be obtained according to the above formula.

[0212] It should be understood that a voltmeter can be provided in the Wheatstone circuit, and the detection voltage V0 detected by the voltmeter can be integrated into the flexible circuit board 1223 or provided at other locations. This is not the only requirement in the embodiment of the present application.

[0213] Please refer to Figure 10, which is a schematic diagram of the connection structure between the sensing electrode and the flexible circuit board in an embodiment of the present application. In some embodiments of the present application, as shown in Figure 10, in some embodiments of the present application, the handwriting erasing device 100 also includes a signal transmitting component (not shown in the figure), which is used to send an erase signal to the electronic device using the touch screen 20.

[0214] It should be understood that the signal transmitting component can be a wireless transmitting module, such as a Bluetooth module. When the handwriting erasing device 100 performs the handwriting erasing operation, the handwriting erasing device 100 establishes a connection with the electronic device using the touch screen 20 via Bluetooth, and transmits an erasing signal to the electronic device using the touch screen 20 in real time via Bluetooth.

[0215] Furthermore, the handwriting erasing device 100 includes a sensing electrode 130A. The sensing electrode 130A constitutes the pressing portion 112 , and the sensing electrode 130A is electrically connected to the flexible circuit board.

[0216] It should be noted that since many conductors are provided inside the touch screen 20, the use of the sensing electrode 130A can generate capacitance between the handwriting erasing device 100 in this application and the touch screen 20 when the handwriting erasing device 100 is close to the touch screen 20. During this process, no other operation is required to enable the handwriting erasing device 100 to interact with the touch screen 20 and enable the pen eraser function, making it more convenient to use.

[0217] It should be understood that the embodiment of the present application uses the sensing electrode 130A as the signal transmitting end of the strain component 120. It can also be understood that the sensing electrode 130A is a capacitive sensor signal transmitting end. The specific structure of the sensing electrode 130A is not limited. For example, the sensing electrode 130A can be a TX electrode.

[0218] When the handwriting erasing device 100 performs a handwriting erasing action, the TX electrode approaches or contacts the touch screen 20 , and a capacitance change occurs between the TX electrode and the touch screen 20 . The capacitance change signal can be used as a trigger signal for enabling the eraser function.

[0219] The following is an explanation of the operating principle of the sensing electrode 130A.

[0220] Specifically, Figure 11 shows a schematic diagram of capacitive sensing. As shown in Figure 11, capacitive sensing is a technology based on capacitive coupling. The human body is a conductor, creating capacitance between it and the sensor. When a finger approaches the sensor, the capacitance increases, and this effect allows detection of the approaching hand. Similarly, when a handwriting eraser uses sensing electrodes, a similar induction effect occurs between the device and the electronic device's screen.

[0221] Please refer to Figures 12a to 12d. Figure 12a is a schematic diagram of the exploded structure of the handwriting erasing device provided in an embodiment of the present application. Figure 12b is a schematic diagram of the cross-sectional structure of the handwriting erasing device provided in an embodiment of the present application. Figure 12c is a schematic diagram of the top view of the handwriting erasing device provided in an embodiment of the present application. Figure 12d is a schematic diagram of the structure of the strain component provided in an embodiment of the present application.

[0222] As shown in Figures 12a and 12b, in some embodiments of the present application, the handwriting erasing device 100 may further include an insulating member 140. The insulating member 140 is disposed between the sensing electrode 130A and the strain sensing assembly 121. The end of the sensing electrode 130A is adapted to be fitted into a groove 141 at the corresponding end of the insulating member 140. In addition, the end of the insulating member 140 away from the sensing electrode 130A also forms a protrusion structure 142 aligned with the geometric center point of the strain substrate 122. When the triggering portion 111 is subjected to force, the protrusion structure 142 of the insulating member 140 presses the strain substrate 122 of the strain sensing assembly 121.

[0223] It should be understood that the end of the sensing electrode 130A fits into the groove 141 of the corresponding end of the insulating member 140 and can be fixed by gluing the contact surface. During assembly, a gasket can be placed in the groove 141 to adjust the height of the sensing electrode 130A.

[0224] The sensing electrode 130A and the triggering part 111 are integrated by an in-film injection molding process or glue bonding. The sensing electrode 130A can be bonded to the inner wall of the housing 160 for fixation, and glue is poured into the gap to form a seamless structure.

[0225] The flexible circuit board 1223 is bonded to the bottom surface of the substrate member 1221. The insulating member 140 is bonded to the top of the substrate member 1221, and the end of the insulating member 140 is fixedly connected to the stepped surface of the bracket 123. The flexible circuit board 1223 and the sensing electrode 130A are compressed and electrically connected by the conductive foam 122A.

[0226] During use, the coding signal on the flexible circuit board 1223 is connected to the sensing electrode 130A through the conductive foam 122A.

[0227] It should be understood that the handwriting erasure device 100 in the embodiment of the present application may include a motherboard with an integrated processor. The coding signal is emitted by the motherboard, passing through the flexible circuit board 1223 and the conductive foam 122A, and ultimately connected to the sensing electrode 130A. Using this signal, the electronic device 30 can locate the point where the handwriting erasure device 100 is slid across the touch screen 20, thereby confirming the erased position. The electrical connection scheme here can also be a conductive and fixed scheme such as a spring or conductive gel.

[0228] It is further necessary to understand that when the sensing electrode 130A is performing a handwriting erasure action in the handwriting erasure device 100, the TX electrode approaches or contacts the touch screen 20, and a capacitance change occurs between the TX electrode and the touch screen 20. This capacitance change can also be used to roughly determine the erasure position and erasure range of the trigger component 110 of the handwriting erasure device 100 relative to the touch screen 20. In the embodiment of the present application, the sensing electrode 130A is connected to the flexible circuit board 1223 through the conductive foam 122A. In this way, the main board in the handwriting erasure device 100 can transmit the coding signal through the flexible circuit board 1223 and the conductive foam 122A, and finally connect to the sensing electrode 130A. In this way, the erasure position and erasure range of the trigger component 110 relative to the touch screen 20 can be determined more accurately, thereby improving the performance of the handwriting erasure device 100.

[0229] It's also important to understand that when the handwriting eraser 100 is used in an electronic stylus, the main board can be the stylus' refill main board. The coding signal on the flexible circuit board 1223 is transmitted to the sensing electrode 130A via the conductive foam 122A. This coding signal is emitted by the refill main board, passes through the flexible circuit board 1223 and the conductive foam 122A, and ultimately reaches the sensing electrode 130A. Using this signal, the electronic device can determine the point where the handwriting eraser slides across the screen, effectively confirming the erase position and range.

[0230] As shown in Figures 12c-12d, the handwriting erasing device 100 also includes a bracket 123, which has a hollow area or a sunken area. One end of a plurality of substrate components 1221 away from the geometric center point is fixed to the bracket 123, and the other ends are interconnected and suspended in the hollow area or the sunken area of ​​the bracket 123 to form an end-fixed beam structure.

[0231] This structure allows the peripheral ends of the substrate member 1221 to be fixed, and the central portion to deform when receiving the pressure. The resistance strain gauges provided on the substrate member 1221 can convert the corresponding tiny deformation into an electrical signal.

[0232] It should be noted that when the trigger component 110 is subjected to pressure (which can be understood as the reaction force applied to the trigger component 110 by the touch screen 20), the trigger component 110 deforms, and the trigger component 110 sequentially transmits the pressure to each substrate member 1221 of the strain substrate 122. Because the other end of each substrate member 1221 (i.e., the end of each substrate member 1221 connected to the trigger component 110) is suspended in the air, a significant deformation can be generated in the axial direction of the pen cap. The greater deformation generated by each substrate member 1221 allows for better transmission of the deformation to the strain sensing element 1211, resulting in a higher sensitivity of the strain sensing assembly 121.

[0233] Please refer to Figure 12e, which is an isometric structural diagram of the handwriting erasing device provided in an embodiment of the present application. In some embodiments, as shown in Figures 12a and 12e, the outer surface of the trigger portion 111 may have a soft protective layer 150 to protect the trigger portion 111.

[0234] Furthermore, as further understood in conjunction with FIG. 12 e , the handwriting erasing device 100 may further include a housing 160 , wherein the trigger component 110 and the strain component 120 are fixed in the housing 160 , and the trigger portion 111 is partially exposed from the housing 160 .

[0235] Please refer to Figure 12f, which illustrates the handwriting erasing device provided by an embodiment of the present application in use. As shown in Figure 12f, when the handwriting erasing device in this embodiment of the present application performs a handwriting erasing action, the reaction force F exerted by the touch screen 20 is sequentially transmitted only to the trigger portion 111, the pressing portion 112, and the insulating member 140 to the corresponding substrate member 1221.

[0236] Furthermore, Figure 13 is a partial cross-sectional view of a handwriting erasing device according to an embodiment of the present application. As shown in Figure 13 , in some embodiments of the present application, the portion of the trigger portion 111 exposed from the housing 160 is shaped like a truncated sphere, and the cross-sectional center angle G of the truncated sphere is within a range of 90° to 150°.

[0237] It should be noted that by configuring the trigger portion 111 to be a truncated spherical structure with a cross-sectional center angle G of the truncated spherical structure within a range of 90° to 150°, the handwriting erasing device 100 of the present application can have a larger erasing range.

[0238] It should be further explained that, in the embodiment of the present application, the cross-sectional center angle G of the truncated spherical structure can be set to any angle within the range of 90° to 150°, for example, the cross-sectional center angle G of the truncated spherical structure can be set to 90°, 125°, 150°, etc.

[0239] Please refer to Figures 14a and 14b. Figure 14a is a schematic diagram of the assembly structure of the pen cap provided in an embodiment of the present application, and Figure 14b is a schematic diagram of the cross-sectional structure of the pen cap provided in an embodiment of the present application.

[0240] Please refer to Figures 14a and 14b. The present application also provides a pen cap for an electronic stylus. The pen cap 10C is set at the end of the electronic stylus 10 and is used to perform the eraser function of the electronic stylus. The pen cap 10C includes the handwriting erasing device 100 of the above-mentioned touch screen structure 20.

[0241] It should be noted that by integrating the handwriting erasing device 100 of the above structure into the pen cap of the electronic stylus, the handwriting erasing device 100 of the above structure can realize the handwriting erasing function, not only achieving different degrees of erasing effects based on the size of the pressing force, but also realizing multi-angle recognition and erasing. The pen cap of the electronic stylus adopts this structure, which not only improves the functional diversification of the electronic stylus pen cap, but also improves the performance of the electronic stylus.

[0242] It should be further explained that, since the pen cap is integrated with the handwriting erasing device 100 of the above structure, the user can achieve different degrees of erasing effects by applying different amounts of pressing pressure to the pen cap.

[0243] Please refer to Figures 15a and 15b. Figure 15a is a schematic diagram of the assembly structure of the electronic stylus provided in an embodiment of the present application, and Figure 15b is a schematic diagram of the cross-sectional structure of the electronic stylus provided in an embodiment of the present application.

[0244] As shown in FIG. 15 a - FIG. 15 b , the present application further provides an electronic stylus 10 , which includes a pen body 10B and a pen tip 10A disposed at one end of the pen body, and further includes a pen cap 10C of the above structure.

[0245] The pen cap 10C provided in the embodiment of the present application is not limited to being used in conjunction with an electronic stylus. When the pen cap 10C is used in conjunction with an electronic stylus, the shell of the electronic stylus can serve as the shell of the pen cap 10C.

[0246] Furthermore, the pen cap 10C can also be used as a separate product and can be plugged and connected to the end of the pen body 10B.

[0247] It should be noted that, since the pen cap of the above structure can realize different degrees and multi-angle recognition based on the size of the pressing force to erase the handwriting on the touch screen 20, the performance of the electronic stylus can be improved.

[0248] During use, if a user accidentally draws an erroneous image due to an accidental touch, a handwriting erasure device is required to erase the erroneous image. The electronic stylus 10 can be rotated 180° so that the cap 10C of the electronic stylus 10 is in contact with the touch screen. The erroneous image can then be erased using the cap 10C. During this process, the user can achieve varying degrees of erasure by applying varying amounts of pressure to the cap.

[0249] It should be further explained that, by plugging and detaching the pen cap to the other end of the pen barrel, the pen cap can also be used independently when the handwriting erasing function is used, which is more convenient to use.

[0250] Specifically, a flange structure may be provided inside the shell of the pen cap 10A, and a groove structure adapted to the flange structure may be provided at the tail of the pen body 10B. The pen cap 10A is pluggably connected to the other end of the pen body 10B using the flange and the groove.

[0251] Please refer to Figures 16a to 16d. Figure 16a is a principle block diagram of the handwriting elimination method provided in an embodiment of the present application. Figure 16a' is another principle block diagram of the handwriting elimination method provided in an embodiment of the present application. Figure 16b is a flow chart of the handwriting elimination method provided in an embodiment of the present application. Figure 16c is a scenario diagram of the handwriting elimination method provided in an embodiment of the present application. Figure 16d is another scenario diagram of the handwriting elimination method provided in an embodiment of the present application.

[0252] As shown in Figures 16a and 16b, the present invention also provides a method for erasing handwriting on a touch screen, which uses the electronic stylus or the cap of the electronic stylus with the above structure to perform the eraser function. The method for erasing handwriting on a touch screen includes:

[0253] The triggering unit 111 of the handwriting erasing device 100 receives a feedback signal from the electronic device 30 using a touch screen to trigger the eraser function of the pen cap.

[0254] Detect and send electrical signal information indicating that the trigger part 111 is subjected to force.

[0255] The target pressure information of the pen cap is determined based on the electrical signal information, and the target pressure information is sent to the electronic device 30 (i.e., the target electronic device), so that the electronic device 30 determines the degree of erasure of the handwriting displayed on the touch screen 20 based on the target pressure information. Specifically, the target pressure information includes the pressure level information of the pen cap.

[0256] For example, as shown in FIG16c, when the cap 10C of the electronic stylus 10 presses the touch screen 20, the feedback signal can be understood as the reaction force applied by the touch screen 20 to the trigger portion 111. The pressure magnitude information is the magnitude of the reaction force.

[0257] When the trigger part 111 is squeezed by the reaction force, in one embodiment, as shown in Figure 3b, the reaction force is directly transmitted to the strain sensing component 121 through the trigger part 111 and the pressing part 112 in sequence. At this time, the strain sensing component 121 detects the reaction force and generates corresponding electrical signal information, which can be voltage information representing the magnitude of the reaction force.

[0258] Specifically, in this embodiment, the strain sensing component 121 can be a structure as shown in Figure 7a. The strain sensing component 121 includes a strain substrate 122 (for example, a strain steel sheet 1222), a flexible circuit board 1223 attached to the side of the strain substrate 122 away from the pressing portion 112, and a plurality of strain sensing elements (for example, a plurality of resistance strain gauges 1211A) attached to the first part of the surface of the flexible circuit board 1223. Each pair of resistance strain gauges 1211A on each substrate component 1221 and the corresponding pair of auxiliary resistors 1224 constitute a Wheatstone circuit. When the reaction force applied to the trigger part 111 by the touch screen 20 is transmitted to the strain sensing component 121, the strain steel sheet 1222 is squeezed and deformed. The resistance value of the resistance strain gauge 1211A attached to the surface of the strain steel sheet 1222 through the flexible circuit board 1223 changes as the strain steel sheet 1222 deforms, so that the resistance strain gauge 1211A and the auxiliary resistor 1224 form a Wheatstone circuit to output corresponding voltage information. This voltage information can be used to characterize the magnitude of the reaction force.

[0259] It can also be a structure as shown in Figures 8a and 8b. The two pairs of resistance strain gauges 1211A on each substrate component 1221 are connected to each other to form a Wheatstone circuit. When the reaction force applied to the trigger part 111 by the touch screen 20 is transmitted to the strain sensing component 121, the strain steel sheet 1222 is squeezed and deformed. The resistance value of the resistance strain gauge 1211A attached to the surface of the strain steel sheet 1222 through the flexible circuit board 1223 changes as the strain steel sheet 1222 deforms, so that the two pairs of resistance strain gauges 1211A form a Wheatstone circuit to output corresponding voltage information, which can be used to characterize the magnitude of the reaction force.

[0260] In this embodiment, the strain sensing component 121 can be a pressure sensor that directly detects the pressing force. The pressure sensor can be a micro pressure sensor commonly found in the art, and its model can be selected based on actual design and usage requirements, and this application does not make a sole requirement.

[0261] In another embodiment, the reaction force shown in Figure 12f is transmitted to the strain sensing component 121 through the trigger part 111, the pressing part 112, and the insulating part 140 in sequence. At this time, the strain sensing component 121 detects the reaction force and generates corresponding electrical signal information, which can be voltage information representing the magnitude of the reaction force.

[0262] When the handwriting erasure method of the present application is used to perform a handwriting erasing action, as shown in FIG16 a and FIG16 c , the electronic stylus 10 may be rotated 180° so that the cap 10C of the electronic stylus 10 contacts and moves relative to the touch screen 20, and then the handwriting erasing action is performed.

[0263] In this embodiment, the electronic stylus 10 may include a processor 10D. The processor 10D may include storage and processing circuitry for supporting the operation of the electronic stylus 10. The storage and processing circuitry may include storage devices such as non-volatile memory (e.g., flash memory or other electrically programmable read-only memory configured as a solid-state drive), volatile memory (e.g., static or dynamic random access memory), etc. The processing circuitry in the processor 10D may be used to control the operation of the electronic stylus 10. The processing circuitry may be based on one or more microprocessors, microcontrollers, digital signal processors, baseband processors, power management units, audio chips, application-specific integrated circuits, etc.

[0264] The processor 10D can be used to run software on the electronic stylus 10 that controls the operation of the electronic stylus 10. During operation of the electronic stylus 10, the software running on the processor 10D can process sensor inputs, button inputs, and inputs from other devices to monitor the movement of the electronic stylus 10 and other user inputs. The software running on the processor 10D can detect user commands and can communicate with the electronic device 30.

[0265] To support wireless communication between the electronic stylus 10 and the electronic device 30, the electronic stylus 10 may include a wireless module 10E. The wireless module 10E may be a type of signal transmitting component, such as a Bluetooth module. The wireless module 10E may also be a Wi-Fi hotspot module, a Wi-Fi point-to-point module, or the like. The Bluetooth module may include a radio frequency transceiver, such as a transceiver. The Bluetooth module may also include one or more antennas. The transceiver may utilize an antenna to transmit and / or receive wireless signals. The wireless signals may be Bluetooth signals, wireless local area network signals, long-range signals such as cellular phone signals, near-field communication signals, or other wireless signals, depending on the type of wireless module. The electronic stylus 10 may also include a charging module, which may support charging of the electronic stylus 10 and provide power to the electronic stylus 10.

[0266] The strain sensing component 121 in this application is in communication with the processor 10D, which can be a wired communication connection or a wireless communication connection. When the strain sensing component 121 outputs voltage information representing target pressure information, the processor 10D obtains the target pressure information and transmits the corresponding target pressure information to the electronic device 30 via the wireless module 10E.

[0267] The electronic device 30 may further include a wireless interface 30C to facilitate electronic communication between the electronic device 30 and the electronic stylus 10. The wireless interface 30C of the electronic device 30 receives target pressure information. In one embodiment, the electronic device 30 may be configured to communicate with the electronic stylus 10 via a low-energy Bluetooth communication interface or a near-field communication interface. In other examples, the communication interface facilitates electronic communication between the electronic device 30 and an external communication network, device, or platform.

[0268] The wireless interface 30C (whether it is a communication interface between the electronic device 30 and the electronic stylus 10 or another communication interface) can be implemented as one or more wireless interfaces, Bluetooth interfaces, near-field communication interfaces, magnetic interfaces, universal serial bus interfaces, inductive interfaces, resonant interfaces, capacitive coupling interfaces, Wi-Fi interfaces, TCP / IP interfaces, network communication interfaces, optical interfaces, acoustic interfaces or any traditional communication interfaces.

[0269] The electronic device 30 further includes a processor 30A, an erasing module 30B, and a display 30D (e.g., a touch screen 20 may be used). The processor 30A is in communication with the erasing module 30B and the wireless interface 30C, respectively, to obtain the target pressure information, and controls the erasing module 30B to perform the corresponding handwriting erasure based on the target pressure information, and controls the display 30D to display an erasing effect interface with which the user can interact.

[0270] As shown in FIG. 16a ′ and FIG. 16d , the pen cap 10C may be used as a product independent of the electronic stylus to perform handwriting erasing. The handwriting erasing is achieved by contacting and relatively moving the pen cap 10C with the touch screen 20 .

[0271] In this embodiment, the pen cap 10C may have a processor 101D that is independent of the processor 10D of the electronic stylus 10. The processor 101D may include storage and processing circuits for supporting the operation of the pen cap 10C. The storage and processing circuits may include storage devices such as non-volatile memory (for example, flash memory or other electrically programmable read-only memory configured as a solid-state drive), volatile memory (for example, static or dynamic random access memory), etc. The processing circuit in the processor 101D can be used to control relevant operations of the pen cap 10C. The processor 101D may be integrated with the strain sensing component 121, or it may be arranged at other locations of the pen cap 10C. The processing circuit may be based on one or more microprocessors, microcontrollers, digital signal processors, baseband processors, power management units, audio chips, application-specific integrated circuits, etc.

[0272] The processor 101D can be used to run software on the pen cap 10C that controls the operation of the pen cap 10C. During operation of the pen cap 10C, the software running on the processor 101D can process sensor inputs, button inputs, and inputs from other devices to monitor movement of the pen cap 10C and other user inputs. The software running on the processor 101D can detect user commands and can communicate with the electronic device 30.

[0273] In order to support wireless communication between the pen cap 10C and the electronic device 30, the pen cap 10C may include a wireless module 101E. The wireless module 101E may be a signal transmitting component, and the wireless module 101 may be a Bluetooth module, or a WI-FI hotspot module, a WI-FI point-to-point module, etc. The Bluetooth module may include a radio frequency transceiver, such as a transceiver. The specific form of the Bluetooth module may be as described above, and will not be elaborated on here.

[0274] The strain sensing component 121 in this application is in communication with the processor 101D, which can be a wired communication connection or a wireless communication connection. When the strain sensing component 121 outputs voltage information representing target pressure information, the processor 10D obtains the target pressure information and sends the corresponding target pressure information to the electronic device 30 via the wireless module 101E.

[0275] The wireless interface 30C of the electronic device 30 may be a communication interface between the electronic device 30 and the pen cap 10C, or may be another communication interface.

[0276] It should be noted that in the above embodiments, the handwriting erasure method can determine the degree of erasure of the handwriting displayed on the touch screen based on the pressure information of the pen cap. When the handwriting erasure function is performed using the pen cap, different erasing effects can be achieved under different erasing force sizes.

[0277] In some embodiments, the strain sensing component 121 includes a strain substrate 122 and multiple strain sensing elements 1211, and all strain sensing elements 1211 are arranged on the strain substrate 122; the multiple strain sensing elements 1211 generate multiple electrical signal information according to the pressing force applied by the pressing part 112, and determine the target pressure information of the pen cap according to the multiple electrical signal information, and send the target pressure information to the electronic device 30, so that the electronic device 30 determines the degree of erasure according to the target pressure information.

[0278] It should be noted that the target pressure information of the pen cap is determined by using multiple electrical signal information, so that the accuracy of the target pressure information can be guaranteed. Even if an error occurs in any electrical signal information, the method can reduce the impact on the target pressure information.

[0279] Please refer to Figures 17a-17c. Figure 17a is a schematic diagram of a bridge circuit in an embodiment of the present application. Figure 17b is a diagram of a pen cap model in an embodiment of the present application. Figure 17c is a schematic diagram of force analysis at a specific point on the pen cap in an embodiment of the present application. As shown in Figures 17a and 17b, the multiple strain sensing elements 1211 correspond to N Wheatstone bridge circuits, each of which outputs a bridge voltage. The multiple electrical signal information is the N bridge voltages output by the N Wheatstone bridge circuits.

[0280] Determining the pressure of the pen cap based on multiple electrical signal information includes:

[0281] The current angle information of the pen cap (which can be understood as θ in Formula 4) is determined based on the N bridge voltages. The current angle information is the angle between the direction of the reaction force applied by the touch screen 20 to the trigger part 111 and the axial direction of the pen cap.

[0282] Determine the current voltage information (which can be understood as Vmax in Formula 5) based on the N bridge voltages and the current angle information;

[0283] The pressure magnitude information (which can be understood as F in Formula 5) is determined based on the current voltage information and the calibration information. The calibration information represents a one-to-one correspondence between different voltage information and different pressure information when the pen cap is subjected to force at a calibration angle (which can be understood as the relationship between Vmax and F). The calibration angle is configured as the angle at which the force direction of the pen cap coincides with the axis of the pen cap.

[0284] It should be noted that the current angle information of the pen cap is determined based on the N bridge voltages, the current voltage information is determined using the N bridge voltages and the current angle information, and the pressure information is determined based on the current voltage information and the calibration information. In this way, the erasing effect can be compensated according to the different inclination angles of the pen cap (or it can be understood that the role of calculating the inclination angle is to provide compensation for the algorithm), avoiding the need to use a larger erasing force due to the weak signal at the edge of the pen cap, so that a consistent erasing effect can be produced at different inclination angles under the same pressing force. This is also conducive to improving the accuracy of executing the handwriting erasing action on the touch screen. Or it can be understood that even when the erasing action is performed at an angle inclined relative to the axis of the pen cap, the target pressure information can more accurately represent the actual pressing force.

[0285] It should be understood that in the present application, the processor is preset with a mathematical model. When the erasing action is performed, when the force direction of the trigger part 111 is tilted relative to the axis of the pen cap, the processor uses the mathematical model to compensate the detection value to obtain more accurate target pressure information, thereby achieving an erasing effect that matches the pressing force.

[0286] The following is an explanation of how the mathematical model is constructed:

[0287] As shown in FIG17c, when the pen cap is used to perform an erasing action, a force F is applied to a certain point of the pen cap, which can be decomposed into F xy and F z , the angle θ between the force F and the pen cap axial time can be calculated by the following formula 1,

[0288] F xy is the horizontal component of F, F z is the vertical component of F. By corresponding the forces in each direction to the electrical signal, we can obtain Formula 2 and Formula 3:

[0289] V 2i-1 and V 2i They represent the current bridge voltages output by two relatively set Wheatstone bridge circuits, such as V1 and V3, V2 and V4 shown in Figure 17a. K2 is the correction coefficient. It can be seen that the horizontal force component F xy Positively correlated to the root of the sum of the squares of the differences in signal quantities between the bridge arms.

[0290] V i Representing the bridge voltage of the corresponding bridge, we can know the vertical force F z Positively correlated to the sum of the signal quantities between each bridge arm.

[0291] 1≤i≤N; K1 is the correction coefficient.

[0292] According to the above formula 2 and formula 3, formula 4 can be obtained:

[0293] It can be seen that the angle θ between the current force direction of the pen cap and the axis of the pen cap can be calculated using the above formula 4:

[0294] Among them, θ represents the angle between the current force direction of the pen cap and the axis of the pen cap; 1≤i≤N; K is the ratio of K2 to K1, that is, a constant.

[0295] Therefore, the pressure F corresponding to the target pressure information can be calculated by formula 5:

[0296] Furthermore, in the embodiment of the present application, the five positions shown in FIG17b are specifically selected, the difference between two adjacent load angles is 15°, and the angle is estimated according to the above formula with the load voltage Vs being 2.8V. See the table below for details:

[0297] According to the table above:

[0298] When the load angle is 0° (corresponding to position 1), V1 is 456.61uV, V2 is 454.85uV, V3 is 454.14uV, V4 is 454.28uV, and the correction coefficient K is 3.5, so the estimated angle is 0.2°.

[0299] When the load angle is 15° (corresponding to position 2), V1 is 456.61uV, V2 is 433.63uV, V3 is 373.04uV, V4 is 501.85uV, the correction coefficient K is 3.5, the load voltage Vs is 2.8V, the estimated angle is 14.5°, and the deviation reaches 3.6%.

[0300] When the load angle is 30° (corresponding to position 3), V1 is 399.47uV, V2 is 379.72uV, V3 is 263.40uV, V4 is 512.06uV, the correction coefficient K is 3.5, the load voltage Vs is 2.8V, the estimated angle is 29.3°, and the deviation reaches 2.3%.

[0301] When the load angle is 45° (corresponding to position 4), V1 is 317.05uV, V2 is 290.07uV, V3 is 125.86uV, V4 is 477.63uV, the correction coefficient K is 3.5, the load voltage Vs is 2.8V, the estimated angle is 45.6°, and the deviation reaches 1.2%.

[0302] When the load angle is 60° (corresponding to position 5), V1 is 136.83uV, V2 is 106.04uV, V3 is 87.39uV, V4 is 327.55uV, the correction coefficient K is 3.5, the load voltage Vs is 2.8V, the estimated angle is 65.7°, and the deviation reaches 8.7%.

[0303] From the above analysis, it can be seen that the embodiment of the present application is more accurate based on the current angle information obtained and can compensate for the deviation angle.

[0304] In some embodiments, before receiving the feedback signal of the electronic device triggering the pen eraser function, it also includes: sending a trigger signal to enable the pen eraser function.

[0305] In one example, the handwriting erasing device 100 is provided with a sensing electrode 130A. When the handwriting erasing device 100 performs a handwriting erasing action, a capacitance change occurs between the sensing electrode 130A of the handwriting erasing device 100 and the touch screen 20. The capacitance change signal can be used as a trigger signal for enabling the pen eraser function.

[0306] It should be noted that the processor can transmit the coding signal through the flexible circuit board 1223 and the conductive foam 122A, and finally electrically conduct it to the sensing electrode 130A, so as to determine the erasing position and erasing range of the trigger component 110 relative to the touch screen 20.

[0307] In the above examples, those skilled in the art can easily understand other advantages and effects of the present application from the contents disclosed in this specification. Although the description of the present application will be introduced in conjunction with some embodiments, this does not mean that the features of this application are limited to the implementation methods. On the contrary, the purpose of introducing the application in conjunction with the implementation methods is to cover other options or modifications that may be extended based on the claims of the present application. In order to provide an in-depth understanding of the present application, the following description will contain many specific details. The present application can also be implemented without using these details. In addition, in order to avoid confusion or blurring the focus of the present application, some specific details will be omitted in the description. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other unless there is a conflict.

[0308] It should be noted that in this specification, similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0309] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate the description of this application and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0310] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0311] In the description of this application, it should be understood that "electrical connection" in this application can be understood as the physical contact and electrical conduction between components; it can also be understood as the connection between different components in the circuit structure through physical lines such as printed circuit board (PCB) copper foil or wires that can transmit electrical signals. "Communication connection" can refer to the transmission of electrical signals, including wireless communication connections and wired communication connections. Wireless communication connections do not require physical media and do not constitute a connection relationship that limits the product structure.

[0312] Obviously, those skilled in the art may make various changes and modifications to this application without departing from the spirit and scope of this application. Thus, if these modifications and variations of this application fall within the scope of the claims of this application and their equivalents, this application is intended to include these modifications and variations.

Claims

1. A handwriting erasing device for a touch screen, characterized in that: The handwriting elimination device comprises: A trigger component, the trigger component comprising a trigger portion in contact with the touch screen, and a pressing portion disposed inside the trigger portion; A strain component, the strain component comprising a strain sensing component arranged opposite to the pressing portion; Among them, the trigger part is in contact with the touch screen and is subjected to force and presses the strain sensing component through the pressing part. The strain sensing component deforms according to the pressing force applied by the pressing part and generates an erasing signal corresponding to the deformation. The erasing signal is used to eliminate the handwriting displayed on the touch screen.

2. The handwriting erasing device for a touch screen as claimed in claim 1, characterized in that: The strain sensing component comprises a strain substrate and a plurality of strain sensing elements, wherein the plurality of strain sensing elements are arranged on the strain substrate; wherein, The multiple strain sensing elements are located in the same plane, a plane parallel to the plane where the multiple strain sensing elements are located is used as a projection plane, and the multiple strain sensing elements are distributed in a uniform array in the projection plane; and The projection of the pressing portion on the projection surface is located within the projection outer contours of the plurality of strain sensing elements on the projection surface.

3. The handwriting erasing device for a touch screen as claimed in claim 2, characterized in that: The strain substrate has a central symmetrical structure as a whole; and The pressing portion is configured as a protruding structure protruding from the inner side of the trigger portion, the protruding direction of the protruding structure is perpendicular to the strain substrate, and the projection point of the geometric center of the end of the protruding structure on the projection surface coincides with the geometric center point of the strain substrate.

4. The handwriting erasing device for a touch screen as claimed in claim 2 or 3, characterized in that: The strain substrate comprises a plurality of substrate components arranged in pairs, and the plurality of substrate components are evenly arranged around a geometric center point of the strain substrate; Every two strain sensing elements among the plurality of strain sensing elements constitute a pair of strain sensing elements, wherein at least one pair of the strain sensing elements is attached to each substrate member among the plurality of substrate members.

5. The handwriting erasing device for a touch screen as claimed in claim 4, characterized in that: Each of the multiple strain sensing elements is configured as a resistance strain gauge, a pair of the resistance strain gauges is attached to each of the multiple substrate components, and the pair of resistance strain gauges on each substrate component is electrically connected to a corresponding pair of auxiliary resistors to form a Wheatstone bridge circuit.

6. The device for erasing handwriting on a touch screen as claimed in claim 4, characterized in that: Each of the plurality of strain sensing elements is configured as a resistance strain gauge, and each of the plurality of substrate components is provided with two pairs of the resistance strain gauges, and the two pairs of the resistance strain gauges are electrically connected to form a Wheatstone bridge circuit; and The two pairs of resistance strain gauges in each Wheatstone bridge are arranged in a ring shape or side by side.

7. The handwriting erasing device for a touch screen according to any one of claims 2 to 6, characterized in that: The strain substrate is configured as a strain steel sheet.

8. The handwriting erasing device for a touch screen according to any one of claims 2 to 7, characterized in that: The strain sensing component also includes a flexible circuit board, which includes a first part and a second part. The first part is stacked with the strain substrate and attached to a side of the strain substrate away from the pressing portion. Each of the plurality of strain sensing elements is attached to a surface of the first part away from the strain substrate, so that the plurality of strain sensing elements are arranged on the strain substrate through the first part of the flexible circuit board, and the second part is bent and extended toward one side of the first part and is located outside the strain substrate.

9. The device for erasing handwriting on a touch screen as claimed in claim 8, characterized in that: When the handwriting erasing device is formed with a Wheatstone bridge circuit, the auxiliary resistor of the Wheatstone bridge circuit is arranged on the second portion of the flexible circuit board.

10. The handwriting erasing device for a touch screen according to any one of claims 1 to 9, characterized in that: The handwriting erasing device further comprises a signal transmitting component, and the signal transmitting component is used to send the erasing signal to the electronic device using the touch screen.

11. The handwriting erasing device for a touch screen according to any one of claims 1 to 10, characterized in that: The handwriting erasing device further comprises a sensing electrode, the sensing electrode constitutes the pressing portion, and when the handwriting erasing device comprises a flexible circuit board, the sensing electrode is electrically connected to the second part of the flexible circuit board.

12. The device for erasing handwriting on a touch screen as claimed in claim 11, characterized in that: The handwriting erasing device also includes an insulating member, which is arranged between the sensing electrode and the strain sensing component. The end of the sensing electrode is adapted to be fitted into a groove at the corresponding end of the insulating member, and one end of the insulating member away from the sensing electrode also forms a protruding structure aligned with the geometric center point of the strain substrate of the strain sensing component. When the triggering part is subjected to force, the protruding structure of the insulating member presses the strain substrate.

13. The handwriting erasing device for a touch screen according to any one of claims 4 to 6, characterized in that: The strain component also includes a bracket, which has a hollow area or a sinking area. One end of each of the multiple substrate components away from the geometric center point is fixed to the bracket, and the other end is connected to each other and suspended in the hollow area or the sinking area of ​​the bracket to form an end-fixed beam structure.

14. The device for erasing handwriting on a touch screen according to any one of claims 1 to 13, characterized in that: The outer surface of the trigger part is provided with a soft protective layer.

15. The device for erasing handwriting on a touch screen according to any one of claims 1 to 14, characterized in that: The handwriting erasing device further comprises a housing, the trigger component and the strain component are fixed in the housing, and the trigger part is partially exposed from the housing.

16. The device for erasing handwriting on a touch screen as claimed in claim 15, characterized in that: The portion of the trigger part exposed from the housing is in a spherical segment structure, and a cross-sectional center angle of the spherical segment structure is in a range of 90° to 150°.

17. A pen cap of an electronic stylus pen, the pen cap being arranged at the end of the electronic stylus pen and being used to perform the eraser function of the electronic stylus pen; characterized in that: The pen cap includes the handwriting erasing device for a touch screen according to any one of claims 1 to 16.

18. An electronic stylus pen, comprising a pen holder and a pen head arranged at one end of the pen holder, characterized in that: It also includes the pen cap as described in claim 17, and the pen cap is pluggable and connected to the other end of the pen barrel.

19. A method for erasing handwriting on a touch screen, characterized in that: The pen cap of the electronic stylus according to claim 17 or the electronic stylus according to claim 18 is used to perform the pen erasing function, and the method for erasing handwriting on the touch screen comprises: Receiving a feedback signal from an electronic device using the touch screen to trigger a pen eraser function of the pen cap; Detecting and sending electrical signal information indicating the force applied to the triggering portion; The target pressure information of the pen cap is determined according to the electrical signal information, and the target pressure information is sent to the electronic device, so that the electronic device determines the degree of erasure of the handwriting displayed on the touch screen according to the target pressure information; wherein the target pressure information includes the pressure size information of the pen cap.

20. The method for erasing handwriting on a touch screen as claimed in claim 19, characterized in that: The strain sensing component comprises a strain substrate and a plurality of strain sensing elements, wherein the plurality of strain sensing elements are arranged on the strain substrate; The multiple strain sensing elements generate multiple electrical signal information according to the pressing force applied by the pressing part, determine the target pressure information of the pen cap according to the multiple electrical signal information, and send the target pressure information to the electronic device, so that the electronic device determines the erasure degree according to the target pressure information.

21. The method for erasing handwriting on a touch screen as claimed in claim 20, characterized in that: The multiple strain sensing elements correspond to N Wheatstone bridge circuits, each Wheatstone bridge circuit outputs a bridge voltage, and the multiple electrical signal information is the N bridge voltages output by the N Wheatstone bridge circuits.

22. The method for erasing handwriting on a touch screen as claimed in claim 21, characterized in that: Determining the pressure information of the pen cap according to the plurality of electrical signal information includes: Determine the current angle information of the pen cap according to the N bridge voltages; the current angle information is calculated according to the following formula; Wherein, θ represents the angle between the current force direction of the pen cap and the axis of the pen cap; V 2i-1 and V 2i They respectively represent the current bridge voltage output by two Wheatstone bridge circuits set relatively, 1≤i≤N; K is the correction coefficient; Determine current voltage information according to the N bridge voltages and the current angle information; The pressure magnitude information is determined according to the current voltage information and the calibration information; wherein the calibration information represents a one-to-one correspondence between different voltage information and different pressure information when the pen cap is subjected to force at a calibration angle; the calibration angle is configured as: the angle when the force direction of the pen cap coincides with the axis of the pen cap.

23. The method for erasing handwriting on a touch screen according to any one of claims 19 to 22, characterized in that: Before receiving the feedback signal of the electronic device triggering the pen eraser function, the method further includes: Sends a trigger signal to enable the eraser function.

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