A pressure detection device based on double sensors and a smart pen

Abstract

The application relates to the technical field of intelligent writing devices, in particular to a pressure detection device based on double sensors and an intelligent pen. The device comprises a pressure receiving part, a first pressure sensor, a second pressure sensor, a controller and a pre-pressing part. The first pressure sensor is used for detecting pressure changes, and is detachably connected with the pressure receiving part and abuts against the pressure receiving part when the pressure receiving part is pressed and is separated from the pressure receiving part when the pressure receiving part is not pressed; the second pressure sensor is used for detecting the pressure size; the controller controls the processing of the second sensor signal according to the signal of the first sensor; the pre-pressing part is a magnetic part, provides a pre-pressure for the second sensor, makes the second sensor always reliably abut against the pre-pressing part and is synchronously pressed when the first sensor is pressed. The device realizes high-precision pressure detection under low power consumption through the cooperative work of the double sensors, effectively improves the linearity and repeatability and avoids the zero offset calibration problem.

Description

[0001] This invention is a divisional application of the invention patent application filed on October 21, 2020, entitled "Pressure Detection Device and Smart Pen", with application number 2020111338479. Technical Field

[0002] This invention relates to the field of intelligent writing device technology, and in particular to a pressure detection device based on dual sensors and an intelligent pen. Background Technology

[0003] With the popularization of distance education and intelligent education, smart pen technology has made significant progress. Existing smart pens not only have the writing function of traditional pens, but can also capture handwriting on printed micro-image arrays and electronically store and transmit the handwriting. The principle is that a camera placed at the pen tip captures the position of the pen tip relative to the printed micro-image array during writing, and then generates handwriting through image processing and coordinate transformation.

[0004] Currently, to represent changes in the thickness of writing strokes based on variations in writing pressure, pressure sensors are often used to measure the pressure applied to the pen refill during writing. One method uses a thin-film resistive strain gauge pressure sensor (FTSS), but this sensor has two drawbacks. First, its pressure-resistance curve has poor linearity, making it unable to effectively distinguish subtle changes in writing pressure. Second, its repeatability is poor; that is, after releasing the pressure and applying the same pressure again, the resistance value shows a large variance. Therefore, using this sensor can result in inconsistent stroke thickness even with the same writing pressure. Another method uses a resistive-bridge pressure sensor, but its pressure-resistance curve is relatively flat, resulting in a small amplitude of the converted voltage signal. This makes it unsuitable for direct use as a microcontroller wake-up signal; the signal must be amplified before AD sampling, and zero-bias calibration is required during use. Summary of the Invention

[0005] In view of this, embodiments of the present invention provide a pressure detection device and a smart pen based on dual sensors to solve the technical problem that existing pressure detection devices and smart pens cannot achieve high-precision pressure measurement under low power consumption.

[0006] The technical solution adopted in this invention is as follows: In a first aspect, the present invention provides a pressure detection device based on dual sensors, comprising: Pressure-bearing components; A first pressure sensor is used to detect pressure changes acting on the pressure-bearing member. The pressure-bearing member and the first pressure sensor are connected in a separable manner. When the pressure-bearing member is under pressure, it abuts against the first pressure sensor. When the pressure-bearing member is not under pressure, it separates from the first pressure sensor. The second pressure sensor is used to detect the magnitude of the pressure acting on the pressure-bearing component; The controller is electrically connected to the first pressure sensor and the second pressure sensor respectively. The controller receives the electrical signal from the first pressure sensor and controls the processing of the electrical signal from the second pressure sensor based on the electrical signal from the first pressure sensor. A pre-compression component is provided, wherein the second pressure sensor abuts against the pre-compression component, and the pre-compression component is a magnetic component, used to provide pre-pressure to the second pressure sensor so that it is compressed synchronously with the first pressure sensor when it is compressed; The second pressure sensor is in a pre-compressed state under the action of the pre-compressing component. The second pressure sensor can also reliably abut against the pre-compressing component even when the pressure-bearing component is not compressed and is separated from the first pressure sensor.

[0007] Preferably, the device further includes a bracket and a first sliding member, wherein the first sliding member is slidably connected to the bracket, and a fixing part is provided at the end of the bracket away from the pressure-bearing member. The first pressure sensor is located at the end of the first sliding member facing the pressure-bearing member, and the second pressure sensor is installed at the end of the first sliding member facing the fixing part. The first pressure sensor slides together with the first sliding member relative to the bracket.

[0008] Preferably, the first sliding member and the fixed part are connected by magnetic attraction, the pre-compression member is disposed at the end of the fixed part facing the second pressure sensor, and the second pressure sensor is connected to the pre-compression member by magnetic attraction.

[0009] Preferably, both the first sliding member and the fixed part are provided with mounting grooves, the mounting groove of the fixed part is provided with a first magnetic element, and the mounting groove of the first sliding member is provided with a second magnetic element.

[0010] Preferably, the first sliding member has a top shaft as a pre-pressing member at one end facing the fixed part, and the second pressure sensor is located between the fixed part and the top shaft. The top shaft is pressed against the second pressure sensor by the attraction of the first magnetic member.

[0011] Preferably, the pressure-bearing component has a second sliding component at one end near the first pressure sensor, and the second sliding component can slide relative to the bracket. When the pressure-bearing component is under pressure, the second sliding component slides to a position that abuts against the first pressure sensor, and when the pressure-bearing component is in a non-pressured state, the second sliding component slides to one end away from the fixed part.

[0012] Preferably, a pressure-contacting element is also provided at the end of the pressure-receiving component facing the first pressure sensor, and the pressure-receiving component drives the pressure-contacting element to press against the first pressure sensor when subjected to pressure.

[0013] Preferably, the system further includes a signal amplification circuit and an analog-to-digital conversion circuit. The signal amplification circuit is electrically connected to the second pressure sensor and the controller, respectively. The analog-to-digital conversion circuit is electrically connected to the signal amplification circuit and the controller, respectively. The controller turns the signal amplification circuit and the analog-to-digital conversion circuit on or off according to the detection signal from the first pressure sensor.

[0014] Secondly, the present invention also provides an electric smart pen, including a housing and the pressure detection device described in the first aspect, wherein the pressure-receiving component serves as the pen core of the smart pen, and the housing is provided with a first chamber for receiving the pen core.

[0015] Beneficial Effects: This invention utilizes a first pressure sensor to detect pressure changes acting on the pressure-bearing component and a second pressure sensor to detect the magnitude of the pressure acting on the component, achieving a collaborative working mechanism between the two sensors. The first and second pressure sensors are installed and connected in a synchronously pressurized manner, allowing the second pressure sensor to synchronously sense the pressure to be measured, thus accurately enabling or disabling the mode that uses the second pressure sensor for precise pressure detection. A controller is electrically connected to both the first and second pressure sensors. The controller receives the electrical signal from the first pressure sensor and controls the processing of the electrical signal from the second pressure sensor based on this signal. This invention configures the pressure-bearing component to be detachable from the first pressure sensor, preventing accidental activation of the first pressure sensor when not under pressure. Therefore, this invention significantly reduces the power consumption of the pressure detection device and the smart pen while significantly improving the detection accuracy of pressure. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the embodiments of the present invention will be briefly introduced below. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort, and these are all within the protection scope of the present invention.

[0017] Figure 1 This is a structural layout diagram of the pressure detection device of the present invention; Figure 2 This is a schematic diagram of the pressure detection device in Embodiment 2 of the present invention; Figure 3 This is a schematic diagram of the pressure detection device in Embodiment 3 of the present invention; Figure 4 This is a schematic diagram of the pressure detection device in Embodiment 4 of the present invention; Figure 5 This is a schematic diagram of the structure of the smart pen that uses the pressure detection device in Embodiment 2 of the present invention; Figure 6 This is a schematic diagram of the structure of the smart pen that uses the pressure detection device in Embodiment 3 of the present invention; Figure 7 This is a schematic diagram of the structure of the smart pen that uses the pressure detection device in Embodiment 4 of the present invention; Figure 8 This is a circuit structure block diagram of the pressure detection device of the present invention; Figure 9-1 A photographic rendering of the first set of text written using the smart pen of this invention. Figure 9-2 This is a diagram showing the first set of text captured using the smart pen of this invention; Figure 9-3 A photographic rendering of the first set of text written using a smart pen with existing technology. Figure 9-4 The first set of text capture results using a smart pen written with existing technology; Figure 10-1 A photographic rendering of the second set of text written using the smart pen of this invention. Figure 10-2 This is a diagram showing the second set of text capture results written using the smart pen of this invention; Figure 10-3 A photographic rendering of a second set of text written using a smart pen with existing technology. Figure 10-4 This is a second set of text capture results obtained using a smart pen written with existing technology; Components and their numbers in the diagram: Pressure-bearing component 10, Pressure-contacting component 11, First pressure sensor 20, Second pressure sensor 30, Bracket 40, Fixing part 50, First magnetic component 51, Second magnetic component 52, Third magnetic component 53, Conductive silicone rubber 54, Metal spring 55, Top shaft 56, First sliding component 61, Second sliding component 62, Housing 71, First PCB board 72, Filter 81, Lens 82, Image sensor 83, Power supply 90. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. In the description of the present invention, it should be understood that the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element. Where there is no conflict, the various features in the embodiments and examples of this invention can be combined with each other, all of which are within the scope of protection of this invention.

[0019] Example 1 like Figure 1 As shown, this embodiment provides a pressure detection device, including: The pressure-receiving component 10 is used to transmit the pressure to be detected to the first sensor and / or the second sensor; A first pressure sensor 20 is used to detect the pressure acting on the pressure-receiving member 10, wherein the pressure-receiving member 10 and the first pressure sensor 20 are connected in a separable manner. The first pressure sensor 20 can be a thin-film resistance strain gauge pressure sensor. This sensor has a large dynamic range of pressure-resistance curve. After the change in resistance is converted into a voltage signal, it can be directly used as a power-on wake-up signal without amplification. It supports automatic power-on function when writing, and can also be directly used for AD sampling and digitization.

[0020] The aforementioned pressure-receiving component 10 serves to transmit pressure. The pressure to be detected is transmitted to the first pressure sensor 20 and the second pressure sensor 30 through the pressure-receiving component 10 for detection. In this embodiment, when the pressure-receiving component 10 is under pressure, it abuts against the first pressure sensor 20; when the pressure-receiving component 10 is not under pressure, it separates from the first pressure sensor 20. This embodiment uses the pressure change detected by the first pressure sensor 20 to determine whether to start or stop processing and acquiring the signal detected by the second pressure sensor 30. When not under pressure, the pressure-receiving component 10 is separated from the first pressure sensor 20, which avoids contact between the pressure-receiving component 10 and the first pressure sensor 20, preventing pressure from being generated on the first pressure sensor 20 and causing inaccurate pressure detection results.

[0021] The second pressure sensor 30 is used to detect the magnitude of the pressure acting on the pressure-bearing component 10; The second pressure sensor 30 can be a bridge-type pressure sensor. This sensor offers advantages such as good linearity in its pressure-resistance curve, effectively distinguishing subtle changes in writing pressure. Furthermore, it exhibits good repeatability; that is, after releasing the pressure and applying the same pressure again, repeated resistance measurements show a small variance in the resistance value. Using this type of sensor can achieve consistent stroke thickness at the same writing pressure.

[0022] The controller is electrically connected to the first pressure sensor 20 and the second pressure sensor 30, respectively. In this embodiment, the pressure detection device brings the pressure-bearing component 10 into contact with the first pressure sensor 20 when under pressure. This allows the first pressure sensor 20 to detect pressure changes in a timely manner, triggering the detection device to process and collect the electrical signal from the second sensor. Simultaneously, the pressure can be transmitted to the second pressure sensor 30 in a timely manner, enabling the detection device to accurately measure the pressure to be detected based on the signal detected by the second pressure sensor 30.

[0023] The controller receives the electrical signal from the first pressure sensor 20. Since the first pressure sensor 20 is a pressure sensor with a large dynamic range of the "pressure-resistance" curve, its voltage signal can be directly sent to the controller without amplification. The controller controls the power-on and wake-up of relevant equipment based on the voltage signal from the first pressure sensor 20, and can also control whether to process and acquire the electrical signal from the second pressure sensor 30 based on the voltage signal from the first pressure sensor 20. Because this embodiment uses a collaborative working method between the first pressure sensor 20 and the second pressure sensor 30, the pressure detection device's operation is controlled by the pressure change detected by the low-power first pressure sensor 20. This ensures that the pressure detection device only uses the highly accurate and repeatable second pressure sensor 30 to accurately acquire the pressure value when the set conditions are met. When the conditions are not met, only the first pressure sensor 20 is used to detect pressure changes. This significantly reduces the power consumption of the pressure detection device and significantly improves its detection accuracy.

[0024] The first pressure sensor 20 and the second pressure sensor 30 are connected in a synchronously pressurized manner.

[0025] The synchronous pressure-bearing connection refers to a connection structure or form that enables the second pressure sensor 30 and the first pressure sensor 20 to synchronously sense the pressure to be detected. This connection structure or form ensures a rigid connection where the force-bearing surfaces of the first pressure sensor 20 and the second pressure sensor 30 maintain a fixed relative position even when the pressure detection device is not subjected to the pressure to be detected. See Examples 2 to 4 for examples of the synchronous pressure-bearing connection structure or form.

[0026] Example 2 like Figure 2 and Figure 3 As shown, in this embodiment, the pressure detection device further includes a pre-compression member, which provides pre-pressure to the second pressure sensor 30. The second pressure sensor 30 abuts against the pre-compression member to be pressurized synchronously with the first pressure sensor 20 when it is pressurized. In this embodiment, the pre-compression member ensures that the second pressure sensor 30 is in a pre-compressed state with a very small force. This allows the second pressure sensor 30 to reliably abut against the pre-compression member even when the pressure-receiving member 10 is not pressurized and is separated from the first pressure sensor 20, leaving no room for free movement for the second pressure sensor 30. When the pressure-receiving member 10 is pressurized and abuts against the first pressure sensor 20, since the second pressure sensor 30 and the pre-compression member remain in a pressed state, the pressure transmitted by the pressure-receiving member 10 can be immediately transmitted to the force-bearing surface of the second pressure sensor 30 through the pre-compression member, ensuring that the second pressure sensor 30 and the first pressure sensor 20 can synchronously sense the pressure action of the pressure-receiving member 10.

[0027] As a preferred example, the second pressure sensor 30 and the pre-compression member are connected by magnetic attraction. Magnetic connection refers to using the principle of opposite poles attracting to maintain the second pressure sensor 30 in contact with the pre-compression member through a magnetic field. Compared to using elastic elements such as springs to maintain the pre-compression state, the magnetic connection method used in this embodiment can provide the second pressure sensor 30 with a precise pre-compression pressure, and this set pressure can be maintained stably for a long time without changing after repeated pressure application, unlike elastic elements.

[0028] To ensure that the first pressure sensor 20 and the second pressure sensor 30 can be pressurized synchronously, the pressure detection device in this embodiment further includes a bracket 40 and a first sliding member 61. The first sliding member 61 is slidably connected to the bracket 40. A fixing part 50 is provided at the end of the bracket 40 away from the pressure-bearing member 10. The first pressure sensor 20 is located at the end of the first sliding member 61 facing the pressure-bearing member 10. The second pressure sensor 30 is installed at the end of the fixing part 50 facing the first sliding member 61. The first sliding member 61 and the fixing part 50 are connected by magnetic attraction.

[0029] In this embodiment, the first pressure sensor 20 and the second pressure sensor 30 are respectively mounted on the first sliding member 61 and the fixed part 50 of the bracket 40. The first pressure sensor 20 can slide together with the first sliding member 61 relative to the bracket 40. Since the first sliding member 61 and the fixed part 50 are connected by magnetic attraction, the first sliding member 61 tends to press against the fixed part 50 under the action of the magnetic field. Since the second pressure sensor 30 is mounted on the end of the fixed part 50 facing the first sliding member 61, under the action of the magnetic field, the end of the first sliding member 61 facing the fixed part 50 presses against the force-bearing surface of the second pressure sensor 30, generating a pre-compression effect on the second pressure sensor 30. At this time, the part of the first sliding member 61 that presses against the second pressure sensor 30 serves as the aforementioned pre-compression member. Since the first pressure sensor 20 is fixed on the first sliding member 61 and moves synchronously with the first sliding member 61, when the pressure-receiving member 10 is subjected to pressure and moves to abut against the first pressure sensor 20, it pushes the first sliding member 61 further towards the second pressure sensor 30 to press against the second sensor. Since the second pressure sensor 30 always remains pressed against the first sliding member 61 under the pre-compression action, the pressure of the pressure-receiving member 10 is transmitted to the second pressure sensor 30 when the first sliding member 61 is pushed by the pressure-receiving member 10, so that it can be pressed synchronously with the first pressure sensor 20.

[0030] To enable the first sliding member 61 and the fixing part 50 to be connected by magnetic attraction, in this embodiment, the fixing part 50 is provided with a first magnetic member 51, and the first sliding member 61 is provided with a second magnetic member 52 that attracts the first magnetic member 51. By providing two mutually attracting magnetic members on the fixing part 50 of the first sliding member 61, the attraction between the two magnetic members drives the first sliding member 61 to press against the fixing part 50, forming a magnetic connection, so that the first sliding member 61 exerts a pre-pressing effect on the second pressure sensor 30. In a specific implementation, a mounting groove can be opened on the first sliding member 61, and the second magnetic member 52 can be installed in the mounting groove. A mounting groove can also be opened on the fixing part 50, and the first magnetic member 51 can be installed in the mounting groove. The aforementioned magnetic members can be made of magnetic materials (Fe, Co, Ni elements and their alloys).

[0031] In this embodiment, a top shaft 56 can also be provided at the end of the first sliding member 61 facing the fixing part 50 as a pre-pressing member. This top shaft 56 abuts against the second pressure sensor 30 under magnetic attraction, thus pre-pressing the second pressure sensor 30. The top shaft 56 can also be made of magnetic material, so that it is pressed tightly against the second pressure sensor 30 under the attraction of the first magnetic member 51. In this embodiment, conductive silicone rubber 54 can also be provided below the bracket 40 corresponding to the position of the first sliding member 61. This conductive silicone rubber 54 forms an electrical connection between the first PCB board 72 and the first pressure sensor 20. A metal spring 55 is provided below the fixing part 50, which forms an electrical connection between the first PCB board 72 and the second pressure sensor 30.

[0032] Example 3 like Figure 3As shown, in this embodiment, the pressure detection device further includes a bracket 40 and a first sliding member 61. The first sliding member 61 is slidably connected to the bracket 40. A fixing part 50 is provided at the end of the bracket 40 away from the pressure-bearing member 10. The first pressure sensor 20 is located at the end of the first sliding member 61 facing the pressure-bearing member 10. The second pressure sensor 30 is installed at the end of the fixing part 50 facing the first sliding member 61. The first sliding member 61 and the fixing part 50 are connected by magnetic attraction. A top shaft 56 is provided at the first end of the first sliding member 61 facing the fixing part 50 as a pre-compression member. The top shaft 56 is a magnetic member made of magnetic material. The second pressure sensor 30 is a pressure sensor that can be attracted by the magnetic member, i.e., the top shaft 56. This pressure sensor can be made of a material that can be attracted by magnetic elements. In this way, the top shaft 56 and the second pressure sensor 30 attract each other through the magnetic field, keeping the top shaft 56 and the second pressure sensor 30 pressed together. By using the aforementioned method, the top shaft 56 can pre-compress the second pressure sensor 30, thereby ensuring that the second pressure sensor 30 and the first pressure sensor 20 can be pressurized synchronously. This embodiment utilizes the magnetic attraction of the top shaft 56 and the second pressure sensor 30, avoiding the need for additional magnetic components. This simplifies the pressure detection device structure, significantly reduces costs, and simplifies manufacturing. In this embodiment, conductive silicone rubber 54 can also be provided below the position corresponding to the first sliding member 61 on the bracket 40. This conductive silicone rubber 54 forms an electrical connection between the first PCB board 72 and the first pressure sensor 20. A metal spring 55 is provided below the fixing part 50, which also forms an electrical connection between the first PCB board 72 and the second pressure sensor 30.

[0033] Example 4 like Figure 4 As shown, in this embodiment, the pressure detection device further includes a bracket 40 and a first sliding member 61. The first sliding member 61 is slidably connected to the bracket 40. A fixing part 50 is provided at the end of the bracket 40 away from the pressure-bearing member 10. The first pressure sensor 20 is located at the end of the first sliding member 61 facing the pressure-bearing member 10. The second pressure sensor 30 is installed at the end of the first sliding member 61 facing the fixing part 50. The first slider and the fixing part 50 are connected by magnetic attraction. The pre-pressure member is provided at the end of the fixing part 50 facing the second pressure sensor 30.

[0034] In this embodiment, the first pressure sensor 20 and the second pressure sensor 30 are respectively installed at both ends of the first sliding member 61, with the first pressure sensor 20 facing the pressure-receiving member 10 and the second pressure sensor 30 facing the fixed part 50. Since both the first pressure sensor 20 and the second pressure sensor 30 are located on the first sliding member 61, and since the first slider and the fixed part 50 are connected by magnetic attraction, the pre-pressing member and the second pressure sensor 30 are always in a pre-pressed state. Therefore, when the pressure-receiving member 10 contacts the first pressure sensor 20, it pushes the first sliding member 61, causing the first sliding member 61 to move the second pressure sensor 30 towards the fixed part 50. The second pressure sensor 30 can immediately sense the pressure exerted by the pre-pressing member, thus achieving synchronous pressure on both the second pressure sensor 30 and the first pressure sensor 20. The pre-pressing member located on the fixed part 50 can be a third magnetic member 53, and the second pressure sensor 30 can be a pressure sensor with its own magnetism. Alternatively, the first magnetic member 51 and the second magnetic member 52 can be respectively located on the fixed part 50 and the first sliding member 61. In this embodiment, a metal spring 55 can also be provided below the position corresponding to the first sliding member 61 on the bracket 40. This metal spring 55 forms an electrical connection between the first PCB board 72 and the second pressure sensor 30. A conductive silicone rubber 54 is provided at the tail end of the pressure-bearing member 10. This conductive silicone rubber 54 forms an electrical connection between the first PCB board 72 and the first pressure sensor 20.

[0035] Example 5 like Figures 2 to 4As shown, this embodiment is a further optimization based on the aforementioned embodiment. In this embodiment, a pressing element 11 is also provided at the end of the pressure-receiving component 10 facing the first pressure sensor 20. When the pressure-receiving component 10 is subjected to pressure, it drives the pressing element 11 to press against the first pressure sensor 20. The pressing element 11 can be made of a material with a certain degree of elasticity, such as silicone, plastic, rubber, or steel. This element can be located at the tail end of the pressure-receiving component 10. When the pressure-receiving component 10 is compressed, this element presses against the first pressure sensor 20, allowing the first pressure sensor 20 to sense the pressure acting on the pressure-receiving component 10. The pressure-receiving component 10 is prone to vibration at the moment of contact and separation from the first pressure sensor 20. Because the pressing element 11 is made of a material with a certain degree of elasticity, when the pressure-receiving component 10 is subjected to pressure, the pressing element 11 can more fully and reliably press against the first pressure sensor 20, further improving the reliability and accuracy of the pressure detection device. To ensure that the pressure-bearing component 10 abuts against the first pressure sensor 20 when under pressure and separates from the first pressure sensor 20 when not under pressure, this embodiment also includes a second sliding component 62. The second sliding component 62 is connected in a manner that allows it to slide relative to the bracket 40. By connecting the pressure-bearing component 10 to the second sliding component 62, the pressure-bearing component 10 can slide relative to the bracket 40. When the pressure-bearing component 10 is under pressure, it slides to a position abutting against the first pressure sensor 20. When the sliding component is not under pressure, it can slide to the end away from the fixing part 50. The first pressure sensor 20 is fixed to the end near the fixing part 50 of the bracket 40 due to magnetic attraction, thereby achieving separation from the first pressure sensor 20. The second sliding component 62 can be installed at the tail of the pressure-bearing component 10, while the aforementioned component can be installed at the end of the second sliding component 62 facing the first pressure sensor 20. Thus, when the pressure-bearing component 10 is subjected to the pressure to be detected, it pushes the second sliding component 62 to slide, and the second sliding component presses against the first pressure sensor 20.

[0036] Example 6 like Figure 5 , Figure 6 and Figure 7As shown, this embodiment provides a smart pen, which includes a housing 71 and the pressure detection device described in the previous embodiment. The pressure-receiving component 10 serves as the pen tip, and the housing 71 has a first chamber for receiving the pen tip. The smart pen in this embodiment is an application of the pressure detection device described in the previous embodiment. The pen tip, serving as the pressure-receiving component 10, can be installed in a groove formed by the housing 71 and the bracket 40, and the pen tip can slide in the groove. The writing end of the pen tip extends outside the housing 71. Components such as the first pressure sensor 20 and the second pressure sensor 30 in the pressure detection device are installed inside the housing 71. The first pressure sensor 20 in the pressure detection device can be used to trigger power-on upon writing. That is, when the pressure detected by the first pressure sensor 20 exceeds a set threshold, the controller controls the smart pen to be in the power-on state. The first pressure sensor 20 can also be used to determine the pen's entry and exit points. For example, when the pressure detected by the first pressure sensor 20 is greater than the set threshold, the controller determines that the writing is in the entry state, and when the pressure detected by the first pressure sensor 20 is less than the set threshold, the controller determines that the writing is in the exit state. When the controller detects a pen stroke by the signal from the first pressure sensor 20, it activates the signal amplification circuit of the second pressure sensor 30 to amplify the signal collected by the second pressure sensor 30. It can also activate the AD sampler to sample the output signal of the amplification circuit. The sampling result is used to control the thickness of the displayed strokes. When the controller detects a pen lift by the first pressure sensor 20, it shuts down the signal amplification circuit of the second pressure sensor 30 and stops AD sampling, thereby saving power. In this embodiment, the passive first pressure sensor 20 is used as the power-on trigger signal and the pen stroke / lift indication signal, thus saving overall power consumption. The second pressure sensor 30 is used to accurately collect the writing pressure of the pen tip, thereby faithfully reproducing the changes in the thickness of the written strokes. Each time the controller detects a pen lift signal, it collects the AD output value of the second pressure sensor 30 N times and calculates the average value as the zero bias value of the second pressure sensor 30 output for the next stroke. Subtracting the zero bias value from the output value of the second pressure sensor 30 yields the calibrated output value of the second pressure sensor 30, thus reproducing the "pen stroke" effect. The aforementioned controller can also determine the pen's lifting and lowering states based on the detection signal from the first pressure sensor. The controller can eliminate the zero-position deviation of the second pressure sensor during writing by using the pressure value detected by the second pressure sensor during the previous pen lifting state. For example, when the pen is lifted, the pressure value of the second pressure sensor is P0 (P0 can be positive or negative). The controller records P0. Then, the pen falls and contacts the writing medium, at which point the pressure value detected by the second pressure sensor is P1. Let the pressure value after eliminating the zero-position deviation be Pr, then Pr = P1 - P0. Because the pressure detection device in this embodiment adopts the aforementioned synchronous pressure connection structure, the second pressure sensor 30 is pre-pressed with a very small force. Simultaneously, the force-bearing surfaces of the first pressure sensor 20 and the second pressure sensor 30 have no free movement space when the pen is lifted. Thus, when pressure is applied to the first pressure sensor 20, it necessarily applies to the second pressure sensor 30 simultaneously, ensuring that the pressure between the pen tip and the paper is simultaneously transmitted to both the first and second pressure sensors. Since the pressure detection device in the smart pen uses magnetic attraction to position the first and second pressure sensors 20 and 30 at one end of the bracket 40, gravity in the pen-lifting state causes the pen tip and the second sliding member 62 holding the pen tip to be located on the other side of the groove. This ensures that the tail of the pen tip is separated from both sensors when the pen is lifted, allowing for accurate judgment of the pen-lifting and pen-lowering states and effectively preventing incorrect stroke connections, such as the incorrect connection between the tail of one independent stroke and the head of the next. Furthermore, this embodiment also includes a power supply 90, which is electrically connected to the controller to supply power to the various components of the smart pen. The smart pen in this embodiment also includes an image acquisition device, which comprises a filter 81, a lens 82, and an image sensor 83. The image sensor 83 is electrically connected to the first PCB board 72. This image acquisition device is used to acquire images during writing. The light from the image to be acquired is filtered by the filter 81 and then focused onto the image sensor 83 by the lens 82. The image sensor 83 converts the light signal into an electrical signal and sends it to the controller.

[0037] For a comparison of the data collection effect of the smart pen writing of this invention, please refer to [link / reference]. Figure 9-1 , Figure 9-2 , Figure 9-3 , Figure 9-4 , 10-1 , Figure 10-2 , Figure 10-3 , Figure 10-4 As can be seen from the aforementioned attached figures... Figure 9-2 and Figure 10-2 The effect of capturing the pen strokes and thickness variations of characters using the smart pen of this invention is better than... Figure 9-4 and Figure 10-4 The smart pen using existing technology captures better variations in the strokes and thickness of characters.

[0038] The above is a detailed description of the pressure detection device and smart pen provided in the embodiments of the present invention.

[0039] It should be clarified that the present invention is not limited to the specific configurations and processes described above and shown in the figures. For the sake of brevity, detailed descriptions of known methods are omitted here. In the above embodiments, several specific steps are described and shown as examples.

[0040] The functional blocks shown in the above structural diagram can be implemented as hardware, software, firmware, or a combination thereof. When implemented in hardware, they can be, for example, electronic circuits, application-specific integrated circuits (ASICs), appropriate firmware, plug-ins, function cards, etc.

[0041] It should also be noted that the exemplary embodiments mentioned in this invention describe methods or systems based on a series of steps or apparatus. However, this invention is not limited to the order of the steps described above; that is, the steps can be performed in the order mentioned in the embodiments, or in a different order, or several steps can be performed simultaneously.

[0042] The above description is merely a specific embodiment of the present invention. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, modules, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here. It should be understood that the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered within the protection scope of the present invention.

Claims

1. A pressure detection device based on dual sensors, characterized in that, include: Pressure-bearing components; A first pressure sensor is used to detect pressure changes acting on the pressure-bearing member. The pressure-bearing member and the first pressure sensor are connected in a separable manner. When the pressure-bearing member is under pressure, it abuts against the first pressure sensor. When the pressure-bearing member is not under pressure, it separates from the first pressure sensor. The second pressure sensor is used to detect the magnitude of the pressure acting on the pressure-bearing component; The controller is electrically connected to the first pressure sensor and the second pressure sensor respectively. The controller receives the electrical signal from the first pressure sensor and controls the processing of the electrical signal from the second pressure sensor based on the electrical signal from the first pressure sensor. A pre-compression component is provided, wherein the second pressure sensor abuts against the pre-compression component, and the pre-compression component is a magnetic component, used to provide pre-pressure to the second pressure sensor so that it is compressed synchronously with the first pressure sensor when it is compressed; A bracket, on which a first sliding member is slidably connected, and a fixed part is provided at the end of the bracket away from the pressure-bearing member, and a second pressure sensor is installed at the end of the first sliding member facing the fixed part; The second pressure sensor is in a pre-compressed state under the action of the pre-compressing component. The second pressure sensor can also reliably abut against the pre-compressing component even when the pressure-bearing component is not compressed and is separated from the first pressure sensor.

2. The pressure detection device based on dual sensors according to claim 1, wherein the first pressure sensor is located at the end of the first sliding member facing the pressure-bearing member, and the first pressure sensor slides together with the first sliding member relative to the bracket.

3. The pressure detection device based on dual sensors according to claim 2, characterized in that, The first sliding member and the fixed part are connected by magnetic attraction. The pre-compression member is disposed at the end of the fixed part facing the second pressure sensor. The second pressure sensor is connected to the pre-compression member by magnetic attraction.

4. The pressure detection device based on dual sensors according to claim 3, characterized in that, Both the first sliding member and the fixed part are provided with mounting grooves. The mounting groove of the fixed part is provided with a first magnetic element, and the mounting groove of the first sliding member is provided with a second magnetic element.

5. The pressure detection device based on dual sensors according to claim 4, characterized in that, The first sliding member has a top shaft as a pre-pressing member at one end facing the fixed part. The second pressure sensor is located between the fixed part and the top shaft. The top shaft is pressed against the second pressure sensor by the attraction of the first magnetic member.

6. The pressure detection device based on dual sensors according to claim 2, characterized in that, The pressure-bearing component is provided with a second sliding component at one end near the first pressure sensor, and the second sliding component can slide relative to the bracket. When the pressure-bearing component is under pressure, the second sliding component slides to the position that abuts against the first pressure sensor. When the pressure-bearing component is in a non-pressured state, the second sliding component slides to the end away from the fixed part.

7. The pressure detection device based on dual sensors according to claim 5, characterized in that, A pressure-contacting element is also provided at the end of the pressure-receiving component facing the first pressure sensor. When the pressure-receiving component is subjected to pressure, it drives the pressure-contacting element to press against the first pressure sensor.

8. The pressure detection device according to any one of claims 1 to 7, characterized in that, It also includes a signal amplification circuit and an analog-to-digital conversion circuit. The signal amplification circuit is electrically connected to the second pressure sensor and the controller, respectively. The analog-to-digital conversion circuit is electrically connected to the signal amplification circuit and the controller, respectively. The controller turns the signal amplification circuit and the analog-to-digital conversion circuit on or off according to the detection signal of the first pressure sensor.

9. A smart pen, characterized in that, The device includes a housing and a pressure detection device based on dual sensors according to any one of claims 1 to 8, wherein the pressure-bearing component serves as the pen core of a smart pen, and the housing is provided with a first chamber for receiving the pen core.

10. The smart pen as described in claim 9, characterized in that, The controller is used to determine the pen lifting state and pen closing state of the smart pen based on the detection signal of the first pressure sensor. The controller is also used to eliminate the zero position deviation of the second pressure sensor when the smart pen is writing based on the pressure value detected by the second pressure sensor when the pen was lifted last time.

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