Pressure detection device and smart pen

Abstract

The present invention belongs to the technical field of intelligent writing devices and provides a pressure detection device and an intelligent pen. The pressure detection device of the present invention includes: a pressure-receiving member for transmitting the pressure to be detected to a first sensor and / or a second sensor; a first pressure sensor for detecting the pressure acting on the pressure-receiving member, the pressure-receiving member being connected to the first pressure sensor in a detachable manner; a second pressure sensor for detecting the magnitude of the pressure acting on the pressure-receiving member; a controller electrically connected to the first pressure sensor and the second pressure sensor, respectively; the first pressure sensor and the second pressure sensor being connected in a synchronously pressurized manner. The intelligent pen includes the aforementioned pressure detection device, and the present invention can not only greatly reduce the power consumption of the pressure detection device and the intelligent pen, but also significantly improve the pressure detection accuracy.

Description

Technical Field

[0001] The present invention relates to the technical field of intelligent writing devices, and in particular to a pressure detection device and an intelligent pen. Background Art

[0002] With the increasing popularity of distance and intelligent education, smart pen technology has made significant progress. Existing smart pens not only have the writing functions of traditional pens but also can capture handwriting when writing on printed micro-patterns, electronically storing and transmitting the handwriting. This works by using a camera mounted on the pen tip to capture the position of the pen tip relative to the printed micro-patterns during writing. This is then converted into handwriting through image processing and coordinate transformation.

[0003] At present, in order to present the thickness changes of written strokes according to the changes in writing force, it is often necessary to use a pressure sensor to measure the pressure exerted on the pen core during writing. Currently, a thin film resistive strain gauge pressure sensor (Force Sensor Resistor) is used to measure the pressure exerted on the pen core during writing. However, this type of pressure sensor cannot effectively distinguish subtle changes in writing pressure due to the poor linearity of its "pressure-resistance" curve. On the other hand, due to its poor repeatability, that is, after releasing the pressure, the same pressure is applied again, and the resistance value is repeatedly measured, the variance of the resistance value is relatively large. Therefore, the use of this sensor will result in the same writing force, but the thickness of the strokes presented is different. Currently, a bridge pressure sensor (Resistive-bridge Pressure Sensor) is also used to measure the pressure exerted on the pen core during writing. However, due to the relatively flat "pressure-resistance" curve of this pressure sensor, the change amplitude of the converted voltage signal is small, and it cannot be directly used as a wake-up signal for the microcontroller. The signal must be amplified before AD sampling, and zero bias calibration is required when using it. Summary of the Invention

[0004] In view of this, embodiments of the present invention provide a pressure detection device and a smart pen to solve the technical problem that the pressure detection device and the smart pen in the prior art cannot achieve high-precision pressure measurement with low power consumption.

[0005] The technical solution adopted in the present invention is:

[0006] In a first aspect, the present invention provides a pressure detection device, comprising:

[0007] a pressure-receiving member, configured to transmit the pressure to be detected to the first sensor and / or the second sensor;

[0008] a first pressure sensor for detecting a pressure change acting on a pressure-receiving member, wherein the pressure-receiving member is detachably connected to the first pressure sensor;

[0009] The second pressure sensor is used to detect the pressure acting on the pressure-bearing member;

[0010] a controller electrically connected to the first pressure sensor and the second pressure sensor, respectively, and configured to start or end processing of an electrical signal from the second pressure sensor according to a detection signal from the first pressure sensor;

[0011] The first pressure sensor and the second pressure sensor are connected in a synchronously pressurized manner.

[0012] Preferably, the pressure-receiving member abuts against the first pressure sensor when it is in a pressurized state, and is separated from the first pressure sensor when it is in a non-pressurized state.

[0013] Preferably, a pre-pressing piece is further included, and the second pressure sensor and the pre-pressing piece are pre-pressed to be pressurized synchronously with the first pressure sensor when the first pressure sensor is pressurized.

[0014] Preferably, the second pressure sensor is connected to the pre-pressed part by magnetic attraction.

[0015] Preferably, it also includes a bracket and a first sliding part, the first sliding part is slidably connected to the bracket, a fixed part is provided at one end of the bracket away from the pressure-bearing part, the first pressure sensor is located at the end of the first sliding part facing the pressure-bearing part, the second pressure sensor is installed at the end of the fixed part facing the first sliding part, and the first sliding part and the fixed part are connected by magnetic attraction.

[0016] Preferably, the pre-pressing member is provided at one end of the first sliding member facing the second pressure sensor, the pre-pressing member is a magnetic member, and the second pressure sensor is a pressure sensor that can be attracted by the magnetic member.

[0017] Preferably, it also includes a bracket and a first sliding part, the first sliding part is slidably connected to the bracket, a fixed part is provided at one end of the bracket away from the pressure-bearing part, the first pressure sensor is located at the end of the first sliding part facing the pressure-bearing part, the second pressure sensor is installed at the end of the first sliding part facing the fixed part, the first sliding part and the fixed part are connected by magnetic attraction, and the pre-pressing part is provided at one end of the fixed part facing the second pressure sensor.

[0018] Preferably, a contact pressure member is further provided at one end of the pressure-receiving member facing the first pressure sensor, and the pressure-receiving member drives the contact pressure member to contact the first pressure sensor when subjected to pressure.

[0019] Preferably, the device 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 activates or deactivates the signal amplification circuit and the analog-to-digital conversion circuit based on the detection signal from the first pressure sensor.

[0020] In a second aspect, the present invention further provides an electric smart pen, comprising a housing and the pressure detection device described in the first aspect, wherein the pressure-bearing member serves as a refill of the smart pen, and a first chamber for receiving the refill is provided in the housing.

[0021] Beneficial Effects: The pressure detection device and smart pen of the present invention utilize a low-power first pressure sensor and a highly accurate second pressure sensor to coordinate pressure detection. The first and second pressure sensors are installed and connected so that they are simultaneously pressurized, allowing the second pressure sensor to sense the pressure being measured synchronously with the first pressure sensor, thereby accurately enabling or disabling a mode for accurately detecting pressure using the second pressure sensor. The present invention also configures the pressure-receiving member to be detachable from the first pressure sensor. This prevents the pressure-receiving member from accidentally contacting the first pressure sensor when not under pressure. Consequently, the present invention significantly reduces the power consumption of the pressure detection device and smart pen while significantly improving the accuracy of pressure detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work, and these are all within the scope of protection of the present invention.

[0023] Figure 1 It is a structural layout diagram of the pressure detection device of the present invention;

[0024] Figure 2 Schematic diagram of the structure of the pressure detection device in Example 2 of the present invention;

[0025] Figure 3 Schematic diagram of the structure of the pressure detection device in Example 3 of the present invention;

[0026] Figure 4 Schematic diagram of the structure of the pressure detection device in Example 4 of the present invention;

[0027] Figure 5 This is a schematic structural diagram of a smart pen that uses the pressure detection device in Example 2 of the present invention;

[0028] Figure 6This is a schematic structural diagram of a smart pen that uses the pressure detection device in Example 3 of the present invention;

[0029] Figure 7 This is a schematic structural diagram of a smart pen that uses the pressure detection device of Example 4 of the present invention;

[0030] Figure 8 This is a circuit structure block diagram of the pressure detection device of the present invention;

[0031] Figure 9-1 A photo of the first set of text written with the smart pen of the present invention;

[0032] Figure 9-2 A graph showing the result of collecting the first set of characters written by the smart pen of the present invention;

[0033] Figure 9-3 Taking a photo of the first set of text written with the prior art smart pen;

[0034] Figure 9-4 A graph showing the result of collecting a first set of characters written using a prior art smart pen;

[0035] Figure 10-1 A photograph showing the effect of a second set of characters written with the smart pen of the present invention;

[0036] Figure 10-2 A graph showing a second set of text collection results written using the smart pen of the present invention;

[0037] Figure 10-3 Taking a photo of the second set of text written with the prior art smart pen;

[0038] Figure 10-4 A result graph of a second set of characters written using a prior art smart pen;

[0039] Parts and numbers in the figure: pressure-bearing member 10, pressure-contacting member 11, first pressure sensor 20, second pressure sensor 30, bracket 40, fixing part 50, first magnetic member 51, second magnetic member 52, third magnetic member 53, conductive silicone rubber 54, metal spring 55, top shaft 56, first sliding member 61, second sliding member 62, housing 71, first PCB board 72, filter 81, lens 82, image sensor 83, power supply 90. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. It should be noted that, in this article, relational terms such as first and second are only used 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 orientation or position relationship indicated by the terms "center", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like is based on the orientation or position relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further limitations, elements defined by the phrase "comprising..." do not preclude the presence of other identical elements in the process, method, article, or apparatus comprising the elements. The various features of the embodiments and examples of the present invention may be combined with each other if there is no conflict, and all are within the scope of protection of the present invention.

[0041] Example 1:

[0042] like Figure 1 As shown, this embodiment provides a pressure detection device, including:

[0043] The pressure-receiving member 10 is used to transmit the pressure to be detected to the first sensor and / or the second sensor;

[0044] A first pressure sensor 20 is used to detect the pressure acting on the pressure-bearing member 10, and the pressure-bearing member 10 is detachably connected to the first pressure sensor 20;

[0045] The first pressure sensor 20 can be a thin-film resistive strain gauge pressure sensor. This sensor has a wide dynamic range in its pressure-resistance curve. The resistance change is converted into a voltage signal, which can be used directly as a power-on wake-up signal without amplification. This supports automatic power-on when writing, and can also be directly used for AD sampling and digitization.

[0046] The aforementioned pressure-bearing part 10 plays the role of transmitting pressure. The pressure to be detected is transmitted to the first pressure sensor 20 and the second pressure sensor 30 through the pressure-bearing part 10 for easy detection. In this embodiment, when the pressure-bearing part 10 is in a pressure state, it abuts against the first pressure sensor 20, and when the pressure-bearing part 10 is in a non-pressure state, it is separated 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 end the processing and collection of the signal detected by the second pressure sensor 30. When the pressure-bearing part 10 is not under pressure, it is separated from the first pressure sensor 20, which can avoid the pressure-bearing part 10 from contacting the first pressure sensor 20, generating pressure on the first pressure sensor 20, and causing inaccurate pressure detection results.

[0047] The second pressure sensor 30 is used to detect the pressure acting on the pressure-bearing member 10;

[0048] The second pressure sensor 30 can be a bridge-type pressure sensor. This sensor has excellent linearity in its pressure-resistance curve, enabling it to discern subtle changes in writing pressure. Furthermore, it offers excellent repeatability. Specifically, when the same pressure is applied after releasing the pressure, the resistance value is repeatedly measured with minimal variance. This type of sensor ensures consistent stroke thickness even with the same writing pressure.

[0049] a controller electrically connected to the first pressure sensor 20 and the second pressure sensor 30 respectively;

[0050] The pressure detection device of this embodiment causes the pressure-bearing part 10 to abut against the first pressure sensor 20 when under pressure, so that the first pressure sensor 20 can detect the pressure change in time, triggering the detection device to process and collect the electrical signal of the second sensor, and at the same time, the pressure can be transmitted to the second pressure sensor 30 in time, so that the detection device can measure the pressure to be detected in time and accurately according to the signal detected by the second pressure sensor 30.

[0051] The controller receives the electrical signal from the first pressure sensor 20. Since the first pressure sensor 20 uses a pressure sensor with a large dynamic range of the "pressure-resistance" curve, the voltage signal from the first pressure sensor 20 can be directly sent to the controller without amplification. The controller controls the power-on and wake-up of related devices based on the voltage signal from the first pressure sensor 20, and can also control whether to process and collect the electrical signal from the second pressure sensor 30 based on the voltage signal from the first pressure sensor 20. Since this embodiment uses the first pressure sensor 20 and the second pressure sensor 30 to work in coordination, the operation mode of the pressure detection device is controlled by using the pressure change detected by the first pressure sensor 20 with low energy consumption. This ensures that the pressure detection device only uses the second pressure sensor 30 with high detection accuracy and good repeatability to accurately obtain the pressure value to be detected when the set conditions are met. When the conditions are not met, only the first pressure sensor 20 is used to detect the pressure change. This greatly reduces the power consumption of the pressure detection device and significantly improves the detection accuracy of the pressure detection device.

[0052] The first pressure sensor 20 and the second pressure sensor 30 are connected in a synchronously pressurized manner.

[0053] The synchronous pressure-bearing connection refers to a connection structure or connection 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 connection form ensures that the force-bearing surfaces of the first pressure sensor 20 and the force-bearing surfaces of the second pressure sensor 30 remain rigidly connected and fixed relative to each other even when the pressure detection device is not subjected to the pressure to be detected. The synchronous pressure-bearing connection structure or connection form is described in Examples 2 to 4.

[0054] Example 2

[0055] like Figure 2 and Figure 3 As shown, in this embodiment, the pressure detection device also includes a pre-pressing member, which is used to provide pre-pressure to the second pressure sensor 30. The second pressure sensor 30 abuts against the pre-pressing member so as to be compressed synchronously with the first pressure sensor 20 when pressure is applied. In this embodiment, the second pressure sensor 30 is placed in a pre-pressed state with very little force through the pre-pressing member, so that the second pressure sensor 30 can reliably abut against the pre-pressing member even when the pressure-bearing member 10 is not under pressure and is separated from the first pressure sensor 20, leaving no space for the second pressure sensor 30 to move freely. When the pressure-bearing member 10 abuts against the first pressure sensor 20 after being pressurized, since the second pressure sensor 30 and the pre-pressing member always maintain a tight abutment, the pressure transmitted by the pressure-bearing member 10 can be immediately transmitted to the force-bearing surface of the second pressure sensor 30 through the pre-pressing member, ensuring that the second pressure sensor 30 and the first pressure sensor 20 can synchronously sense the pressure of the pressure-bearing member 10.

[0056] As a preferred example, the second pressure sensor 30 is connected to the preload element via magnetic attraction. Magnetic connection leverages the principle of opposite magnets attracting each other, maintaining contact between the second pressure sensor 30 and the preload element through the action of a magnetic field. Compared to methods that use elastic elements such as springs to maintain preload, the magnetic connection employed in this embodiment provides a precise preload pressure for the second pressure sensor 30. This set pressure is maintained stably over time, unlike elastic elements that experience fluctuations after repeated pressure exposure.

[0057] To ensure that the first pressure sensor 20 and the second pressure sensor 30 can be pressurized synchronously, the pressure detection device of this embodiment also includes a bracket 40 and a first sliding member 61. The first sliding member 61 is slidingly connected to the bracket 40. The bracket 40 is provided with a fixed portion 50 at one end 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 portion 50 facing the first sliding member 61. The first sliding member 61 and the fixed portion 50 are connected by magnetic attraction.

[0058] 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 portion 50 of the bracket 40. The first pressure sensor 20 can slide relative to the bracket 40 along with the first sliding member 61. Since the first sliding member 61 and the fixed portion 50 are connected by magnetic attraction, the first sliding member 61 tends to press against the fixed portion 50 under the action of the magnetic field. Since the second pressure sensor 30 is mounted on the end of the fixed portion 50 facing the first sliding member 61, the end of the first sliding member 61 facing the fixed portion 50 presses against the force-bearing surface of the second pressure sensor 30 under the action of the magnetic field, 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-bearing member 10 is moved by pressure to abut against the first pressure sensor 20 to generate pressure on the first pressure sensor 20, the first sliding member 61 is pushed further toward the second pressure sensor 30 to press the second sensor. Since the second pressure sensor 30 always remains in contact with the first sliding member 61 under the action of pre-compression, the pressure of the pressure-bearing member 10 is transferred to the second pressure sensor 30 when the first sliding member 61 is pushed by the pressure-bearing member 10, so that it can be pressurized synchronously with the first pressure sensor 20.

[0059] In order to connect the first sliding member 61 and the fixed portion 50 through magnetic attraction, in this embodiment, the fixed portion 50 is provided with a first magnetic member 51, and the first sliding member 61 is provided with a second magnetic member 52 that is attracted to the first magnetic member 51. By respectively providing two mutually attractive magnetic members on the fixed portion 50 of the first sliding member 61, the attraction of the two magnetic members is utilized to drive the first sliding member 61 and the fixed portion 50 to press against each other, forming a magnetic connection, so that the first sliding member 61 exerts a pre-tightening 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, and a mounting groove can be opened on the fixed portion 50, and the first magnetic member 51 can be installed in the mounting groove. The aforementioned magnetic member can be made of magnetic material (Fe, Co, Ni elements and their alloys).

[0060] In this embodiment, a top shaft 56 serving as a pre-compression member may be provided at one end of the first sliding member 61 facing the fixed portion 50. This top shaft 56 is used to abut the second pressure sensor 30 under magnetic attraction, thereby pre-compressing the second pressure sensor 30. This top shaft 56 may also be made of a magnetic material, so that it is pressed against the second pressure sensor 30 under the attraction of the first magnetic member 51. In this embodiment, a conductive silicone rubber 54 may also be provided below the corresponding position of the bracket 40 and the first sliding member 61. This conductive silicone rubber 54 establishes an electrical connection between the first PCB 72 and the first pressure sensor 20. A metal spring 55 is provided below the fixed portion 50 to establish an electrical connection between the first PCB 72 and the second pressure sensor 30.

[0061] Example 3

[0062] 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 portion 50 is provided at the end of the bracket 40 facing away from the pressure-receiving member 10. The first pressure sensor 20 is located at the end of the first sliding member 61 facing the pressure-receiving member 10, and the second pressure sensor 30 is mounted on the end of the fixing portion 50 facing the first sliding member 61. The first sliding member 61 and the fixing portion 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 portion 50 as a pre-compression member. The top shaft 56 is a magnetic member made of a magnetic material. The second pressure sensor 30 is a pressure sensor that is attracted to the magnetic member, i.e., the top shaft 56. Such a pressure sensor can be made of a material that is attracted to the magnetic member. The top shaft 56 and the second pressure sensor 30 are thus attracted to each other by the magnetic field, maintaining a tight contact between the top shaft 56 and the second pressure sensor 30. In this manner, the top shaft 56 pre-compresses the second pressure sensor 30, thereby ensuring that the second pressure sensor 30 and the first pressure sensor 20 are simultaneously pressurized. The structure of this embodiment utilizes the inherent magnetic attraction of the top shaft 56 and the second pressure sensor 30, eliminating the need for additional magnetic components. This simplifies the structure of the pressure detection device, significantly reduces costs, and facilitates manufacturing. In this embodiment, a conductive silicone rubber 54 can also be disposed below the corresponding position of the bracket 40 and the first sliding member 61. This conductive silicone rubber 54 establishes an electrical connection between the first PCB 72 and the first pressure sensor 20. A metal spring 55 is disposed below the fixing portion 50 to establish an electrical connection between the first PCB 72 and the second pressure sensor 30.

[0063] Example 4

[0064] like Figure 4 As shown, in this embodiment, the pressure detection device also includes a bracket 40 and a first sliding member 61, the first sliding member 61 is slidably connected to the bracket 40, and a fixing portion 50 is provided at one 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, and the second pressure sensor 30 is installed at the end of the first sliding member 61 facing the fixing portion 50. The first slider and the fixing portion 50 are connected by magnetic attraction, and the pre-pressing member is provided at one end of the fixing portion 50 facing the second pressure sensor 30.

[0065] In this embodiment, the first pressure sensor 20 and the second pressure sensor 30 are mounted on opposite 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 portion 50. Since both the first and second pressure sensors 20 and 30 are mounted on the first sliding member 61 and the first slider and the fixed portion 50 are connected by magnetic attraction, the pre-compression element and the second pressure sensor 30 are always pre-compressed. 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 toward the fixed portion 50. The second pressure sensor 30 can immediately sense the pressure exerted by the pre-compression element on the second pressure sensor 30, thereby achieving simultaneous pressure on the second and first pressure sensors 30. The pre-compression element mounted on the fixed portion 50 can utilize a third magnetic element 53, while the second pressure sensor 30 can utilize a self-magnetic pressure sensor. Alternatively, the first and second magnetic elements 51 and 52 can be mounted on the fixed portion 50 and the first sliding member 61, respectively. In this embodiment, a metal spring 55 may be further disposed below the corresponding position of the bracket 40 and the first sliding member 61 to form an electrical connection between the first PCB 72 and the second pressure sensor 30. A conductive silicone rubber 54 is disposed at the rear end of the pressure-receiving member 10 to form an electrical connection between the first PCB 72 and the first pressure sensor 20.

[0066] Example 5

[0067] like Figures 2 to 4As shown, this embodiment is a further optimization of the previous embodiment. In this embodiment, a contact member 11 is further provided at the end of the pressure-receiving member 10 facing the first pressure sensor 20. When pressure is applied to the pressure-receiving member 10, the contact member 11 drives the contact member 11 to contact the first pressure sensor 20. The contact member 11 can be made of a material with a certain degree of elasticity, such as silicone, plastic, rubber, or steel. This member can be positioned at the rear end of the pressure-receiving member 10. When pressure is applied to the pressure-receiving member 10, the contact member 11 contacts the first pressure sensor 20, allowing the first pressure sensor 20 to sense the pressure acting on the pressure-receiving member 10. The pressure-receiving member 10 is prone to vibration at the moment of contact and separation with the first pressure sensor 20. Because the contact member 11 is made of a material with a certain degree of elasticity, when pressure is applied to the pressure-receiving member 10, the contact member 11 can more fully and reliably contact the first pressure sensor 20, further improving the reliability and accuracy of the pressure detection device. To achieve the goal of the pressure-receiving member 10 abutting the first pressure sensor 20 when in a pressurized state and separating from the first pressure sensor 20 when in a non-pressurized state, this embodiment further provides a second sliding member 62, which is connected in a manner that allows it to slide relative to the bracket 40. The pressure-receiving member 10 is connected to the second sliding member 62 so that the pressure-receiving member 10 can slide relative to the bracket 40. When the pressure-receiving member 10 is under pressure, it slides to a position abutting the first pressure sensor 20. When the sliding member is in a non-pressurized state, it can slide to an end away from the fixed portion 50. The first pressure sensor 20 is fixed to the end near the fixed portion 50 of the bracket 40 due to magnetic attraction, thereby achieving separation from the first pressure sensor 20. The second sliding member 62 can be installed at the rear end of the pressure-receiving member 10, and the aforementioned member can be installed at the end of the second sliding member 62 facing the first pressure sensor 20. In this way, when the pressure-receiving member 10 is subjected to the pressure to be detected, it pushes the second sliding member 62 to slide, and the second sliding member contacts and presses the first pressure sensor 20.

[0068] Example 5

[0069] like Figure 5 、 Figure 6 and Figure 7As shown, this embodiment provides a smart pen comprising a housing 71 and the pressure detection device described in the previous embodiment. The pressure-receiving member 10 serves as a refill for the smart pen, and the housing 71 is provided with a first chamber for receiving the refill. The smart pen in this embodiment is an application of the pressure detection device described in the previous embodiment. The refill, serving as the pressure-receiving member 10, can be installed in a slide groove formed by the housing 71 and the bracket 40, and can slide within the slide groove. The writing end of the refill extends outside the housing 71. 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. That is, when the pressure detected by the first pressure sensor 20 exceeds a set threshold, the controller controls the smart pen to power on. The first pressure sensor 20 can also be used to determine whether the pen is in the down state or the up state. For example, when the pressure detected by the first pressure sensor 20 exceeds a set threshold, the controller determines that the pen is in the down state; when the pressure detected by the first pressure sensor 20 is less than the set threshold, the controller determines that the pen is in the up state. When the controller determines that the pen has been put down through the detection signal of the first pressure sensor 20, it turns on the signal amplification circuit of the second pressure sensor 30, amplifies the signal collected by the second pressure sensor 30, and can start the AD sampler to sample the output signal of the amplification circuit. The sampling result is used to control the thickness of the stroke display. After the controller determines that the pen has been lifted through the first pressure sensor 20, it turns off the signal amplification circuit of the second pressure sensor 30 and stops AD sampling, thereby achieving the purpose of saving power consumption. Since this embodiment uses the passive first pressure sensor 20 as a power-on trigger signal and a pen-down and pen-lift indication signal, it can save the power consumption of the entire machine; the second pressure sensor 30 is used to collect the writing pressure of the pen tip with high precision, and then the thickness change of the handwriting is restored with high fidelity. Each time the controller detects a pen-lift signal, it collects the AD output values ​​of the second pressure sensor 30 N times and calculates the average value as the output zero bias value of the second pressure sensor 30 for the next stroke. The output value of the second pressure sensor 30 is subtracted from the zero bias value to obtain the calibrated output value of the second pressure sensor 30, thereby reproducing the "pen tip" effect of writing. The controller can also determine the pen-up state and pen-down state of the smart pen based on the detection signal of the first pressure sensor, wherein the controller can eliminate the zero 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 smart pen was last lifted. For example, when the smart pen is lifted, the pressure value of the second pressure sensor is P0 (P0 can be positive or negative), the controller records P0, and then the smart pen is lowered to contact the writing medium. At this time, the pressure value detected by the second pressure sensor is P1, and the pressure value after eliminating the zero deviation is set to P r , then P r =P1-P0

[0070] Because the pressure detection device in this embodiment utilizes the aforementioned synchronous pressure connection structure, the second pressure sensor 30 is preloaded with minimal force. This also leaves the pressure-bearing surfaces of the first and second pressure sensors 20, 30 with no free space to move when the pen is lifted. Consequently, when pressure acts on the first pressure sensor 20, it also acts on the second pressure sensor 30, ensuring that the pressure between the pen tip and the paper surface is simultaneously transmitted to the first and second pressure sensors 20, 30. Because the pressure detection device in the smart pen magnetically positions the first and second pressure sensors 20, 30 at one end of the bracket 40, gravity forces the pen refill and the second slider 62 holding the refill to the other side of the slide when the pen is lifted. This ensures that the end of the refill is separated from both sensors when the pen is lifted, enabling accurate determination of the lift-off and down state, effectively preventing incorrect stroke connections, such as the end of one stroke being mistakenly connected to the beginning of the next. Furthermore, this embodiment includes a power supply 90, which is electrically connected to the controller to power the various components of the smart pen. The smart pen of this embodiment also includes an image acquisition device, which includes a filter 81, a lens 82, and an image sensor 83. The image sensor 83 is electrically connected to the first PCB 72. This image acquisition device is used to capture images during writing. Light from the image to be captured is filtered by the filter 81 and then focused by the lens 82 onto the image sensor 83. The image sensor 83 converts the optical signal into an electrical signal, which is then transmitted to the controller.

[0071] The collection effect of the smart pen writing of the present invention can be compared with Figure 9-1 、 Figure 9-2 、 Figure 9-3 、 Figure 9-4 、 10-1 、 Figure 10-2 、 Figure 10-3 、 Figure 10-4 From the above figures, it can be seen that Figure 9-2 and Figure 10-2 The effect of the change of pen tip and stroke thickness of the text collected by the smart pen of the present invention is better than that of the pen tip and stroke thickness of the text collected by the smart pen of the present invention. Figure 9-4 and Figure 10-4 The effect of the change of pen strokes and stroke thickness of the text collected by the existing smart pen is better.

[0072] The above is a detailed introduction to the pressure detection device and smart pen provided by the embodiments of the present invention.

[0073] It should be understood that the present invention is not limited to the specific configurations and processes described above and shown in the figures. For the sake of simplicity, a detailed description of known methods is omitted here. In the above embodiments, several specific steps are described and shown as examples.

[0074] The functional blocks shown in the above structural block diagram can be implemented as hardware, software, firmware or a combination thereof. When implemented in hardware, it can be, for example, an electronic circuit, an application specific integrated circuit (ASIC), appropriate firmware, a plug-in, a function card, etc.

[0075] It should also be noted that the exemplary embodiments described herein describe methods or systems based on a series of steps or devices. However, the present invention is not limited to the order of the steps described above. In other words, the steps may be performed in the order described in the embodiments, or in a different order, or several steps may be performed simultaneously.

[0076] The above description is only a specific embodiment of the present invention. Those skilled in the art will clearly understand that for the convenience and brevity of description, the specific working processes of the systems, modules and units described above can refer to the corresponding processes in the aforementioned method embodiments, and will not be repeated here. It should be understood that the protection scope of the present invention is not limited to this. Any person skilled in the art can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present invention, and these modifications or replacements should be included in the protection scope of the present invention.

Claims

1. A pressure detection device, characterized in that: include: a pressure-receiving member, configured to transmit the pressure to be detected to the first sensor and / or the second sensor; a first pressure sensor for detecting a pressure change acting on a pressure-receiving member, wherein the pressure-receiving member is detachably connected to the first pressure sensor; The second pressure sensor is used to detect the pressure acting on the pressure-bearing member; a controller electrically connected to the first pressure sensor and the second pressure sensor, respectively, and configured to start or end processing of an electrical signal from the second pressure sensor according to a detection signal from the first pressure sensor; The first pressure sensor and the second pressure sensor are connected in a synchronously pressurized manner; It also includes a pre-pressing piece, and the second pressure sensor and the pre-pressing piece are pre-pressed to be pressed synchronously with the first pressure sensor when the first pressure sensor is pressed.

2. The pressure detection device according to claim 1, characterized in that: The pressure-receiving member contacts the first pressure sensor when the pressure-receiving member is in a pressurized state, and is separated from the first pressure sensor when the pressure-receiving member is in a non-pressurized state.

3. The pressure detection device according to claim 2, characterized in that: The second pressure sensor is connected to the pre-pressed component through magnetic attraction.

4. The pressure detection device according to claim 3, characterized in that: It also includes a bracket and a first sliding member, the first sliding member is slidably connected to the bracket, a fixed portion is provided at one end of the bracket away from the pressure-bearing member, the first pressure sensor is located at one end of the first sliding member facing the pressure-bearing member, the second pressure sensor is installed at one end of the fixed portion facing the first sliding member, and the first sliding member and the fixed portion are connected by magnetic attraction.

5. The pressure detection device according to claim 4, characterized in that: The pre-pressing member is arranged at one end of the first sliding member facing the second pressure sensor. The pre-pressing member is a magnetic member, and the second pressure sensor is a pressure sensor that can be attracted by the magnetic member.

6. The pressure detection device according to claim 4, characterized in that: The pre-pressing member is disposed at one end of the fixing portion facing the second pressure sensor.

7. The pressure detection device according to claim 1, characterized in that: A contact pressure member is further provided at one end of the pressure-receiving member facing the first pressure sensor. When the pressure-receiving member is subjected to pressure, the contact pressure member drives the contact pressure member to contact 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, and the controller turns on or off the signal amplification circuit and the analog-to-digital conversion circuit according to the detection signal of the first pressure sensor.

9. Smart pen, characterized in that, The invention comprises a housing and the pressure detection device according to any one of claims 1 to 8, wherein the pressure-bearing member serves as a refill of the smart pen, and the housing is provided with a first chamber for accommodating the refill.

10. The smart pen according to claim 9, wherein: The controller is used to determine the pen-up state and pen-down 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 during the last pen-up state.

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