Pressure sensing device for electronic pen and electronic pen

Abstract

The present invention proposes a pressure sensing device for an electronic pen, wherein the electronic pen comprises a pen head and a pen body, the pressure sensing device is arranged on the top of the pen head, the pressure sensing device comprises a magnetic component, a magnetic field detector and a pressure acquisition circuit, the magnetic component can move up and down inside the pen head, the magnetic field detector is located above the magnetic component, and a gap is left between the magnetic field detector and the magnetic component, the magnetic field detector is used to detect the change of the magnetic field during the movement of the magnetic component, the pressure acquisition circuit is arranged inside the pen body, the pressure acquisition circuit is used to acquire the voltage signal output by the magnetic field detector when the magnetic field changes, the voltage signal output end of the magnetic field detector is connected to the voltage signal input end of the pressure acquisition circuit, and the voltage signal output end of the pressure acquisition circuit outputs the amplified voltage signal. The present invention can realize accurate pressure detection.

Description

Technical Field

[0001] The present application relates to the field of electronic accessories, and in particular to a pressure sensing device for an electronic pen and an electronic pen. Background Art

[0002] With the improvement of technology and quality of life, more and more smart devices are appearing in people's daily work and life, and touch devices are one of them. People can operate directly on the display screen through touch devices, without the need for a mouse or other devices for wired or wireless operation, which is convenient and fast. At the same time, electronic pens that can write on touch devices have also emerged. People can write freely on touch devices by using electronic pens just like using real pens.

[0003] In order to make the electronic pen more realistically simulate the writing feeling of a physical pen, a pressure sensing module is added to the electronic pen so that the handwriting output by the electronic pen changes with the amount of force applied by the user. However, the pressure sensing modules of existing electronic pens still have problems with low sensitivity and linearity. In addition, the pressure sensing modules of existing electronic pens usually directly contact the pressure sensor with the pen tip to detect the pressure information transmitted by the pen tip. Since the pressure sensor is a very precise and fragile electronic device, this direct contact can easily cause damage to the pressure sensor, seriously affecting the overall reliability of the pressure sensing module and poor anti-interference performance. Summary of the invention

[0004] In order to solve one of the above technical problems, the present invention provides a pressure sensing device for an electronic pen and an electronic pen.

[0005] A first aspect of an embodiment of the present invention provides a pressure sensing device for an electronic pen, wherein the electronic pen comprises a pen tip and a pen body, wherein the pen tip is arranged at the front end of the pen body, and the pressure detection device is arranged on the top of the pen tip, wherein the pressure sensing device comprises a magnetic component, a magnetic field detector and a pressure acquisition circuit, wherein the magnetic component can move up and down inside the pen tip, the magnetic field detector is located above the magnetic component, and a gap is left between the magnetic field detector and the magnetic component, the magnetic field detector is used to detect changes in the magnetic field during the movement of the magnetic component, and the pressure acquisition circuit is arranged inside the pen body, and the pressure acquisition circuit is used to acquire a voltage signal output by the magnetic field detector when the magnetic field changes, the voltage signal output end of the magnetic field detector is connected to the voltage signal input end of the pressure acquisition circuit, and the voltage signal output end of the pressure acquisition circuit outputs an amplified voltage signal.

[0006] Preferably, the device also includes a limiting part, a conducting part and a first spring, a fixing groove is opened at the top center of the conducting part, a magnetic component is fixed in the fixing groove, the magnetic field detector is located above the magnetic component, and a gap is left between the magnetic component and the magnetic field detector, the outer wall of the conducting part protrudes outward to form a boss, the first spring is sleeved on the outside of the conducting part, and one end of the first spring is fixedly connected to the top surface of the boss, and the other end of the first spring is fixedly connected to the bottom surface of the conductive plate, an insertion groove is opened at the bottom center of the conducting part along the length direction of the conducting part, the end of the pen tip is inserted into the insertion groove, and the front end of the pen tip is exposed to the outside of the conducting part, the limiting part is sleeved on the outside of the conducting part, and the inner side wall of the limiting part protrudes inward to form a convex ring, and the inner diameter of the convex ring is smaller than the outer diameter of the boss.

[0007] Preferably, the initial state of the first spring is a compressed state, and when the first spring is in the initial state, the bottom surface of the boss contacts the top surface of the convex ring.

[0008] Preferably, the pen tip further includes a second spring, which is sleeved on the outside of the conductive part, and one end of the second spring is fixedly connected to the bottom surface of the boss, and the other end of the second spring is fixedly connected to the top surface of the convex ring.

[0009] Preferably, the middle section of the boss is recessed inward to form a recessed area, and a partial area of ​​the recessed area is connected to the internal plug-in slot of the conductive part. A fastening part is provided in the recessed area, and the fastening part is tightly matched with the pen tip in the plug-in slot of the conductive part.

[0010] Preferably, the pressure acquisition circuit includes an acquisition circuit, a reference circuit, a differential circuit and an amplifying circuit, the voltage signal output end of the magnetic field detector is connected to the voltage signal input end of the acquisition circuit, the voltage signal output end of the acquisition circuit is connected to the first voltage signal input end of the differential circuit, the voltage signal output end of the reference circuit is connected to the second voltage signal input end of the differential circuit, the voltage signal output end of the differential circuit is connected to the voltage signal input end of the amplifying circuit, and the voltage signal output end of the amplifying circuit outputs the amplified voltage signal.

[0011] Preferably, the device further comprises a processor, a voltage signal input terminal of the processor is connected to a voltage signal output terminal of the pressure acquisition circuit, and a pressure signal output terminal of the processor outputs pressure information.

[0012] A second aspect of the embodiments of the present invention provides an electronic pen, wherein the electronic pen comprises the pressure sensing device according to the first aspect of the embodiments of the present invention.

[0013] Preferably, the electronic pen also includes an inner frame, which is arranged in the pen body, and the outer wall of the inner frame is tightly matched with the inner wall of the pen body, the front end of the inner frame is fixedly connected to the end of the pressure sensing device, and the pressure collection circuit is arranged in the inner frame.

[0014] The beneficial effects of the present invention are as follows: the present invention detects the characteristics of the magnetic field generated by the magnetic component during the up and down movement through the magnetic field detector, thereby outputting the voltage value when the magnetic component is located at different positions, and then converting the voltage value into a pressure value, thereby achieving accurate pressure detection. In the present invention, the magnetic component is in the moving device, and there is no contact between the magnetic field detector and the magnetic component. The non-contact pressure sensing detection eliminates the influence caused by device damage, and improves the reliability and anti-interference of the pressure sensing detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0016] Figure 1 A schematic diagram of the structure of a pressure sensing device for an electronic pen according to Embodiment 1 of the present invention;

[0017] Figure 2 Another schematic diagram of the structure of the pressure sensing device for an electronic pen according to Embodiment 1 of the present invention;

[0018] Figure 3 This is a schematic diagram of the principle of the pressure collection circuit described in Example 1 of the present invention;

[0019] Figure 4 This is a circuit diagram of the pressure collection circuit described in Example 1 of the present invention;

[0020] Figure 5 A circuit diagram of the acquisition circuit described in Embodiment 1 of the present invention;

[0021] Figure 6 A circuit diagram of the reference circuit described in Embodiment 1 of the present invention;

[0022] Figure 7 is a circuit diagram of the differential circuit described in Embodiment 1 of the present invention;

[0023] Figure 8 is a circuit diagram of the amplifier circuit described in Example 1 of the present invention;

[0024] Fig. 9 This is a schematic diagram of the overall appearance of the pressure sensing device for an electronic pen according to Embodiment 2 of the present invention;

[0025] Fig.10 A schematic diagram of a structure in which the pressure sensing device for an electronic pen according to an embodiment of the present invention is applied to a capacitive stylus;

[0026] Fig.11 This is another structural schematic diagram of the pressure sensing device for an electronic pen according to an embodiment of the present invention being applied to a capacitive stylus.

[0027] Reference numerals:

[0028] 1. Pen tip, 2. Limiting part, 3. Transmitting part, 4. Conducting part, 5. Conductive plate, 6. First spring, 7. Magnetic component, 8. Magnetic field detector, 9. Boss, 10. Boss ring, 11. Second spring, 12. Fastening part, 13. Pen body. DETAILED DESCRIPTION

[0029] In order to make the technical solutions and advantages in the embodiments of the present application clearer, the exemplary embodiments of the present application are further described in detail in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present application, rather than an exhaustive list of all embodiments. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. Furthermore, in order to provide a clearer description and make it easier to understand the present application, the parts in the drawings are not drawn according to their relative sizes, and some sizes have been exaggerated compared to other related scales; irrelevant details are not fully drawn to simplify the drawings.

[0030] Example 1

[0031] like Figure 1 As shown, this embodiment proposes a pressure sensing device for an electronic pen, the electronic pen comprises a pen tip 1 and a pen body 13, the pen tip 1 is arranged at the front end of the pen body 13, the pressure detection device is arranged on the top of the pen tip 1, the pressure sensing device comprises a magnetic component 7, a magnetic field detector 8 and a pressure acquisition circuit, the magnetic component 7 can move up and down inside the pen tip 1, the magnetic field detector 8 is located above the magnetic component 7, and a gap is left between the magnetic field detector 8 and the magnetic component 7, the magnetic field detector 8 is used to detect the change of the magnetic field during the movement of the magnetic component 7, the pressure acquisition circuit is arranged inside the pen body 13, the pressure acquisition circuit is used to collect the voltage signal output by the magnetic field detector 8 when the magnetic field changes, the voltage signal output end of the magnetic field detector 8 is connected to the voltage signal input end of the pressure acquisition circuit, and the voltage signal output end of the pressure acquisition circuit outputs the amplified voltage signal.

[0032] Specifically, the device proposed in this embodiment also includes a limit part 2, a conducting part 4 and a first spring 6. A fixed groove is provided at the top center of the conducting part 4, and a magnetic component 7 is arranged in the fixed groove. The magnetic component 7 can be any magnetic material, such as a magnet. A gap is left between the magnetic field detector 8 and the magnetic component 7. The magnetic field detector 8 can detect the magnetic field changes that occur in the movement of the magnetic component 7. In this embodiment, the magnetic field detector 8 can adopt a Hall effect sensor, which can realize non-contact detection of pressure, and has the characteristics of fast response speed, high measurement accuracy and good linearity. Therefore, when the front end of the pen tip 1 contacts an external object and moves upward due to force or moves downward due to loss of force, the magnetic component 7 will also move upward or downward under the drive of the conducting part 4, thereby changing the relative position between the magnetic component 7 and the magnetic field detector 8. In this way, since the magnetic field information detected by the magnetic field detector 8 when the position of the magnetic component 7 changes is different, the signal output by the magnetic field detector 8 is also different. Therefore, in this embodiment, the magnetic field detector 8 outputs different signals corresponding to the pressure value according to the magnetic field change to realize the detection of pressure. For example, when the distance between the magnetic component 7 and the magnetic field detector 8 is 0.5 mm, the corresponding pressure value is 100 N; when the distance between the magnetic component 7 and the magnetic field detector 8 is 0.1 mm, the corresponding pressure value is 300 N. In this way, when the user uses the electronic pen to operate on the touch screen, the corresponding pressure value will be generated, and then the writing track effect corresponding to different pressure states will be presented on the touch screen.

[0033] In this embodiment, in addition to being able to play a role in signal transmission, the first spring 6 can also be compressed when the pen tip 1 is forced to move upward, and when the pen tip 1 loses force during the upward movement, it can reversely act on the conductive part 4, thereby causing the pen tip 1 to return to its initial position to achieve normal use by the user. In order to make the conductive part 4 move up and down in the limiting part 2 more stable, a convex ring 10 is provided on the inner side wall of the limiting part 2 in this embodiment, and the convex ring 10 is formed by the inner side wall of the limiting part 2 protruding inward. The convex ring 10 is located below the boss 9 of the conductive part 4, and the inner diameter of the convex ring 10 is ensured to be smaller than the outer diameter of the boss 9. When the conductive part 4 moves downward, the obstruction of the convex ring 10 will limit the conductive part 4 from continuing to move downward, thereby playing a role in positioning and stabilizing the conductive part 4. In addition, when the pen tip 1 is not acted upon by external force and is in the initial position, the initial state of the first spring 6 is a compressed state, and at the same time, it is ensured that the bottom surface of the boss 9 is in contact with the top surface of the convex ring 10. In this way, the stability of the movement of the conducting part 4 in the limiting part 2 is ensured by the compression state of the first spring 6 and the structural characteristics of the mutual obstruction between the convex ring 10 and the boss 9 .

[0034] In addition, under normal circumstances, the effective connection between the pen tip 1 and the conductive part 4 is achieved by the friction between the outer wall of the pen tip 1 and the inner wall of the conductive part 4, so that the pen tip 1 will not be loosened or misplaced inside the conductive part 4. However, in actual use, due to the continuous force on the pen tip 1 and the relaxation of the structural part caused by long-term use, it is inevitable that the friction between the pen tip 1 and the conductive part 4 will be reduced. In order to prevent the pen tip 1 from being loosened or misplaced between the pen tip 1 and the conductive part 4, the middle section of the boss 9 is first recessed inward to form a recessed area in this embodiment. Part of the recessed area is connected to the plug-in slot inside the conductive part 4. Then a fastening part 12 is arranged in the recessed area, and the fastening part 12 can be tightly matched with the pen tip 1 located in the plug-in slot of the conductive part 4. The fastening part 12 can be an object with a certain degree of elasticity, such as a rubber band, a rubber band, etc., which can "bind" the pen tip 1 and the conductive part 4 together.

[0035] Furthermore, in this embodiment, since the first spring 6 is in a compressed state in the initial state, in this compressed state, the first spring 6 will apply a downward force to the conductive part 4. If the pressure generated when the front end of the pen tip 1 contacts the external device at this time is less than the downward force applied by the first spring 6 to the conductive part 4, the pen tip 1 will not move upward. Then the gap between the magnetic component 7 and the magnetic field detector 8 will not change, resulting in the electronic pen being in a "no pressure output" state at this time. However, at this time, the pen tip 1 has already formed contact and generated pressure between the external device, which cannot ensure that there is pressure output at the moment when the pen tip 1 contacts the external device. In order to solve this defect, in this embodiment, a second spring 11 is further provided between the convex ring 10 and the boss 9, and the second spring 11 is sleeved on the outside of the conductive part 4. The function of the second spring 11 is to offset the downward force applied by the first spring 6 to the conductive part 4 in the initial state, thereby ensuring that the pen tip 1 will move upward at the moment when the pen tip 1 contacts the external device, thereby changing the gap between the magnetic component 7 and the magnetic field detector 8, and then outputting the correct pressure value. In order to offset the downward force applied by the first spring 6 to the conductive part 4 in the initial state, the elastic coefficient of the first spring 6 is preferably the same as the elastic coefficient of the second spring 11, and the initial state of the first spring 6 is ensured to be the same as the initial state of the second spring 11, that is, the compression amount is the same. Of course, this embodiment does not exclude the situation where the characteristic parameters of the first spring 6 and the second spring 11 are different, as long as the second spring 11 can offset the downward force applied by the first spring 6 to the conductive part 4 in the initial state. In addition, the length and hardness of the first spring 6 in the initial state can also be adjusted to adjust the stroke of the magnetic component 7 moving up and down, thereby achieving more flexible pressure sensing detection.

[0036] In addition, the present embodiment adopts a double spring structure, which not only ensures the immediacy and accuracy of the pressure output, but also plays a buffering role in the force transmission process due to the elasticity of the spring, thereby achieving a silencing effect and preventing the pen tip 1 from generating loud noise when contacting external devices, thereby improving the user experience.

[0037] Furthermore, if Figure 3 and Figure 4 As shown, the pressure acquisition circuit specifically includes an acquisition circuit, a reference circuit, a differential circuit and an amplifier circuit. The voltage signal output end of the magnetic field detector 8 is connected to the voltage signal input end of the acquisition circuit, the voltage signal output end of the acquisition circuit is connected to the first voltage signal input end of the differential circuit, the voltage signal output end of the reference circuit is connected to the second voltage signal input end of the differential circuit, the voltage signal output end of the differential circuit is connected to the voltage signal input end of the amplifier circuit, and the voltage signal output end of the amplifier circuit outputs the amplified voltage signal.

[0038] In this embodiment, the acquisition circuit of the pressure acquisition circuit can acquire the voltage signal output by the magnetic field detector 8, and output a voltage signal that can be linearly variable with the voltage signal based on the voltage signal, and then send the voltage signal to the differential circuit as an input signal of the differential circuit.

[0039] The reference circuit can be configured to output a reference voltage, and use the reference voltage as another input signal of the differential circuit. In the differential circuit, the voltage output by the acquisition circuit and the reference voltage are calculated to obtain a difference voltage. Finally, the difference voltage is amplified N times by the amplifier circuit and output to the processor for subsequent processing. The processor can be an electronic device with logic processing function such as a single-chip microcomputer and FPGA.

[0040] In the above process, when the magnetic field detector 8 detects the change in the magnetic field caused by the change in the position of the magnetic component 7, a voltage signal will be output, and the acquisition circuit will collect and output the voltage signal, for example, 0.5V. At the same time, the reference circuit is configured to output a 0.6V voltage, so after the differential circuit performs the difference calculation, a 0.1V difference voltage is output. Assuming that the amplification factor of the amplifier circuit is set to 10 times, the amplifier circuit finally outputs an amplified voltage of 1V. When the magnetic component 7 is closer to the magnetic field detector 8, the voltage value collected and output by the acquisition circuit can be changed to 0.6V. Then, after being processed by the differential circuit and the amplifier circuit, an amplified voltage of 2V is output. It can be seen that after the pressure acquisition circuit of this embodiment, the change in the voltage value output by the magnetic field detector 8 is amplified from 0.1V to 1V. In this way, the voltage value and the voltage change amplitude received by the processor are larger, so the processor can more accurately identify subtle pressure changes, thereby realizing more levels of pressure detection.

[0041] Specifically, Figure 5 As shown, the acquisition circuit includes a first resistor R1, a second resistor R2 and a first capacitor C1, both ends of the first resistor R1 are connected to the pressure signal output end of the pressure sensing chip M1 as the pressure signal input end of the acquisition circuit, one end of the first resistor R1 is connected to a power supply, and the other end of the first resistor R1 is connected to one end of the first capacitor C1, one end of the second resistor R2 and the first voltage signal input end of the differential circuit as the voltage signal output end of the acquisition circuit, and the other end of the first capacitor C1 is connected to the other end of the second resistor R2 and grounded.

[0042] like Figure 6 As shown, the reference circuit includes a third resistor R3, a fourth resistor R4, a second capacitor C2, a third capacitor C3 and a first operational amplifier U1, one end of the third resistor R3 is connected to a power supply, the other end of the third resistor R3 is simultaneously connected to one end of the fourth resistor R4 and a non-inverting input end of the first operational amplifier U1, the other end of the fourth resistor R4 is grounded, the power supply end of the first operational amplifier U1 is simultaneously connected to one end of the second capacitor C2, one end of the third capacitor C3 and a power supply, the other end of the second capacitor C2 is connected to the other end of the third capacitor C3 and is grounded, the ground end of the first operational amplifier U1 is grounded, and the output end of the first operational amplifier U1 is connected to the inverting input end of the first operational amplifier U1 and the second voltage signal input end of the differential circuit as a voltage signal output end of the reference circuit.

[0043] like Figure 7As shown, the differential circuit includes a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a fourth capacitor C4, a fifth capacitor C5, a diode D1 and a second operational amplifier U2, one end of the fifth resistor R5 is connected to the pressure signal output end of the acquisition circuit as the first pressure signal input end of the differential circuit, the other end of the fifth resistor R5 is connected to the inverting input end of the second operational amplifier U2 and one end of the eighth resistor R8, one end of the sixth resistor R6 is connected to the voltage signal output end of the reference circuit as the second voltage signal input end of the differential circuit, and the sixth resistor The other end of R6 is simultaneously connected to one end of the seventh resistor R7 and the non-inverting input end of the second operational amplifier U2; the output end of the second operational amplifier U2 is simultaneously connected to the voltage signal input end of the amplifier circuit and the other end of the eighth resistor R8 as the voltage signal output end of the differential circuit; the power supply end of the second operational amplifier U2 is simultaneously connected to the cathode of the diode D1, one end of the fourth capacitor C4, one end of the fifth capacitor C5 and the power supply; the anode of the diode D1 is connected to the power supply; the other end of the fourth capacitor C4 is connected to the other end of the fifth capacitor C5 and is grounded; the ground end of the second operational amplifier U2 is grounded.

[0044] like Figure 8 As shown, the amplifier circuit includes a ninth resistor R9, a tenth resistor R10, an eleventh resistor R11, a twelfth resistor R12, a thirteenth resistor R13, a sixth capacitor C6 and a third operational amplifier U3, the non-phase input terminal of the third operational amplifier U3 is connected to the voltage signal output terminal of the differential circuit as the voltage signal input terminal of the amplifier circuit, the inverting input terminal of the third operational amplifier U3 is simultaneously connected to one end of the ninth resistor R9 and one end of the tenth resistor R10, the other end of the ninth resistor R9 is simultaneously connected to the output end of the third operational amplifier U3 and one end of the twelfth resistor R12, the other end of the twelfth resistor R12 is simultaneously connected to one end of the thirteenth resistor R13 and one end of the sixth capacitor C6 as the voltage signal output terminal of the amplifier circuit and outputs the amplified voltage signal, the other end of the thirteenth resistor R13 is connected to the other end of the sixth capacitor C6 and is grounded, the other end of the tenth resistor R10 is connected to one end of the eleventh resistor R11, and the other end of the eleventh resistor R11 is grounded.

[0045] Example 2

[0046] like Fig. 9As described above, this embodiment proposes an electronic pen, which includes the pressure sensing device proposed in Example 1, wherein the specific working principle and structural composition of the pressure sensing device will not be repeated here. The electronic pen proposed in this embodiment also includes an inner frame, which is arranged in the pen body 13. The inner frame and the pen body 13 can be connected by a tight fit to facilitate installation and disassembly. The pen tip 1 is arranged at the front end of the pen body 13, and the end of the pen tip 1 is fixedly connected to the front end of the inner frame. The connection method can be a snap connection or a bolt connection, etc., which is not specifically limited in this embodiment. The inner frame carries a circuit board, and electronic devices and circuit structures such as a pressure acquisition circuit and a processor are all welded on the circuit board to ensure the stability of each electronic device and circuit structure in the electronic pen.

[0047] The following takes the actual application of the pressure sensing device proposed by the present invention in a capacitive stylus as an example to illustrate the specific usage and working principle of the pressure sensing device of the present invention.

[0048] like Figures 9 to 11 As shown, this embodiment proposes a capacitive pen, which includes a pen tip 1, a pen body 13 and a pressure collection circuit, and the pen tip 1 is arranged at the front end of the pen body 13. Among them, the pressure sensing device includes a limiting part 2, a conducting part 4 and a first spring 6. In addition, the capacitive pen also includes a transmitting part 3 and a conductive plate 5. Specifically, the pen tip 1, the limiting part 2, the transmitting part 3, the conducting part 4, the conductive plate 5 and the first spring 6 are all made of conductive materials. A plug-in slot is provided at the bottom center of the conducting part 4 along the length direction of the conducting part 4. The pen tip 1 can be inserted into the plug-in slot to achieve a tight fit connection between the conducting part 4 and the pen tip 1. A portion of the front end of the pen tip 1 is exposed to the outside of the conducting part 4. The outer side wall of the conducting part 4 protrudes outward to form a boss 9.

[0049] A fixing groove is provided at the top center of the conducting part 4, and a magnetic component 7 is arranged in the fixing groove. The magnetic component 7 can be any magnetic material, such as a magnet. A conductive plate 5 is provided above the magnetic component 7, and a gap is left between the magnetic component 7 and the conductive plate 5. A signal line connected to an external circuit can extend from the conductive plate 5. A first spring 6 is provided between the conductive plate 5 and the concave platform of the conducting part 4, and the first spring 6 is sleeved on the conducting part 4. In this way, the pen tip 1, the conducting part 4, the first spring 6 and the conductive plate 5 form a signal transmission path. The pen tip 1 receives a signal sent by an external device, which is transmitted by the conducting part 4 and the first spring 6 and finally sent by the conductive plate 5 to the subsequent circuit for processing. A magnetic field detector 8 is provided on the conductive plate 5. The magnetic field detector 8 can detect the magnetic field changes that occur in the magnetic component 7 during the movement process.

[0050] A limiting part 2 is also sleeved on the outside of the conducting part 4, and the conducting part 4, the first spring 6 and most of the pen tip 1 except the front end part are all covered inside the limiting part 2. When the pen tip 1 is subjected to external force or loses the external force, the conducting part 4 can move up and down in the limiting part 2. A transmitting part 3 is sleeved on the outside of the limiting part 2, and the transmitting part 3 can be a conductive spring wound on the outer wall of the limiting part 2. A signal line connected to the external circuit is also extended on the transmitting part 3. The conductive plate 5 sends the signal received by the pen tip 1 to the subsequent circuit for processing, and then sends the processed signal to the external device through the transmitting part 3, thereby forming a complete signal transmission route. The limiting part 2 can completely isolate the signal received by the pen tip 1 from the signal sent out, ensuring that the received signal and the sent signal are not interfered with each other.

[0051] In this embodiment, in addition to being able to play a role in signal transmission, the first spring 6 can also be compressed when the pen tip 1 is forced to move upward, and when the pen tip 1 loses force during the upward movement, it can reversely act on the conductive part 4, thereby causing the pen tip 1 to return to its initial position to achieve normal use by the user. In order to make the conductive part 4 move up and down in the limiting part 2 more stable, a convex ring 10 is provided on the inner side wall of the limiting part 2 in this embodiment, and the convex ring 10 is formed by the inner side wall of the limiting part 2 protruding inward. The convex ring 10 is located below the boss 9 of the conductive part 4, and the inner diameter of the convex ring 10 is ensured to be smaller than the outer diameter of the boss 9. When the conductive part 4 moves downward, the obstruction of the convex ring 10 will limit the conductive part 4 from continuing to move downward, thereby playing a role in positioning and stabilizing the conductive part 4. In addition, when the pen tip 1 is not acted upon by external force and is in the initial position, the initial state of the first spring 6 is a compressed state, and at the same time, it is ensured that the bottom surface of the boss 9 is in contact with the top surface of the convex ring 10. In this way, the stability of the movement of the conducting part 4 in the limiting part 2 is ensured by the compression state of the first spring 6 and the structural characteristics of the mutual obstruction between the convex ring 10 and the boss 9 .

[0052] In addition, under normal circumstances, the effective connection between the pen tip 1 and the conductive part 4 is achieved by the friction between the outer wall of the pen tip 1 and the inner wall of the conductive part 4, so that the pen tip 1 will not be loosened or misplaced inside the conductive part 4. However, in actual use, due to the continuous force on the pen tip 1 and the relaxation of the structural part caused by long-term use, it is inevitable that the friction between the pen tip 1 and the conductive part 4 will be reduced. In order to prevent the pen tip 1 from being loosened or misplaced between the pen tip 1 and the conductive part 4, the middle section of the boss 9 is first recessed inward to form a recessed area in this embodiment. Part of the recessed area is connected to the plug-in slot inside the conductive part 4. Then a fastening part 12 is arranged in the recessed area, and the fastening part 12 can be tightly matched with the pen tip 1 located in the plug-in slot of the conductive part 4. The fastening part 12 can be an object with a certain degree of elasticity, such as a rubber band, a rubber band, etc., which can "bind" the pen tip 1 and the conductive part 4 together.

[0053] Further, in this embodiment, since the first spring 6 is in a compressed state in the initial state, in this compressed state, the first spring 6 will apply a downward force to the conductive part 4. If the pressure generated when the front end of the pen tip 1 contacts the external device at this time is less than the downward force applied by the first spring 6 to the conductive part 4, the pen tip 1 will not move upward. Then the gap between the magnetic component 7 and the magnetic field detector 8 will not change, resulting in the capacitive pen being in a "no pressure output" state at this time. However, at this time, the pen tip 1 has already formed contact and generated pressure between the external device, which cannot guarantee that there is pressure output at the moment when the pen tip 1 contacts the external device. In order to solve this defect, the second spring 11 is further provided between the convex ring 10 and the boss 9 in this embodiment, and the second spring 11 is sleeved on the outside of the conductive part 4. The function of the second spring 11 is to offset the downward force applied by the first spring 6 to the conductive part 4 in the initial state, thereby ensuring that the pen tip 1 will move upward at the moment when it contacts the external device, thereby changing the spacing between the magnetic component 7 and the magnetic field detector 8, and then outputting the correct pressure value. In order to offset the downward force applied by the first spring 6 to the conducting part 4 in the initial state, the elastic coefficient of the first spring 6 is preferably the same as the elastic coefficient of the second spring 11, and the initial state of the first spring 6 is ensured to be the same as the initial state of the second spring 11, that is, the compression amount is the same.

[0054] The present invention detects the characteristics of the magnetic field generated by the magnetic component during the up and down movement through a magnetic field detector, thereby outputting the voltage value when the magnetic component is at different positions, and then converting the voltage value into a pressure value, thereby achieving accurate pressure detection. In the present invention, the magnetic component is in the moving device, and there is no contact between the magnetic field detector and the magnetic component. The non-contact pressure sensing detection eliminates the influence caused by device damage, and improves the reliability and anti-interference of the pressure sensing detection.

[0055] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A pressure sensing device for an electronic pen, the electronic pen comprising a pen head and a pen body, the pen head being arranged at the front end of the pen body, characterized in that: The pressure detection device is arranged on the top of the pen tip, and the pressure sensing device includes a magnetic component, a magnetic field detector and a pressure collection circuit. The magnetic component can move up and down inside the pen tip, and the magnetic field detector is located above the magnetic component, and a gap is left between the magnetic field detector and the magnetic component. A conductive plate is arranged above the magnetic component, and a gap is left between the magnetic component and the conductive plate. The magnetic field detector is arranged on the conductive plate, and the magnetic field detector is used to detect the change of the magnetic field during the movement of the magnetic component. The pressure collection circuit is arranged inside the pen body, and the pressure collection circuit is used to collect the voltage signal output by the magnetic field detector when the magnetic field changes. The voltage signal output end of the magnetic field detector is connected to the voltage signal input end of the pressure collection circuit, and the voltage signal output end of the pressure collection circuit outputs the amplified voltage signal; The device also includes a limiting part, a conducting part and a first spring, a fixing groove is provided at the top center of the conducting part, a magnetic component is fixed in the fixing groove, an outer side wall of the conducting part protrudes outward to form a boss, the first spring is sleeved on the outside of the conducting part, and one end of the first spring is fixedly connected to the top surface of the boss, and the other end of the first spring is fixedly connected to the bottom surface of the conductive plate, an insertion groove is provided at the bottom center of the conducting part along the length direction of the conducting part, the end of the pen tip is inserted into the insertion groove, and the front end of the pen tip is exposed to the outside of the conducting part, the limiting part is sleeved on the outside of the conducting part, and the inner side wall of the limiting part protrudes inward to form a convex ring, and the inner diameter of the convex ring is smaller than the outer diameter of the boss; The initial state of the first spring is a compressed state, and when the first spring is in the initial state, the bottom surface of the boss contacts the top surface of the convex ring; The pen tip also includes a second spring, which is sleeved on the outside of the conductive part, and one end of the second spring is fixedly connected to the bottom surface of the boss, and the other end of the second spring is fixedly connected to the top surface of the convex ring, the elastic coefficient of the first spring is the same as the elastic coefficient of the second spring, and the initial state of the first spring is the same as the initial state of the second spring.

2. The device according to claim 1, characterized in that The middle section of the boss is recessed inward to form a recessed area, and a partial area of ​​the recessed area is connected to the internal plug-in slot of the conductive part. A fastening part is arranged in the recessed area, and the fastening part is tightly matched with the pen tip in the plug-in slot of the conductive part.

3. The device according to claim 1, characterized in that The pressure acquisition circuit includes an acquisition circuit, a reference circuit, a differential circuit and an amplifier circuit. The voltage signal output end of the magnetic field detector is connected to the voltage signal input end of the acquisition circuit, the voltage signal output end of the acquisition circuit is connected to the first voltage signal input end of the differential circuit, the voltage signal output end of the reference circuit is connected to the second voltage signal input end of the differential circuit, the voltage signal output end of the differential circuit is connected to the voltage signal input end of the amplifier circuit, and the voltage signal output end of the amplifier circuit outputs the amplified voltage signal.

4. The device according to claim 3, characterized in that The device also includes a processor, a voltage signal input terminal of the processor is connected to a voltage signal output terminal of the pressure acquisition circuit, and a pressure signal output terminal of the processor outputs pressure information.

5. An electronic pen, characterized in that: The electronic pen comprises the pressure sensing device according to any one of claims 1 to 4.

6. The electronic pen according to claim 5, characterized in that: The electronic pen also includes an inner frame, which is arranged in the pen body, and the outer wall of the inner frame is tightly matched with the inner wall of the pen body, the front end of the inner frame is fixedly connected to the end of the pressure sensing device, and the pressure collection circuit is arranged in the inner frame.

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