A capacitive stylus

Abstract

The present invention discloses a capacitive stylus pen, comprising a refill PCB board, a main board, and a pen tip. The refill PCB board is located at one end of the main board and is integrally and coaxially extended with the main board. The refill PCB board is sequentially spaced along the extension direction from the end connected to the main board to the end remote from the main board, with a first ground electrode, a first emitter, a second ground electrode, and a second emitter being formed by a metal edging process. The first ground electrode, the first emitter, the second ground electrode, and the second emitter are all electrically connected to the main board; and the second emitter is connected to the pen tip. The capacitive stylus pen of the present invention integrates the refill PCB board with the main board, reducing the processing steps and manual assembly steps of the refill PCB board. Manual assembly and soldering are no longer required, effectively improving production efficiency and product yield while ensuring consistent product performance.

Description

Technical Field

[0001] The present invention relates to the technical field of capacitive pens, and in particular to a capacitive stylus. Background Art

[0002] Existing capacitive stylus refills are assembled using multiple hardware components and an insulating sleeve. This manual assembly is costly, inefficient, and prone to short circuits. The spacing between the ground, first, and second emitters is also inconsistent, affecting the pen's tilting effect.

[0003] In the prior art, a Chinese utility model with announcement number CN216748690U discloses a capacitive pen refill and a capacitive pen. The refill of the capacitive pen adopts a multi-layer PCB metal edging process to form a first ground electrode, a first emitter, a second emitter and a second ground electrode, so that the distance between the three electrodes required by the capacitive pen is consistent; the connection between the refill PCB board and the main board adopts a dazed design, so that workers will not have assembly errors during assembly; the support member plays the role of fixing the pen tip and facilitates the assembly and production of the entire capacitive pen.

[0004] However, in the actual processing and production process, the refill PCB board of the capacitive pen needs to be soldered to the main board for the second time. The welding requires a fixture for positioning, otherwise it is easy to deviate and cause the refill to be off-center. The consistency of manual assembly is not easy to control, and after the welding assembly is completed, it is necessary to test whether there is a short circuit, which consumes a lot of labor costs! Summary of the Invention

[0005] In view of the defects in the prior art, the present invention provides a capacitive stylus to solve the problems of the existing capacitive stylus such as complicated processing process, time-consuming and labor-intensive manual assembly, and non-centering of the pen core.

[0006] A capacitive stylus pen comprises a refill PCB board, a main board, and a pen tip, wherein the refill PCB board is located at one end of the main board and is integral with and coaxially extended from the main board;

[0007] The refill PCB is provided with a first ground electrode, a first emitter, a second ground electrode, and a second emitter in sequence along the extension direction from the end connected to the main board to the end away from the main board, wherein the first ground electrode, the first emitter, the second ground electrode, and the second emitter are all formed by a metal edging process;

[0008] The first ground electrode, the first emitter electrode, the second ground electrode and the second emitter electrode are all electrically connected to the mainboard;

[0009] The second emitter is connected to the pen tip.

[0010] Furthermore, the second emitter is connected to the pen tip through a pen tip spring pin.

[0011] Furthermore, the refill PCB board extends outward so that the second emitter is directly connected to the pen tip.

[0012] Furthermore, the length of the first ground electrode is 5mm-10mm;

[0013] The length of the first emitter is 3mm-7mm;

[0014] The length of the second ground electrode is 0.5 mm to 3.5 mm.

[0015] Furthermore, the mainboard is also integrated with a zero-power consumption circuit;

[0016] The shutdown zero-power consumption circuit includes an input node for power input, an output node for powering a subsequent system, and a switch circuit located between the input node and the output node; the switch circuit includes a trigger module and a switch tube, and the switch tube is electrically connected to the trigger module;

[0017] The switch tube is connected between the input node and the output node;

[0018] The trigger module controls the switching on or off of the switch tube to control the input node and the output node to be connected or disconnected.

[0019] Furthermore, the switch tube is a PMOS tube; the drain of the PMOS tube is connected to the input node, and the source of the PMOS tube is connected to the output node;

[0020] The trigger module includes a trigger switch, a first NMOS transistor and a second NMOS transistor; wherein,

[0021] One end of the trigger switch is electrically connected to the input node, and the other end of the trigger switch is connected to a first resistor and then grounded;

[0022] The gate of the first NMOS transistor is connected in parallel to the first resistor, the drain of the first NMOS transistor is connected in series with a second resistor and a second diode and then connected to the input node, and the second resistor is connected to the input node;

[0023] The gate of the PMOS tube and the drain of the second NMOS tube are connected in parallel between the second resistor and the second diode; the source of the second NMOS tube is grounded, and the gate of the second NMOS tube is electrically connected to the power supply maintenance port of the microcontroller on the mainboard.

[0024] Furthermore, the gate of the second NMOS transistor is grounded through a third resistor.

[0025] Furthermore, the trigger module further includes a third NMOS tube;

[0026] The drain of the third NMOS tube is connected in parallel with the drain of the first NMOS tube, the source of the third NMOS tube is grounded, and the gate of the third NMOS tube is connected to the wireless charging trigger interface.

[0027] Furthermore, the drain of the first NMOS tube is electrically connected to a trigger port of the microcontroller on the mainboard, and a first diode is connected in series between the drain of the first NMOS tube and the trigger port.

[0028] Furthermore, a wireless charging circuit is integrated on the mainboard;

[0029] The wireless charging circuit includes a wireless charging coil, a fourth NMOS transistor, a fifth NMOS transistor, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor and a rectifier and voltage stabilization circuit; wherein,

[0030] The gate of the fourth NMOS transistor and the gate of the fifth NMOS transistor are connected in parallel to the control port of the microcontroller on the mainboard;

[0031] The drain of the fourth NMOS transistor is connected in series with the first capacitor and then connected to one end of the wireless charging coil, and the source of the fourth NMOS transistor is grounded;

[0032] The drain of the fifth NMOS transistor is connected in series with the second capacitor and then connected to the other end of the wireless charging coil, and the source of the fifth NMOS transistor is grounded;

[0033] The third capacitor and the fourth capacitor are connected to the wireless charging coil in parallel with the first capacitor, and the other ends of the third capacitor and the fourth capacitor are connected to the input end of the rectifier and voltage stabilization circuit.

[0034] The beneficial effects of the present invention are embodied in:

[0035] The capacitive stylus of the present invention integrates the refill PCB board with the main board, thereby reducing the number of refill PCB board processing steps and manual assembly steps. Manual assembly and welding are no longer required, which can effectively improve production efficiency, increase product yield, and better ensure consistent product performance.

[0036] Furthermore, the motherboard integrates a zero-power shutdown circuit, which completely cuts off power after shutdown, effectively extending the battery's standby life. Furthermore, this zero-power shutdown circuit provides system power via a dual-path wakeup mechanism, using both a trigger switch and a charging signal. It also features a self-locking mechanism. After powering on, the trigger switch signal also serves as an input for the microcontroller.

[0037] Finally, the motherboard also integrates a wireless charging circuit, through which the purpose of wireless charging can be achieved without being restricted by the encryption restrictions of the power supply equipment manufacturer. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly describes the drawings required for the specific embodiments or the description of the prior art. Similar elements or parts are generally identified by similar reference numerals throughout the drawings. Elements or parts in the drawings are not necessarily drawn to scale.

[0039] Figure 1 A schematic structural diagram of a capacitive stylus provided in an embodiment of the present invention;

[0040] Figure 2 A schematic diagram of a first connection structure between a refill PCB board and a pen tip provided in an embodiment of the present invention;

[0041] Figure 3 A schematic diagram of a second connection structure between a refill PCB board and a pen tip provided in an embodiment of the present invention;

[0042] Figure 4 A schematic structural diagram of a refill PCB board provided in an embodiment of the present invention;

[0043] Figure 5 A circuit diagram of a shutdown zero-power consumption circuit provided by an embodiment of the present invention;

[0044] Figure 6 A circuit diagram of a wireless charging circuit provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0045] The following embodiments of the technical solution of the present invention will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention and are therefore only examples and are not intended to limit the scope of protection of the present invention.

[0046] It should be noted that, unless otherwise specified, the technical or scientific terms used in this application should have the common meanings understood by those skilled in the art to which the present invention belongs.

[0047] like Figure 1 、 Figure 2 and Figure 3 As shown, a capacitive stylus provided by an embodiment of the present invention comprises a refill PCB board 2, a main board 1 and a pen tip 3. The refill PCB board 2 is located at one end of the main board 1 and is integral with the main board 1 and coaxially extended. Figure 4As shown, the refill PCB board 2 is sequentially spaced along its extension direction from the end connected to the mainboard 1 to the end away from the mainboard 1. The first ground electrode 4, first emitter 5, second ground electrode 6, and second emitter 7 are formed using a metal cladding process. The first ground electrode 4, first emitter 5, second ground electrode 6, and second emitter 7 are all electrically connected to the mainboard 1. The first ground electrode 4 is used to shield capacitive interference from the human hand. The capacitive signal generated by the first emitter 5 is used for tilting, thickening strokes, and eraser functions. The second ground electrode 6 is used to isolate the first emitter 5 from the second emitter 7 to prevent crosstalk between the two electrodes. The capacitive signal generated by the second emitter 7 is used to generate strokes on the touch screen. The second emitter 7 is connected to the pen tip 3.

[0048] In this embodiment, Figure 2 As shown, the second emitter 7 can be connected to the pen tip 3 through the pen tip elastic needle 8. When using the pen tip elastic needle 8 for connection, one end of the pen tip elastic needle 8 is connected to the second emitter 12, and the other end is connected to the pen tip 3. The length of the pen tip elastic needle 8 is 1mm-3.5mm.

[0049] Or, to reduce production costs, e.g. Figure 3 As shown, the refill PCB board 2 can be extended outward by 1 mm to 3.5 mm so that the second emitter 7 is directly connected to the pen tip 3 .

[0050] Alternatively, the pen tip 3 and the refill PCB board 2 can be directly injection-molded into one piece, so that there is no need to use a pen tip containing a pen tip elastic needle 8. The cost of a pen tip without a pen tip elastic needle is much lower than that of a pen tip with a pen tip elastic needle, thereby reducing production costs.

[0051] In this embodiment, to meet the above design requirements, the length of the first ground electrode 4 is 5 mm-10 mm; the length of the first emitter 5 is 3 mm-7 mm; and the length of the second ground electrode 6 is 0.5 mm-3.5 mm.

[0052] The mainboard 1 of the capacitive stylus pen still consumes 10-50 microamperes of power even when it is turned off. If the battery is left for a long time or is not charged in time, it will easily run out of power. It is unlikely that the battery can be activated by wireless charging all at once after it runs out of power. This will cause the product to be unable to be charged and used.

[0053] In order to completely cut off the power supply of the mainboard 1 after shutting down and effectively prolong the standby time of the power battery, in this embodiment, the mainboard 1 is also integrated with a zero power consumption circuit. Figure 5 As shown, the shutdown zero-power consumption circuit includes an input node 10 for power input, an output node 11 for powering a subsequent system, and a switch circuit located between the input node 10 and the output node 11 .

[0054] The switching circuit includes a trigger module and a switching transistor, which is electrically connected to the trigger module. The switching transistor is connected between input node 10 and output node 11. The trigger module controls the switching transistor to connect or disconnect input node 10 and output node 11. When the trigger module controls the switching transistor to disconnect, the power supply is completely disconnected from the motherboard 1, preventing the motherboard 1 from consuming power when powered off.

[0055] Specifically, such as Figure 5 As shown, the switch tube is a PMOS tube 9, the drain of the PMOS tube 9 is connected to the input node 10, and the source of the PMOS tube 9 is connected to the output node 11. The trigger module includes a trigger switch 12, a first NMOS tube 13 and a second NMOS tube 14, wherein one end of the trigger switch 12 is electrically connected to the input node 10, and the other end of the trigger switch 12 is connected to the first resistor 15 and then to ground. The gate of the first NMOS tube 13 is connected in parallel with the first resistor 15, and the drain of the first NMOS tube 13 is connected in series with the second resistor 16 and the second diode 17 and then connected to the input node 10, and the second resistor 16 is connected to the input node 10. The gate of the PMOS tube 9 and the drain of the second NMOS tube 14 are connected in parallel between the second resistor 16 and the second diode 17; the source of the second NMOS tube 14 is grounded, and the gate of the second NMOS tube 14 is electrically connected to the power maintenance port of the microcontroller on the motherboard 1.

[0056] In this embodiment, trigger switch 12 can be a touch button or key. When trigger switch 12 outputs a high level, first NMOS transistor 13 turns on, which in turn turns on PMOS transistor 9 via a second diode, thereby connecting input node 10 and output node 11. Output node 11 then supplies power to the subsequent system. When the power supply maintenance port of the microcontroller on mainboard 1 outputs a high level, second NMOS transistor 14 turns on, and PMOS transistor 9 remains in a continuously conducting state, allowing output node 11 to supply power to the subsequent system and maintain its self-locking state.

[0057] The drain of first NMOS transistor 13 is electrically connected to the trigger port of the microcontroller on motherboard 1. A first diode 20 is connected in series between the drain of first NMOS transistor 13 and the trigger port. When trigger switch 12 outputs a high level and first NMOS transistor 13 turns on, the voltage at the trigger port is pulled down via first diode 20, signaling the microcontroller to power on. After powering on, the voltage at the trigger port also serves as the input signal for trigger switch 12, enabling other applications such as single-click / double-click shutdown.

[0058] Furthermore, the gate of the second NMOS transistor 14 is grounded via a third resistor 18. The third resistor 18 has the same function as the first resistor 15, and both are used as pull-down resistors to prevent accidental startup due to interference signals.

[0059] Furthermore, the trigger module also includes a third NMOS transistor 19. The drain of the third NMOS transistor 19 is connected in parallel with the drain of the first NMOS transistor 13, the source of the third NMOS transistor 19 is grounded, and the gate of the third NMOS transistor 19 is connected to the wireless charging trigger interface. When a wireless charging signal is received from the wireless charging trigger interface, the third NMOS transistor 19 turns on, similarly turning on the PMOS transistor 9 through the second diode 17, and then lowering the voltage of the trigger port through the first diode 20, instructing the microcontroller to turn on.

[0060] Furthermore, a wireless charging circuit is integrated on the mainboard 1. Figure 6 As shown, the wireless charging circuit includes a wireless charging coil 21, a fourth NMOS transistor 22, a fifth NMOS transistor 23, a first capacitor 24, a second capacitor 25, a third capacitor 26, a fourth capacitor 27, and a rectifier and voltage regulator circuit 28. The gates of the fourth NMOS transistor 22 and the fifth NMOS transistor 23 are connected in parallel to the control port of the microcontroller on the motherboard 1. The drain of the fourth NMOS transistor 22 is connected in series with the first capacitor 24 and then to one end of the wireless charging coil 21. The source of the fourth NMOS transistor 22 is grounded. The drain of the fifth NMOS transistor 23 is connected in series with the second capacitor 25 and then to the other end of the wireless charging coil 21. The source of the fifth NMOS transistor 23 is grounded. The third capacitor 26 and the fourth capacitor 27 are connected in parallel with the first capacitor 24 to the wireless charging coil 21. The other ends of the third capacitor 26 and the fourth capacitor 27 are connected to the input of the rectifier and voltage regulator circuit 28.

[0061] During operation, the microcontroller's control port controls the CLMP to output a 10ms-500ms signal every 1-5 seconds. The wireless charging coil 21 switches states at a high frequency, causing the transmitter to output an AC detection waveform according to a certain pattern. This voltage is rectified and stabilized into DC power by the coil, resonant capacitor, and subsequent rectifier and voltage regulator circuit 28, which then charges the battery through the charging management chip, thus achieving wireless charging. The wireless charging coil 21, third capacitor 26, and fourth capacitor 27 form a resonant circuit to achieve energy conversion. Using this wireless charging method, the capacitive stylus can achieve wireless charging without being restricted by encryption restrictions imposed by power supply equipment manufacturers.

[0062] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and description of the present invention.

Claims

1. A capacitive pen, comprising a pen core PCB board (2), a main board (1) and a pen tip (3), characterized in that: The refill PCB board (2) is located at one end of the main board (1) and is integral with and coaxially extended from the main board (1); The refill PCB board (2) is provided with a first ground electrode (4), a first emitter (5), a second ground electrode (6) and a second emitter (7) in sequence along the extension direction from the end connected to the main board (1) to the end away from the main board (1), wherein the first ground electrode (4), the first emitter (5), the second ground electrode (6) and the second emitter (7) are all formed by a metal edging process; The first ground electrode (4), the first emitter (5), the second ground electrode (6) and the second emitter (7) are all electrically connected to the mainboard (1); The second emitter (7) is connected to the pen tip (3), wherein the second emitter (7) is connected to the pen tip (3) via a pen tip spring pin (8), or the pen core PCB board (2) extends outward so that the second emitter (7) is directly connected to the pen tip (3); The length of the first ground electrode (4) is 5mm-10mm; The length of the first emitter (5) is 3 mm to 7 mm; The length of the second ground electrode (6) is 0.5mm-3.5mm; The mainboard (1) is also integrated with a zero-power consumption circuit; The shutdown zero-power consumption circuit comprises an input node (10) for power input, an output node (11) for powering a subsequent system, and a switch circuit located between the input node (10) and the output node (11); the switch circuit comprises a trigger module and a switch tube, and the switch tube is electrically connected to the trigger module; The switch tube is connected between the input node (10) and the output node (11); The trigger module controls the switching on or off of the switch tube to control the input node (10) and the output node (11) to be connected or disconnected; The mainboard (1) is also integrated with a wireless charging circuit; The wireless charging circuit comprises a wireless charging coil (21), a fourth NMOS transistor (22), a fifth NMOS transistor (23), a first capacitor (24), a second capacitor (25), a third capacitor (26), a fourth capacitor (27) and a rectifier and voltage stabilization circuit (28); wherein, The gate of the fourth NMOS transistor (22) and the gate of the fifth NMOS transistor (23) are connected in parallel to the control port of the microcontroller on the mainboard (1); The drain of the fourth NMOS transistor (22) is connected in series with the first capacitor (24) and then connected to one end of the wireless charging coil (21), and the source of the fourth NMOS transistor (22) is grounded; The drain of the fifth NMOS transistor (23) is connected in series with a second capacitor (25) and then connected to the other end of the wireless charging coil (21), and the source of the fifth NMOS transistor (23) is grounded; The third capacitor (26) and the fourth capacitor (27) are connected in parallel with the first capacitor (24) to the wireless charging coil (21), and the other ends of the third capacitor (26) and the fourth capacitor (27) are connected to the input end of the rectifier and voltage stabilization circuit (28).

2. The capacitive stylus according to claim 1, wherein: The switch tube is a PMOS tube (9); the drain of the PMOS tube (9) is connected to the input node (10), and the source of the PMOS tube (9) is connected to the output node (11); The trigger module comprises a trigger switch (12), a first NMOS transistor (13) and a second NMOS transistor (14); wherein, One end of the trigger switch (12) is electrically connected to the input node (10), and the other end of the trigger switch (12) is connected to a first resistor (15) and then grounded; The gate of the first NMOS transistor (13) is connected in parallel to the first resistor (15); the drain of the first NMOS transistor (13) is connected in series with a second resistor (16) and a second diode (17) and then connected to an input node (10); and the second resistor (16) is connected to the input node (10); The gate of the PMOS tube (9) and the drain of the second NMOS tube (14) are connected in parallel between the second resistor (16) and the second diode (17); the source of the second NMOS tube (14) is grounded, and the gate of the second NMOS tube (14) is electrically connected to a power supply maintenance port of the microcontroller on the mainboard (1).

3. The capacitive stylus pen according to claim 2, wherein: The gate of the second NMOS transistor (14) is grounded via a third resistor (18).

4. The capacitive stylus according to claim 2, wherein: The trigger module further includes a third NMOS tube (19); The drain of the third NMOS tube (19) is connected in parallel with the drain of the first NMOS tube (13), the source of the third NMOS tube (19) is grounded, and the gate of the third NMOS tube (19) is connected to the wireless charging trigger interface.

5. The capacitive stylus according to claim 2, wherein: The drain of the first NMOS tube (13) is electrically connected to a trigger port of a microcontroller on the mainboard (1), and a first diode (20) is connected in series between the drain of the first NMOS tube (13) and the trigger port.

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