A controller and electromagnetic handwriting device

Abstract

The application provides a controller and an electromagnetic handwriting device. The controller comprises a rotating wheel assembly and a transceiving unit. The rotating wheel assembly comprises a rotating wheel. The transceiving unit comprises an LC resonant circuit. The transceiving unit is accommodated in the rotating wheel assembly, so that the rotating wheel drives the transceiving unit to rotate.

Description

Technical Field

[0001] This invention relates to the field of electronic sensor technology, and more particularly to a controller and an electromagnetic handwriting device. Background Technology

[0002] A graphics tablet, also known as a digital tablet, drawing tablet, or sketching tablet, is an input device for computers, tablets, embedded systems, etc. It typically consists of a tablet and a pressure-sensitive stylus. Primarily targeted at design professionals, it's used for drawing and creative purposes, and is mainly for design and art students and teachers, advertising companies and design studios, as well as for Flash vector animation production. The hardware of a graphics tablet uses electromagnetic induction; cursor positioning and movement are entirely accomplished through electromagnetic induction. With continuous technological advancements, graphics tablets are evolving towards greater ease of use and maintenance. Passive wireless graphics tablets have become a major new technological development direction. "Passive" means the stylus contains no battery, and "wireless" means the tablet and host computer communicate wirelessly, eliminating the need for traditional cables.

[0003] Encoding switches for handwriting tablets include mechanical, photoelectric, and Hall effect switches. They all transmit the rotation information from the hand-operated rotary wheel (or disc) to a microcontroller, which then determines the rotation direction and performs a series of operations accordingly, similar to Hall effect switch encoding switches. However, current encoding switches suffer from rotational noise or high cost. Therefore, finding a low-noise, low-cost encoding switch for handwriting tablets is a pressing issue that needs to be addressed. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the present invention provides a controller and an electromagnetic handwriting device.

[0005] A first aspect of the present invention provides a controller for an electromagnetic handwriting device, the controller comprising: a rotating wheel assembly and a transceiver unit, the rotating wheel assembly comprising: a rotating wheel. The transceiver unit comprising: an LC resonant circuit. The transceiver unit is housed in the rotating wheel assembly such that the rotating wheel drives the transceiver unit to rotate.

[0006] Optionally, the LC resonant circuit includes a capacitor C1 and an inductor L1, and the transceiver unit further includes a micro switch electrically connected in series with the capacitor C1 for changing the resonant frequency of the LC resonant circuit.

[0007] Optionally, the wheel assembly further includes a control module board, which is disposed inside the wheel.

[0008] Optionally, the number of LC resonant circuits provided on the control module board is one or more.

[0009] Optionally, when the number of LC resonant circuits is 1, the number of micro switches is set to 1, and the micro switch is placed at the center of the rotating wheel.

[0010] Optionally, when the number of LC resonant circuits is 1, the number of micro switches is set to N, and each micro switch is arranged alternately at a preset angle A° on the edge of the rotating wheel, with the N micro switches corresponding to N directions.

[0011] Optionally, when there are two LC resonant circuits, the number of micro switches is set to one. The inductor of one LC resonant circuit is located on the rotation axis of the wheel, and the inductor of the other LC resonant circuit is located at the edge of the wheel. The resonant frequencies of the two LC resonant circuits are higher and lower than the operating frequency of the stylus, respectively. The stylus is included in the electromagnetic handwriting device.

[0012] Optionally, the controller further includes an upper housing and a base, the upper housing driving the wheel assembly to rotate or press relative to the base.

[0013] A second aspect of the present invention also provides a controller applied to an electromagnetic handwriting device. The controller includes a rotating wheel assembly, a transceiver unit, and a control circuit. The rotating wheel assembly includes a rotating wheel. The transceiver unit includes an LC resonant circuit for receiving electromagnetic energy transmitted by the electromagnetic handwriting device and transmitting an oscillation signal to the electromagnetic handwriting device. The control circuit is used to control the state of the LC resonant circuit according to the rotation direction information of the rotating wheel, or to transmit the rotation direction information of the rotating wheel. The transceiver unit is housed in the rotating wheel assembly so that the rotating wheel drives the transceiver unit to rotate.

[0014] The present invention also provides an electromagnetic handwriting device, characterized in that the electromagnetic handwriting device includes: a handwriting module and the controller described above, the handwriting module includes a stylus and a handwriting board corresponding to the stylus, the handwriting board is provided with a transmitting and receiving unit, and the controller and the handwriting module share the transmitting and receiving unit.

[0015] Optionally, the handwriting module includes a stylus and a handwriting tablet corresponding to the stylus. The stylus and the controller have different operating frequencies. When the controller is in working state, it is placed in the handwriting area of ​​the handwriting tablet.

[0016] Optionally, the transmitting and receiving unit includes: an antenna disposed below the rotating wheel, used to transmit electromagnetic waves of a preset frequency during the transmission cycle, so that the first LC resonant circuit receives energy during the transmission cycle; the rotating wheel assembly also includes a bearing, and the rotating wheel is fixed above the antenna by the bearing.

[0017] In this embodiment, the controller includes a rotating wheel assembly and a transceiver unit. The rotating wheel assembly includes a control module board and a rotating wheel. The control module board is disposed within the rotating wheel. The transceiver unit includes a first LC resonant circuit, wherein the first LC resonant circuit includes a first inductor L1 and a first capacitor C1. The first inductor L1 has a ferrite core. The transceiver unit is housed in the rotating wheel assembly, so that the rotating wheel assembly drives the transceiver unit to rotate. In this embodiment, the rotation of the controller wheel causes a change in the controller's position coordinates. This change in trajectory determines the rotation direction of the controller wheel, allowing for adjustments to be made based on this rotation direction. This controller is a coding switch, with a flexible structural design suitable for various devices, flexible and noiseless operation, and lower cost than traditional coding switches. Attached Figure Description

[0018] Figure 1 A schematic diagram of a handwriting device provided in an embodiment of this application;

[0019] Figure 2 A system block diagram of a possible electromagnetic handwriting device provided in an embodiment of this application;

[0020] Figure 3 A possible structural block diagram of an LC resonant circuit provided in this application embodiment;

[0021] Figure 4 This is a structural cross-sectional view of a possible electromagnetic handwriting device provided in an embodiment of this application. Detailed Implementation

[0022] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] Please see Figure 1 This is a possible electromagnetic handwriting device in the prior art. The electromagnetic handwriting device 1 includes a handwriting tablet 10 and a stylus 20 for use. When the electromagnetic handwriting device 1 is working, the stylus 20 emits electromagnetic waves. After the sensors arranged on the handwriting tablet 10 detect the waves, they calculate the position of the stylus 20 and report it to the computer. Then the computer makes a corresponding action such as moving the cursor.

[0024] For a better understanding of this solution, please refer to [link / reference]. Figure 2 , Figure 2This application provides a system block diagram of an electromagnetic handwriting device 20 with a controller. The electromagnetic handwriting device includes a controller, wherein the controller operates on the same principle as the electromagnetic stylus, but uses a different operating frequency, and can work simultaneously with the electromagnetic stylus on the handwriting area of ​​the handwriting tablet. Please refer to the following for details. Figure 2 The controller includes a rotating wheel assembly and a transceiver unit. The rotating wheel assembly includes a rotating wheel. In practical applications, the rotating wheel assembly may also include a control module board, meaning that a control module board may or may not be provided inside the rotating wheel. For ease of description, this application embodiment uses the rotating wheel assembly including the control module board, and the control module board being a PCB board, as an example. In practical applications, the control module board may also be an FPC (flexible printed circuit), and there is no specific limitation. The PCB board is disposed inside the rotating wheel; the transceiver unit includes an LC resonant circuit 2120. The LC resonant circuit 2120 includes a first inductor L1 and a first capacitor C1 connected to the first inductor L1. The first inductor L1 has a ferrite core and is used to receive and transmit electromagnetic waves, such as... Figure 3 The diagram shown is a possible structural block diagram of an LC resonant circuit provided in an embodiment of this application. Optionally, the transceiver unit may further include a microswitch R1 electrically connected in series with the first capacitor C1, wherein pressing the microswitch will change the resonant frequency of the first LC resonant circuit 2120.

[0025] The transceiver unit includes: a first antenna 2121, located below the rotating wheel, for transmitting electromagnetic waves of a preset frequency during the transmission cycle, so that the LC resonant circuit 2120 receives energy during the transmission cycle; and an antenna selection switch connected to the first antenna 2121.

[0026] It should be noted that the rotary wheel assembly may also include a coil assembly, which is used to receive electromagnetic waves and generate electrical energy, and can also be used to transmit pressure-sensitive signals. Of course, the coil assembly may consist of only one coil, which can realize the functions of generating electrical energy and transmitting pressure-sensitive signals, or it may include two coils, one coil for generating electrical energy and the other coil for transmitting pressure-sensitive signals.

[0027] In practical applications, the wheel is fixed above the antenna by bearings, making the rotation more stable and flexible.

[0028] The LC resonant circuit 2120 includes a first inductor L1 and a first capacitor C1 connected to the first inductor L1. A ferrite core is disposed in the first inductor L1. By changing the position of the core in the inductor L1, the inductance of the inductor L1 is changed, thereby changing the resonant frequency of the LC resonant circuit 2120.

[0029] Optionally, the transceiver unit includes a first antenna 2121, an antenna selection switch 2122 connected to the antenna 2121, a first amplifier 2123, a second amplifier 2124, a comparator 2125, an MCU processor 2126 connected in series with the antenna selection switch 2122, a detector 2128 and a sample-and-hold circuit 2129 connected in series between the second amplifier 2124 and the MCU processor 2126, an antenna transmit signal driver 2130 connected in series between the antenna selection switch 2122 and the MCU processor 2126, a USB interface (not shown) connected to the MCU processor 2126, and a power management unit (not shown) and a rechargeable battery (not shown) connected in series with the USB interface (not shown).

[0030] In practical applications, the first antenna 2121 is constructed from a ring-shaped copper foil trace. The width and shape of the copper foil determine the electrical performance characteristics of the first antenna 2121. The copper foil can be distributed in both the X and Y directions, and the shape of the first antenna 2121 in both directions is consistent, both being a "U" shape. One end of the first antenna 2121 is connected to the input terminal of the first amplifier 2123 through the antenna selection switch 2122, and the other end of the first antenna 2121 is grounded through the antenna selection switch 2122 or directly grounded.

[0031] In an optional embodiment of the present invention, the antenna selection switch 2122 is an 8-to-1 analog switch. The number of 8-to-1 analog switches used is selected according to the number of antennas 2121, generally 5 to 8 are used. The first amplifier 2123 and the second amplifier 2124 are integrated operational amplifiers with a low-noise gain-bandwidth product greater than 10MHz. The MCU processor 2126 has ADC, USB, and SPI interfaces, and its operating clock frequency is 40MHz. The detector 2128 is a diode detector circuit. The antenna transmit signal driver 2130 is an emitter follower circuit. The wireless communication module is a Bluetooth module with an SPI interface. The sample-and-hold circuit 2129 is composed of an RC integrator circuit.

[0032] It should be noted that the amplification and MCU control sections can be integrated into a single chip, and then communicate with the product's main control MCU via a serial port.

[0033] Additionally, the controller includes logic circuitry or an MCU, which can control the state of the LC resonant circuit according to the rotation direction of the wheel, or transmit the wheel rotation direction information via radio frequency. Optionally, in this embodiment, the number of LC resonant circuits on the purplish-red paper on the PCB board is one or more.

[0034] When the PCB board is provided with a set of LC resonant circuits 2120, the number of micro switches is set to 1, wherein the micro switch is placed in the center of the rotary wheel, and pressing the switch indicates selection confirmation.

[0035] Optionally, when the PCB is further provided with a set of the first LC resonant circuit, N microswitches can be set, each microswitch being spaced apart by a preset angle A°, arranged at the edge of the rotating wheel. The N microswitches correspond to N directions, and it can be understood that A*N = 360°. For example, when N is 4, it means that there are 4 microswitches on the PCB, each spaced 360 / 4 = 90° apart, arranged at the edge of the rotating wheel, and each of the 4 microswitches corresponds to 4 directions.

[0036] Optionally, the PCB may also include two sets of LC resonant circuits and a micro switch, each with a resonant frequency different from that of the stylus. One set of LC resonant circuits has its first inductor located on the rotation axis of the wheel, used to position the controller on the writing pad antenna; the other set of LC resonant circuits has its first inductor located at the edge of the wheel, used to detect the wheel's rotation. It is important to note that the resonant frequencies of the two sets of LC resonant circuits should be higher than and lower than the stylus's operating frequency, respectively. That is, one set of LC resonant circuits has a higher resonant frequency than the stylus's operating frequency, and the other set has a lower resonant frequency than the stylus's operating frequency. This prevents mutual interference on the same antenna and also allows for button status identification through signal amplitude.

[0037] The resonant frequencies of the two sets of LC resonant circuits are higher and lower than the operating frequency of the stylus, respectively, and the stylus is included in the electromagnetic handwriting device.

[0038] For easier understanding, please refer to Figure 4This is a cross-sectional view of a possible electromagnetic handwriting device provided in an embodiment of this application. The electromagnetic handwriting device 400 is a dual-core device, including a first core 401 and a second core 402. The first core 401 is located at the axis of a rotating wheel 403. The rotating wheel 403 is fixed to a base 408 by a bearing 404. It should be noted that the bearing 404 can be replaced by a ball bearing or omitted entirely. A spring or sheet spring is used to ensure micro-motion when the rotating wheel is not pressed down, with the micro switch 405 in the open state. When the rotating wheel 403 is pressed down, the micro switch 405 closes and conducts. A second PCB board 407 is fixed inside the top of the rotating wheel 403. In practical applications, the fixing method can be clip fixing, screw fixing, or adhesive fixing, which is not limited here. When there is only one set of LC resonant circuits, the micro switch 405 can be placed in the center of the first PCB board 406, that is, at the axis of the rotating wheel 403. It should be noted that if the controller is a single core, then the first core is not present.

[0039] In addition, the electromagnetic handwriting device 20 also includes a handwriting module, which includes a handwriting tablet and a stylus 22. The stylus 22 includes a second LC resonant circuit 221 and a second antenna 222. The second antenna 222 is used to transmit and receive energy with the second LC resonant circuit 221.

[0040] Optionally, the controller further includes a base and an upper shell, the upper shell being able to rotate or press the wheel assembly relative to the base. In practical applications, the first inductor L1 on the PCB board can be positioned close to the base and at its edge.

[0041] In this embodiment of the application, the controller and the stylus 22 share the transmitting and receiving unit of the writing tablet.

[0042] It should be noted that while the controller is structurally independent, it must be placed within the handwriting area of ​​the handwriting tablet during operation for the tablet to detect it. Furthermore, the controller operates at a different frequency than the stylus to ensure accurate recognition by the handwriting tablet.

[0043] It should be noted that in this embodiment, the transceiver unit can be set to one or three. For example, when the transceiver unit is set to three, a set of LC resonant circuits is provided on the PCB board of the impeller. In summary, in this embodiment, electromagnetic induction technology is used. The PCB of the controller is provided with a first LC resonant circuit, and the first inductor L1 has a ferrite core. The core inductor can receive and transmit electromagnetic waves. A loop antenna made of copper foil of the printed circuit board is provided below the impeller. During operation, the loop antenna transmits electromagnetic waves at a frequency of several hundred kHz to ensure that the LC resonant circuit rotating above the loop antenna can sense the signal. After the transmission continues for a certain period of time, it stops and then switches to receiving signals. The LC resonant circuit receives energy during the transmission phase. After the transmission stops, L and C exchange energy and generate a free oscillation with gradually decaying amplitude at the inherent resonant frequency. After the loop antenna switches to receiving, it will receive this free oscillation signal with gradually decaying amplitude. This signal is amplified and sent to the microcontroller for processing. The frequency and amplitude of this signal are obtained, and the rotation direction of the impeller can be determined based on this information. Therefore, the handwriting device provided in this application embodiment has an electromagnetic encoding switch that operates flexibly and without noise; and its cost is lower than that of traditional encoding switches.

[0044] In another possible embodiment, the controller, in addition to the rotary assembly and transceiver unit, also includes a control circuit. The rotary assembly includes a rotary wheel. The transceiver unit includes an LC resonant circuit for receiving electromagnetic energy transmitted by the electromagnetic handwriting device and sending oscillation signals to the electromagnetic handwriting device. The transceiver unit is housed in the rotary assembly, causing the rotary wheel to drive the transceiver unit to rotate. The control circuit controls the state of the LC resonant circuit based on the rotation direction information of the rotary wheel, or transmits the rotation direction information of the rotary wheel. That is, the control circuit controls the state of the LC resonant circuit using a digitally encoded signal similar to 101010 to represent the rotation direction information of the rotary wheel.

[0045] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A controller for use in an electromagnetic handwriting device, characterized in that, The controller comprises a base, a rotating wheel assembly and a transceiving unit, The rotating wheel assembly comprises: a rotating wheel arranged on the base through bearings or balls, forming a receiving space with the base, and the rotating wheel can rotate relative to the base; and a control module plate fixed on the inner top end of the rotating wheel; The transceiving unit comprises: two LC resonance circuits arranged on the control module plate and downward, wherein the magnetic core of one of the LC resonance circuits is arranged at the axis of the rotating wheel, for positioning the position of the controller on the antenna of the handwriting board; the magnetic core of the other LC resonance circuit is arranged at the edge position of the rotating wheel, for detecting the rotation of the rotating wheel, and the transceiving unit is driven to rotate by the rotating wheel; and an antenna cooperating with the two LC resonance circuits, arranged below the rotating wheel.

2. The controller of claim 1, wherein, The LC resonance circuit comprises a capacitor C1 and an inductor L1, and the transceiving unit further comprises: a micro switch electrically connected in series with the capacitor C1, for changing the resonance frequency of the LC resonance circuit, the micro switch is arranged on the control module plate and downward, and the micro switch is closed and conducted when the rotating wheel is pressed down, and the micro switch is in an open state when the rotating wheel is not pressed.

3. The controller of claim 2, wherein, The micro switch is pressed down to indicate selection confirmation.

4. The controller of claim 3, wherein, The number of the micro switch is one, the resonance frequencies of the two LC resonance circuits are higher and lower than the working frequency of the handwriting pen, and the handwriting pen is included in the electromagnetic handwriting device, so that the two LC resonance circuits share the transmitting and receiving unit of the handwriting board with the handwriting pen, and the handwriting board is included in the electromagnetic handwriting device.

5. A controller for application to an electromagnetic handwriting device, characterized in that The controller comprises a base, a rotating wheel assembly, a transceiving unit and a control circuit, The rotating wheel assembly comprises: a rotating wheel arranged on the base through bearings or balls, forming a receiving space with the base, and the rotating wheel can rotate relative to the base; and a control module plate fixed on the inner top end of the rotating wheel; The transceiving unit comprises: two LC resonance circuits for receiving electromagnetic energy transmitted by the electromagnetic handwriting device and transmitting oscillation signals to the electromagnetic handwriting device, the two LC resonance circuits are arranged on the control module plate and downward, wherein the magnetic core of one of the LC resonance circuits is arranged at the axis of the rotating wheel, for positioning the position of the controller on the antenna of the handwriting board; the magnetic core of the other LC resonance circuit is arranged at the edge position of the rotating wheel, for detecting the rotation of the rotating wheel, and the transceiving unit is driven to rotate by the rotating wheel; and an antenna cooperating with the two LC resonance circuits, arranged below the rotating wheel; and The control circuit is used for controlling the state of the LC resonance circuit according to the rotation direction information of the rotating wheel, or transmitting the rotation direction information of the rotating wheel.

6. An electromagnetic handwriting device, characterized by The electromagnetic handwriting device comprises a handwriting module and the controller according to any one of claims 1-4, the handwriting module comprises a handwriting pen and a handwriting board corresponding to the handwriting pen, the handwriting board is provided with a transmitting-receiving unit, and the controller and the handwriting pen share the transmitting-receiving unit.

7. The electromagnetic handwriting device according to claim 6, wherein, The working frequency of the handwriting pen is different from that of the controller, and the controller is placed in the handwriting area of the handwriting board when the controller is in the working state.

8. The electromagnetic handwriting device according to claim 7, wherein, The antenna transmits electromagnetic waves of a preset frequency in a transmission period, so that the resonant circuit receives energy in the transmission period.

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