Induction device for electromagnetic pen, electronic device and electromagnetic induction system

Abstract

The present invention discloses an induction device, electronic device and electromagnetic induction system for an electromagnetic pen, the device comprises a signal receiving circuit, a first pulse generating circuit and a signal processing circuit connected in sequence; the signal receiving circuit receives the electromagnetic signal sent by the electromagnetic pen, and transmits the electromagnetic signal to the first pulse generating circuit; the electromagnetic signal comprises a sine wave signal corresponding to a first digital code and a low level signal corresponding to a second digital code; the first pulse generating circuit is configured to shape each sine wave signal in the electromagnetic signal into a high level signal representing the first digital code, obtain a first pulse signal composed of a high level signal and a low level signal, and output the first pulse signal to the signal processing circuit; the signal processing circuit is configured to obtain digital code information represented by the electromagnetic signal according to the first pulse signal. The invention thereby performs data transmission based on digital signals, can effectively avoid interference from the external environment, and improves the accuracy of data transmission.

Description

Technical Field

[0001] The present invention relates to the technical field of electromagnetic pens, and more specifically, to an induction device for an electromagnetic pen, an electronic device, and an electromagnetic induction system. Background Art

[0002] Electromagnetic touch technology has opened up a new era of original handwriting input. The electromagnetic pen writing on the electromagnetic screen can achieve the advantages of original handwriting signature and original handwriting text record. Electromagnetic touch technology has gradually been recognized and accepted by consumers, and its application fields are becoming more and more extensive.

[0003] In the prior art, there are two electromagnetic touch schemes depending on whether the electromagnetic pen has a power supply device, one is a passive electromagnetic pen touch scheme, and the other is an active electromagnetic pen touch scheme. The passive electromagnetic pen touch scheme is that the electromagnetic screen's induction device sends electromagnetic waves of a certain frequency, and the resonant circuit built into the electromagnetic pen resonates, and the induction device detects the electromagnetic pen by receiving the resonance signal.

[0004] The active electromagnetic pen touch solution transmits its own information by sending electromagnetic signals to the electromagnetic screen, so that the electromagnetic screen can detect the electromagnetic pen. In the existing active electromagnetic pen touch solution, the electromagnetic pen uses analog signals to generate changing electromagnetic signals. For example, the frequency of the electromagnetic signal is changed by changing the capacitance value of the electromagnetic signal generating circuit. Since analog signals are easily interfered by the external environment, errors will occur when the sensing device obtains the state of the electromagnetic pen according to the electromagnetic signal, such as when obtaining the pen tip pressure of the electromagnetic pen. Therefore, it is difficult for the pen pressure of the electromagnetic pen to change steadily and linearly, which will greatly reduce the writing experience. Therefore, it is very necessary to improve the way the electromagnetic pen sends electromagnetic signals and correspondingly improve the circuit structure of the sensing device sensing electromagnetic signals to improve the anti-interference ability of the electromagnetic induction system. Summary of the invention

[0005] An object of an embodiment of the present invention is to provide a sensing device for an active electromagnetic pen to improve the anti-interference capability of an electromagnetic induction system.

[0006] According to a first aspect of the present invention, there is provided a sensing device for an electromagnetic pen, which comprises a signal receiving circuit, a first pulse generating circuit and a signal processing circuit connected in sequence;

[0007] The signal receiving circuit receives the electromagnetic signal sent by the electromagnetic pen, and transmits the electromagnetic signal to the first pulse generating circuit; wherein the electromagnetic signal includes a sine wave signal corresponding to the first digital code and a low level signal corresponding to the second digital code;

[0008] The first pulse generating circuit is configured to shape each section of the sinusoidal wave signal in the electromagnetic signal into a high-level signal representing the first digital code, obtain a first pulse signal composed of the high-level signal and the low-level signal, and output the first pulse signal to the signal processing circuit;

[0009] The signal processing circuit is configured to obtain digital coded information represented by the electromagnetic signal according to the first pulse signal.

[0010] Optionally, the first pulse generating circuit comprises a threshold circuit, an integration circuit and a first shaping circuit connected in sequence;

[0011] The threshold circuit is configured to convert each section of the sine wave signal in the electromagnetic signal into a pulse sequence, obtain a front-stage pulse signal composed of the pulse sequence and the low-level signal, and output the front-stage pulse signal to the integration circuit;

[0012] The integration circuit is configured to integrate each pulse sequence of the preceding pulse signal, obtain a subsequent pulse signal composed of an integrated waveform obtained by the integration and the low-level signal, and output the subsequent pulse signal to the first shaping circuit;

[0013] The first shaping circuit shapes the integrated waveform into the high-level signal, obtains the first pulse signal and outputs it to the signal processing circuit.

[0014] Optionally, the electromagnetic signal includes an identification signal and a data signal that are sent successively, the duration of the sinusoidal wave signal in the identification signal is greater than or equal to a set time, and the duration of the sinusoidal wave signal in the data signal is less than the set time;

[0015] The sensing device further includes a second pulse generating circuit, which is configured to only shape each section of the sinusoidal wave signal in the identification signal into a high-level signal representing the first digital code, obtain a second pulse signal, and output the second pulse signal to the signal processing circuit;

[0016] The signal processing circuit is further configured to obtain digital coded information represented by the electromagnetic signal according to the second pulse signal.

[0017] Optionally, the second pulse generating circuit comprises a threshold circuit, an integration circuit and a second shaping circuit connected in sequence;

[0018] The threshold circuit is configured to convert each section of the sine wave signal in the electromagnetic signal into a pulse sequence, obtain a front-stage pulse signal composed of the pulse sequence and the low-level signal, and output the front-stage pulse signal to the integration circuit;

[0019] The integration circuit is configured to integrate each pulse sequence of the preceding pulse signal, obtain a subsequent pulse signal composed of an integrated waveform obtained by the integration and the low-level signal, and output the subsequent pulse signal to the second shaping circuit;

[0020] The second shaping circuit is configured to only shape the integrated waveform corresponding to the identification signal into a high-level signal representing the first digital code, and obtain the second pulse signal to output to the signal processing circuit.

[0021] Optionally, the threshold circuit includes a comparator and a reference voltage circuit, the reference voltage circuit is connected to the inverting input terminal of the comparator to provide a reference voltage to the inverting input terminal; the non-inverting input terminal of the comparator receives the electromagnetic signal provided by the signal receiving circuit, and the threshold circuit outputs the preceding-order pulse signal through the output terminal of the comparator.

[0022] Optionally, the pulse generating circuit further includes a rectifier circuit, and one end of the threshold circuit outputting the preceding-order pulse signal is connected to the integrating circuit via the rectifier circuit.

[0023] Optionally, the shaping circuit comprises an inverter.

[0024] According to a second aspect of the present invention, an electronic device is provided, which comprises the sensing device according to the first aspect of the present invention.

[0025] According to a third aspect of the present invention, there is provided an electromagnetic induction system, which comprises an electromagnetic pen and the induction device according to the first aspect of the present invention; or comprises an electromagnetic pen and the electronic device according to the second aspect of the present invention;

[0026] The electromagnetic pen comprises a signal generating circuit and a signal processing circuit. The signal processing circuit of the electromagnetic pen generates an electromagnetic signal by controlling the on and off of the signal generating circuit. The signal generating circuit generates a sinusoidal wave signal in an on state and generates a low level signal in an off state.

[0027] Optionally, the electromagnetic pen also includes a switching circuit, which is controlled by a signal processing circuit of the electromagnetic pen. The switching circuit has a first switching state and a second switching state. The switching circuit is connected to the signal generating circuit, and the connection is configured so that the switching circuit connects the signal generating circuit to generate the sinusoidal wave signal in the first switching state, and disconnects the signal generating circuit to generate the low-level signal in the second switching state.

[0028] One beneficial effect of the present invention is that the electromagnetic pen of the embodiment of the present invention generates an electromagnetic signal based on digital coding information, wherein the sine wave signal and the low-level signal in the electromagnetic signal correspond to the first digital code and the second digital code respectively, and the sensing device obtains the digital coding information represented by the electromagnetic signal by shaping the electromagnetic signal sent by the electromagnetic pen, and then can obtain the data information represented by the digital coding information according to the communication protocol between the electromagnetic pen and the sensing device, thereby realizing the transmission of data information from the electromagnetic pen to the sensing device. Since the electromagnetic pen and the sensing device of the embodiment of the present invention transmit data based on digital signals, it can effectively avoid interference from the external environment and improve the accuracy of data transmission.

[0029] Further features and advantages of the present invention will become apparent from the following detailed description of exemplary embodiments of the present invention with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

[0031] Figure 1 A schematic diagram of the structure of an electromagnetic induction system according to an embodiment of the present invention;

[0032] Figure 2 is a schematic principle block diagram of an electromagnetic pen according to an embodiment of the present invention;

[0033] Figure 3 is a schematic principle block diagram of a signal processing circuit of an electromagnetic pen according to an embodiment of the present invention;

[0034] Figure 4 is a schematic flow chart of an interaction process between an electromagnetic pen and a sensing device according to an embodiment of the present invention;

[0035] Figure 5 is a schematic principle block diagram of an electromagnetic pen according to another embodiment of the present invention;

[0036] Figure 6 is a schematic circuit diagram of a signal generating circuit of an electromagnetic pen according to an embodiment of the present invention;

[0037] Figure 7 is a schematic structural diagram of an electromagnetic pen according to an embodiment of the present invention;

[0038] Figure 8 is a schematic principle block diagram of a sensing device according to an embodiment of the present invention;

[0039] Fig. 9 is a schematic principle block diagram of a first pulse generating circuit according to an embodiment of the present invention;

[0040] Fig.10 is a schematic principle block diagram of a sensing device according to another embodiment of the present invention;

[0041] Fig.11 is a schematic principle block diagram of a pulse generating circuit according to an embodiment of the present invention;

[0042] Fig.12 is a schematic circuit diagram of a threshold circuit according to an embodiment of the present invention;

[0043] Fig.13 is a schematic circuit diagram of an integration circuit and a shaping circuit according to an embodiment of the present invention;

[0044] Fig.14 A schematic diagram of the waveform correspondence between the electromagnetic signal and the first pulse signal according to an embodiment of the present invention;

[0045] Fig.15 A schematic diagram of the waveform correspondence between the first identification signal and the second pulse signal according to an embodiment of the present invention;

[0046] Fig.16 Schematic diagram of the waveform correspondence between the second identification signal and the second pulse signal according to an embodiment of the present invention. DETAILED DESCRIPTION

[0047] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that the relative arrangement of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention unless otherwise specifically stated.

[0048] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.

[0049] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered as part of the specification.

[0050] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0051] It should be noted that like reference numerals and letters refer to similar items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0052] <Electromagnetic induction system>

[0053] Figure 1 It is a schematic diagram of the composition structure of the electromagnetic induction system of an embodiment of the present invention.

[0054] according to Figure 1 As shown, the electromagnetic induction system of the embodiment of the present invention includes an electromagnetic pen 1000 and a sensing device 2000. The electromagnetic pen 1000 transmits information by sending electromagnetic signals, and the sensing device 2000 obtains the information transmitted by the electromagnetic pen 1000 by receiving electromagnetic signals.

[0055] In one example, the information transmitted by the electromagnetic pen 1000 may include data.

[0056] For example, the data transmitted from the electromagnetic pen 1000 to the sensing device 2000 includes the pen tip pressure data of the electromagnetic pen 1000 .

[0057] For another example, the information transmitted by the electromagnetic pen 1000 to the sensing device 2000 includes the status data of the electromagnetic pen 1000 , and the status data may include at least one of identity data (ID data) and key status data.

[0058] In one example, the information transmitted by the electromagnetic pen 1000 may also include a data identifier to identify the data type of the data sent thereafter, for example, to identify that the data sent thereafter is pen tip pressure data; or to identify that the data sent thereafter is electromagnetic pen status data.

[0059] In one example, the information transmitted by the electromagnetic pen 1000 may also include an interrupt command corresponding to a data bit, so that the sensing device reads a subsequent data bit according to the interrupt command.

[0060] In one example, the sensing device 2000 can be disposed in an electronic product, so that the electronic product can be used in conjunction with the electromagnetic pen.

[0061] In this example, the sensing device 2000 may be an electromagnetic plate, which may be integrated into the screen of the electronic product to form an electromagnetic screen, that is, the electromagnetic screen includes an electromagnetic plate in addition to the glass panel and liquid crystal screen of the existing screen.

[0062] In this embodiment, the basic working principle of the electromagnetic induction system is: the electromagnetic pen 1000 generates an electromagnetic signal through a signal generating circuit during operation, and the electromagnetic signal is composed of a sine wave signal and a low-level signal, that is, the electromagnetic signal is a changing electromagnetic signal, and the electromagnetic signal carries the information to be sent. Within the induction range of the electromagnetic signal, the induction device 2000 can receive the changing electromagnetic signal, and decode the changing electromagnetic signal according to the protocol of the communicating parties, and then obtain the information to be sent by the electromagnetic pen 1000.

[0063] Figure 2 1 is a structural block diagram of the electromagnetic pen 1000 according to an embodiment of the present invention.

[0064] according to Figure 2 As shown, an electromagnetic pen 1000 at least includes a signal generating circuit 1010, a signal processing circuit 1020 and a power supply circuit 1030, wherein the signal processing circuit 1020 is used to process the information to be sent to obtain digital coding information for controlling the signal generating circuit 1010.

[0065] In this embodiment, the electromagnetic pen 1000 is an active electromagnetic pen. The active electromagnetic pen can be an electromagnetic pen with its own power supply circuit, or it can be an electromagnetic pen that is connected to an electronic product by wire so that the electronic product can power the electromagnetic pen. The electromagnetic pen 1000 with its own power supply circuit 1030 is used as an example for explanation below.

[0066] The power supply circuit 1030 includes, for example, a battery and a voltage conversion circuit, wherein the voltage conversion circuit is used to convert the voltage of the battery into the working voltage required by the electrical components of the electromagnetic pen 1000 , such as the signal processing circuit 1020 and the signal generating circuit 1010 .

[0067] Figure 3 is a schematic diagram of the hardware structure of the signal processing circuit 1020 according to an embodiment of the present invention.

[0068] according to Figure 3 As shown, the signal processing circuit 1020 may include one or more memories 1021 and one or more processors 1022 .

[0069] The memory 1021 may include, for example, a ROM (Read Only Memory), a RAM (Random Access Memory), a nonvolatile memory such as a hard disk, or the like.

[0070] The processor 1022 may be a mobile processor or a single-chip microcomputer.

[0071] The memory 1021 is used to store instructions, which are used to control the processor 1022 to operate to digitally encode the information to be sent, obtain digitally encoded information, and control the signal generating circuit 1010 to generate a changing electromagnetic signal according to the digitally encoded information.

[0072] Figure 4 2 is a schematic flow chart of the interaction process between the electromagnetic pen 1000 and the sensing device 2000 according to an embodiment of the present invention.

[0073] according to Figure 1 and Figure 4 As shown, the interaction process of this embodiment may include the following steps:

[0074] In step S4110 , the signal processing circuit 1020 of the electromagnetic pen 1000 obtains information to be sent.

[0075] In step S4120 , the signal processing circuit 1020 of the electromagnetic pen 1000 digitally encodes the information to obtain corresponding digitally encoded information.

[0076] According to step S4120, the digital coding is a coding using binary numbers 0 and 1, and the digital coding information can be composed of binary numbers 0 and 1.

[0077] In this embodiment, any digital encoding method may be used as long as the information to be sent can be decoded according to the agreement between the sender and the receiver. The digital encoding method may be, for example but not limited to, non-return-to-zero encoding, Manchester encoding or differential Manchester encoding.

[0078] In step S4130 , the signal processing circuit 1020 of the electromagnetic pen 1000 controls the signal generating circuit 1010 of the electromagnetic pen 1000 according to the digital code information, so that the signal generating circuit 1010 generates a changing electromagnetic signal.

[0079] In step S4140 , the signal generating circuit 1010 generates and radiates a changing electromagnetic signal under the control of the signal processing circuit 1020 .

[0080] The electromagnetic signal consists of a sinusoidal wave signal and a low level signal.

[0081] According to step S4120, for digital code 1, the control signal generating circuit 1010 generates a sinusoidal wave signal, and for digital code 0, the control signal generating circuit 1010 generates a low-level signal, thereby generating an electromagnetic signal composed of a sinusoidal wave signal and a low-level signal, and the digital code information is represented by the electromagnetic signal.

[0082] Step S4210 , after receiving the electromagnetic signal, the sensing device 2000 decodes the received electromagnetic signal to obtain the information sent by the electromagnetic pen 1000 .

[0083] The information at least includes the data to be sent by the electromagnetic pen, the information may also include a data identifier of the data, and the information may also include an interrupt command corresponding to each data bit.

[0084] The decoding includes processing the electromagnetic signal to shape the sinusoidal wave signal in the electromagnetic signal into the first information code represented, that is, the digital code 1, and shaping the low-level signal in the electromagnetic signal into the second information code represented, that is, the digital code 0, so as to restore the electromagnetic signal to the above-mentioned digital code information.

[0085] After decoding the electromagnetic signal to obtain the information, the sensing device 2000 can respond to the information sent by the electromagnetic pen 1000.

[0086] In one example, the information includes pen tip pressure data, and the sensing device 2000 can respond to the pen tip pressure data and perform corresponding processing on the written notes.

[0087] In this example, since the electromagnetic signal representing the pen tip pressure data sent by the electromagnetic pen 1000 is a digital signal, it has a strong anti-interference ability. Therefore, the sensing device 2000 can accurately decode the pen tip pressure data after receiving the electromagnetic signal, and then obtain the stable linear change of the pen pressure of the electromagnetic pen. Writing processing based on this will be able to significantly improve the writing experience.

[0088] In one example, the information includes key status data in the status data, and the sensing device 2000 can execute a corresponding function in response to the key status data. For example, if the function corresponding to the key status data is an eraser function, the sensing device will execute an erase operation according to the key information.

[0089] In this example, since the electromagnetic signal representing the key status data sent by the electromagnetic pen 1000 is a digital signal, it has a strong anti-interference ability. Therefore, after receiving the electromagnetic signal, the sensing device 2000 can accurately decode the key status data and make an accurate response, thereby improving the accuracy and reliability of the electromagnetic induction system.

[0090] According to the technical solution provided by the embodiment of the present invention, the electromagnetic pen 1000 can control the signal generating circuit 1010 to generate an electromagnetic signal composed of a sinusoidal wave signal and a low-level signal based on the digital coding information. After receiving the electromagnetic signal, the sensing device 2000 decodes it based on the communication protocol agreed upon by the sender and receiver, and then obtains the signal sent by the electromagnetic pen 1000 and responds. Here, since the digital signal has a strong anti-interference ability, the sensing device 2000 can accurately decode the received changing electromagnetic signal to complete accurate interaction, which is effective in improving the user experience.

[0091] <Electromagnetic pen embodiment>

[0092] Figure 5 1 is a schematic principle block diagram of the circuit structure of the electromagnetic pen 1000 according to an embodiment of the present invention.

[0093] according to Figure 5 As shown, the electromagnetic pen 1000 of this embodiment may include a signal generating circuit 1010 , a signal processing circuit 1020 for performing signal processing, and a power supply circuit 1030 for supplying power to the signal generating circuit 1010 and the signal processing circuit 1020 .

[0094] In one embodiment, the information sent by the electromagnetic pen 1000 to the sensing device 2000 may include pen tip pressure data detected by the pressure sensor 1040 .

[0095] Correspondingly, in this embodiment, the electromagnetic pen 1000 may also include: Figure 7 The pen tip 1050 and the pressure sensor 1040 are shown, and the pressure sensor 1040 is used to provide an electrical signal representing the pen tip pressure to the signal processing circuit 1020, and the signal processing circuit 1020 is used to obtain the pen tip pressure data according to the electrical signal.

[0096] In one embodiment, the information sent by the electromagnetic pen 1000 to the sensing device 2000 may include status data of the electromagnetic pen.

[0097] Correspondingly, in this embodiment, the electromagnetic pen 1000 may also include an operation detection circuit 1060, which includes an operating part, and the operating part is exposed to the outside through the pen shell of the electromagnetic pen 1000. The operation detection circuit 1060 is configured to output a corresponding electrical signal according to the state of the operating part, and the signal processing circuit 1020 is used to obtain the state data of the electromagnetic pen according to the electrical signal provided by the operation detection circuit 1060.

[0098] The operating part may include at least one of a key, a button, a sliding component, and a rolling component. The operating part is exposed to the outside through the pen shell of the electromagnetic pen 1000 for user operation.

[0099] Taking the operation part as an example, the operation detection circuit 1060 may include a pull-up resistor and a switch controlled by the operation part, the pull-up resistor and the switch are connected in series between the power supply terminal and the ground terminal, when the operation part is operated to close the switch, the operation detection circuit 1060 can output a low-level signal through the potential point between the pull-up resistor and the switch, and when the operation part is reset to open the switch, the operation detection circuit 1060 can output a high-level signal through the potential point. In this way, the signal processing circuit 1020 can obtain the state data of the electromagnetic pen according to the electrical signal output by the operation detection circuit 1060.

[0100] Taking the example of an operation part using a sliding component such as a slider, the operation detection circuit 1060 may include a sliding rheostat that changes its resistance by sliding the sliding component. The operation detection circuit 1060 may output a voltage signal that has a mapping relationship with the resistance of the sliding rheostat. In this way, the signal processing circuit 1020 can obtain the position of the sliding component based on the voltage signal, and then obtain the status data of the electromagnetic pen.

[0101] In one embodiment, the electromagnetic pen 1000 may also include a switching circuit 1080, which is controlled by the signal processing circuit 1020 and has a first switching state and a second switching state. The switching circuit 1080 is connected to the signal generating circuit 1010, and the connection is set so that the switching circuit 1080 connects the signal generating circuit 1010 in the first switching state, at which time the signal generating circuit 1010 generates a sinusoidal wave signal of a set frequency, and disconnects the signal generating circuit 1010 in the second switching state, at which time the signal generating circuit 1010 does not work and generates a low-level signal.

[0102] According to this embodiment, the signal processing circuit 1020 can control the switch circuit 1080 to switch between the first switch state and the second switch state according to the digital code information, thereby generating a changed electromagnetic signal.

[0103] In one embodiment, Figure 6 As shown, the switch circuit 1080 may include a first switch corresponding to a first switch state and a second switch corresponding to a second switch state. The first switch and the second switch may have a common connection terminal to form a single-pole double-throw analog switch circuit.

[0104] For example, the signal generating circuit adopts an LC oscillation circuit, which includes a capacitor C and an inductor L, one end of the inductor L is connected to one end of the capacitor C, the other end of the capacitor C is connected to the power supply terminal VCC, the other end of the inductor L is connected to the common connection terminal of the switching circuit, the free end of the first switch is connected to the power supply terminal VCC, and the free end of the second switch is connected to the ground terminal via the resistor R.

[0105] The switch circuit 1080 has a gate control terminal connected to the signal processing circuit 1020 to receive a gate control signal output by the signal processing circuit 1020 according to the digital coding information. When the switch circuit 1080 is gated to connect to the first switch, the signal generating circuit 1010 is turned on, for example, an LC oscillation circuit is formed to generate a resonant signal, i.e., a sine wave signal. When the switch circuit 1080 is gated to connect to the second switch, the signal generating circuit 1010 is disconnected, the capacitor and the inductor are connected to the ground in series, and a constant low-level signal is generated.

[0106] In one embodiment, the electromagnetic pen 1000 may further include a power switch 1090 , which is connected to an output circuit of the power circuit 1030 for supplying power to the signal generating circuit 1010 and the signal processing circuit 1020 .

[0107] In this embodiment, the power switch 1090 is the main switch of the electromagnetic pen 1000, which is used to control whether the power circuit 1030 provides the working voltage to the electrical components of the electromagnetic pen 1000. When the power switch 1090 is closed, the electromagnetic pen 1000 starts to work, and when the power switch 1090 is closed, the electromagnetic pen 1000 stops working.

[0108] Figure 7 Schematic diagram of the structure of an electromagnetic pen 1000 according to an embodiment of the present invention.

[0109] according to Figure 7 As shown, the electromagnetic pen 1000 may include a pen housing 1100 , a PCB substrate 1300 , and a pen tip 1050 disposed at the front end of the pen housing 1100 .

[0110] In this embodiment, the signal generating circuit 1010 , the signal processing circuit 1020 , the switch circuit 1080 , and the operation detecting circuit 1060 etc. may all be disposed on the PCB substrate 1300 .

[0111] The electromagnetic pen 1000 may further include a function button 1071 disposed on the pen housing 1100, and the user may trigger a corresponding function according to an operation mode corresponding to the function setting, wherein the function button 1071 is an operation part of the electromagnetic pen 1000. For example, the electromagnetic pen 1000 may be started, an object may be selected and opened, and functions such as copying and pasting may be performed, which are not limited in any way in the embodiment of the present invention.

[0112] The electromagnetic pen 1000 may further include an eraser button 1072 disposed at the rear end of the pen housing 1100 , and the eraser button 1072 is used to implement an erasing function, wherein the eraser button 1072 is another operating part of the electromagnetic pen.

[0113] The electromagnetic pen 1000 may further include a battery 1200. The battery 1200, as a part of the power circuit 1030, is located inside the pen housing 1100, for example, it may be located at the rear end of the electromagnetic pen 1000. The battery 1200 may be a 1.5V lithium battery or other batteries, which are not limited here.

[0114] The power supply circuit 1030 may further include a voltage conversion circuit, wherein the voltage conversion circuit is used to convert the voltage of the battery into the working voltage required by the electrical components of the electromagnetic pen 1000 .

[0115] <Induction device embodiment>

[0116] Figure 8 is a structural block diagram of a sensing device 2000 according to an embodiment of the present invention.

[0117] according to Figure 8 As shown, the sensing device 2000 of this embodiment includes a signal receiving circuit 2010, a signal processing circuit 2020 and a first pulse generating circuit 2030 connected in sequence, that is, the signal output end of the signal receiving circuit 2010 is connected to the signal input end of the pulse generating circuit 2030, and the signal output end of the pulse generating circuit 2030 is connected to the signal input end of the signal processing circuit 2020.

[0118] The signal receiving circuit 2010 is configured to receive the electromagnetic signal sent by the electromagnetic pen 1000 and provide the electromagnetic signal to the first pulse generating circuit 2030, wherein the electromagnetic signal includes: Fig.13 The sine wave signal and the low level signal shown, the sine wave signal corresponds to the first digital code, such as digital code 1, and the low level signal corresponds to the second digital code, such as digital code 0.

[0119] The signal receiving circuit 2010 may include an antenna and a matching circuit of the antenna to receive the electromagnetic signal sent by the electromagnetic pen 1000, and transmit the electromagnetic signal to the first pulse generating circuit 2030 through the signal output terminal of the signal receiving circuit 2010. The signal receiving circuit 2010 of this embodiment may adopt any circuit structure for receiving electromagnetic signals, which is not limited here.

[0120] The signal input end of the first pulse generating circuit 2030 is connected to the signal output end of the signal receiving circuit 2010 to obtain the electromagnetic signal provided by the signal receiving circuit 2010 for shaping, so as to shape each sine wave signal in the electromagnetic signal into a high level signal corresponding to the first digital code, thereby obtaining a first pulse signal composed of a high level signal and a low level signal, and outputting the first pulse signal to the signal processing circuit 2020, wherein the high level signal corresponds to the digital code 1, and the low level signal corresponds to the digital code 0. In this way, the electromagnetic signal sent by the electromagnetic pen 1000 can be shaped or restored to the corresponding digital code information through the pulse generating circuit 2030.

[0121] Each of the above sine wave signals refers to each continuous sine wave signal.

[0122] See also Fig.14 As shown, the first pulse generating circuit 2030 shapes the first longer sinusoidal wave signal into a high-level signal that lasts for the same period of time, shapes each sinusoidal wave signal that lasts for T3 time into a high-level signal that lasts for the same period of time, shapes each sinusoidal wave signal that lasts for T2 time into a high-level signal that lasts for the same period of time, and the low-level signal (which may have glitches) in the electromagnetic signal is still shaped into a low-level signal (standard signal).

[0123] In one example, the electromagnetic signal can represent different information by setting the duration of the sine wave signal. For example, a sine wave signal and a low level signal that lasts for T2 time represent a data bit of the data to be sent. For another example, a sine wave signal that lasts for T3 time represents an interrupt command. For another example, a sine wave signal and a low level signal that lasts for T time represents a data identifier, etc.

[0124] In one example, see Fig.14 As shown, any segment of the sine wave signal lasting for T2 time corresponds to a digital code 1 of the data to be sent, and any segment of the low level signal lasting for T2 time corresponds to a digital code 0 of the data to be sent.

[0125] In this example, see Fig.14 As shown, the electromagnetic signal has a sinusoidal wave signal lasting T3 time before each sinusoidal wave signal lasting T2 time and each low-level signal lasting T2 time. The high-level signal obtained by shaping the sinusoidal wave signal lasting T3 time by the first pulse generating circuit 2030 is provided to the signal processing circuit 2020 as an interrupt command. In this way, the signal processing circuit 2020 can read a digital code (digital code 1 or digital code 0) sent subsequently after receiving each interrupt command.

[0126] See also Fig.14For example, the digital code information of the data to be sent by the electromagnetic pen is 1010, and the corresponding electromagnetic signal is sent in sequence: the first section of the sine wave signal lasting T3 time → the first section of the sine wave signal lasting T2 time → the second section of the sine wave signal lasting T3 time → the first section of the low level signal lasting T2 time → the third section of the sine wave signal lasting T3 time → the second section of the sine wave signal lasting T2 time → the fourth section of the sine wave signal lasting T3 time → the second section of the low level signal lasting T2 time, wherein there is a low level signal interval lasting a set time between the above two adjacent signal sections. For the above electromagnetic signals, after being shaped by the first pulse generating circuit 2030, the first pulse signal corresponding to the digital code information 1010 is obtained as shown in FIG. Fig.14 As shown, two adjacent digital codes are separated by an interrupt command (or interrupt pulse).

[0127] The signal input end of the signal processing circuit 2020 is connected to the signal output end of the first pulse generating circuit 2030 to obtain the first pulse signal output by the first pulse generating circuit 2030, and obtain the digital coding information sent by the electromagnetic pen according to the first pulse signal.

[0128] Furthermore, the signal processing circuit 2020 can decode the digital coded information according to the communication protocol agreed upon by both parties to obtain the information to be sent by the electromagnetic pen.

[0129] Fig. 9 is a schematic structural diagram of a first pulse generating circuit 2030 according to an embodiment of the present invention.

[0130] according to Fig. 9 As shown, the first pulse generating circuit 2030 of this embodiment may include a threshold circuit 2031, an integrating circuit 2032 and a first shaping circuit 2033 connected in sequence.

[0131] The signal input terminal of the threshold circuit 2031 is connected to the signal output terminal of the signal receiving circuit as the signal input terminal of the pulse generating circuit 2030 to receive the electromagnetic signal.

[0132] The function of the threshold circuit 2031 is to detect the signal amplitude of the electromagnetic signal, and output a high level when the signal amplitude is greater than the reference voltage, and output a low level when the signal amplitude is less than or equal to the reference voltage. Therefore, the threshold circuit 2031 can convert each sine wave signal in the electromagnetic signal into a corresponding pulse sequence, and then obtain and output a pre-order pulse signal composed of each pulse sequence and a low-level signal. For example, Fig.14The sine wave signal lasting for T2 time is converted into a pulse sequence including three pulses, the sine wave signal lasting for T3 time is converted into a pulse sequence including one pulse, the first sine wave signal lasting for a longer time is converted into a pulse sequence including multiple pulses, and so on.

[0133] In an example, Fig.12 As shown, the threshold circuit 2031 may include a comparator U11 and a reference voltage circuit, wherein the output end of the reference voltage circuit is connected to the inverting input end of the comparator U11 to provide a reference voltage to the inverting input end. The non-inverting input end of the comparator U11 serves as a signal input end of the threshold circuit 2031 to receive the electromagnetic signal Zin provided by the signal receiving circuit 2010, and the output end of the comparator U11 serves as an output end of the threshold circuit 2031 to output a pre-order pulse signal Zout.

[0134] In this example, the reference voltage circuit may include a voltage divider circuit connected between the power supply terminal VDD and the ground terminal, and a voltage dividing point of the voltage divider circuit is connected to the inverting input terminal of the comparator U11 as an output terminal of the reference voltage circuit.

[0135] For example, the voltage divider circuit includes a resistor R11 and a resistor R12 connected in series, and the potential point between the resistor R11 and the resistor R12 is a voltage divider point of the voltage divider circuit.

[0136] For another example, the voltage divider circuit may further include a capacitor C11 and a resistor R12 connected in parallel.

[0137] In this example, the threshold circuit 2031 may further include a resistor R13 connected between the output terminal of the comparator U11 and the power supply terminal VDD to play a pull-up role.

[0138] The integration circuit 2032 is connected to the input end of the first shaping circuit 2033 and is configured to integrate each pulse sequence of the previous-stage pulse signal to obtain an integration waveform corresponding to each pulse sequence, and then output a subsequent-stage pulse signal composed of the integration waveform and a low-level signal.

[0139] In this embodiment, the integration circuit 2032 performs integration processing on each pulse sequence to obtain an envelope waveform corresponding to each pulse sequence.

[0140] In one example, refer to Fig.13 As shown, the integration circuit 2032 includes a resistor R22 and a capacitor C22, and the resistor R22 and the capacitor C22 are connected in parallel.

[0141] The first shaping circuit 2033 shapes the integrated waveform into a regular high-level signal to obtain a first pulse signal composed of a high-level signal and a low-level signal.

[0142] In one example, the first shaping circuit 2033 includes an inverter, so as to shape the latter-stage pulse signal through the inverter and output the first pulse signal DIN1 that meets the requirements of the digital signal.

[0143] For example, Fig.13 As shown, the first shaping circuit 2033 includes an inverter U21 and an inverter U23, the input end of the inverter U21 is connected to the integration circuit 2032 as the input end of the first shaping circuit 2033, the output end of the inverter U21 is connected to the input end of the inverter U23, and the output end of the inverter U23 outputs the first pulse signal DIN1.

[0144] In an example, the first shaping circuit 2033 further includes a filtering circuit connected to one end of the first shaping circuit 2033 outputting the first pulse signal DIN1 .

[0145] For example, Fig.13 As shown, the filtering circuit includes a resistor R25, a resistor R26 and a capacitor C25, the first end of the resistor R26 is connected to the output end of the inverter U23, the resistor R25 is connected between the second end of the resistor R26 and one end of the output first pulse signal DIN1 of the first shaping circuit 2033, and the capacitor C25 is connected between the second end of the resistor R26 and the ground end.

[0146] Fig.10 is a schematic structural diagram of a sensing device according to a second embodiment of the present invention.

[0147] In this embodiment, the electromagnetic signal includes an identification signal and a data signal that are sent successively, the duration of the sinusoidal wave signal in the identification signal is greater than or equal to the set time, and the duration of the sinusoidal wave signal in the data signal is less than the set time.

[0148] For example, Fig.14 The duration of the first sine wave signal in is greater than the set time, which is the identification signal. Fig.14 The T2 time in is less than the set time, and it is a data signal.

[0149] relatively Figure 8 In the embodiment shown, the sensing device 2000 of this embodiment also includes a second pulse generating circuit 2040, which is configured to only shape each segment of the sinusoidal wave signal in the identification signal into a high-level signal representing the first digital code, obtain a second pulse signal composed of a high-level signal and a low-level signal, and output the second pulse signal to the signal processing circuit 2020.

[0150] The signal processing circuit 2020 is also configured to obtain digital coding information represented by the electromagnetic signal according to the second pulse signal, that is, to obtain the digital coding information represented by the electromagnetic signal according to the first pulse signal and the second pulse signal, and the data content represented by the digital coding information.

[0151] For example, Fig.15 As shown, the electromagnetic signal includes three sinusoidal wave signals of duration T, and the time T is greater than the set time. Therefore, the three sinusoidal wave signals of duration T constitute the first identification signal, which indicates that the pen tip pressure data will be sent next. After the second pulse generating circuit 2040, the digital coding information obtained by shaping the three sinusoidal wave signals of duration T is 111, that is, the digital coding information 111 represents the data type identification of the pen tip pressure data to be sent.

[0152] For example, Fig.16 As shown, the electromagnetic signal includes two sine wave signals of duration T, with a low level signal interval of duration T in between. This part of the signal constitutes a second identification signal, which indicates that the state data of the electromagnetic pen will be sent next. After the second pulse generating circuit 2040, the digital code information obtained by shaping is 101, that is, the digital code information 101 represents the data type identification of the sent state data.

[0153] According to this embodiment, since the second pulse signal only contains a data type identifier but not specific data content, the signal processing circuit 2020 can accurately identify the data type of the data encoding information following the first pulse signal based on the second pulse signal, thereby achieving accurate decoding.

[0154] According to this embodiment, since the data type identification is not completely dependent on the data type identifier in the first pulse signal, the decoding accuracy can be improved.

[0155] According to this embodiment, since the sensing device 2000 detects the position of the electromagnetic pen 1000, the electromagnetic pen needs to send a stable and continuous sinusoidal wave signal for a long period of time. Therefore, according to this embodiment, since the second pulse signal is identified by the sinusoidal wave signal that lasts for a long time, the sensing device 2000 can locate the electromagnetic pen according to the second pulse signal, and obtain the data sent by the electromagnetic pen 1000 according to the first pulse signal.

[0156] In one example, see Fig.11 The second pulse generating circuit 2040 includes a threshold circuit 2031, an integrating circuit 2032 and a second shaping circuit 2041 connected in sequence.

[0157] In this example, the second pulse generating circuit 2040 shares the threshold circuit 2031 and the integrating circuit 2032 with the first pulse generating circuit 2030 .

[0158] In another example, the second pulse generating circuit 2040 and the first pulse generating circuit 2030 may also be respectively configured with a separate threshold circuit 2031 and / or integration circuit 2032 .

[0159] The integration circuit 2032 is connected to the input end of the second shaping circuit 2041 to output the latter-order pulse signal to the second shaping circuit. The second shaping circuit 2041 is configured to only shape the integral waveform of the corresponding identification signal into a high-level signal, and to shape other signals into low-level signals, to obtain and output the second pulse signal DIN2 to the signal processing circuit 2030, so as to send the data type identification separately through the second pulse signal DIN2.

[0160] In one example, the second shaping circuit 2041 also includes an inverter.

[0161] In one example, the first shaping circuit 2033 and the second shaping circuit 2041 may share some inverters.

[0162] In one example, see Fig.13 The second shaping circuit 2041 may include an inverter U21, an inverter U22 and a signal extraction circuit. The input end of the inverter U21 is connected to the integration circuit 2032 as the input end of the second shaping circuit 2041, the output end of the inverter U21 is connected to the signal extraction circuit, the output end of the signal extraction circuit is connected to the inverter U22, and the output end of the inverter U22 is connected to one end of the output second pulse signal DIN2 of the second shaping circuit.

[0163] The signal extraction circuit includes a resistor R23, a resistor R21, a diode D21 and a capacitor C23, wherein the resistor R23 is connected between the output end of the inverter U21 and the first end of the capacitor C23, the anode of the diode D21 is connected to the output end of the inverter U21, the cathode of the diode D21 is connected to the first end of the capacitor C23, and the second end of the capacitor C23 is connected to the power supply terminal VDD via the resistor R21.

[0164] The signal extraction circuit uses resistors and diodes to make the capacitor C23 have different charging and discharging times, and only when the duration of the low-level signal output by the inverter U21 is greater than or equal to the set time, can the low-level signal be output to the inverter U23 through the first end of the capacitor C23 accordingly. Therefore, through the signal extraction circuit, the inverter U23 will only be able to output a high-level signal with a duration greater than or equal to the set time, indicating a data type identifier.

[0165] In an example, the second shaping circuit 2041 may also include a filtering circuit, which is connected to one end of the output second pulse signal, and may include a resistor R24, a diode D22 and a capacitor C24. The resistor R24 ​​is connected between the output end of the inverter U22 and one end of the output second pulse signal DIN2 of the second shaping circuit 2041, the cathode of the diode D22 is connected to the output end of the inverter U22, the anode of the diode D22 is connected to one end of the output second pulse signal DIN2 of the second shaping circuit 2041, and the capacitor C24 is connected between one end of the output second pulse signal DIN2 of the second shaping circuit and the ground end.

[0166] In one embodiment, any pulse generating circuit 2030 or 2040 may further include a rectifying circuit, so that the threshold circuit 2031 is connected to the integrating circuit 2032 via the rectifying circuit 2034 , so as to eliminate negative burrs in the previous-stage pulse signal through the rectifying circuit.

[0167] In one example, the first and second pulse generating circuits 2030 and 2040 both include and share a Fig.11 The rectifier circuit 2034 is shown.

[0168] In one example, refer to Fig.13 As shown, the rectifier circuit 2034 may include a diode D23 and a diode D24, one end of the output front-stage pulse signal of the threshold circuit 20 is respectively connected to the anode of the diode D23 and the cathode of the diode D24, the cathode of the diode D23 is connected to the integration circuit 2032, and the anode of the diode D24 is connected to the ground terminal.

[0169] Embodiments of the present invention have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or technical improvements in the marketplace, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein. The scope of the present invention is defined by the appended claims.

Claims

1. A sensing device for an electromagnetic pen, characterized in that: comprising a signal receiving circuit, a first pulse generating circuit and a signal processing circuit connected in sequence; The signal receiving circuit receives the electromagnetic signal sent by the electromagnetic pen, and transmits the electromagnetic signal to the first pulse generating circuit; wherein the electromagnetic signal includes a sine wave signal corresponding to the first digital code and a low level signal corresponding to the second digital code; The first pulse generating circuit is configured to shape each section of the sinusoidal wave signal in the electromagnetic signal into a high-level signal representing the first digital code, obtain a first pulse signal composed of the high-level signal and the low-level signal, and output the first pulse signal to the signal processing circuit; The signal processing circuit is configured to obtain digital coded information represented by the electromagnetic signal according to the first pulse signal; The electromagnetic signal includes an identification signal and a data signal that are sent successively, the duration of the sinusoidal wave signal in the identification signal is greater than or equal to a set time, and the duration of the sinusoidal wave signal in the data signal is less than the set time; The sensing device further includes a second pulse generating circuit, which is configured to only shape each section of the sinusoidal wave signal in the identification signal into a high-level signal representing the first digital code, obtain a second pulse signal, and output the second pulse signal to the signal processing circuit; The signal processing circuit is further configured to obtain digital coded information represented by the electromagnetic signal according to the second pulse signal.

2. The sensing device according to claim 1, characterized in that: The first pulse generating circuit comprises a threshold circuit, an integrating circuit and a first shaping circuit connected in sequence; The threshold circuit is configured to convert each section of the sine wave signal in the electromagnetic signal into a pulse sequence, obtain a front-stage pulse signal composed of the pulse sequence and the low-level signal, and output the front-stage pulse signal to the integration circuit; The integration circuit is configured to integrate each pulse sequence of the preceding pulse signal, obtain a subsequent pulse signal composed of an integrated waveform obtained by the integration and the low-level signal, and output the subsequent pulse signal to the first shaping circuit; The first shaping circuit shapes the integrated waveform into the high-level signal, obtains the first pulse signal and outputs it to the signal processing circuit.

3. The sensing device according to claim 1, characterized in that: The second pulse generating circuit comprises a threshold circuit, an integrating circuit and a second shaping circuit connected in sequence; The threshold circuit is configured to convert each section of the sine wave signal in the electromagnetic signal into a pulse sequence, obtain a front-stage pulse signal composed of the pulse sequence and the low-level signal, and output the front-stage pulse signal to the integration circuit; The integration circuit is configured to integrate each pulse sequence of the preceding pulse signal, obtain a subsequent pulse signal composed of an integrated waveform obtained by the integration and the low-level signal, and output the subsequent pulse signal to the second shaping circuit; The second shaping circuit is configured to only shape the integrated waveform corresponding to the identification signal into a high-level signal representing the first digital code, and obtain the second pulse signal to output to the signal processing circuit.

4. The sensing device according to claim 2 or 3, characterized in that: The threshold circuit includes a comparator and a reference voltage circuit, wherein the reference voltage circuit is connected to the inverting input terminal of the comparator to provide a reference voltage to the inverting input terminal; the non-inverting input terminal of the comparator receives the electromagnetic signal provided by the signal receiving circuit, and the threshold circuit outputs the preceding-order pulse signal through the output terminal of the comparator.

5. The sensing device according to claim 2 or 3, characterized in that: The pulse generating circuit further includes a rectifying circuit, and one end of the threshold circuit outputting the preceding-step pulse signal is connected to the integrating circuit via the rectifying circuit.

6. The sensing device according to claim 2 or 3, characterized in that: The shaping circuit includes an inverter.

7. An electronic device, characterized in that: A sensing device comprising the sensing device according to any one of claims 1 to 6.

8. An electromagnetic induction system, characterized in that: An electromagnetic pen and the sensing device according to any one of claims 1 to 6, or an electromagnetic pen and the electronic device according to claim 7; The electromagnetic pen comprises a signal generating circuit and a signal processing circuit. The signal processing circuit of the electromagnetic pen generates an electromagnetic signal by controlling the on and off of the signal generating circuit. The signal generating circuit generates a sinusoidal wave signal in an on state and generates a low level signal in an off state.

9. The electromagnetic induction system according to claim 8, characterized in that: The electromagnetic pen also includes a switching circuit, which is controlled by a signal processing circuit of the electromagnetic pen. The switching circuit has a first switching state and a second switching state. The switching circuit is connected to the signal generating circuit, and the connection is configured so that the switching circuit connects the signal generating circuit to generate the sinusoidal wave signal in the first switching state and disconnects the signal generating circuit to generate the low-level signal in the second switching state.

Images