WO2011091752A1

WO2011091752A1 - Electronic handwriting pen

Info

Publication number: WO2011091752A1
Application number: PCT/CN2011/070655
Authority: WO
Inventors: 刘中华
Original assignee: 北京爱易玛克科技有限公司
Priority date: 2010-01-27
Filing date: 2011-01-26
Publication date: 2011-08-04
Also published as: CN101727218A

Abstract

An electronic handwriting pen is disclosed, which comprises: a penholder and a pen head mounted in a through-hole on the head of the penholder; wherein, a pressure-detecting sensor is mounted between the pen head and the sensor bracket of the penholder, and is the one that the output value thereof is a continuous amount having a unique corresponding relationship with the pressure; in the penholder is set a circuit system for supporting the operation of the electronic handwriting pen and a power supply apparatus for supplying the power for the circuit system, and the circuit system includes a pressure signal conditioning circuit and a signal output unit; the signal conditioning circuit is connected with the output end of the pressure-detecting sensor, the signal output unit is connected with the output end of the signal conditioning circuit, and the signal output unit is used for outputting the signal or data which corresponds to the pressure signal output by the pressure-detecting sensor to the specified port of the system which cooperates with the electronic handwriting pen. The handwriting changes of the electronic handwriting pen are abundant and nearly to be the natural writing, thus expanding the applications of the handwriting input product in the aspects of calligraphy, and brushwork and so on.

Description

Electronic stylus This application claims priority to Chinese Patent Application No. 201010101907.9, entitled "Electronic stylus with pressure value detection function", filed on January 27, 2010, the entire contents of which are hereby incorporated by reference. Combined in this application. Technical field

The present invention relates to computer human-computer interaction device technology, and more particularly to an electronic stylus for an electronic whiteboard or a handwriting board. Background technique

Computer tablets and interactive whiteboards for online communication, text graphics input, teaching, conference systems have become more and more widely used. Existing technologies for such products mainly include resistive films, electromagnetic induction, capacitance, surface acoustic waves, ultrasonic, infrared, image processing and the like. Although these techniques can realize the input of handwritten text, some of the writing features that need to express the writer, such as changing the thickness of the stroke by the writing strength of the writer, to achieve a certain effect, such as painting, calligraphy, etc. The application, many technologies are difficult to adapt. Even with software to simulate, it is difficult to achieve real results. Among these technologies, the electromagnetic induction technology itself has a pressure sensing function, but since the electromagnetic induction technology requires a bottom plate on which an inductive conductor is mounted, the bottom plate is neither opaque nor fixed in size, so it is not suitable for many occasions, such as moving, or Used on the surface of flat panel displays. Handwriting boards, electronic whiteboards, and touch screens that use resistive films, capacitors, surface acoustic waves, and dual-camera image recognition technology do not require the use of a dedicated pen, so it is difficult to detect pressure sensitivity without using a specially designed special pen. Ultrasonic technology and electronic whiteboards, writing screens and writing tablets constructed by image recognition technology that uses a single camera to capture the entire writing surface generally require the use of a dedicated pen, so there is a possibility of implementing pressure sensing. However, in the prior art, there is no application of pressure sensing technology for these two technologies, thus limiting the application field of products using these two technologies. Hehe.

The Chinese invention patent number 03158995. 2 discloses a stylus that can simulate a brush stroke, and includes a pressure sensor. The technique of simulating the stroke by the simulation device of the main control system mainly describes the use of different pressure values in the main control system. The technical solution to simulate the writing strength of the stylus solves the problem of the relationship between the pressure value and the displayed image, but still does not solve the problem of pressure value acquisition, data processing, and data transmission, that is, it does not solve what kind of internal passage of the stylus The structure is able to obtain the problem of pressure values, especially for the internal structure of the stylus used in handwriting input devices for ultrasonic and single camera image recognition techniques.

The Chinese invention patent number 03158994. 4 discloses a bendable pressure-sensing stylus in which a gear, a rotational speed detector, and a pressure value generator mounted in the tip are used to detect rotational speed data and rotational direction data. And generating a pressure value based on the rotational speed data and the rotational direction data, and transmitting to the main system via the signal transmission line. The invention adopts a mechanically-conducted structure, and although it can detect the pressure value at the time of writing, there are disadvantages such as fixed directionality of the rotating member, easy damage, and low accuracy of pressure value detection, and cannot be used for ultrasonic and single-camera image recognition technology. Handwriting input device.

The Chinese utility model patent number 200420040580. 9 discloses a multi-function stylus which also includes a pressure sensor. However, the main function of the pressure sensor here is to judge the writing state of the pen, not the strength of the pen when writing, so it is impossible to solve the problem of obtaining the pressure value. Summary of the invention

The invention provides an electronic stylus capable of detecting the pressure value of the stylus pen in the writing state and transmitting it to the main control system.

In order to achieve the object of the present invention, an electronic stylus pen includes: a pen holder and a pen tip mounted in a through hole of the pen head, wherein a pressure detecting sensor is mounted between the pen head and the sensor holder of the pen holder, wherein The pressure detecting sensor is a continuous amount of sensors whose output value has a unique correspondence with the magnitude of the pressure;

a circuit system supporting the operation of the electronic stylus is disposed in the pen holder, and the electric system is a power supply device for supplying power to the road system;

The circuit system includes a pressure signal conditioning circuit and a signal output unit, the signal conditioning circuit is coupled to an output of the pressure detecting sensor, and the signal output unit is coupled to an output of the signal conditioning circuit;

The signal output unit is configured to output a signal or data corresponding to the pressure signal output by the pressure detecting sensor to a designated port of the system working with the electronic stylus.

In the technical solution of the present invention, the pressure detecting sensor can be used in a wide variety of types, a strain gauge, a Hall (displacement) sensor, an electret (capacitance) sensor similar to an electret microphone, or even a special structure. Electret microphone. These sensors can output the pressure signal in the form of voltage output. Therefore, the output of the sensor or sensor detection circuit can be connected to a front-end adaptation circuit that matches the sensor type, such as a signal amplification circuit, which is generally composed of an operational amplifier. If these pressure signals are to be digitized, an A/D converter can also be used to connect to the output of the amplifier circuit. If further processing is performed to convert these digital pressure data into a more suitable data format, an encoder can be connected to the output of the A/D converter, and the encoder can be constructed using a microcontroller. The pressure signals output by all of the above circuit units can be transmitted as available data to designated ports of the system that work with the stylus. Among them, because the signal amplifying circuit outputs an analog quantity, it is more suitable for wired output, and the digital quantities output by the other two circuit unit A/D converters or encoders can be wired or wireless. Transfer to the designated port of the system that works with the stylus. There are two ways to wirelessly transmit: one is to build an output unit with an RF module, and use RF radio to transmit pressure data; the other is to use an infrared transmitting module to build an output unit that uses infrared to transmit pressure data.

The above-mentioned sensors can detect the pressure on the tip by a suitable mounting structure, wherein:

The strain gauge can be mounted on the bow top position on the arch beam which can amplify the strain caused by the pressure of the pen head. Two strain gauges can be used to be mounted on the inner and outer surfaces of the bow top, and then connected to the two resistors to detect electricity. Bridge, output pressure signal. The Hall sensor can be installed in the middle of a magnetic circuit composed of two magnets. The magnets of the same name are opposite to each other, one piece is mounted on the sensor holder in the pen, and the other piece is mounted on the end of the pen head. A magnet is mounted on the end of the magnetic circuit with the tip of the pen.

It is also possible to mount a Hall sensor at the end of the tip and deep into the magnetic gap of the magnetic circuit formed by the magnet and the shoe iron respectively mounted on the two magnetic poles of the magnet; the magnet and the shoe iron are mounted On the sensor holder in the pen, the pen tip is also elastically mounted on the pen sensor holder or the magnet and the shoe iron.

For the electret sensor, one of the electret-containing diaphragm and the electrode diaphragm can be mounted on the sensor holder in the pen, and the other is mounted on the end of the pen tip and elastically mounted in the pen sensor holder or another film. On-chip, a charge amplifier generally composed of FETs is disposed. The electret microphone is used as a pressure detecting sensor, and can be hermetically connected to an open end of an elastic gas having an open end and penetrated into the air vent, and the other end of the air vent is closed and installed at the end of the tip.

In the technical solution of the present invention, a pressure detecting sensor with a variable capacitance and a variable inductance structure can also be used, and the magnetic pole of the capacitor or the magnetic conductor of the inductor is moved by the writing head under the writing pressure, thereby changing the capacitance of the sensor or The way of the inductance value enables the detection of pressure. The front-end adaptation circuit of the two sensors can use an oscillating signal generator, and the variable capacitance or the inductance sensor can be connected to the oscillating tank of the oscillating signal generator, and then a frequency detecting unit such as a frequency meter, a timer, etc. A circuit unit that measures the change in the oscillator output frequency due to pressure. Then, as described above, it can be directly outputted by the output unit in a wired or wireless manner, or after being encoded, the pressure value is output through the output unit.

The variable capacitance structure pressure detecting sensor is composed of two plates, one of which is mounted on the sensor holder in the pen, the other plate is connected to the end of the pen tip, and is elastically mounted in the pen sensor holder or another An air gap is formed between the plates and the plates mounted on the sensor holders in the pen. The pressure detecting sensor of the variable inductance structure is composed of a coil wound on the open core and a magnet in front of the core opening; the iron core is mounted on the sensor bracket in the pen, and the magnet is connected to the end of the tip And elastically mounted on the sensor holder or core of the pen, forming an air gap with all or part of the core. The present invention also provides a handwritten light pen or an ultrasonic stylus pen for use in an electronic whiteboard, a writing screen, and a tablet for use in ultrasonic technology and image recognition technology that uses a single camera to capture a whole writing surface. Integrated technical solutions. Because the stylus of these two applications has an infrared transmitting tube, it is possible to use a mixer to input the pressure data signal from the output of the signal conditioning circuit to the original stylus in the handwritten stylus. The infrared light drive signals of the position and motion trajectory, or the original drive signals used to transmit the infrared time scale signals in the ultrasonic pen are added and mixed, and then their existing launch tubes are used to transmit the pressure data of the stylus. In addition, an excitation switch controlled by the pressure data output from the signal conditioning circuit may be disposed in the circuit system in the pen body, and the pressure data is received by the circuit system; after receiving the pressure data of the specified value, the The electronic pen emits corresponding infrared or ultrasonic waves that are used to detect the stylus position and motion trajectory.

Since various pressure detecting sensors that can be used in the present invention have errors in manufacturing, installation, and the like, and are also affected by factors such as temperature, humidity, and gain deviation of the amplifier, even when the pressure of the writing head is 0, signal conditioning The data output from the circuit is also difficult to be 0 or a specified value, that is, zero drift occurs. Therefore, in the circuit system of the present invention, a manual switch is also provided; manually operating the manual switch, the zero drift can be eliminated in three ways, respectively: first, controlling the circuit system, and conditioning the signal After the signal or data corresponding to the pressure signal outputted by the circuit is added with a specific identifier, it is directly outputted through the output unit to the main control system working with the stylus as an initial value for calculating the writing pressure; Controlling the circuit system, such as an encoder, to set a signal or data corresponding to a pressure signal output by the signal conditioning circuit to a set initial value, such as 0; third, controlling the circuit system, adjusting The parameter or the preset value of the component in the signal conditioning circuit is such that the signal or data corresponding to the pressure signal outputted by the signal is a set initial value, such as 0.

The electronic stylus provided by the invention adopts a continuous amount of pressure detecting sensor whose output value has a unique correspondence with the magnitude of the pressure, so that the strength of the writer when writing with the stylus can be accurately measured within a certain range, The aspect can make the writing effect closer to natural writing, the handwriting changes more richly and more distinctively; on the other hand, a wide variety of handwriting boards and electronic whiteboards are expanded. The application range of the handwriting screen is more suitable for art applications such as painting and calligraphy, and for the first time, the pressure sensitive writing is realized at a lower cost on the display screen of a data processing device such as a computer. At the same time, the technical solution of the present invention can use a plurality of different types of sensors to detect the writing strength, so in the design and production process, different technical solutions can be selected according to the characteristics of different sensors, so as to be applicable to different applications and environments. . Furthermore, the various sensors used in the technical solutions of the present invention have the characteristics of low cost, so that the pressure sensing function can be added to the existing multiple handwriting input products without increasing the cost of the components. DRAWINGS

1 is a basic structural diagram of a pressure sensitive handwritten light pen using a wireless transmission unit according to an embodiment of the present invention;

2 is another basic structural diagram of a pressure sensitive handwritten light pen using a wireless transmission unit according to an embodiment of the present invention;

3 is a schematic view showing a mounting structure of a strain gauge on a bow beam according to an embodiment of the present invention; FIG. 4 is a structural view of a pressure detecting bridge formed by using a strain gauge according to an embodiment of the present invention; Schematic diagram of a pressure sensing structure of a sensor as a pressure detecting sensor;

6 is a schematic diagram of another pressure sensing structure using a Hall sensor as a pressure detecting sensor according to an embodiment of the present invention;

7 is a schematic diagram of a pressure sensing structure using an electret microphone as a pressure detecting sensor according to an embodiment of the present invention;

FIG. 8A is a schematic diagram of a pressure sensing structure using an electret as a pressure detecting sensor according to an embodiment of the present invention; FIG. 10 is a block diagram showing the structure of a pressure detecting circuit for transmitting pressure data by wire according to an embodiment of the present invention;

11 is a block diagram showing another structure of a pressure detecting circuit using wired transmission pressure data according to an embodiment of the present invention;

12 is a block diagram showing the structure of a pressure detecting circuit for transmitting pressure data using a wireless module according to an embodiment of the present invention;

FIG. 1 is a block diagram showing a circuit structure of an infrared transmitting tube in a handwritten light pen as a pressure data transmission element according to an embodiment of the present invention; a basic structure diagram of a sensing ultrasonic pen;

Figure 15 is a block diagram showing the circuit configuration of an infrared transmitting tube in a handwriting ultrasonic pen as a pressure data transmitting element according to the present invention. detailed description

The technical solutions in the embodiments of the present invention are clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present invention. It is a partial embodiment of the invention, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

According to the object and content of the present invention, embodiments of the present invention can be classified into two types. The first type is an embodiment applied to various pressure detecting sensors in the present invention, and mainly describes various types and structures of the pressure detecting sensors that can be used in the present invention, mounting methods, and specific embodiments of the matched external circuits, which are suitable for A general implementation of any stylus that contains a circuit structure. The second type is an electronic stylus used in a conventional handwriting input device that uses ultrasonic technology or single camera image recognition technology, and is a specific embodiment of the present invention. Wherein, the sensor of the present invention is a continuous amount of pressure sensor, for example, a sensor made of a material whose pressure force varies with resistance can be used as the sensor of the present invention. First, an embodiment for various sensors will be described.

First, Fig. 1 and Fig. 2 show the general structure of a stylus to which the present invention is applied and which transmits pressure data using an infrared transmission module. The difference between the two figures mainly lies in the difference of the stylus outer casing. Figure 1 is a more ergonomic stylus structure, and Figure 2 is the most commonly used stylus structure. In the figure, 101 is a stylus housing; 102 is a stylus pen; 103 is a pressure detecting sensor; 104 is a sensor holder in the pen; 105 is a sensor fitting circuit; 106 is a subsequent processing portion of the pressure signal conditioning circuit; 107 is pressure The signal output unit 108 is an infrared transmitting tube of the infrared output module; 109 is the original circuit system in the stylus; 110 is a power supply system of the stylus. Since the two drawings differ in the structure of the outer casing 101, the optimum mounting position of the infrared transmitting tube 108 is also different. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a specific embodiment of the present invention will be described based on the conventional structure shown in FIG. 2, in conjunction with the drawings, when different types of sensor elements are used as the pressure detecting sensor.

Embodiment 1 : Using a strain gauge as a pressure detecting sensor

Fig. 3 and Fig. 4 show the structure of the mounting structure of the strain gauge and the structure of the basic detecting circuit when the strain gauge is used as the pressure detecting sensor. In the figure, 301 is an arched beam for enlarging the writing pressure of the writing head. One end of the arched beam is mounted on the sensor bracket 104 in the pen, and the other end is connected with the end of the pen head 102, and can be fixedly connected or hinged and suspended, as long as the pen tip is secured. The pressure of 102 can be smoothly transmitted to the bow beam. At the opening of the arched beam is a slit 304 to ensure that the arched beam can deform under the writing pressure, but the deformation is not too large and exceeds the elastic range of the beam, resulting in plastic deformation of the beam. 302 and 303 are two pieces of resistance strain gauges respectively mounted on the inner and outer surfaces of the arcuate top of the arch beam, and respectively form a pressure detecting circuit of the bridge structure with the other two resistors R1 and R2, as shown in FIG. 4 . In FIG. 4, 401 is a detection bridge driving circuit; 402 is a signal processing circuit adapted to the bridge, and the main part generally uses a voltage amplifying circuit composed of an operational amplifier, and in some cases, a current amplifying circuit can be used. For details on the use of resistance strain gauge force measurement, please refer to the relevant content in "Strain Electrical Measurement and Sensing Technology" edited by China Metrology Publishing House and edited by Ma Liangzhu. The unified book number is ISBN 7-5026-0630 -0/TM - 5 ₀

Embodiment 2: Using a Hall sensor as a pressure detecting sensor

See Figure 5 and Figure 6. Hall sensors that can output continuous analog quantities are widely used in tiny The detection aspect of displacement. In the present invention, the writing pressure can be detected by moving the magnet or the Hall sensor by the movement of the writing pressure and the reaction force of the elastic member in the pen. Figure 5 shows a detection structure using a Hall sensor as a sensor. In FIG. 5, the Hall sensor 501 is a Hall sensor mounted between the magnetic poles of the same polarity of the two sheet magnets 502, 503, and two magnets are mounted on the sensor holder 104 in the pen, and the other piece is mounted. At the end of the pen tip 102. Here, the repulsive force between the isotropic magnetic poles is used as the restoring force of the writing head resetting, that is, the position of the writing head returns to the unwritten state after the pressure of the writing head 4 is flashed. Since the magnitude of this repulsive force uniquely corresponds to the distance between the two magnets, the electrical signal output by the Hall sensor also uniquely corresponds to the pressure of the pen tip.

Figure 6 shows another mounting structure for the Hall sensor. The Hall sensor 501 is mounted at the end of the pen tip 102 and penetrates between the magnetic gaps of the magnetic paths formed by the magnets 603 and the two shoe irons 602 respectively mounted on the two magnetic poles of the magnet 603. The magnet 603 and the two shoe irons 602 are mounted on the sensor holder 104 in the pen, and the pen head 102 is elastically mounted on the pen inner sensor bracket 104 or the magnet and the shoe iron through the elastic member 601 (the figure shows the installation) On the boot iron 602).

The structures shown in Figures 5 and 6 each have advantages and disadvantages. The structure shown in Fig. 5 has a large linear range, but the output sensitivity is low; the structure shown in Fig. 6 has high sensitivity, but the linear range is small.

Embodiment 3: Using an electret microphone as a pressure detecting sensor

As shown in Figure 7, a universal electret microphone (electret microphone) can also be used to detect the writing pressure of the pen. 701 is an elastic gas cylinder; 702 is an electret microphone; the electret sensor is composed of an elastic gas cylinder 701 and an electret microphone 702. One end of the elastic gas cylinder 701 closes the other end opening, the open end is hermetically connected to the electret microphone 702, and the electret microphone 702 penetrates into the elastic gas cylinder 701; the other end of the elastic gas cylinder 701 is installed in the chamber The end of the pen head 102 is described. In this configuration, the outer wall of the elastic gas cylinder 701 serves as an elastic member mainly supporting the pen head 102, which generates a restoring force under the writing pressure; the air in the elastic gas cylinder serves as a conduction medium for the writing pressure, and the pressure is applied when the air cylinder is compressed. Applying to the elastic diaphragm inside the electret microphone 702, the distance between the elastic diaphragm and the internal fixed electrode is changed as the size of the air bladder is compressed, thereby realizing the detection of the writing pressure. In this configuration, the elastic force of the outer wall of the elastic gas 嚢 701 is to ensure the air enthalpy The air inside is not excessively compressed, which causes the microphone diaphragm to stick to the surface of the internal fixed electrode, which is a key factor causing the sensor failure. If necessary, a mechanism for stopping or limiting the tip 102 or the air is provided to ensure the gas. You are not over-compressed. In addition, this structure is preferably provided with an air passage which can be gradually and evenly pressurized between the air and the atmosphere, such as a gas permeability similar to leather, to ensure atmospheric pressure inside and outside the gas cylinder under conditions of temperature and humidity change. Equilibrium can be achieved within a certain period of time, but does not affect the transmission of instantaneous pressure during writing.

Embodiment 4: Using an electret sensor as a pressure detecting sensor

As shown in Fig. 8A, the electret sensor is actually a kind of capacitive sensor, but because the electret surface has a permanent charge, the sensor can also have a built-in charge amplifier like an electret microphone, so here and before Several types of sensors are grouped together as a "pressure/voltage" output type of sensor rather than a purely capacitive sensor. The electret sensor is composed of electrode pads 801, 803, spacer washer 806, elastic holder 802, and a charge amplifier (not shown). One of the two electrode diaphragms is an electret diaphragm or a metal diaphragm coated with an electret film material; the two diaphragms are mounted on the sensor holder 104 in the pen, and the other diaphragm is mounted on the The end of the pen tip 102 is mounted to the sensor holder 104 or another diaphragm in the pen by a resilient bracket 802. The spacer gasket is annular and is mounted between the two diaphragms. Another mounting structure is to omit the elastic bracket 802, and directly mount the spacer gasket 806 between the two electrode diaphragms, and use the elastic force of the electrode diaphragm to generate a restoring force to the tip. Two diaphragms are connected to the input of the charge amplifier. Here, the charge amplifier can use an amplifier of the same structure as the electret microphone, such as a charge amplifier constructed using a field effect transistor as a core element.

The sensors used in the above embodiments can output the pressure signal in the form of voltage (or current, but not commonly used) output. Therefore, the rear end of the sensor or sensor detection circuit needs to be connected with a front end adaptation matching the sensor type. The circuit, such as the signal amplifying circuit 402 of FIG. 4, is also a structure of the front end adapting unit 105 of FIG. If further processing is performed, a subsequent processing unit 106 may be added after the adaptation unit 105, which may include an A/D converter for digitizing the pressure signals, and an encoder may be added to apply the pressure data in the digital form. Convert to a data format that is more suitable for transmission. The pressure signal output by all the above circuit units, Both can be transmitted as available data to a designated port of the system that works with the stylus. Wherein, since the signal amplifying circuit outputs an analog quantity, it is more suitable to be output in a wired manner. As shown in FIG. 10, the pressure data is transmitted to work with the stylus by using the data line 1001 as the output unit 107 in FIG. The specified port of the system. The digital quantity output after adding one or two subsequent processing units, the A/D converter unit and the encoder unit, can be transmitted in both wired and wireless manners, as shown in FIG. 11 and FIG. It can be transmitted through the data line 1001 or through the infrared or radio frequency wireless module 1201.

Embodiment 5: Using a variable capacitor as a pressure detecting sensor

Fig. 8B is a schematic view showing an embodiment of the present invention using a variable capacitor as a sensor. The difference from the use of an electret sensor is that the two electrode diaphragms 8011 and 8031 no longer have a permanent charge on them, but are simply conductive plates. The rest of the structure is the same as that of Embodiment 4, and an air gap constituting a capacitance is formed between the two plates. The front end adapting circuit corresponding to the variable capacitance pressure detecting sensor may be an oscillating signal generator 804, that is, another structure of the front end adapting unit 105 in FIG. 1, which is included in the signal conditioning circuit in the pen holder. . The terminal of the variable capacitance pressure detecting sensor is connected to the oscillating tank of the oscillating signal generator. When the writing pressure is transmitted to the electrode diaphragm of the capacitive sensor through the tip of the pen, the capacitance between the two diaphragms will change as the distance between the plates changes, so that the oscillation frequency of the oscillating signal generator will also change. . Thus, by detecting the change in the output frequency of the oscillator by using the frequency measuring unit 805 such as a frequency meter or a timer or a counter, the magnitude and variation of the writing pressure can be obtained. Here, if the frequency measuring unit 805 uses a presettable counter, such as lmS in a unit time, according to the measurement, the output frequency of the oscillator is not written in the writing head, that is, the output frequency of the oscillator when the writing head is idlely lifted, and is pre-intermitted in the counter under manual intervention. Setting a pulse value detected in the unit time will make the output of the frequency measuring unit zero, which is more convenient for data processing of other parts such as an encoder or a system working with the stylus.

Embodiment 6: Using a variable inductor as a pressure detecting sensor

As shown in Fig. 9, the variable inductance pressure detecting sensor is composed of a coil 903 wound around the open core 902, and a magnet 901 located in front of the opening of the core 902. Wherein the iron core is mounted on the sensor holder 104 in the pen, and the magnet 901 is connected to the end of the pen head 102, and An elastomer (not shown) similar to the elastic member 802 of Fig. 8A is mounted on the in-pen sensor holder 104 or the core to form an air gap with all or part of the core. The mounting structure shown in Fig. 9 is one of many available structures, and is directly mounted in the opening direction of the core by a diaphragm-shaped elastic magnetic conductor, and the edge is in contact with the iron core, and the center of the elastic diaphragm and the core core column An air gap is formed between them. This elastic magnetized diaphragm also provides a restoring force to the tip. As in the fifth embodiment, the front end matching circuit matched with the variable inductance sensor may be an oscillating signal generator 804, and the output end of the variable inductor is connected to the oscillating circuit of the oscillating signal generator, and then used. The frequency detecting unit 805 detects a change in the output frequency of the oscillator, thereby obtaining the magnitude and variation of the writing pressure.

Similarly to Embodiments 1-4, Embodiments 5 and 6 can also transmit pressure data using a wired or wireless structure as shown in Fig. 10, Fig. 11, or Fig. 12.

The encoders of the above embodiments 1-6 can be constructed using a microcontroller system, such as the microcontroller system 109 in the original circuitry of the stylus. For the embodiments 1-4, the microcontroller system is connected to the control terminal and the output terminal of the A/D converter through a set of I/O interfaces, and through another set of I/O interfaces and the circuit system The output units are connected; for Embodiment 5-6, the microcontroller system is connected to the control and output terminals of the oscillating signal generator or frequency detecting unit through a set of I/O interfaces, and through another group I/ The O interface is coupled to an output unit in the circuitry. As the microcontroller becomes more powerful, the above A/D can also use the A/D that is available on most existing microcontrollers. The frequency detection unit can also use the timer inside the microcontroller. In this configuration, the above I/O interfaces are virtual interfaces that can be implemented by programming the microcontroller.

Example 7: Pressure sensitive handwritten light pen

Figure 13 is a block diagram showing a circuit configuration of an electronic stylus that can be used in a handwriting input device using a single camera image recognition technique. Since the stylus itself has one or a group of infrared transmitting tubes 1301 and its driving circuit 1302, infrared light signals for detecting the position and motion trajectory of the stylus are emitted. Therefore, a signal mixer 1305 can be implemented in the pen by a microcontroller system 1303, and the pressure data signal from the output of the signal conditioning circuit in the pen can be used to detect the position and motion track of the stylus in the handwritten light pen. Infrared light signals are added, mixed, and then The existing infrared emission tube 1 301 is used to transmit the pressure data of the stylus. Generally speaking, the light pen emits continuous light, but the image sensor (commonly known as the camera) used in such a handwriting device can also collect infrared light signals modulated to a certain frequency, as long as the modulation frequency is higher than that of the image sensor. The frame rate (the number of frames captured per second) can be several times higher. For example, if the scanning frame rate of the image sensor is 100 frames/second, then the image sensor can completely acquire the infrared light signal amplitude modulated at several tens of kHz, as long as the non-lighting time of the modulated infrared light is not more than 10 mS. . According to the Nyquist principle, the carrier frequency is greater than twice the frequency of the modulated signal, and the modulated signal can be completely transmitted. Therefore, the stylus can be completely transmitted at a large rate by using a carrier with a proper frequency. Pressure data.

The basic structure of the pressure sensitive handwritten pen is basically the same as that shown in Fig. 1 or Fig. 2, except that the infrared transmitting tube for pressure data transmission is the same as the infrared transmitting tube for stylus position and motion track detection, and is installed in The nib portion within the pen tip 102.

Example 8: Pressure sensitive handwriting ultrasonic pen

Referring to Fig. 14, there is shown a block diagram of a circuit configuration of an electronic stylus which can be used for an ultrasonic handwriting input device. Since the ultrasonic stylus itself has a set of infrared transmitting tubes 1401 and its driving circuit 1402, an infrared pulse that is used to emit a time stamp signal is emitted. The time-scale signal mentioned here is actually a synchronization signal. Since the speed of light propagation in the air is much higher than the propagation speed of the ultrasonic wave, when the ultrasonic wave transmitting driving circuit 1404 in the stylus drives the ultrasonic wave transmitter 1403 to emit ultrasonic waves, the infrared emitting tube 1401 emits a width of only a few microseconds. The synchronization pulse is sent to the receiving portion of the ultrasonic wave, and after the receiving portion receives the optical pulse, the "0" timing of the timer is calibrated, and timing is started to detect the propagation time of the ultrasonic wave in the air, so the infrared light pulse is called the time-scale signal. . Therefore, the signal mixer 1 305 shown in FIG. 13 can still be used to add the pressure data signal from the output of the signal conditioning circuit in the pen to the time-scale signal generated in the original circuit system 1405 in the ultrasonic pen. Then, the existing infrared emission tube 1401 is used to transmit the pressure data of the stylus. At the receiving end, as long as the corresponding demodulator and splitter are matched, the pressure data signal can be received simultaneously or after receiving the time-scale signal.

The basic structure of the pressure sensitive handwriting ultrasonic pen is shown in Fig. 15. Similar to Embodiment 7, ultrasonic emission The device 1501 is mounted on the pen body near the pen tip; the infrared emission tube group 1502 is also mounted on the pen body; the ultrasonic pen is equipped with a circuit system 1503, which includes a front end adapting unit and a control microcontroller for the pressure detecting sensor system.

For Embodiments 7, 8, it is also possible to provide an activation switch 1304 controlled by the pressure data output from the signal conditioning circuit in the circuitry within the body, through which the pressure data is received. After receiving the pressure data of the specified value through the setting of the software of the microcontroller in the pen body, the control electronic pen emits corresponding infrared or ultrasonic waves which are used to detect the position and motion track of the stylus. This embodiment can replace the micro-switches originally used for inductive writing pressure in the two stylus pens, and can set the starting pressure according to the writing requirements, not only can output the writing pressure data, but also effectively increase the sensitivity of the stylus writing. , eliminating the disadvantage that the pressure of the micro switch is often large, resulting in insufficient writing.

Because various pressure detecting sensors have errors in manufacturing, installation, etc., and are also affected by the discrete factors of temperature, humidity, and circuit parameters, even when the pressure of the writing head is 0, the data output by the signal conditioning circuit is also It is difficult to specify a value of 0 or a. Therefore, in the circuit system of the present invention, a manual switch is also provided. As shown in FIGS. 13 and 14, the switch can be installed in the operation button group 1 306 of the stylus and set separately. A button or a combination of the original button group. When the manual switch is manually operated, the zero drift can be eliminated by three technical solutions, which are:

First, controlling the circuit system (generally a microcontroller system, the same below), adding a specific identifier to a signal or data corresponding to the pressure signal output by the signal conditioning circuit, and directly passing through the output unit Output to the main control system working with the stylus as a reference initial value for calculating the writing pressure level;

Second, controlling the circuit system, such as an encoder, to set a signal or data corresponding to the pressure signal output by the signal conditioning circuit to a set initial value, such as by performing mathematical operations in the encoder, The initial value is set to 0;

Third, controlling the circuit system, using a negative feedback manner, adjusting parameters of the components in the signal conditioning circuit, such as using a digital potentiometer, or changing the detection bridge of the resistance strain gauge The resistor R1 or R2 of the bridge arm or the reference voltage of the differential amplifier in the front-end adaptive amplifier circuit 402 is adjusted so that the signal or data corresponding to the pressure signal output is a set initial value, such as 0. Or, according to the output frequency of the oscillating signal, an initial value is preset in the frequency detecting circuit 804 such that the result of the detection output is a specific value, such as 0.

The above embodiments give the main structural solutions that can be implemented by the present invention, but the available structural solutions for implementing the present invention are not limited to the specific structures given by these embodiments. For example, various sensors can have a variety of specific structures, as well as different force-bearing structures, different sensor mounting structures, different elastic support structures, and the like, and the arrangement thereof is difficult to count. Therefore, the technical solutions of the present invention, such as improvements, substitutions, omissions, and transplantations, are all within the scope of the present invention.

Claims

Rights request

What is claimed is: 1. An electronic stylus comprising: a pen holder and a pen tip mounted in a through hole of the pen head, wherein a pressure detecting sensor is mounted between the pen head and the sensor holder of the pen bar, wherein the pressure detecting sensor is an output a continuous amount of sensors having a unique correspondence with the magnitude of the pressure; a circuit system supporting the operation of the electronic stylus and a power supply device for supplying power to the circuit system;

The electronic stylus according to claim 1, wherein said signal conditioning circuit comprises a signal amplifying circuit, an A/D converter and an encoder, wherein:

An input end of the signal amplifying circuit is connected to an output end of the pressure detecting sensor, an output end of the signal amplifying circuit is connected to an input end of the A/D converter; an output end of the A/D converter Connected to an input of the encoder; the signal output unit of the output of the encoder is connected.

The electronic stylus according to claim 2, wherein the pressure detecting sensor is a strain gauge.

The electronic stylus according to claim 3, wherein the number of the resistance strain gauges is two, respectively installed on the inner and outer surfaces of the arcuate cymbal, and the two resistances form a pressure detecting circuit; One end of the cymbal is mounted on a sensor holder in the sheath, and the other end of the cymbal is connected to the end of the tip.

The electronic stylus according to claim 2, wherein the pressure detecting sensor is a Hall sensor.

The electronic stylus according to claim 5, wherein said Hall sensor is mounted between magnetic poles of the same polarity of two magnets; one of said two magnets is mounted in said sheath On the sensor holder, another piece is mounted at the end of the tip.

The electronic stylus according to claim 5, wherein the Hall sensor is mounted at an end of the pen tip, and the Hall sensor is located at a shoe iron provided by a magnet and two poles respectively mounted on the magnet Between the magnetic gaps of the formed magnetic circuit; the magnet is mounted on a sensor holder in the sheath, and the tip is elastically mounted on a sensor holder or magnet in the sheath.

The electronic stylus according to claim 2, wherein the pressure detecting sensor is an electret sensor.

The electronic stylus according to claim 8, wherein the electret sensor is composed of an electrode diaphragm, an isolating gasket and a charge amplifier; and one of the two electrode diaphragms is an electret film a sheet, or a metal diaphragm coated with an electret film material; one of the two electrode membranes is mounted on a sensor holder in the sheath, and the other is mounted at the end of the tip, and Elastically mounted on the sensor holder or another electrode membrane in the sheath; the isolation gasket is mounted between the two electrode membranes; the two electrode membranes are respectively connected to the input end of the charge amplifier.

The electronic stylus according to claim 8, wherein the electret sensor is composed of an electret microphone and an elastic gas cylinder; the elastic gas chamber has one end closed and the other end has an opening; The open end of the crucible is hermetically connected to the electret microphone, and the electret microphone penetrates into the elastic gas chamber; the closed end of the elastic gas chamber is installed at the end of the tip.

11. The electronic stylus according to claim 1, wherein said signal conditioning circuit comprises an oscillating signal generator, a frequency measuring device and an encoder, wherein:

An oscillating tank of the oscillating signal generator is connected to an output end of the pressure detecting sensor, an output end of the oscillating signal generator is connected to an input end of the frequency measuring device; an output end of the frequency measuring device is The input end of the encoder is connected; the output end of the encoder is connected to the signal output unit.

The electronic stylus according to claim 11, wherein the pressure detecting sensor is a pressure detecting sensor of a variable capacitance structure.

The electronic stylus according to claim 11, wherein the variable capacitance junction The pressure detecting sensor is composed of two plates, one of which is mounted on the sensor holder in the pen holder, and the other is connected to the end of the pen head and is elastically mounted on the pen holder An air gap is formed between the inner sensor bracket or the other pole plate and the pole plate mounted on the sensor bracket of the pen.

The electronic stylus according to claim 11, wherein the pressure detecting sensor is a pressure detecting sensor of a variable inductance structure.

The electronic stylus according to claim 14, wherein the variable inductance structure pressure detecting sensor comprises a coil wound on the open core, and a magnetizer located in front of the opening of the open core Constructing; the iron core is mounted on a sensor bracket in the pen holder, the magnetizer is connected to an end of the pen tip, and is elastically mounted on the sensor bracket or the iron core in the pen holder, and all Or an air gap is formed between some of the cores.

16. The electronic stylus according to claim 1, wherein the electronic stylus is a handwritten stylus capable of emitting infrared light used to detect a stylus position and a motion trajectory, the handwritten stylus including one or a set of infrared light-emitting tubes driven by an infrared emission driving circuit;

The circuitry further includes a code modulator, the output of the signal conditioning circuit being coupled to an input of the coded modulator;

The handwritten light pen further includes: a generating circuit for detecting an infrared light signal of the stylus position and the motion track, wherein an output end of the infrared light signal generating circuit is connected to another input end of the code modulator;

An output of the code modulator is coupled to an input of a drive circuit of the infrared light pipe.

17. The electronic stylus according to claim 1, wherein the electronic stylus is an ultrasonic stylus capable of transmitting ultrasonic waves used for detecting a stylus position and a motion trajectory, the ultrasonic stylus comprising a group An infrared light-emitting tube driven by an infrared emission driving circuit for emitting an infrared time-scale signal;

The circuitry further includes a code modulator, an output of the signal conditioning circuit coupled to an input of the coded modulator;

The ultrasonic stylus further includes: an infrared time-scale signal for calibrating the emission timing of the ultrasonic wave a circuit, an output of the infrared time-scale signal generating circuit is coupled to another input of the code modulator;

An output of the coded modulator is coupled to an input of the infrared transmit drive circuit.

The electronic stylus according to claim 16 or 17, wherein the circuit system further comprises:

Exciting a switch, the excitation switch is controlled by pressure data outputted from the signal conditioning circuit, and after receiving pressure data of a specified value, controlling the electronic stylus to emit correspondingly used to detect the stylus position and Infrared or ultrasonic waves of the motion track.

19. The electronic stylus according to claim 1, wherein the circuit system further comprises a manual switch, wherein the manual switch is configured to control a signal or data output to the output unit to be a set initial value or An identifier.