CN203673444U - active capacitive pen - Google Patents

Abstract

The utility model discloses an active capacitive pen, which comprises a conductive pen tip, a signal processing module and a capacitor. When in use, the conductive pen tip contacts a touch screen to detect a touch screen driving signal emitted by the touch screen and emits a feedback driving signal output by the signal processing module; the signal processing module acquires and processes the touch screen driving signal received by the conductive pen tip and generates a synchronous feedback driving signal to the conductive pen tip; the capacitor is arranged between the conductive pen tip and the signal processing module. Through the utility model, the purpose of accurately locating the position of the conductive pen tip of the active capacitive pen can be achieved.

Description

active capacitive pen

technical field

The utility model relates to an input device used on a touch screen, in particular to an active capacitance pen.

Background technique

With the development and progress of science and technology, users have higher and higher requirements for the input methods of mobile phones and tablet computers. They are no longer satisfied with traditional keyboard input, and gradually tend to convenient touch input. Currently, the touch input devices on the market are mainly Resistive and capacitive screens. Capacitive screens have the advantages of high sensitivity and easy multi-touch. They are gradually replacing resistive screens as the mainstream touch input screens. They are divided into surface capacitive and projected capacitive. The projected capacitive screen is divided into two types: mutual capacitance and self capacitance. The mutual capacitance touch screen includes two sets of vertical electrode arrays and a touch screen controller. One electrode array is used as the driving electrode, and the other electrode array is In order to detect the electrodes, a mutual capacitance is formed between the electrodes, and a self-capacitance is formed between the electrodes and the ground. The driving electrodes are driven by the driving module of the touch screen controller to transmit the touch screen driving signals, and the detection electrodes receive the above touch screen driving signals. When the grounded conductive object (finger etc.) When approaching the capacitive screen, it affects the value of the mutual capacitance between the driving electrode and the detection electrode. The detection electrode realizes touch positioning by detecting the capacitance change; The sensor will drive an electrode, and then detect the change of the capacitance value of the electrode to judge whether there is a grounded conductive object nearby; the surface capacitive touch screen electrodes are drawn from the four corners, and the basic principle is to detect the capacitance change when the conductor approaches to sense the touch point location information.

The stylus is divided into passive stylus and active stylus according to whether it uses power supply. The passive stylus simply uses conductive objects (conductors or conductive rubber, etc.) to simulate human fingers, and forms a capacitance between the pen tip and the touch screen driving conductive strip to affect the detection results of the touch screen, but the disadvantages of the passive stylus are The nib is relatively large (often larger than 2mm).

There is a signal processing module inside the active capacitive pen, which will actively detect the driving signal of the touch screen. Its conductive tip can be very thin, just like the probe of an oscilloscope, and the signal is coupled to the signal processing module inside the active capacitive pen for processing and output. There are also two types of active stylus: inductive pen (EMR) and active capacitive pen. The inductive pen (EMR) needs to add a layer of inductive sensing screen or sensor (Sensor) on the touch screen, which requires additional hardware to realize the writing function, which not only increases the thickness, but also increases the cost. Of course, the industrial design is more ugly, and it cannot be used in existing There are only traditional touch screen products on the market; active capacitive pens do not require inductive sensing screens or sensors, and do not increase the thickness of the screen, and can be directly used on touch screens in the existing market.

US20120154340 "ACTIVE STYLUS FOR USE WITHTOUCH-SENSITIVE INTERFACES AND CORRESPONDING METHOD" and US20130002606 "STYLUS AND STYLUS CIRCUITRY FOR CAPACITIVETOUCH SCREENS" respectively disclose an active capacitive pen. Has the following disadvantages:

One of the disadvantages is that when most people write, they will properly tilt the body of the pen to meet the user's writing habits. U.S. patents US20120154340 and US20130002606 use a relatively large pen tip or pen body to transmit feedback drive signals, and the pen tip or pen body will have a certain distance from the touch screen. When the user tilts the pen body of the active capacitive pen, the feedback drive signal will be displayed on the touch screen. The intensity distribution will not be centered on the tip of the pen, but will be biased towards the side of the pen body that is closer to the touch screen. This deviation cannot be corrected by subsequent algorithms. Because the touch screen controller or the host has no way of knowing the tilting range of the active capacitive pen body;

The second shortcoming is that US patents US20120154340 and US20130002606 both adopt the design that the detection electrode and the driving electrode are separated, and the detection and emission feedback drive are carried out at the same time. If there is no good isolation between the two poles, the transmitted drive feedback signal will be Coupling to the detection electrode causes oscillations.

Utility model content

In order to overcome the deficiencies in the prior art above, one purpose of the present invention is to provide an active capacitive pen, which can not only accurately locate the position of the conductive tip of the active capacitive pen, but also easily distinguish whether the conductive object is a finger or an active pen. Capacitive pen.

Another object of the present invention is to provide an active capacitive pen, which can transmit feedback driving signals of different strengths according to settings.

In order to achieve the above and other purposes, in one of the preferred embodiments of the utility model, the utility model proposes an active capacitor pen, which includes a conductive pen tip, a signal processing module and a capacitor, and the conductive pen When the pen tip touches the touch screen to detect the touch screen drive signal emitted by the touch screen and transmit the feedback drive signal output by the signal processing module; the signal processing module acquires and processes the touch screen drive signal received by the conductive pen tip and generates synchronization The feedback driving signal of the conductive pen tip is sent to the conductive pen tip; the capacitor is arranged between the conductive pen tip and the signal processing module.

Further, the signal processing module includes:

A detection circuit, connected to the conductive pen tip through the capacitor, to detect the rising or falling edge of the touch screen driving signal emitted by the touch screen;

The control circuit is connected to the output terminal of the detection circuit, so that when the detection circuit detects the rising edge or falling edge of the touch screen driving signal, it controls the signal processing module to enter the feedback driving state from the detection state, and according to the setting The starting and ending time of the feedback driving signal or the delay of the rising and falling edges of the feedback driving signal or the voltage of the feedback driving signal may be adjusted by setting.

Feedback driving circuit, connecting the control circuit and the conductive pen tip, the feedback driving circuit adopts a three-state output, and its output is high impedance during detection so that the conductive pen tip is in a suspended state. The control circuit transmits the feedback driving signal to the conductive pen tip.

Further, the feedback driving signal ends before the rising edge or falling edge of the next touch screen driving signal arrives, and the control circuit controls the signal processing module to enter the detection state again from the driving state.

Further, the signal processing module further includes a protection circuit, the protection circuit is composed of two or more anti-parallel diodes, one end of which is connected to a fixed bias voltage, and the other end is connected to the input end of the detection circuit.

Further, the active capacitive pen further includes an auxiliary detection electrode, and the auxiliary detection electrode is arranged at the input end of the signal processing module.

In another preferred embodiment of the utility model, the utility model provides an active capacitive stylus, the active capacitive stylus includes a detection electrode, a drive electrode and a signal processing module; the detection electrode contacts the touch screen during use Sensing the touch screen drive signal emitted by the touch screen and sending it to the signal processing module; the signal processing module acquires and processes the touch screen drive signal received by the detection electrode and generates a synchronous feedback drive signal to the drive electrode; the feedback drive The signal is transmitted to the touch screen from the driving electrode, the driving electrode is a conductive pen tip, and the detection electrode is made of a conductive pen tip or a conductive pen body or a metal wire or a circuit board printed line.

Compared with the prior art, the utility model is an active capacitive pen. By separating the detection circuit and the feedback drive circuit in sequence, it can effectively prevent the signal processing module from forming a closed-loop loop to generate self-excited oscillation. It can not only accurately locate the active pen The position of the conductive pen tip of the type capacitive pen, and it is easier to distinguish whether the conductive object is a finger or an active capacitive pen. At the same time, the active capacitive pen of the utility model can also transmit feedback driving signals of different strengths according to settings.

Description of drawings

FIG. 1 is a schematic structural diagram of a common touch screen system;

Fig. 2 is the overall structural diagram of the active capacitance pen applied by the utility model;

Fig. 3 is the structure diagram of the first preferred embodiment of an active capacitive pen of the present invention;

Fig. 4 is the basic architecture diagram of the signal processing module in the first preferred embodiment of the utility model;

5a to 5c are timing diagrams of touch screen driving signals and feedback driving signals in a preferred embodiment of the present invention;

FIG. 6 is an internal schematic diagram of a second preferred embodiment of an active capacitive pen of the present invention;

Detailed ways

The implementation of the utility model will be described below through specific examples and in conjunction with the accompanying drawings. Those skilled in the art can easily understand other advantages and effects of the utility model from the content disclosed in this specification. The utility model can also be implemented or applied through other different specific examples, and various modifications and changes can be made to the details in this specification based on different viewpoints and applications without departing from the spirit of the utility model.

Before explaining the utility model, first briefly explain the working principle of the touch screen. FIG. 1 is a schematic structural diagram of a common touch screen system. The touch screen system includes a touch screen, a touch screen controller and a host. The touch screen includes multiple conductive strips in the X-axis direction and multiple conductive strips in the Y-axis direction. Generally, the X-axis is perpendicular to the Y-axis. The intersection of the X-axis conductive strip and the Y-axis conductive strip forms a mutual capacitor (mutual capacitor) array. When an equivalently grounded conductive object, such as a human finger, approaches or touches the touch screen, it will change the capacitance value of the mutual capacitance near the conductive object. By detecting the change in the capacitance value of each mutual capacitance of these mutual capacitance arrays, you can The position of the equivalently grounded conductive object on the touch screen is calculated by an algorithm.

The utility model is applicable to both mutual-capacitance and self-capacitance touch screens. Taking the mutual-capacitance touch screen as an example, the mutual-capacitance touch screen controller will send a touch screen driving signal to drive the driving electrodes one by one. The driving electrodes can be X-axis or Y-axis conductive. The touch screen driving signal can be a group of pulse trains or a group of sine waves or a group of triangular waveforms, etc. (only one group of pulse waveforms is shown in Figure 1), and a group of pulses contains multiple pulses. The conductive strips of the other axis that are not being driven are sense electrodes. When one driving electrode is driven by the touch screen controller, the driving signal will be coupled to the detecting electrode through the mutual capacitance between the driving electrode and the detecting electrode. If a conductive object touches or is close to the driving electrode and the detecting electrode, the capacitance value of the mutual capacitance between the driving electrode and the detecting electrode will be changed. The touch screen controller detects the capacitance value of each mutual capacitance in the mutual capacitance array and compares it with the capacitance value when no conductive object is in contact with or close to, so as to obtain the capacitance change image. The capacitance change image can be sent to the host computer to calculate the position of the conductive object by algorithm.

Fig. 2 is the overall structure diagram of the active capacitive pen used in the present invention. As shown in Fig. 2, the active capacitive pen used in the present invention includes a nib, a nib and a pen body. FIG. 3 is a schematic structural diagram of a first preferred embodiment of an active capacitive pen of the present invention, and FIG. 4 is a basic structure diagram of a signal processing module in the first preferred embodiment of the present invention. As shown in Figure 3 and Figure 4, an active capacitive pen of the present invention, in addition to the power supply (battery in the preferred embodiment of the present invention), at least includes: a conductive pen tip 10, a pen body, buried in the pen body The signal processing module 30 and a capacitor C.

Among them, the conductive pen tip 10 is connected with the pen body by mechanical contact, and its function is as a tool for clicking the target area of the touch screen, and as a coupling device to detect the touch screen drive signal emitted by the touch screen and the feedback drive signal output by the signal processing module 30 , that is, the conductive pen tip is used as both the detection electrode and the driving electrode; the signal processing module 30 is used to process the touch screen drive signal received by the conductive pen tip 10 and generate a synchronous feedback drive signal, receive the touch screen drive signal of the touch screen in the detection stage, and drive In this stage, the processed feedback drive signal is sent; the capacitor C is arranged between the conductive pen tip 10 and the signal processing module 30, and during detection, the capacitor C is used to couple the touch screen drive signal obtained by the conductive pen tip 10 to the input terminal of the signal processing module 30, When the touch screen is driven by feedback, the capacitor C is used to isolate the feedback drive signal.

The signal processing module 30 includes a detection circuit 301 , a control circuit 302 and a feedback drive circuit 303 . The detection circuit 301 is used to detect the rising or falling edge of the touch screen drive signal emitted by the touch screen; the control circuit 302, when the detection circuit 301 detects the rising or falling edge of the touch screen drive signal, the control circuit 302 controls the signal processing module to enter from the detection state Feedback driving state, adjust the start and end time of the feedback driving signal or the delay of the rising and falling edges of the feedback driving signal or the voltage of the feedback driving signal according to the setting, so that the feedback driving signal arrives at the rising or falling edge of the next touch screen driving signal Before the end, the signal processing module 30 is made to enter the detection state again from the driving state; the feedback driving circuit 303 adopts a three-state output, and when detecting, its output is a high impedance so that the conductive pen tip 10 is in a suspended state. 302 transmits the feedback driving signal to the conductive pen tip 10 under the control of 302 to realize the feedback driving of the touch screen.

When working, the touch screen controller will scan the drive electrodes of the touch screen row by row, and the controller will send a group of pulses to the drive electrodes of the touch screen every time the drive electrodes of the touch screen are scanned. A coupling capacitance is formed between the conductive tip 10 of the active capacitive pen and each detection electrode on the touch screen. The closer the driving electrode of the touch screen is to the conductive pen tip, the greater the coupling capacitance between the conductive pen tip and the detection electrode of the touch screen. When the touch screen controller scans the drive electrodes that are relatively close to the conductive pen tip 10, the conductive pen tip 10 can be coupled to a touch screen drive signal of sufficient strength, and the signal will be coupled to the input terminal of the active capacitive pen signal processing module 30 through the capacitor C, The signal processing module 30 will adjust the intensity of the feedback driving signal according to the setting. The feedback drive signal of the active capacitive pen couples the feedback drive signal to the detection electrode of the touch screen through the coupling capacitance between the conductive pen tip 10 and the detection electrode on the touch screen. In order to couple a signal with sufficient strength to the detection electrode of the touch screen, the feedback driving signal sometimes requires a high voltage, such as 15v, and accordingly the capacitor C also needs to withstand a voltage of 15v. The capacitor C in FIG. 3 can be built into the chip or external to the chip. Since the capacitor will not isolate the AC signal, when the voltage of the conductive pen tip rises, the voltage at the other end of the capacitor, that is, the input end of the signal processing module 30 will also rise accordingly. In order to prevent the high voltage from burning out the circuit at the input end of the signal processing module, In a preferred embodiment of the present invention, a protection circuit 305 is added at the input end of the signal processing module 30. The protection circuit 305 may be composed of two or more diodes connected in antiphase and parallel, one end of which is connected to a fixed bias voltage Vref, Vref is generally set to about half of the power supply voltage of the analog circuit (for example, the power supply voltage is 5V, then Vref is about 2.5v±1.5v), and the other end is connected to the input end of the detection circuit 301, so that when the high-voltage feedback drive signal arrives, the The voltage at the input terminal of the detection circuit 301 is limited to Vref±Vd, where Vd is the diode threshold. In addition, in order to strengthen the active capacitive pen to detect the touch screen driving signal, an auxiliary detection electrode 50 can be selectively added at the input end of the signal processing module. The auxiliary detection electrode 50 can be a conductive pen tip, or a conductive pen body, or a printed circuit board line, or a conductive metal line.

The working principle of the signal processing module is described in detail below: when the signal processing module 30 is in the detection state, the detection circuit 301 can detect the voltage of the input terminal of the signal processing module 30, when the detection circuit 301 detects the rising or falling edge of the touch screen drive signal Output signal to the control circuit 302, when the signal processing module 30 is in the detection state, the output of the feedback drive circuit 303 is high impedance, the conductive pen tip 10 is in a suspended state, so that the conductive pen tip 10 couples the driving signal from the touch screen, the active capacitive pen The control circuit 302 of the detection circuit 301 receives the output of the detection circuit 301, and the control circuit 302 will control the signal processing module 30 to enter the feedback driving state; in the feedback driving state, the output of the detection circuit 301 will be ignored by the control circuit 302, and the feedback driving circuit 303 will end High impedance output, the control circuit 302 will adjust the intensity of the feedback drive signal according to the set output. In a preferred embodiment of the present invention, the control circuit 302 adopts the following method to adjust the intensity of the feedback drive signal: change the start and end of the drive signal Time, change the delay of the rising or falling edge of the feedback drive signal, change the voltage of the feedback drive signal, change the delay between the rising edge and the falling edge, or the delay between the falling edge and the rising edge, active capacitive pen feedback drive It will end before the arrival of the next touch screen driving signal, and the signal processing module 30 will return to the initial detection state.

A complete active capacitive pen should allow the touch screen to accurately locate the position of the conductive pen tip on the touch screen, and distinguish whether the conductive object is a capacitive pen or a finger.

5a to 5c are timing diagrams of touch screen driving signals and active capacitive pen feedback driving signals in a preferred embodiment of the present invention. The detection and feedback driving process of the active capacitive pen signal processing module will be described in detail below with reference to FIGS. 5 a to 5 c.

As shown in Figure 5a, when the active capacitive pen approaches or touches the touch screen during use, the touch screen controller scans the touch screen drive electrodes one by one, and each time a touch screen drive electrode is driven, the touch screen controller sends a set of touch screen drive signals (as shown in Figure 5a, the first waveform), in this embodiment the driving signal is a group of pulses, however, the driving signal can also be a group of triangular waves or a group of sine waves. When the driven electrode of the touch screen is far away from the conductive pen tip of the active capacitive pen, the strength of the touch screen driving signal coupled to the conductive pen tip is relatively weak, and the active capacitive pen cannot detect the touch screen driving signal. When the touch screen controller drives the touch screen drive electrodes near the conductive pen tip, the conductive pen tip can be coupled to a relatively strong touch screen drive signal, and then the signal is coupled to the input of the active capacitive pen signal processing module 30 through the capacitor C (Figure 3). Terminal, that is, the input terminal of the detection circuit 301, when the detection circuit 301 detects the touch screen drive signal, the detection result will be output to the control circuit 302 of the active capacitive pen signal processing module, and the control circuit 302 will control the feedback drive circuit 303 to The touch screen sends out a feedback drive signal (as shown in Figure 5a, the third and fourth waveforms).

The second waveform in FIG. 5 a is a touch screen driving signal among a group of touch screen driving signals. This touch screen driving signal includes a high level and a low level. When the touch screen drive signal rises from low level to high level at t ₀ , the touch screen drive electrode makes a positive charge to all touch screen detection electrodes through the coupling capacitance between the touch screen drive electrode and the touch screen detection electrode, that is, the touch screen detection electrode voltage is pulled high. When the driving signal drops from a high level to a low level at _t3 , the touch screen driving electrode performs a reverse charge on all the touch screen detection electrodes, that is, the voltage of the touch screen detection electrodes is pulled down. The touch screen detection electrodes start to discharge after each forward or reverse charge. The touch screen controller will detect the discharge of the detection electrodes to determine whether there is any change in the coupling capacitance between the drive electrodes and the detection electrodes, so as to further determine whether there is a conductive object nearby.

The third and fourth waveforms in FIG. 5a are the feedback driving signals of the active capacitive pen corresponding to the touch screen driving signal of the second waveform. As shown by the third and fourth waveforms, the signal processing module of the active capacitive pen is in the detection state at the beginning. At this time, the output of the feedback drive circuit 303 is high impedance, and the conductive pen tip is in a suspended state, which is convenient for the conductive pen tip to sense the touch screen controller. The driving signal sent to the driving electrodes of the touch screen. After the detection circuit 301 of the active capacitive pen detects the rising edge of the touch screen driving signal (t ₀ ), the detection circuit 301 outputs a signal to notify the control circuit 302 of detecting the rising edge of the touch screen driving signal. The control circuit 302 then controls the active capacitive pen to enter the feedback driving state. According to the setting, the control circuit 302 ends the high-impedance output of the feedback drive circuit 303 after a certain delay (t ₁ ), and sends a positive phase to the touch screen with a certain falling delay (t ₁ to t ₂ ) (as shown in Figure 5a, the third waveform) or an inverted (as shown in Figure 5a, fourth waveform) feedback drive signal. The start time of the feedback drive (Fig. 5a, t ₁ ), the end time (Fig. 5a, t ₂ ), the delay of the rising or falling edge (Fig. 5a, t ₁ to t ₂ ), and the voltage of the feedback drive signal can also be determined according to Settings adjustments. The entire feedback driving process of the active capacitive pen to the touch screen will end before the next falling edge of the touch screen drive signal (Fig. 5a, t ₃ ). The active capacitive pen will enter the detection state again. From t ₀ to t ₃ , the signal processing module 30 of the active capacitive pen completes a detection and feedback driving cycle.

The strength of the feedback drive signal of the active capacitive pen can be realized by adjusting the start and end time of the feedback drive, the delay of the rising edge and falling edge of the feedback drive signal, the voltage of the feedback drive signal, or the same detection and feedback drive cycle. The delay between rising and falling edges, or the delay between falling and rising edges within the same detection and feedback drive cycle.

In Figure 5b, as shown by the third and fourth waveforms in Figure 5b, the signal processing module of the active capacitive pen is in the detection state at the beginning, at this time, the output of the feedback drive circuit 303 is high impedance, and the conductive pen tip is in a suspended state , it is convenient for the conductive pen tip to sense the drive signal sent by the touch screen controller to the touch screen drive electrode. After the detection circuit 301 of the active capacitive pen detects the rising edge of the touch screen driving signal (t ₀ ), the detection circuit 301 outputs a signal to notify the control circuit 302 of detecting the rising edge of the touch screen driving signal. The control circuit 302 then controls the active capacitive pen to enter the feedback driving state. According to the setting, the control circuit 302 ends the high-impedance output of the feedback drive circuit 303 after a certain delay (t ₁ ), and sends N rising or falling edges in phase with the detected rising or falling edges to the touch screen with a certain rising or falling delay edge or falling edge, and N+1 rising or falling edges that are opposite to the detected rising or falling edge (as shown in Figure 5b, the fourth waveform). The strength of the feedback driving signal can be adjusted by setting t ₂ , t ₃ and t ₄ . The whole feedback driving process will end before the next falling edge of the touch screen driving signal (Figure 5b, t ₅ ). The active capacitive pen will enter the detection state again. From t ₀ to t ₅ , the signal processing module 303 of the active capacitive pen completes a detection and feedback driving cycle.

Figure 5c shows another touch screen drive signal. The first waveform in Fig. 5c shows a set of touch screen driving waveforms, and the second waveform shows a waveform of a touch screen driving signal. The waveform of this touch screen driving signal also has high level and low level, but the touch screen controller is not like Figure 5a and Figure 5b. During the period of a touch screen driving waveform, when the high level and low level, each through the coupling capacitance to the detection electrode once Instead of charging, the detection electrode is charged forward or reverse only once through the switch during a drive waveform. When using the active capacitive pen, the active capacitive pen approaches or touches the touch screen, and when the touch screen controller drives the driving electrodes near the conductive pen tip, the conductive pen tip can be coupled to the touch screen driving signal. According to the setting, the control circuit 302 of the active capacitive pen ends the high impedance output of the feedback drive circuit 303 after a certain delay (Figure 5c, _t1 ), and sends a signal to the touch screen with a certain falling delay (Figure 5c, t1 to t2). Inverse phase (as shown in Figure 5c, the third waveform) or send a positive phase (as shown in Figure 5c, the fourth waveform) feedback drive signal to the touch screen with a certain rising delay (Figure 5c, t1 to t2). The start time (Fig. 5c, t1) and end time (Fig. 5c, t4) of the feedback drive, and the voltage of the feedback drive signal can be adjusted according to the settings. The entire feedback driving process will end before the next rising edge of the touch screen driving signal (Fig. 5c, t ₅ ). The active capacitive pen will enter the detection state again. From t ₀ to t ₅ , the signal processing module of the active capacitive pen completes a detection and feedback driving cycle.

FIG. 6 is an internal schematic diagram of a second preferred embodiment of an active capacitive pen of the present invention. As shown in Figure 6, in the second preferred embodiment of the present invention, the active capacitive pen of the present invention includes: detection electrode 601, drive electrode 602 and signal processing module 603; The touch screen driving signal is sent to the signal processing module 603; the signal processing module 603 is used to process the touch screen driving signal received by the detection electrode 601 and generate a synchronous feedback driving signal; the feedback driving signal is transmitted to the touch screen by the driving electrode 602, and is used in the touch screen positioning algorithm Accurate positioning is realized under cooperation. In the present embodiment, the driving electrode is a conductive pen tip, and the detection electrode 601 can be a conductive pen tip, or a conductive pen body, or an electric wire, or a circuit board printed line. Since the signal processing module 603 and the first preferred The signal processing modules in the embodiments have the same structure and function, which will not be repeated here.

In summary, an active capacitive pen of the present invention separates the detection circuit and the feedback drive circuit in sequence, effectively avoiding the signal processing module from forming a closed-loop loop to generate self-excited oscillation, which can not only precisely position the active capacitive pen The position of the conductive pen tip, and it is easier to distinguish whether the conductive object is a finger or an active capacitive pen. At the same time, the active capacitive pen of the present invention can also transmit feedback driving signals of different strengths according to settings.

The above-mentioned embodiments only illustrate the principles and effects of the present utility model, but are not intended to limit the present utility model. Any person skilled in the art can modify and change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Therefore, the protection scope of the utility model should be as listed in the claims.

Claims (6)

1. an active electric capacity pen, it is characterized in that: described active electric capacity pen comprises conduction nib, signal processing module and an electric capacity, described conduction nib contacts touch-screen in the time using, and to detect touch-screen, the touch-screen driving signal of launching the feedback of launching described signal processing module output drive signal; Described signal processing module obtains and processes described touch-screen that described conduction nib receives and drives signal and produce synchronous feedback and drive signal to described conduction nib; Described electric capacity is arranged between described conduction nib and described signal processing module.

2. the active electric capacity pen of one as claimed in claim 1, is characterized in that, this signal processing module comprises:

Testing circuit, connects described conduction nib by described electric capacity, drives rising edge or the negative edge of signal to detect the touch-screen of described touch-screen transmitting;

Control circuit, be connected to the output terminal of this testing circuit, when detecting that in described testing circuit described touch-screen drives the rising edge of signal or negative edge, control described signal processing module and enter feedback driving condition by detected state, and adjust according to setting the voltage that the start and end time of described feedback driving signal or the delay of feedback driving signal rising edge and negative edge or feedback drive signal

Feedback driving circuit, connect described control circuit and described conduction nib, described feedback driving circuit adopts ternary output, in the time detecting, it is output as high resistance makes described conduction nib in vacant state, in the time that feedback drives, under described control circuit control, drive signal to be sent to described conduction nib described feedback.

3. the active electric capacity pen of one as claimed in claim 2, it is characterized in that: described feedback drives signal to drive the rising edge of signal or negative edge to finish before arriving at next touch-screen, signal processing module enters detected state again by driving condition described in described control circuit control.

4. the active electric capacity pen of one as claimed in claim 3; it is characterized in that: described signal processing module also comprises a holding circuit; described holding circuit is made up of the diode of two or more parallel connected in reverse phase, one termination fixed-bias transistor circuit, the input end of testing circuit described in another termination.

5. the active electric capacity pen of one as claimed in claim 3, is characterized in that: described active electric capacity pen also comprises an auxiliary detection electrode, and described auxiliary detection electrode is arranged at the input end of described signal processing module.

6. an active electric capacity pen, is characterized in that: described active electric capacity pen comprises detecting electrode, drive electrode and signal processing module; Described detecting electrode contacts touch-screen and drives signal and be sent to described signal processing module with the touch-screen of induction touch panel transmitting in the time using; The touch-screen that described signal processing module obtained and processed this detecting electrode reception drives signal and produces synchronous feedback driving signal to described drive electrode; Described feedback drives signal to be launched to described touch-screen by described drive electrode, and described drive electrode is conduction nib, and described detecting electrode utilizes conductive pen point or conductive stylus body or metal wire or wiring board track to make.

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