CN104111741A - Active stylus - Google Patents
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- CN104111741A CN104111741A CN201410381605.XA CN201410381605A CN104111741A CN 104111741 A CN104111741 A CN 104111741A CN 201410381605 A CN201410381605 A CN 201410381605A CN 104111741 A CN104111741 A CN 104111741A
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Abstract
Disclosed is an active stylus. The active stylus comprises a conductive stylus point, an amplification circuit, an output portion and a power supply circuit, wherein the portion of the conductive stylus point which is in contact with a capacitive screen produces coupling capacitance and meantime transmits coupling voltage differences or coupling currents sensed by the coupling capacitance to the amplification circuit; the amplification circuit is used for converting input of the stylus point into in-phase voltage signals which are in proportion to the coupling voltage difference and outputting the in-phase voltage signals, and the gain bandwidth of the amplification circuit is at least 10MHz; the output portion is used for connecting output of the amplification circuit and the shell of a tablet personal computer, the earth or a human body; the power supply circuit is used for powering the amplification circuit. Due to the fact that the output portion is connected with the human body, the earth or the earth pole of the tablet personal computer, the effect which equals that a proportional voltage inverted with the coupling voltage differences is additionally added to the conductive stylus point is achieved, and at this time, the coupling capacitance will receive larger coupling currents; meanwhile, a capacitator inside the capacitive screen can also sense the inverted potential, such feedback and cycle achieve the effect that finally the capacitive screen can evidently judge the existence of the conductive stylus point according to the value of the coupling currents or the calculated value of the coupling capacitance.
Description
Technical field
The present invention relates to initiatively pointer, the active pointer that especially coordinates panel computer capacitive touch screen to use.
Background technology
Obviously, panel computer will more and more replace books, become the instrument for recording that people are indispensable, so on panel computer for write and draw a picture pen just seem that demand is urgent.What current more than 90% panel computer used is capacitive touch screen, also has part to install electromagnetic induction module additional here.For the capacitive touch screen of panel computer (except installing electromagnetic induction module additional), more than 90% pen is all passive pointer.The written diameter of passive pointer is at least greater than 5mm, to have enough conductive areas contacting with touch screen.Enough conductive contact areas are used for and shield formation coupling capacitance, can attract enough small alternating currents from touch screen, thereby make touch screen know the position of contact.The pen that nib diameter is 5mm is obviously not enough to attract people accurately to locate on panel computer, writes and draws a picture.Conventionally the written diameter of ball pen is at 2-3mm, so the pointer that written diameter is 3mm just seems, demand is urgent.If the diameter of pointer is 3mm, under the condition driving at the hardware and software of not changing current touch screen, the characteristic electron that can only improve pointer just can reach, namely increase by a circuit in pointer, even under the written condition of 3mm, still can make touch screen know the position of contact, such pointer is called initiatively pointer at present.At present, there are a lot of patents that the initiatively implementation method of pointer is being discussed, but based on the diversity of capacitive touch screen, the initiatively diversity of touch control pen structure and circuit arrangement, and the diversity of active pointer and capacitive touch screen interactive mode, how to invent the implementation method of a suitable active pointer, just seem particularly important.
Summary of the invention
Technical matters to be solved by this invention is to provide a kind of initiatively pointer, and written diameter can do littlely, to facilitate smooth writing.
For solving the problems of the technologies described above, technical scheme of the present invention is:
A kind of initiatively pointer, comprising:
Contact out generation coupling capacitance with capacitance plate, the poor or couple current of the coupled voltages that simultaneously coupling capacitance sensed passes to the conduction nib of amplifying circuit;
The input of nib is transformed to and the also amplifying circuit of output of the poor proportional in-phase voltage signal of coupled voltages, and the gain bandwidth (GB) of described amplifying circuit is at least 10MHz;
For connecting the output of the output of amplifying circuit and the shell of panel computer, the earth or human body;
For the power-supply circuit of amplifying circuit power supply.
Principle of work of the present invention: due to the earth polar of efferent tap human body, the earth or panel computer, so conduction nib equal an additional described ratio with the poor anti-phase voltage of described coupled voltages, so at this moment coupling capacitance will receive larger couple current; Meanwhile, the electric capacity of capacitance plate inside also can be experienced this anti-phase electromotive force, so feeds back and circulates to such an extent as to last capacitance plate can obviously determine according to the calculated value of the value of couple current or coupling capacitance the existence of conduction nib.So the improved circuit structure according to the present invention, is not changing under the prerequisite of capacitance plate, the nib diameter that can make to conduct electricity does littlely, writes to facilitate.
According to the theory of the principle of capacitance plate and mimic channel, with respect to other existing published patent or application, present patent application has obvious feature in the interactive mode of active pointer and capacitance plate: the receiving pole of the disclosed reception screen signal of present patent application and send to the transmission of screen signal to be integrated extremely altogether, for nib, can make like this position of capacitance plate perception touch point more accurately single.The disclosed amplifier circuit of present patent application is all followed the signal of screen all the time, and output; This makes the anti-phase electromotive force on nib can affect exactly capacitance plate all the time, makes capacitance plate experience the initiatively position of pointer touch-control.
As improvement, the gain bandwidth (GB) of described amplifying circuit is 40-80MHz, can enough respond discharging and recharging of capacitance plate.
As improvement, the floating ground of described amplifying circuit, the earth polar of amplifying circuit is with human body or under any condition, be not connected greatly, can make like this circuit relatively simple.
As improvement, described amplifying circuit is made up of a noninverting integrator and a homophase operation amplifier circuit, wherein the input of noninverting integrator is connected with described conduction nib, output is connected with the input of homophase operation amplifier circuit, and homophase operation amplifier circuit amplifies the output homophase of noninverting integrator and is delivered to described output.Described noninverting integrator can be a simple integrating circuit, also can realize with operational amplifier; Described homophase operation amplifier circuit comprises more than one homophase operational amplifier; Described amplifying circuit also can be realized with boostrap circuit.
As improvement, described amplifying circuit is made up of two rp-op amp circuit, wherein the input of first rp-op amp circuit is connected with described conduction nib, output is connected with the input of second rp-op amp circuit, and second rp-op amp circuit is by anti-phase the output of the first rp-op amp circuit amplification and be delivered to described output.Described rp-op amp circuit comprises more than one rp-op amp.
As improvement, by the gain ratio of gain control circuit controls amplifying circuit, such as adopting automatic gain control circuit (agc circuit), utilize the voltage amplitude of output current or output to control the proportion resistor of second level amplifier by digital regulation resistance.
As improvement, described power-supply circuit is not to be with the dry cell power supply circuit of charging or the storage battery power supply circuit of band charging or the change-over circuit of directly being powered by extra power of charged pool not, and described battery charging circuit comprises wired charging circuit and wireless charging circuit.
As improvement, described output is metallic sheath or the metal part being arranged on penholder shell, and output stage and the penholder of amplifying circuit combine together, and in the time of operation active pointer, staff nature contacts with output.
As improvement, described conductive stylus nose part or be all enclosed with the material of insulation, in order to ensure that the coupled signal of input avoids the impact of other noises to the full extent.
As improvement, described output divides directly and is connected with the power interface of panel computer by cable with power suppling part.Can reduce like this power suppling part and divide shared volume and weight, also can be used as initiatively anti-lost means of pen.
The beneficial effect that the present invention compared with prior art brought is:
Due to the earth polar of efferent tap human body, the earth or panel computer, thus conduction nib equal an additional described ratio with the poor anti-phase voltage of described coupled voltages, so at this moment coupling capacitance will receive larger couple current; Meanwhile, the electric capacity of capacitance plate inside also can be experienced this anti-phase electromotive force, so feeds back and circulates to such an extent as to last capacitance plate can obviously determine according to the calculated value of the value of couple current or coupling capacitance the existence of conduction nib.So the improved circuit structure according to the present invention, is not changing under the prerequisite of capacitance plate, the nib diameter that can make to conduct electricity does littlely, writes to facilitate.
Brief description of the drawings
Fig. 1 is the outside drawing of active pointer.
Fig. 2 is embodiment 1 amplification circuit diagram.
Fig. 3 is embodiment 2 amplification circuit diagrams.
Fig. 4 is the relation of staff and capacitance plate.
Fig. 5 is the relation of pointer nib and capacitance plate.
Embodiment
Below in conjunction with Figure of description, the invention will be further described.
As shown in Figure 1, a kind of initiatively pointer, comprises conduction nib 1, amplifying circuit, output 2 and power-supply circuit.
Described nib 1 contacts out generation coupling capacitance with capacitance plate, coupling capacitance is sensed to the poor or couple current of coupled voltages passes to described amplifying circuit simultaneously.Described amplifying circuit transforms to input and the poor proportional in-phase voltage signal of coupled voltages, and is delivered to output 2; The floating ground of described amplifying circuit.Described output 2 is as the medium connecting between the output of amplifying circuit and the shell of panel computer, the earth, human body, such as the shell of pen, the output line of pen are connected to shell or the earth polar etc. of panel computer.Described power-supply circuit part refers to the part into the power supply of described amplifying circuit, such as dry cell and likely additional booster circuit, accept receiving circuit that the power supply of wired or wireless external power supply supplies with and additional storage circuit etc. likely.
Because output 2 connects the earth polar of human body, the earth or panel computer, thus conduction nib 1 equal an additional described ratio with the poor anti-phase voltage of described coupled voltages, so at this moment coupling capacitance will receive larger couple current; Meanwhile, the electric capacity of capacitance plate inside also can be experienced this anti-phase electromotive force, so feedback and circulation to such an extent as to last capacitance plate can obviously determine according to the calculated value of the value of couple current or coupling capacitance the existence of conduction nib 1 (contact), so improved circuit structure according to the present invention, do not changing under the prerequisite of capacitance plate, nib 1 diameter that can make to conduct electricity does littlely, writes to facilitate.
Illustrate further for example enforcement special case of the present invention below:
Embodiment 1
As shown in Figure 1, 2, a kind of initiatively pointer, comprises conduction nib 1, amplifying circuit 3, output 2 and power-supply circuit.
Described nib 1 contacts out generation coupling capacitance with capacitance plate, coupling capacitance is sensed to the poor or couple current of coupled voltages passes to described amplifying circuit 3 simultaneously.Described conduction nib 1 is partly or entirely enclosed with the material of insulation, avoids to the full extent the impact of other noises in order to the coupled signal of guarantee input.Conduction nib 1 diameter of the present embodiment can be accomplished 3mm, because nib 1 is thinner, it not only can not tap easily capacitance plate and send instruction, but also can be on capacitance plate smooth writing, paint, so can widen the range of application of panel computer in people's daily life, as do the instant expression etc. of interim notes, interim drawing, word.
As shown in Figure 1, 2, described amplifying circuit 3 transforms to input and the poor proportional in-phase voltage signal of coupled voltages, and is delivered to output 2.Described amplifying circuit 3 is made up of two rp-op amp circuit, wherein the input of first rp-op amp circuit is connected with described conduction nib 1, output is connected with the input of second rp-op amp circuit, and second rp-op amp circuit is by anti-phase the output of the first rp-op amp circuit amplification and be delivered to described output 2.Described rp-op amp circuit comprises more than one rp-op amp, and the present embodiment describes as an example of two rp-op amps example, the floating ground of described amplifying circuit.The gain bandwidth (GB) of described amplifying circuit 3 is at least 10MHz, and it is the amplifying circuit 3 of 80MHz that the present embodiment is selected gain bandwidth (GB).The gain ratio of described amplifying circuit 3 can regulate automatically, by the gain ratio of gain control circuit controls amplifying circuit 3, such as adopting automatic gain control circuit (agc circuit), utilize the voltage amplitude of output current or output to control the proportion resistor of second level amplifier by digital regulation resistance.
The principle of work of the present embodiment amplifying circuit 3:
The simple computation formula of coupling capacitance:
As shown in Figure 4,5, with respect to the earth, the electromotive force Uh of staff 4, the electromotive force Us of capacitance plate 5, panel computer is supposed Uh=0 conventionally, then according to Q (or i) and U calculate the size of coupling capacitance.Nib 1 diameter of the coupling capacitance that current most of capacitance plate can be identified is at least greater than 5mm, if the nib of pointer 1 diameter is 3mm, under the condition driving at the hardware and software of not changing current touch screen, can only improve pointer, even if make capacitance plate touch an active nib 1 of 3mm, also can perceive the coupling capacitance that is equivalent to 5mm nib 1.
Q＝CU＝C(Us-Ua)＝C*d(Us-Ua)
With respect to the earth, initiatively the electromotive force of pointer nib 1 is Ua, the electromotive force of capacitance plate is Us, in the time using active pointer, if can make the voltage of Ua be less than 0, the voltage difference between coupling capacitance will be large than usual so, and the electric charge of acquisition is just many, then, the coupling capacitance Cc that capacitance plate calculates just increases.
The dynamic current that starts most coupling capacitance output is i, and the voltage difference at two ends is v,
Coupling capacitance Cc is assumed to 0.15pf
With respect to the earth terminal GND1 of rp-op amp, the voltage Vtip=0 of nib 1
The output voltage of first order rp-op amp is Vo1, and the output voltage of second level rp-op amp is Vo2, is all the voltage with respect to GND1.
Vtip ?Vo2 be that nib is with respect to the voltage on ground.
Then the both end voltage of written coupling capacitance is poor is just original 1.1 times, then the dynamic current that nib is coupled is just 1.1 times of a upper circulation, the both end voltage of nib coupling capacitance is poor increasing with electric current this electric capacity, this just as the nib of passive pointer and the contact area of screen increasing, until capacitance plate is cognitive to enough couple currents.First order rp-op amp gathers the electric current of written coupling capacitance; Become reverse voltage signal through first order rp-op amp; Zoom into and the in-phase voltage signal of written coupling capacitance voltage difference through second level rp-op amp again; Finally handle (the earth) mirror to, nib magnitude of voltage be the voltage signal anti-phase with of written coupling capacitance voltage difference, thereby widen the coupled voltages between coupling capacitance, affect capacitance plate.
As shown in Figure 1, 2, described output 2 is as the medium connecting between the output of amplifying circuit 3 and the shell of panel computer, the earth, human body, such as the shell of pen, the output line of pen are connected to shell or the earth polar etc. of panel computer.Described output 2 is for being arranged on the metallic sheath on penholder shell, and output stage and the penholder of amplifying circuit 3 combine together, and in the time of operation active pointer, staff nature contacts with output 2.Described output 2 divides and can directly be connected with the power interface of panel computer by cable with power suppling part, can reduce like this power suppling part and divide shared volume and weight, also can be used as initiatively anti-lost means of pointer.
Described power-supply circuit part refers to the part of powering for described amplifying circuit 3.Described power-supply circuit is not to be with the dry cell power supply circuit of charging or the storage battery power supply circuit of band charging or the change-over circuit of directly being powered by extra power of charged pool not, and described battery charging circuit comprises wired charging circuit and wireless charging circuit.
Because output 2 connects the earth polar of human body, the earth or panel computer, thus conduction nib 1 equal an additional gain with the poor anti-phase voltage of described coupled voltages, so at this moment coupling capacitance will receive larger couple current; Meanwhile, the electric capacity of capacitance plate inside also can be experienced this anti-phase electromotive force, so feedback and circulation to such an extent as to last capacitance plate can obviously determine according to the calculated value of the value of couple current or coupling capacitance the existence of conduction nib 1 (contact), so improved circuit structure according to the present invention, changing under the prerequisite of capacitance plate, nib 1 diameter that can make to conduct electricity does littlely, writes to facilitate.
Embodiment 2
As shown in Figure 1,3, a kind of initiatively pointer, comprises conduction nib 1, amplifying circuit 3, output 2 and power-supply circuit.
As shown in Figure 1,3, described nib 1 contacts out generation coupling capacitance with capacitance plate, coupling capacitance is sensed to the poor or couple current of coupled voltages passes to described amplifying circuit 3 simultaneously.Described conduction nib 1 is partly or entirely enclosed with the material of insulation, avoids to the full extent the impact of other noises in order to the coupled signal of guarantee input.Conduction nib 1 diameter of the present embodiment can be accomplished 3mm, because nib 1 is thinner, it not only can not tap easily capacitance plate and send instruction, but also can be on capacitance plate smooth writing, paint, so can widen the range of application of panel computer in people's daily life, as do the instant expression etc. of interim notes, interim drawing, word.
As shown in Figure 1,3, described amplifying circuit 3 transforms to input and the poor proportional in-phase voltage signal of coupled voltages, and is delivered to output 2.Described amplifying circuit 3 is made up of a noninverting integrator and a homophase operation amplifier circuit, wherein the input of integrator is connected with described conduction nib 1, output is connected with the input of homophase operation amplifier circuit, and homophase operation amplifier circuit amplifies the output homophase of integrator and is delivered to described output 2.Described integrator can be a simple integrating circuit, also can realize with operational amplifier; Described homophase operation amplifier circuit comprises more than one homophase operational amplifier, the floating ground of described amplifying circuit; Described amplifying circuit 3 also can be realized with boostrap circuit; The present embodiment describes as an example of two homophase operational amplifiers example.The gain bandwidth (GB) of described amplifying circuit 3 is at least 10MHz, and it is the amplifying circuit 3 of 60MHz that the present embodiment is selected gain bandwidth (GB).The gain ratio of described amplifying circuit 3 can regulate automatically, by the gain ratio of gain control circuit controls amplifying circuit 3, such as adopting automatic gain control circuit (agc circuit), utilize the voltage amplitude of output current or output to control the proportion resistor of second level amplifier by digital regulation resistance.
Described output 2 is as the medium connecting between the output of amplifying circuit 3 and the shell of panel computer, the earth, human body, such as the shell of pen, the output line of pen are connected to shell or the earth polar etc. of panel computer.Described output 2 is for being arranged on the metallic sheath on penholder shell, and output stage and the penholder of amplifying circuit 3 combine together, and in the time of operation active pointer, staff nature contacts with output 2.Described output 2 divides directly and is connected with the power interface of panel computer by cable with power suppling part, can reduce like this power suppling part and divide shared volume and weight, also can be used as initiatively anti-lost means of pen.
Described power-supply circuit part refers to the part of powering for described amplifying circuit 3.Described power-supply circuit is not to be with the dry cell power supply circuit of charging or the storage battery power supply circuit of band charging, and described battery charging circuit comprises wired charging circuit and wireless charging circuit or the change-over circuit of directly being powered by extra power of charged pool not.Because output 2 connects the earth polar of human body, the earth or panel computer, thus conduction nib 1 equal an additional gain with the poor anti-phase voltage of described coupled voltages, so at this moment coupling capacitance will receive larger couple current; Meanwhile, the electric capacity of capacitance plate inside also can be experienced this anti-phase electromotive force, so feedback and circulation to such an extent as to last capacitance plate can obviously determine according to the calculated value of the value of couple current or coupling capacitance the existence of conduction nib 1 (contact), so improved circuit structure according to the present invention, do not changing under the prerequisite of capacitance plate, nib 1 diameter that can make to conduct electricity does littlely, writes to facilitate.
Claims (10)
1. an active pointer, is characterized in that, comprising:
Contact out generation coupling capacitance with capacitance plate, the poor or couple current of the coupled voltages that simultaneously coupling capacitance sensed passes to the conduction nib of amplifying circuit;
The input of nib is transformed to and the also amplifying circuit of output of the poor proportional in-phase voltage signal of coupled voltages, and the gain bandwidth (GB) of described amplifying circuit is at least 10MHz;
For connecting the output of the output of amplifying circuit and the shell of panel computer, the earth or human body;
For the power-supply circuit of amplifying circuit power supply.
2. a kind of initiatively pointer according to claim 1, is characterized in that: the gain bandwidth (GB) of described amplifying circuit is 40-80MHz.
3. a kind of initiatively pointer according to claim 1, is characterized in that: the floating ground of described amplifying circuit.
4. a kind of initiatively pointer according to claim 1, it is characterized in that: described amplifying circuit is made up of a noninverting integrator and an in-phase amplification circuit, wherein the input of noninverting integrator is connected with described conduction nib, output is connected with the input of in-phase amplification circuit, and in-phase amplification circuit amplifies the output homophase of noninverting integrator and is delivered to described output.
5. a kind of initiatively pointer according to claim 1, it is characterized in that: described amplifying circuit is made up of two rp-op amp circuit, wherein the input of first rp-op amp circuit is connected with described conduction nib, output is connected with the input of second rp-op amp circuit, and second rp-op amp circuit is by anti-phase the output of the first rp-op amp circuit amplification and be delivered to described output.
6. a kind of initiatively pointer according to claim 1, is characterized in that: by the gain ratio of gain control circuit controls amplifying circuit.
7. a kind of initiatively pointer according to claim 1, it is characterized in that: described power-supply circuit be not with the dry cell power supply circuit of charging or the storage battery power supply circuit of band charging or not charged pool directly by the voltage conversion circuit of external power source, described battery charging circuit comprises wired charging circuit and wireless charging circuit.
8. a kind of initiatively pointer according to claim 1, is characterized in that: described output is metallic sheath or the metal part being arranged on penholder shell.
9. a kind of initiatively pointer according to claim 1, is characterized in that: described conductive stylus nose part or be all enclosed with the material of insulation.
10. a kind of initiatively pointer according to claim 1, is characterized in that: described output divides directly and is connected with the power interface of panel computer by cable with power suppling part.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410381605.XA CN104111741A (en) | 2014-08-05 | 2014-08-05 | Active stylus |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410381605.XA CN104111741A (en) | 2014-08-05 | 2014-08-05 | Active stylus |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN104111741A true CN104111741A (en) | 2014-10-22 |
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ID=51708563
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201410381605.XA Pending CN104111741A (en) | 2014-08-05 | 2014-08-05 | Active stylus |
Country Status (1)
| Country | Link |
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| CN (1) | CN104111741A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107463279A (en) * | 2016-06-04 | 2017-12-12 | 昆盈企业股份有限公司 | Touch control pen |
| US10019079B2 (en) | 2014-12-07 | 2018-07-10 | Microsoft Technology Licensing, Llc | Stylus for operating a digitizer system |
| WO2020001283A1 (en) * | 2018-06-28 | 2020-01-02 | 京东方科技集团股份有限公司 | Active pen, touch input system, and driving method |
| US10997109B2 (en) | 2016-12-08 | 2021-05-04 | Huawei Technologies Co., Ltd. | Device with USB port |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN102681691A (en) * | 2011-03-02 | 2012-09-19 | 胜华科技股份有限公司 | Touch control pen |
| WO2013165466A1 (en) * | 2012-04-29 | 2013-11-07 | Jcm Electronic Stylus Llc | Stylus and stylus circuitry for capacitive touch screens |
| CN103645813A (en) * | 2009-12-24 | 2014-03-19 | 义隆电子股份有限公司 | Stylus and method for initiatively transmitting signal of stylus |
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2014
- 2014-08-05 CN CN201410381605.XA patent/CN104111741A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103645813A (en) * | 2009-12-24 | 2014-03-19 | 义隆电子股份有限公司 | Stylus and method for initiatively transmitting signal of stylus |
| CN102681691A (en) * | 2011-03-02 | 2012-09-19 | 胜华科技股份有限公司 | Touch control pen |
| WO2013165466A1 (en) * | 2012-04-29 | 2013-11-07 | Jcm Electronic Stylus Llc | Stylus and stylus circuitry for capacitive touch screens |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US10019079B2 (en) | 2014-12-07 | 2018-07-10 | Microsoft Technology Licensing, Llc | Stylus for operating a digitizer system |
| CN107463279A (en) * | 2016-06-04 | 2017-12-12 | 昆盈企业股份有限公司 | Touch control pen |
| US10997109B2 (en) | 2016-12-08 | 2021-05-04 | Huawei Technologies Co., Ltd. | Device with USB port |
| WO2020001283A1 (en) * | 2018-06-28 | 2020-01-02 | 京东方科技集团股份有限公司 | Active pen, touch input system, and driving method |
| US11379055B2 (en) | 2018-06-28 | 2022-07-05 | Beijing Boe Optoelectronics Technology Co., Ltd. | Active pen, touch input system, method for driving active pen, and method for driving touch input system |
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Application publication date: 20141022 |