CN108205381B

CN108205381B - Active stylus

Info

Publication number: CN108205381B
Application number: CN201611169300.8A
Authority: CN
Inventors: 陈耿男; 朱家颐; 陈翰宁; 林文琦; 陈惠忠
Original assignee: Silicon Integrated Systems Corp
Current assignee: Silicon Integrated Systems Corp
Priority date: 2016-12-16
Filing date: 2016-12-16
Publication date: 2021-09-24
Anticipated expiration: 2036-12-16
Also published as: CN108205381A

Abstract

An active stylus includes a touch element and a pressure sensing module; one end of the touch element is arranged at the pen point part of the active touch pen and is used for receiving external pressure; the pressure sensing module is connected with the touch element and used for generating an oscillation signal, when the touch element receives external pressure and the external pressure is smaller than a first threshold value, the oscillation signal oscillates at a first frequency, when the touch element receives the external pressure and the external pressure reaches the first threshold value, the oscillation frequency of the oscillation signal is adjusted to a second frequency, and the difference value between the first frequency and the second frequency is larger than a second threshold value. According to the active touch pen provided by the invention, by setting the threshold value of the external pressure, the active touch pen can generate oscillation signals at different first frequencies and second frequencies respectively according to whether the external pressure reaches the threshold value, so that the active touch pen can avoid the situation that the active touch pen generates false alarm points or water leakage due to noise disturbance of an external environment.

Description

Active stylus

Technical Field

The present invention relates to a touch pen, and more particularly, to an active touch pen for frequency disturbance caused by noise.

Background

With the rapid development of the touch industry, electronic products with touch functions are becoming more and more popular, such as smart phones, tablet computers, car navigation devices, and so on. The user can input desired information on such electronic products by means of a stylus. Generally, a stylus with pressure sensing capability generates corresponding information on a touch panel by means of pressure sensing. When the touch pen is connected to the touch panel and senses the change of the external pressure, the sensing frequency is changed, so that the touch panel receives a signal sent by the touch pen to generate a relative handwriting.

However, when the touch pen is about to touch the touch panel, a false alarm point (or commonly referred to as "water leakage") is easily generated between the touch pen and the touch panel due to the interference of environmental noise or other reasons. Therefore, the touch pen needs a mechanism for preventing the false alarm point or water leakage, so as to avoid the trouble of the touch pen user.

Disclosure of Invention

The present invention is directed to an active stylus pen, which is configured to oscillate at different frequencies with intervals between a touch state and an untouched state when the active stylus pen is touched, so as to avoid a false alarm point or a water leakage of the active stylus pen caused by noise disturbance of an external environment.

The technical problem to be solved by the invention is realized by the following technical scheme:

an active stylus comprises a touch element and a pressure sensing module; one end of the touch element is arranged at the pen point part of the active touch pen, and the touch element is used for receiving external pressure; the pressure sensing module is connected with the touch element and is used for generating an oscillation signal, when the touch element receives the external pressure and the external pressure is smaller than a first threshold value, the oscillation signal oscillates at a first frequency, when the touch element receives the external pressure and the external pressure reaches the first threshold value, the oscillation frequency of the oscillation signal is adjusted to a second frequency, and the difference value between the first frequency and the second frequency is larger than a second threshold value.

Preferably, the pressure sensing module includes: the first active circuit is provided with a first receiving end, a second receiving end and a first output end, wherein the first receiving end is electrically connected with a trigger end point, and the second receiving end receives a working voltage; an inductor having a first end and a second end, the first end of the inductor being electrically connected to the first output end of the first active circuit, the second end of the inductor being electrically connected to the trigger terminal; and an adjustable element electrically connected to the first active circuit and the inductor, wherein when the touch element receives the external pressure and the external pressure does not reach the first threshold value, a characteristic of the adjustable element is unchanged, the oscillation signal oscillates at the first frequency, and when the touch element receives the external pressure and the external pressure reaches the first threshold value, the characteristic of the adjustable element starts to change, so that the oscillation signal oscillates at the second frequency.

Preferably, the adjustable element comprises: a first capacitor having a first end and a second end, the second end of the first capacitor receiving a ground voltage; the adjustable capacitor is provided with a first end and a second end, and the second end of the adjustable capacitor receives the grounding voltage; and a first switch button electrically connected to the first end of the first capacitor and the first end of the adjustable capacitor, wherein when the touch element receives the external pressure and the external pressure does not reach the first threshold value, the first switch button is disabled, the oscillation signal oscillates at the first frequency, when the touch element receives the external pressure and the external pressure reaches the first threshold value, the first switch button is enabled, and the oscillation signal oscillates at the second frequency, wherein the characteristic of the element corresponds to the capacitance value of the adjustable capacitor.

Preferably, the adjustable element comprises: a first capacitor having a first end and a second end, the second end of the first capacitor receiving a ground voltage; the adjustable inductor is provided with a first end and a second end, and the second end of the adjustable inductor receives the grounding voltage; and a first switch button electrically connected to the first end of the first capacitor and the first end of the adjustable inductor, wherein when the touch element receives the external pressure and the external pressure does not reach the first threshold value, the first switch button is disabled, the oscillation signal oscillates at the first frequency, when the touch element receives the external pressure and the external pressure reaches the first threshold value, the first switch button is enabled, and the oscillation signal oscillates at the second frequency, wherein the characteristic of the element corresponds to the inductance value of the adjustable inductor.

Preferably, the adjustable element comprises: a first capacitor having a first end and a second end, the second end of the first capacitor receiving a ground voltage; the adjustable resistor is provided with a first end and a second end, and the second end of the adjustable resistor receives the grounding voltage; and a first switch button electrically connected to the first end of the first capacitor and the first end of the adjustable resistor, wherein when the touch element receives the external pressure and the external pressure does not reach the first threshold value, the first switch button is disabled, the oscillation signal oscillates at the first frequency, when the touch element receives the external pressure and the external pressure reaches the first threshold value, the first switch button is enabled, and the oscillation signal oscillates at the second frequency, wherein the characteristic of the element corresponds to the resistance value of the adjustable resistor.

Preferably, the first active circuit comprises: a first resistor having a first end and a second end, wherein the first end of the first resistor receives the working voltage; the first end of the second resistor is electrically connected with the second end of the first resistor, and the second end of the second resistor is electrically connected with the first output end; and a first operational amplifier having a first voltage input terminal, a second voltage input terminal and a voltage output terminal, wherein the first voltage input terminal is electrically connected to the trigger terminal, the second voltage input terminal is electrically connected to the second terminal of the first resistor and the first terminal of the second resistor, and the voltage output terminal is electrically connected to the first output terminal.

Preferably, the pressure sensing module includes: a second active circuit having a third receiving terminal, a fourth receiving terminal and a second output terminal, wherein the fourth receiving terminal receives a working voltage; the inductor is provided with a first end and a second end, and the first end of the inductor is electrically connected with the second output end of the second active circuit; and a first capacitor having a first end and a second end, the second end of the first capacitor receiving a ground voltage.

Preferably, the nib has a hole structure, and the pressing member includes: the adjustable capacitor is provided with a first electrode, a second electrode and an elastic body, the elastic body is positioned between the first electrode and the second electrode, the second electrode of the adjustable capacitor receives the grounding voltage, the first electrode is fixed at the pen point part, the second electrode is fixed at a pen body of the active touch control pen, and the pen point part can move along the axial direction of the pen body of the active touch control pen; and a linkage element, part of which is slidable along the hole structure and has a metal region, wherein the first end of the first capacitor, the second end of the inductor and the third receiving end are in contact with the metal region, when the touch element receives the external pressure and the external pressure reaches the first threshold value, the linkage element slides towards the adjustable capacitor along the axial direction of the pen point part, so that the metal region touches the first electrode of the adjustable capacitor to conduct a current path between the first end of the first capacitor and the first electrode of the adjustable capacitor, and the oscillation frequency of the oscillation signal is less than or equal to the second frequency.

Preferably, when the touch element receives the external pressure, the linking element slides towards the adjustable capacitor, if the external pressure does not reach the first threshold value, the metal area does not touch the first end of the adjustable capacitor, so that the current path between the first end of the first capacitor and the first end of the adjustable capacitor is not conducted, and the oscillation signal oscillates at the first frequency.

Preferably, the second active circuit comprises: a third resistor having a first end and a second end, the first end of the third resistor receiving the working voltage; a fourth resistor having a first end and a second end, the first end of the fourth resistor being electrically connected to the second end of the third resistor, the second end of the fourth resistor being electrically connected to the second output end; and a second operational amplifier having a third voltage input terminal, a fourth voltage input terminal and a second voltage output terminal, wherein the third voltage input terminal is electrically connected to the third receiving terminal, the fourth voltage input terminal is electrically connected to the second terminal of the first resistor and the first terminal of the second resistor, and the second voltage output terminal is electrically connected to the second output terminal.

In summary, the active stylus provided in the present invention, by setting the threshold value of the external pressure, the active stylus can generate the oscillation signals at the first frequency and the second frequency respectively according to whether the external pressure reaches the threshold value, so that the active stylus can avoid the situation of false alarm or water leakage of the active stylus due to noise disturbance of the external environment.

The foregoing summary of the invention, as well as the following detailed description of the embodiments, is provided to illustrate and explain the principles and spirit of the invention, and to provide further explanation of the invention as claimed.

Drawings

FIG. 1 is a block diagram of an active stylus according to an embodiment of the present invention;

FIG. 2A is a schematic diagram of frequency variation according to an embodiment of the present invention;

FIG. 2B is a schematic diagram of frequency variation according to another embodiment of the present invention;

FIG. 3 is a schematic diagram of an active stylus according to an embodiment of the present invention;

FIG. 4 is a schematic diagram of capacitance variation according to an embodiment of the present invention;

FIG. 5 is a schematic diagram of an active stylus according to an embodiment of the present invention;

FIG. 6 is a schematic diagram of an active stylus according to an embodiment of the present invention;

fig. 7 is an equivalent circuit diagram of an active stylus according to an embodiment of the invention.

[ description of reference ]

1: active stylus

10. 10': contact-pressure element

102. 1241': adjustable capacitor

1021: a first electrode

1022: second electrode

1023: elastic body

104: linkage element

11: pen point

12. 12': pressure sensing module

120: a first active circuit

120': second active circuit

1202: a first resistor

1203: second resistance

1202': third resistance

1203': fourth resistor

1201: a first operational amplifier

1201': a second operational amplifier

124': adjustable element

1240': first capacitor

1242': first switch button

122. 122': inductance

14: pen body

E1: first receiving end

E2: second receiving end

E3: a first output terminal

E1': third receiving end

E2': the fourth receiving end

E3': second output terminal

V_tri: trigger endpoint

VD: operating voltage

L: length of

GND: ground voltage

f 1: first frequency

f 2: second frequency

f 3: third frequency

C1, C2: capacitance value

T1: first threshold value

T2: second threshold value

UTCH: non-touch area

TCH (traffic channel): touch control area

Detailed Description

The detailed features and advantages of the present invention are described in detail in the following embodiments, which are sufficient for a person skilled in the art to understand the technical contents of the present invention and to implement the present invention, and the related objects and advantages of the present invention can be easily understood by the person skilled in the art from the contents described in the present specification, the scope of protection of the claims and the accompanying drawings. The following examples further illustrate aspects of the present invention in detail, but are not intended to limit the scope of the invention in any way.

Referring to fig. 1 and fig. 2A together, fig. 1 is a block diagram of an active stylus according to an embodiment of the invention, and fig. 2A is a schematic diagram of frequency variation according to an embodiment of the invention. As shown in fig. 1, the active stylus 1 includes a touch device 10 and a pressure sensing module 12. One end of the touch element 10 is disposed at the pen tip 11 of the active stylus 1, and a part of the touch element 10 is exposed outside the pen tip 11. The pressing member 10 is configured to receive an external pressure. In one example, the external pressure refers to a reaction force applied by the touch panel to the active stylus 1 when the active stylus 1 touches the touch panel. The pressure sensing module 12 is connected with the touch pressure element 10. The pressure sensing module 12 is used for generating an oscillation signal. The oscillation signal is sent by the active stylus 1 and transmitted to the corresponding touch panel to generate corresponding actions, for example, different handwriting is generated on the touch panel. In this embodiment, as shown in fig. 1 and fig. 2A, when the touch device 10 receives the external pressure and the external pressure is smaller than the first threshold T1, the oscillation signal oscillates at the first frequency f 1. When the touch-pressure element 10 receives the external pressure, and when the external pressure reaches the first threshold T1, the oscillation frequency of the oscillation signal is adjusted to the second frequency f 2. The difference between the first frequency f1 and the second frequency f2 is greater than a second threshold T2.

Specifically, in the embodiment of fig. 2A, when the touch pressure element 10 of the active stylus 1 receives an external pressure less than the first threshold T1, the oscillation signal generated by the pressure sensing module 12 has the first frequency f 1. On the contrary, when the touch element 10 of the active stylus 1 receives the external pressure reaching the first threshold T1, the oscillation signal generated by the pressure sensing module 12 has the second frequency f 2. As shown in fig. 2A, when the external pressure is less than the first threshold T1, the frequency of the oscillation signal is maintained at the first frequency f1, and the active stylus 1 is in an untouched state, i.e., the untouched area UTCH in fig. 2A. When the touch panel receives the oscillation signal with the first frequency f1, no corresponding action is generated. In other words, the active stylus 1 and the touch panel determine that the user does not substantially perform the touch operation. Correspondingly, when the external pressure reaches the first threshold T1 and continues to increase gradually, the frequency of the oscillating signal decreases accordingly. In other words, the frequency of the oscillating signal gradually decreases from the second frequency f2 according to the external pressure. At this time, the active stylus 1 is in a touch state, i.e. the touch area TCH in fig. 2A. In the touch area TCH, the external pressure of different degrees can change the frequency of the oscillation signal, so that the touch panel can display different corresponding actions, such as different types of handwriting.

Please refer to fig. 1 and fig. 2B together. Fig. 2B is a schematic diagram of frequency variation according to another embodiment of the present invention. As shown in fig. 2B, in the embodiment, when the touch device 10 receives the external pressure and the external pressure is smaller than the first threshold T1, the oscillation signal oscillates at the first frequency f1, and the active stylus 1 is in an untouched state, i.e., the untouched area UTCH in fig. 2B. When the touch pressure element 10 receives the external pressure, and when the external pressure reaches the first threshold T1, the oscillation frequency of the oscillation signal is adjusted to the third frequency f 3. The difference between the first frequency f1 and the third frequency f3 is greater than a second threshold T2. The embodiment of fig. 2B is different from the embodiment of fig. 2A in that in the embodiment of fig. 3, when the external pressure reaches the first threshold T1 and continues to increase gradually, the frequency of the oscillating signal increases accordingly. In other words, the frequency of the oscillating signal gradually increases from the third frequency f3 according to the external pressure. At this time, the active stylus 1 is in a touch state, i.e. a touch area TCH in fig. 2B.

For convenience of explanation, the following embodiments are described with reference to the schematic diagram of frequency variation in fig. 2A. Fig. 3 is a schematic circuit diagram and a structure of an active stylus according to an embodiment of the invention. As shown in fig. 3, for clearly explaining the operation of the active stylus, fig. 3 is divided into a right circuit diagram and a left structure diagram to respectively indicate an equivalent circuit diagram of the pressure sensing module 12 and an internal structure diagram of the touch pressure device 10. As shown in the right circuit diagram of fig. 3, the pressure sensing module 12 includes a first active circuit 120, an inductor 122 and a first capacitor 124. The first active circuit 120 has a first receiving terminal E1, a second receiving terminal E2 and a first output terminal E3. The second receiving terminal E2 receives the operating voltage VD. The inductor 122 has a first end and a second end, and the first end of the inductor 122 is electrically connected to the first output end E3 of the first active circuit 120. The first capacitor 124 has a first terminal and a second terminal, and the second terminal of the first capacitor 124 receives the ground voltage GND. In an embodiment, as shown in the left structural diagram of fig. 3, the tip portion of the active stylus 1 has a hole structure 110. The touch device 10 includes an adjustable capacitor 102 and a linkage device 104. The tunable capacitor 102 has a first electrode 1021, a second electrode 1022, and an elastic member 1023. The elastic body 1023 is located between the first electrode 1021 and the second electrode 1022.

In practice, the elastic body 1023 is made of an insulating elastic material, such as rubber, silicone or a plastic spring with elastic characteristics. The first electrode 1021 and the second electrode 1022 connected to both sides of the elastic body 1023 store charges to form a capacitor. The capacitance of the tunable capacitor 102 can be changed by adjusting the distance between the first electrode 1021 and the second electrode 1022 through the application of pressure. The second electrode 1022 of the tunable capacitor 102 receives the ground voltage GND, and the first electrode 1021 is fixed to the nib portion 11. The second electrode 1022 is fixed to the pen body 14, and the pen tip 11 is movable along the axial direction of the pen body 14 of the active stylus 1.

Part of the linking elements 104 can slide along the hole structure 110. The linking element 104 has a metal region 1041. The first end of the first capacitor 124, the second end of the inductor 122 and the first receiving end E1 are in contact with the metal region 1041 of the linking element 104. Referring to fig. 4, fig. 4 is a schematic diagram of capacitance variation according to an embodiment of the invention. As shown in fig. 4, the capacitance variation diagram of fig. 4 corresponds to the frequency variation diagram of fig. 2A. When the touch element 10 starts to receive the external pressure and the external pressure does not reach the first threshold F1, the linking element 104 gradually slides toward the adjustable capacitor 102 along the axial direction of the pen tip 11. At this time, since the metal region 1041 and the first electrode 1021 of the tunable capacitor 102 are not yet touched, the capacitance of the active stylus 1 is kept at the capacitance C1, and the oscillation signal oscillates at the first frequency f 1. At this time, the active stylus 1 is in a non-touch state, i.e. the non-touch area UTCH of fig. 2A and 4. Referring to fig. 5, fig. 5 is a schematic circuit diagram and a structure of an active stylus according to an embodiment of the invention. As shown in fig. 5, when the external pressure gradually increases to reach the first threshold T1, the linking element 104 contacts the second electrode 1022 of the tunable capacitor 102. Meanwhile, since the linking element 104 slides toward the tunable capacitor 102 by the length L, the metal region 1041 and the first electrode 1021 of the tunable capacitor 102 touch each other, and a current path between the first end of the first capacitor 124 and the first electrode 1021 of the tunable capacitor 102 is conducted. At this time, the capacitance of the active stylus 1 is increased from the capacitance C1 to the capacitance C2, and the oscillation frequency of the oscillation signal is exactly equal to the second frequency f 2.

Referring to fig. 6, fig. 6 is a schematic circuit diagram and a structure of an active stylus according to an embodiment of the invention. As shown in fig. 6, after the linking element 104 contacts the second electrode 1022 of the tunable capacitor 102, if the external pressure continues to increase and exceeds the first threshold T1, the linking element 104 will continue to slide toward the tunable capacitor 102, and further press the first electrode 1021. As shown in fig. 6, since the first electrode 1021 is fixed to the nib 11, when the first electrode 1021 is pressed, the nib 11 is further driven to slide toward the second electrode 1022, and the elastic body 1023 sandwiched between the first electrode 1021 and the second electrode 1022 is compressed. Referring to fig. 6 again, since the second electrode 1022 is fixedly disposed on the pen body 14, when the elastic body 1023 is compressed, the distance between the first electrode 1021 and the second electrode 1022 is gradually decreased, so that the capacitance of the adjustable capacitor 102 is gradually increased from the capacitance C2. At this time, the active stylus 1 is in a touch state, i.e. the touch area TCH in fig. 2 and fig. 4. In another example, when the external pressure reaches the first threshold T1 and continues to increase gradually, the frequency of the oscillation signal increases, and the capacitance value correspondingly decreases.

In one embodiment, the first active circuit 120 includes a first resistor 1202 and a second resistor 1203. The first resistor 1202 has a first end and a second end, and the first end of the first resistor 1203 receives the operating voltage VD. The second resistor 1203 has a first terminal and a second terminal. A first terminal of the second resistor 1203 is electrically connected to the second terminal of the first resistor 1202, and a second terminal of the second resistor 1203 is electrically connected to the first output terminal E3. The first operational amplifier 1201 has a first voltage input terminal, a second voltage input terminal, and a third voltage output terminal. The first voltage input terminal is electrically connected to the first receiving terminal E1, the second voltage input terminal is electrically connected to the second terminal of the first resistor 1203 and the first terminal of the second resistor 1203, and the third voltage output terminal is electrically connected to the first output terminal E3.

Generally, when a user uses an active stylus for touch operation, the active stylus and the touch panel are often misjudged due to the influence of external environmental noise. For example, when the active stylus is held by the user in close proximity to the touch panel, the user does not substantially input information on the touch panel, but the touch panel displays corresponding unexpected actions due to external environmental noise, i.e. so-called "water leakage". By the active stylus 1 provided by the present invention, the difference between the first frequency f1 and the second frequency f2 added between the touched state and the non-touched state enables the active stylus 1 to more accurately determine whether the user wants to perform the touch operation, so as to avoid the problem of water leakage, which affects the use experience of the active stylus.

Referring to fig. 7, fig. 7 is an equivalent circuit diagram of an active stylus according to an embodiment of the present invention, as shown in fig. 7, which corresponds to the active stylus of fig. 1, in this embodiment, the pressure sensing module 12 'includes a second active circuit 120', an inductor 122 ', and an adjustable element 124'. The second active circuit 120 'has a third receiving terminal E1', a fourth receiving terminal E2 ', and a second output terminal E3'. The first receiving terminal E1' is electrically connected to the trigger terminal V_triAnd the second receiving end receives the working voltage VD. The inductor 122' has a first terminal and a second terminal. The first terminal of the inductor 122 ' is electrically connected to the second output terminal E3 ' of the second active circuit 120 ', and the second terminal is electrically connected to the trigger terminal V_tri. The tunable element 124 ' is electrically connected to the second active circuit 120 ' and the inductor 122 '. When the touch device 10 'receives the external pressure and the external pressure does not reach the first threshold T1, the adjustable device 124' has the same device characteristics, and the oscillation signal oscillates at the first frequency f 1. When the touch device 10 'receives the external pressure and the external pressure reaches the first threshold T1, the device characteristic of the adjustable device 124' begins to change, so that the oscillation signal oscillates at the second frequency f 2. In one example, the tunable element 124' includes a tunable capacitor, and the characteristic of the tunable element corresponds to a capacitance of the tunable capacitor. In another example, the tunable device 124' includes a tunable inductor, and the device characteristic corresponds to an inductance value of the tunable inductor. In another example, the tunable element 124' includes a tunable resistor, and the characteristic of the tunable element corresponds to a resistance value of the tunable resistor.

In one embodiment, the adjustable element 124 'includes a first capacitor 1240', an adjustable capacitor 1241 'and a first switch button 1242'. The first capacitor 1240 'has a first terminal and a second terminal, and the second terminal of the first capacitor 1240' receives the ground voltage Vd. The tunable device 124' has a first terminal and a second terminal, and the second terminal receives the ground voltage GND. The first switch button 1242 ' is electrically connected to a first end of the first capacitor 1240 ' and a first end of the tunable capacitor 1241 '. When the touch element 10 'receives the external pressure and the external pressure does not reach the first threshold T1, the first switch button 1242' is disabled and the oscillation signal oscillates at the first frequency f 1. When the touch device 10 receives the external pressure and the external pressure reaches the first threshold T1, the first switch button 1242' is enabled (switch on), and the oscillation signal oscillates at the second frequency f 2. For a practical example, when the active stylus 1 lightly touches the touch panel, assuming that the touch force has not yet reached the first threshold T1, the first switch button 1242' is in a non-conducting state, and at this time, as shown in fig. 2, the oscillation signal is fixed to oscillate at the first frequency f1, and the touch panel does not display the corresponding action. When the touch force reaches the first threshold value T1, the first switch button 1242' is turned on. At this time, the oscillation frequency of the oscillation signal is decreased from the first frequency f1 to the second frequency f2, and the touch panel starts to display corresponding actions. If the touch force continues to increase and exceeds the first threshold T1, the oscillation frequency of the oscillation signal also increases, thereby displaying different corresponding actions on the touch panel.

For another practical example, the first switch button 1242' may be a button on the active stylus holder 1. When the user holds the active stylus 1, if the user does not want to perform any operation on the touch panel, the user does not need to press the button. In this situation, the first switch button 1242' is in the disabled state (the switch is not turned on), the oscillation signal emitted by the active stylus pen 1 is fixed to oscillate at the first frequency f1, and the touch panel will not generate corresponding actions. On the contrary, when the user wants to perform a manipulation operation on the touch panel, such as writing or drawing, the user can press the button to enable the first switch button 1242', and at this time, the oscillation frequency of the oscillation signal is less than or equal to the second frequency f2, and the touch panel starts to display a corresponding action.

In one embodiment, the second active circuit 120 'includes a third resistor 1202', a fourth resistor 1203 'and a second operational amplifier 1201'. The third resistor 1202' has a first terminal and a second terminal, and the first terminal receives the operating voltage VD. The fourth resistor 1203 ' has a first end and a second end, the first end is electrically connected to the second end of the third resistor 1202 ', and the second end is electrically connected to the second output end E3 '. The second operational amplifier 1201' has a first voltage input terminal, a second voltage input terminal, and a voltage output terminal. The first voltage input end is electrically connected with the trigger end point V_triThe second voltage input terminal is electrically connected to the second terminal of the third resistor 1202 ' and the first terminal of the fourth resistor 1203 ', and the voltage output terminal is electrically connected to the second output terminal E3 '.

The active stylus pen proposed in the above embodiment utilizes the capacitance change of the adjustable capacitor 1241' to match the structure of fig. 3 or the structure of the button, so as to prevent the water leakage problem. However, in other embodiments, the active stylus utilizes other adjustable devices to prevent water leakage. For example, the tunable capacitor 1241 'included in the tunable device 124' of the active stylus pen in fig. 7 may be replaced by a tunable inductor, and a user may change the inductance value by pressing a button, adjusting the position of the metal core of the tunable inductor in the coil, or adjusting the number of turns of the coil of the tunable inductor, thereby achieving the operation mode of the active stylus pen. In another example, the tunable element 124 'of the active stylus of fig. 7 may include a tunable capacitor 1241' instead of a tunable resistor, and the user may also press a button or adjust a sliding contact between two ends of the tunable resistor to change the resistance value to achieve the operation of the active stylus. The invention is not limited to the adjustable devices described in the above embodiments.

In summary, according to the active stylus of the present invention, by means of the pressure applied to the active stylus from the outside and the setting of the switch element (or the linkage element), a difference exists between the first frequency and the second frequency of the oscillation signal, so that the active stylus can avoid the problem of error reporting or water leakage caused by noise disturbance generated by the external environment, and a user can have better touch experience.

Claims

1. An active stylus, comprising:

a touch element, one end of which is arranged at a pen point part of the active touch pen, the touch element is used for receiving an external pressure; and

the pressure sensing module is connected with the touch element and used for generating an oscillation signal, when the touch element receives the external pressure and the external pressure is smaller than a first threshold value, the oscillation signal oscillates at a first frequency, when the touch element receives the external pressure and the external pressure reaches the first threshold value, the oscillation frequency of the oscillation signal is adjusted to a second frequency;

wherein a difference between the first frequency and the second frequency is greater than a second threshold;

the pressure sensing module includes:

the first active circuit is provided with a first receiving end, a second receiving end and a first output end, wherein the first receiving end is electrically connected with a trigger end point, and the second receiving end receives a working voltage;

an inductor having a first end and a second end, the first end of the inductor being electrically connected to the first output end of the first active circuit, the second end of the inductor being electrically connected to the trigger terminal; and

an adjustable element electrically connected to the first active circuit and the inductor, wherein when the touch element receives the external pressure and the external pressure does not reach the first threshold, a characteristic of the adjustable element is unchanged, the oscillation signal oscillates at the first frequency, and when the touch element receives the external pressure and the external pressure reaches the first threshold, the characteristic of the adjustable element starts to change, so that the oscillation signal oscillates at the second frequency;

the adjustable element comprises:

a first capacitor having a first end and a second end, the second end of the first capacitor receiving a ground voltage;

the adjustable capacitor is provided with a first end and a second end, and the second end of the adjustable capacitor receives the grounding voltage; and

a first switch button electrically connected to the first end of the first capacitor and the first end of the adjustable capacitor, when the touch element receives the external pressure and the external pressure does not reach the first threshold, the first switch button is disabled, the oscillation signal oscillates at the first frequency, when the touch element receives the external pressure and the external pressure reaches the first threshold, the first switch button is enabled, the oscillation signal oscillates at the second frequency, wherein the characteristic of the element corresponds to the capacitance value of the adjustable capacitor.

2. An active stylus, comprising:

the pressure sensing module includes:

the adjustable element comprises:

the adjustable inductor is provided with a first end and a second end, and the second end of the adjustable inductor receives the grounding voltage; and

a first switch button electrically connected to the first end of the first capacitor and the first end of the adjustable inductor, when the touch element receives the external pressure and the external pressure does not reach the first threshold, the first switch button is disabled, the oscillation signal oscillates at the first frequency, when the touch element receives the external pressure and the external pressure reaches the first threshold, the first switch button is enabled, the oscillation signal oscillates at the second frequency, wherein the characteristic of the element corresponds to the inductance value of the adjustable inductor.

3. An active stylus, comprising:

the pressure sensing module includes:

the adjustable element comprises:

the adjustable resistor is provided with a first end and a second end, and the second end of the adjustable resistor receives the grounding voltage; and

a first switch button electrically connected to the first end of the first capacitor and the first end of the adjustable resistor, when the touch element receives the external pressure and the external pressure does not reach the first threshold, the first switch button is disabled, the oscillation signal oscillates at the first frequency, when the touch element receives the external pressure and the external pressure reaches the first threshold, the first switch button is enabled, the oscillation signal oscillates at the second frequency, wherein the characteristic of the element corresponds to the resistance value of the adjustable resistor.

4. The active stylus of any one of claims 1-3, wherein the first active circuit comprises:

a first resistor having a first end and a second end, wherein the first end of the first resistor receives the working voltage;

the first end of the second resistor is electrically connected with the second end of the first resistor, and the second end of the second resistor is electrically connected with the first output end; and

the first operational amplifier is provided with a first voltage input end, a second voltage input end and a voltage output end, wherein the first voltage input end is electrically connected with the trigger end point, the second voltage input end is electrically connected with the second end of the first resistor and the first end of the second resistor, and the voltage output end is electrically connected with the first output end.

5. An active stylus, comprising:

the pressure sensing module includes:

a second active circuit having a third receiving terminal, a fourth receiving terminal and a second output terminal, wherein the fourth receiving terminal receives a working voltage;

the inductor is provided with a first end and a second end, and the first end of the inductor is electrically connected with the second output end of the second active circuit; and

the nib portion has a hole structure, and the touch element includes:

the adjustable capacitor is provided with a first electrode, a second electrode and an elastic body, the elastic body is positioned between the first electrode and the second electrode, the second electrode of the adjustable capacitor receives the grounding voltage, the first electrode is fixed at the pen point part, the second electrode is fixed at a pen body of the active touch control pen, and the pen point part can move along the axial direction of the pen body of the active touch control pen; and

and a linkage element, part of which is slidable along the hole structure, the linkage element having a metal region, the first end of the first capacitor, the second end of the inductor and the third receiving end being in contact with the metal region, when the touch element receives the external pressure and the external pressure reaches the first threshold value, the linkage element slides toward the adjustable capacitor along the axial direction of the pen point portion, so that the metal region touches the first electrode of the adjustable capacitor to conduct a current path between the first end of the first capacitor and the first electrode of the adjustable capacitor, thereby making the oscillation frequency of the oscillation signal less than or equal to the second frequency.

6. The active stylus of claim 5, wherein when the touch element receives the external pressure, the linking element slides toward the tunable capacitor, and if the external pressure does not reach the first threshold, the metal area does not touch the first end of the tunable capacitor, such that a current path between the first end of the first capacitor and the first end of the tunable capacitor is not conducted, and the oscillation signal oscillates at the first frequency.

7. The active stylus of claim 5, wherein the second active circuit comprises:

a third resistor having a first end and a second end, the first end of the third resistor receiving the working voltage;

a fourth resistor having a first end and a second end, the first end of the fourth resistor being electrically connected to the second end of the third resistor, the second end of the fourth resistor being electrically connected to the second output end; and

the second operational amplifier is provided with a third voltage input end, a fourth voltage input end and a second voltage output end, wherein the third voltage input end is electrically connected with the third receiving end, the fourth voltage input end is electrically connected with the second end of the first resistor and the first end of the second resistor, and the second voltage output end is electrically connected with the second output end.