CN103324366B - Capacitance detecting device and apply the capacitance touch control system of this capacitance detecting device - Google Patents

Abstract

The present invention provides a kind of capacitance detecting device, is connected to a testing capacitance, comprises the first electric capacity, the second electric capacity, control module and judge module.This first electric capacity and this second electric capacity are connected to this testing capacitance through an input node.This control module is in order to provide this first electric capacity one first cross-pressure to change, and provides this testing capacitance one second cross-pressure to change, and thereby makes this second electric capacity produce one the 3rd cross-pressure change.The change of this first cross-pressure makes the electric charge flowing to this input node from this first electric capacity positive and negative identical with the electric charge flowing into this testing capacitance from this input node with the change of this second cross-pressure.This judge module is in order to the capacitance according to this first electric capacity, the capacitance of this second electric capacity, the change of this first cross-pressure, the change of this second cross-pressure and the change of the 3rd cross-pressure, it is judged that the capacitance of this testing capacitance.

Description

Capacitance detecting device and apply the capacitance touch control system of this capacitance detecting device

Technical field

The present invention is relevant to the technology of measurement, and especially relevant to the improvement of circuit measuring capacitance.

Background technology

Along with science and technology is showing improvement or progress day by day, the most more and more hommization of the operation interface of the most various electronic products.For example, Through Touch Screen, user can directly operation sequence, input message/word/pattern on screen with finger or pointer, save Go to use the trouble of the input equipment such as keyboard or button.It practice, Touch Screen is typically by induction panel and is arranged at sensing The display composition at panel rear.The position that electronic installation can be touched on induction panel according to user, and show at that time Show the picture that device is presented, judge the meaning of this touching and perform corresponding operating result.

For capacitive touch device, the touching of user can affect the electric field of touched point, in turn results in corresponding Capacitance variation.Sensitivity and the correctness of measuring the circuit of capacitance variation are most important.Block in Fig. 1 (A) 100 is a capacitive detection circuit example.This testing circuit comprise operational amplifier 12, weld pad (pad) 14, feedback electric capacity Cfb, two An individual first switch SW1 and second switch SW2.Weld pad 14 is in order to by position at the testing capacitance Cx outside testing circuit 100 even It is connected to operational amplifier 12.Whether testing capacitance Cx position, in induction panel, can be touched along with user and change.

In the first stage of detection process, two first switch SW1 are set to path, and second switch SW2 is set to Open circuit；Circuit in Fig. 1 (A) is equal to the circuit shown in Fig. 1 (B).In that case, the outfan of operational amplifier 12 And the voltage of positive-negative input end all can be equal to reference voltage VL (Vout).Therefore back coupling electric capacity Cfb is discharged to there is not electric charge, Testing capacitance Cx is then to be charged to there is electric charge Cx*VL.Subsequently, at the second stage of detection process, two first switch SW1 Being switched to open circuit, second switch SW2 is switched to path；Circuit in Fig. 1 (A) is equal to shown in Fig. 1 (C).In these feelings Under condition, the voltage of the positive-negative input end of operational amplifier 12 all can become reference voltage VH.Electric charge after redistributing, outfan Voltage can be expressed as follows:

$\mathrm{Vout}=\mathrm{VH}+(\mathrm{VH}-\mathrm{VL})*\frac{\mathrm{Cx}}{\mathrm{Cfb}}.---\left(1\right)$

Owing to the numerical value of reference voltage VL, VH and back coupling electric capacity Cfb is all it is known that can calculate according to output voltage Vout Go out the size of testing capacitance Cx.If testing capacitance Cx is disassembled the background capacitance for i.e. existing before not affected by user further Cbg and touch the summation of capacitance change Csig of generation because of user, formula (1) can be rewritten as:

$\mathrm{Vout}=\mathrm{VH}+(\mathrm{VH}-\mathrm{VL})*\frac{\mathrm{Cbg}}{\mathrm{Cfb}}+(\mathrm{VH}-\mathrm{VL})*\frac{\mathrm{Csig}}{\mathrm{Cfb}}.---\left(2\right)$

Actually background capacitance Cbg substantially definite value.Therefore, main measurement is to liking capacitance change Csig.In order to Avoiding output voltage Vout saturated, back coupling electric capacity Cfb can not be designed to be the least.But, last by formula (2) can be seen Going out, back coupling electric capacity Cfb is bigger, and the resolution measuring capacitance change Csig is the poorest.

Summary of the invention

For solving the problems referred to above, the several embodiment of the present invention proposes a kind of new capacitance detecting device and applies this electric capacity to examine Survey the capacitance touch control system of device.Testing capacitance is suitably supplied at electric charge by the outer newly-increased electric capacity at back coupling electric capacity The quantity of electric charge needed in re-allocation process, can overcome in prior art according to the capacitance detecting device of the several embodiment of the present invention It is difficult to take into account measurement resolution and avoid the problem that output voltage is saturated.It should be noted that to use and connect on primary circuit plate Parasitic capacitance between line and screen layer, as this newly-increased electric capacity, thereby reaches to save the effect of chip area.

A specific embodiment according to the present invention is a kind of capacitance detecting device, is connected to a testing capacitance, and this electric capacity is examined Survey device and comprise one first electric capacity, one second electric capacity, a control module and a judge module.This first electric capacity and this second electric capacity It is connected to this testing capacitance through an input node.This control module in order to provide this first electric capacity one first cross-pressure to change, and There is provided this testing capacitance one second cross-pressure to change, thereby make this second electric capacity produce one the 3rd cross-pressure change.This first cross-pressure becomes Change to change with this second cross-pressure and make to flow to the electric charge of this input node with to flow into this from this input node to be measured from this first electric capacity The electric charge of electric capacity is positive and negative identical.This judge module in order to the capacitance according to this first electric capacity, the capacitance of this second electric capacity, should First cross-pressure change, the change of this second cross-pressure and the change of the 3rd cross-pressure, it is judged that the capacitance of this testing capacitance.

Another specific embodiment according to the present invention is a kind of capacitance touch control system, wherein comprises a display, multiple Inductance capacitance, one first electric capacity, one second electric capacity, a control module and a judge module.The plurality of inductance capacitance is the most corresponding A provider location on this display.This first electric capacity and this second electric capacity are connected to the plurality of sensing through an input node Electric capacity one of them as a testing capacitance.This control module is in order to provide this first electric capacity one first cross-pressure to change, and provides This testing capacitance one second cross-pressure changes, and thereby makes this second electric capacity produce one the 3rd cross-pressure change.This first cross-pressure change with The change of this second cross-pressure makes to flow to the electric charge of this input node from this first electric capacity and flow into this testing capacitance from this input node Electric charge positive and negative identical.This judge module in order to the capacitance according to this first electric capacity, the capacitance of this second electric capacity, this first Cross-pressure change, the change of this second cross-pressure and the change of the 3rd cross-pressure, it is judged that the capacitance of this testing capacitance.

Advantage and spirit about the several embodiment of the present invention can obtain by following detailed description and accompanying drawings further Understanding.

Accompanying drawing explanation

Fig. 1 (A)～Fig. 1 (C) illustrates the capacitive detection circuit in prior art.

Fig. 2 (A)～Fig. 2 (C) is to change signal according to the capacitance detecting device in one embodiment of the invention and state thereof Figure.

Fig. 3 (A)～Fig. 3 (C) depicts the capacitance detecting device according to the present invention and utilizes the example of external capacitive.

Its state of capacitance detecting device change during Fig. 4 (A)～Fig. 4 (C) illustrates according to another embodiment of the present invention is shown It is intended to.

Main element symbol description

100: capacitive detection circuit 12: operational amplifier

14,28: weld pad Cfb: back coupling electric capacity

SW1～SW5: switch Cx: testing capacitance

200: capacitance detecting device 22,42: operational amplifier

24,44: input node 26,46: judge module

29: control module 400: connecting line

500: chip 600: induction panel

48: driving node C1, C2, C1A, C1B: electric capacity

Detailed description of the invention

It is the capacitance detecting device 200 as shown in Fig. 2 (A) according to one embodiment of the invention, wherein comprises two electric capacity C1～C2, five switch SW1～SW5, operational amplifier 22, input node 24 and judge modules 26.Testing capacitance Cx is through defeated Ingress 24 is connected to capacitance detecting device 200.If capacitance detecting device 200 and testing capacitance Cx are positioned at different encapsulation chip In, input node 24 can be a weld pad, but is not limited.In practice, capacitance detecting device 200 can be individually present, also can quilt It is integrated in other systems having detection capacitance demand.

The state of switch SW1～SW5 can be determined by a control module (not shown).In the first stage of detection process, open Close SW1, SW3, SW4 and be first set to path, and switch SW2, SW5 and be set to open circuit；Circuit in Fig. 2 (A) is equal to Circuit (ignoring judge module 26 temporarily) shown in Fig. 2 (B).Under setting at this, the outfan (Vout) of operational amplifier 22 and just The voltage of negative input end all can be equal to reference voltage VL.Electric capacity C2 is discharged to not have electric charge, and electric capacity C1 is charged to be had Electric charge C1*VL, testing capacitance Cx are then to be charged to there is electric charge Cx*VL.

Subsequently, in the second stage of detection process, switch SW1, SW3, SW4 are switched to open circuit, and switch SW2, SW5 are cut It is changed to path；Circuit in Fig. 2 (A) is equal to the circuit (ignoring judge module 26 temporarily) shown in Fig. 2 (C).Under setting at this, fortune The voltage of the positive-negative input end calculating amplifier 22 is all the control nodes X of reference voltage VH, electric capacity C1 side by reconfiguration to controlling Voltage VS.

Between above-mentioned two benches switch switching the cross-pressure of each electric capacity can be caused to change, in turn result in electric charge electric capacity C1, C2, Redistribute between Cx.Charge balance relation corresponding to input node 24 may be expressed as:

(VS+VL-VH) * C1+ (Vout-VH) * C2=(VH-VL) * Cx.(3)

Reference voltage VH in this embodiment is higher than VL, and control voltage VS is designed to higher than (VH-VL).Accordingly, by Formula (3) can be seen that, flows into testing capacitance Cx and by self-capacitance C1 flow direction input joint at second stage electric current from input node 24 Point 24, in other words, flowing into the positive charge of testing capacitance Cx at least part of from input node 24 is to be flowed to defeated by self-capacitance C1 The positive charge of ingress 24 is contributed.As for self-capacitance C2 impact part in one's power, if Vout is more than VH, electric current is from self-capacitance C2 flows to input node 24, and i.e. flow to input node 24 by self-capacitance C2 is positive charge；If Vout is less than VH, electric current is from input Node 24 flows to self-capacitance C2, and i.e. flow to input node 24 by self-capacitance C2 is negative charge.It is different from electricity to be measured in Fig. 1 (C) The electric charge of appearance Cx changes completely by feedbacking the electric capacity Cfb situation of contribution, and in the present embodiment, the electric charge change of testing capacitance Cx is By electric capacity C1, C2 joint contribution.

Formula (3) can be further rewritten as:

$\mathrm{Vout}=\mathrm{VH}+(\mathrm{VH}-\mathrm{VL})*\frac{\mathrm{Cx}}{C2}-(\mathrm{VS}+\mathrm{VL}-\mathrm{VH})*\frac{C1}{C2}.---\left(4\right)$

Owing to the numerical value of voltage VL, VH, VS and electric capacity C1, C2 is all it is known that according to output voltage Vout or electric capacity Cross-pressure change (being become Vout-VH from zero) at C2 two ends, it is judged that module 26 can extrapolate the size of testing capacitance Cx.If will treat Survey electric capacity Cx and disassemble the total of background capacitance Cbg for i.e. existing before not affected by user and capacitance change Csig further With, formula (4) can be rewritten as:

$\mathrm{Vout}=\mathrm{VH}+(\mathrm{VH}-\mathrm{VL})*\frac{\mathrm{Cbg}}{C2}+(\mathrm{VH}-\mathrm{VL})*\frac{\mathrm{Csig}}{C2}-(\mathrm{VS}+\mathrm{VL}-\mathrm{VH})*\frac{C1}{C2}.---\left(5\right)$

Be can be seen that by formula (5), owing to reference voltage VH is higher than VL, and control voltage VS is designed to higher than (VH-VL), electricity The electric charge holding C1 contribution can offset the electric charge of background capacitance Cbg contribution, makes voltage Vout be less susceptible to reach saturation.Therefore, Even if selecting less electric capacity C2 to improve the resolution of capacitance change Csig, voltage Vout also will not be made to be easy for because of mistake High and saturated.In other words, as long as selecting the electric capacity C1 that size is suitable, capacitance detecting device 200 can provide good measurement solution Analysis degree, and there is not the problem that output voltage is the most saturated.

From the viewpoint of charge distributing, the feature of capacitance detecting device 200 flows to input node for utilizing self-capacitance C1 The electric charge of 24, as flowing into the electric charge of background capacitance Cbg from input node 24, reaches electric charge payment effect, makes voltage Vout less Easily reach saturation.In the case of reference voltage VH is higher than VL, it is designed as control voltage VS can making certainly higher than (VH-VL) It is positive charge (be equal to electric current and flow to input node 24 from self-capacitance C1), certainly input that electric capacity C1 flows to the electric charge of input node 24 It is also positive charge (be equal to electric current and flow into background capacitance Cbg from input node 24) that node 24 flows into the electric charge of background capacitance Cbg. In the case of reference voltage VH is less than VL, it is designed as control voltage VS self-capacitance C1 to be made to flow to input less than (VH-VL) The electric charge of node 24 is negative charge (be equal to electric current and flow to self-capacitance C1 from input node 24), flows into background from input node 24 The electric charge of electric capacity Cbg is also negative charge (is equal to electric current and flows into input node 24 from background capacitance Cbg), can reach aforementioned equally Electric charge payment effect.In sum, as long as changing by the cross-pressure of appropriately designed such electric capacity so that self-capacitance C1 flows to input The electric charge of node 24 is positive and negative identical with the electric charge flowing into testing capacitance Cx from input node 24, can overcome in prior art and be difficult to Take into account measurement resolution and avoid the problem that output voltage is saturated.

According to another embodiment of the present invention for the capacitance detecting device as shown in Fig. 3 (A).In this embodiment, electric capacity C1 is arranged on outside the chip 500 at operational amplifier 22 place.It is true that no matter electric capacity C1 whether with operational amplifier 22 etc. Element is comprised in same chip, can reach foregoing advantages.It should be noted that the electric capacity C1 profit in this embodiment Realize by the parasitic capacitance of connecting line 400.In case of capacitive touch device, testing capacitance Cx be typically formed in On one induction panel (block 600 illustrated in such as figure), and through the line line on flexible circuit board or printed circuit board (PCB) 400 are connected with chip 500.

In this embodiment, the circuit board at connecting line 400 place has a shielding (shielding) layer, is present in connection The parasitic capacitance of line 400 and this shielding interlayer is i.e. as electric capacity C1.The circuit board at connecting line 400 place has one and adjustable connects Ground terminal potential Vact, as shown in Fig. 3 (A), switch SW4, SW5 that this earth terminal is connected in chip 500 through weld pad 28.By Control the keying of switch SW4, SW5, can reach according to the control module (not shown) in the capacitance detecting device of the present invention and change The effect of the cross-pressure of C1 is held in power transformation.In other words, the change of the cross-pressure on electric capacity C1 can be by the earth terminal electricity controlling this screen layer Position Vact realizes.Should be noted that, as long as suitably planning the characteristics such as the shape of connecting line 400, length, thickness, parasitic capacitance (electricity Hold C1) size be and can accurately estimate, control.In other words, this connecting line 400 and this screen layer are controlled through design, i.e. Earth terminal current potential Vact and parasitic capacitance (electric capacity C1) can be adjusted flexibly, to realize controlling the effect of the cross-pressure change on electric capacity C1 Really.In another embodiment, through active shield (active shielding) or subtract the means such as consumption (subtraction), also Equivalence can find out the electric capacity C1 that can change by the earth terminal current potential Vact controlling this screen layer.This way is advantageous in that can Save and the space occupied by electric capacity C1 is set in chip 500, the most effectively utilize and be originally considered verbose or negative factor Parasitic capacitance.

As shown in Fig. 3 (B), in another embodiment, electric capacity C1 also can be disassembled and be two parts: be arranged at chip 500 Outer electric capacity C1A and the electric capacity C1B being arranged in chip 500.Electric capacity C1B is designed to main in order to compensate because of process variation The electric capacity C1A Size Error caused, therefore need not the biggest.For example, the grade of electric capacity C1B can be in 1～2 micromicrofarads (pF), but be not limited.

As shown in Fig. 3 (C), in another embodiment, electric capacity C1A and electric capacity C1B can be designed as each by different Control voltage influence.In this example, when switch SW5 is path, and electric capacity C1B can be connected to provide the voltage controlling voltage VS Source, but the change in voltage of electric capacity C1A is controlled the control of module 29.Similarly, defeated as long as making self-capacitance C1A, C1B flow to The electric charge of ingress 24 is positive and negative identical with the electric charge flowing into testing capacitance Cx from input node 24, and it is difficult to overcome in prior art To take into account measurement resolution and to avoid the problem that output voltage is saturated.

Aforementioned several embodiment is all in case of the voltage of input node 24 can change.It practice, input node The voltage of 24 is also designed to immobilize, such as the embodiment shown in Fig. 4 (A).Refer to Fig. 4 (A), switch SW1～SW5 State can be determined by a control module (not shown), and the two ends of testing capacitance Cx are respectively through input node 44 with drive joint Point 48 connects so far capacitance detecting device.

In the first stage of detection process, switch SW1, SW2, SW4 are first set to path, and switch SW3, SW5 quilt It is set as open circuit；Circuit in Fig. 4 (A) is equal to Fig. 4 (B) those shown (ignoring judge module 46 temporarily).In that case, fortune The voltage of the outfan (Vout) and positive-negative input end of calculating amplifier 22 all can be equal to reference voltage Vref.Electric capacity C2 is discharged to Not having electric charge, electric capacity C1 is charged to there is electric charge C1* (VL-Vref), and testing capacitance Cx is then to be charged to there is electric charge Cx*(VH-Vref)。

Subsequently, in the second stage of detection process, switch SW1, SW2, SW4 are first set to open circuit, and switch SW3, SW5 is set to path；Circuit in Fig. 4 (A) is equal to Fig. 4 (C) those shown (ignoring judge module 46 temporarily).In this situation Under, the voltage of the positive-negative input end of operational amplifier 22 is still maintained at equal to reference voltage Vref, the control joint of electric capacity C1 side Point is by reconfiguration to providing the power supply unit controlling voltage VH, and driving node 48 is then to be relayed to provide the electricity controlling voltage VL Source supply.

Between above-mentioned two benches switch switching the cross-pressure of each electric capacity can be caused to change, in turn result in electric charge electric capacity C1, C2, Redistribute between Cx.Charge balance relation corresponding to input node 44 may be expressed as:

(VH-VL) * C1+ (Vout-Vref) * C2=(VH-VL) * Cx.(6)

Reference voltage VH in this embodiment is higher than VL.Accordingly, formula (6) can be seen that, at second stage electric current from input Node 44 flows into testing capacitance Cx and is flowed to input node 44 by self-capacitance C1, in other words, flows into be measured from input node 44 The positive charge of electric capacity Cx is at least part of is to be flowed to the positive charge of input node 44 by self-capacitance C1 contributed.As for self-capacitance C2 impact part in one's power, if Vout is more than Vref, electric current is to flow to input node 44 from self-capacitance C2, is i.e. flowed by self-capacitance C2 To input node 44 is positive charge；If Vout is less than Vref, electric current flows to self-capacitance C2 from input node 44, i.e. by self-capacitance What C2 flowed to input node 44 is negative charge.It is by electric capacity C1, C2 joint contribution that the electric charge of testing capacitance Cx changes.

Formula (6) can be further rewritten as:

$\mathrm{Vout}=\mathrm{Vref}+(\mathrm{VH}-\mathrm{VL})*\frac{\mathrm{Cx}}{C2}-(\mathrm{VH}-\mathrm{VL})*\frac{C1}{C2}.---\left(7\right)$

Owing to the numerical value of voltage VL, VH, Vref and electric capacity C1, C2 is all it is known that according to output voltage Vout or electricity Hold cross-pressure change (being become Vout-Vref from zero) at C2 two ends, it is judged that module 46 can extrapolate the size of testing capacitance Cx.If Testing capacitance Cx is disassembled further background capacitance Cbg for i.e. existing before not affected by user and capacitance change Csig Summation, formula (7) can be rewritten as again:

$\mathrm{Vout}=\mathrm{Vref}+(\mathrm{VH}-\mathrm{VL})*\frac{\mathrm{Cbg}}{C2}+(\mathrm{VH}-\mathrm{VL})*\frac{\mathrm{Csig}}{C2}-(\mathrm{VH}-\mathrm{VL})*\frac{C1}{C2}.---\left(8\right)$

Be can be seen that by formula (8), the electric charge of electric capacity C1 contribution can offset the electric charge of background capacitance Cbg contribution, makes voltage Vout It is less susceptible to reach saturation.Therefore, even if selecting less electric capacity C2 to improve the resolution of capacitance change Csig, the most not Voltage Vout can be made to be easy for because of too high and saturated.In other words, as long as selecting the electric capacity C1 that size is suitable, this capacitance detecting fills Put the measurement resolution that can provide good, and there is not the problem that output voltage is the most saturated.

Capacitance detecting device shown in Fig. 4 (A) may be used to coordinate such as mutual capacitance type touch-control system.More particularly, input Node 44 can be connected to the induction electrode in mutual capacitance type touch-control system, and driving node 48 can be connected to mutual capacitance type touch-control system In drive electrode, and testing capacitance Cx is exactly the mutual tolerance (mutual between this induction electrode and this drive electrode capacitance)；Switching is supplied to the voltage of driving node 48 and is supply driving signal.Additionally, with aforementioned several embodiments Identical, the electric capacity C1 in Fig. 4 (A) also can comprise or be entirely the parasitic capacitance between screen layer and connecting line.

In sum, the concept used according to the capacitance detecting device of the present invention is: provide electric capacity C1 mono-first cross-pressure Change, and provide testing capacitance Cx mono-second cross-pressure to change, thereby make electric capacity C2 one the 3rd cross-pressure change occur, further according to electric capacity The capacitance of C1, C2 and the change of such cross-pressure judge the capacitance of testing capacitance Cx.As long as by the first cross-pressure change with second Cross-pressure change is designed such as self-capacitance C1 and flows to the electric charge of input node and the electric charge flowing into testing capacitance Cx from input node Positive and negative identical, so that it may to overcome and prior art is difficult to take into account measurement resolution and avoid the problem that output voltage is saturated.

It is a capacitance touch control system according to another embodiment of the present invention, wherein comprises a display, multiple faradism Hold and one or more such as Fig. 2 (A), Fig. 3 (A), Fig. 3 (B), Fig. 3 (C) or the capacitance detecting device shown in Fig. 4 (A).The plurality of Inductance capacitance respectively correspond tos the provider location on this display, and its size variation can be filled by these one or more capacitance detecting The detection put.Function mode about capacitance detecting device refers to the related description of previous embodiment, repeats no more.

As it has been described above, embodiments above of the present invention proposes a kind of new capacitance detecting device and applies this capacitance detecting The capacitance touch control system of device.Testing capacitance is suitably supplied at electric charge weight by the outer newly-increased electric capacity at back coupling electric capacity The quantity of electric charge needed in new assigning process, can overcome prior art according to the capacitance detecting device of embodiments above of the present invention In be difficult to take into account measurement resolution and avoid the problem that output voltage is saturated.In addition to matching with capacitive touch-control system, according to The capacitance detecting device of embodiments above of the present invention also can be widely used in other various occasions needing to measure capacitance.

Detailed description by embodiments above, it would be desirable to more clearly describe inventive feature and spirit, and not With above-mentioned disclosed preferred embodiment, scope of the invention is any limitation as.On the contrary, its objective is to wish to contain Cover in the category being arranged in the scope of the claims that the present invention to be applied for of various change and tool equality.

Claims (14)

1. a capacitance detecting device, is connected to a testing capacitance, and this capacitance detecting device comprises:

One first electric capacity and one second electric capacity, be connected to this testing capacitance through an input node all the time；

One control module, in order to provide this first electric capacity one first cross-pressure to change, and provides this testing capacitance one second cross-pressure to become Changing, thereby make generation one the 3rd cross-pressure change of this second electric capacity, wherein the change of this first cross-pressure makes certainly with the change of this second cross-pressure The electric charge that this first electric capacity flows to this input node is positive and negative identical with the electric charge flowing into this testing capacitance from this input node；And

One judge module, in order to the capacitance according to this first electric capacity, the capacitance of this second electric capacity, this first cross-pressure change, The change of this second cross-pressure and the change of the 3rd cross-pressure, it is judged that the capacitance of this testing capacitance.

2. capacitance detecting device as claimed in claim 1, it is characterised in that this capacitance detecting device passes through with this testing capacitance The connecting line being formed on a circuit board connects, and this circuit board has a screen layer, and wherein this first electric capacity comprises this connection One parasitic capacitance of line and this shielding interlayer, and this control module controls this screen layer to provide this first electric capacity this first cross-pressure Change.

3. capacitance detecting device as claimed in claim 2, it is characterised in that this circuit board is a flexible circuit board or a printing Circuit board.

4. capacitance detecting device as claimed in claim 1, it is characterised in that this first electric capacity is connected to this input node and Controlling between node, this second electric capacity is connected between this input node and an output node；This control module supplied in a very first time Should input node and this output node one first input voltage control voltage for node one first should be controlled；This control mould Block in one second the time for should input node one second input voltage and for should control node one second control voltage；This is years old One input voltage is less than this first control voltage and the difference of this second control voltage with the difference of this second input voltage.

5. capacitance detecting device as claimed in claim 4, it is characterised in that this control module comprises:

One operational amplifier, has a first input end, the second input and an outfan, and this first input end is this input joint Point, this outfan is this output node；

One first switch, is connected between first input end and this outfan, is path in this very first time, in this second time be Open circuit；

One second switch, is connected between this second input and one second input voltage supply, is open circuit in this very first time, It is path in this second time；

One the 3rd switch, is connected between this second input and one first input voltage supply, is path in this very first time, It is open circuit in this second time；

One the 4th switch, is connected between this control node and an earth terminal, is path in this very first time, in this second time be Open circuit；And

One the 5th switch, is connected to this control node and one first and controls between Voltage Supply Device, be open circuit in this very first time, in This second time is path.

6. capacitance detecting device as claimed in claim 1, it is characterised in that this testing capacitance is connected to this input node and Between driving node, this first electric capacity is connected to this input node and and controls between node, and this second electric capacity is connected to this input joint Between point and an output node；This control module in a very first time for should input node and this output node one reference voltage, For controlling node one first voltage, supplying should driving node one second voltage；This control module was supplied in one second time This reference voltage of this input node, confession should control this second voltage of node, supplying should this first voltage of driving node；This is first years old Voltage is different from this second voltage.

7. capacitance detecting device as claimed in claim 6, it is characterised in that this control module comprises:

One operational amplifier, has a first input end, the second input and an outfan, and this first input end is this input joint Point, this outfan is this output node, and this second input is connected to a reference voltage supplies device；

One first switch, is connected between first input end and this outfan, is path in this very first time, in this second time be Open circuit；

One second switch, is connected between this driving node and one second Voltage Supply Device, is path in this very first time, in this Two times were open circuit；

One the 3rd switch, is connected between this driving node and one first Voltage Supply Device, is open circuit in this very first time, in this Two times were path；

One the 4th switch, is connected between this control node and this first Voltage Supply Device, is path in this very first time, in this Two times were open circuit；And

One the 5th switch, is connected between this control node and this second Voltage Supply Device, is open circuit in this very first time, in this Two times were path.

8. a capacitance touch control system, comprises:

One display；

Multiple inductance capacitances, respectively correspond to the provider location on this display；And

One capacitance detecting device, this capacitance detecting device comprises:

One first electric capacity and one second electric capacity, all the time through an input node be connected to the plurality of inductance capacitance one of them, with Using this inductance capacitance as a testing capacitance；

One control module, in order to provide this first electric capacity one first cross-pressure to change, and provides this testing capacitance one second cross-pressure to become Changing, thereby make generation one the 3rd cross-pressure change of this second electric capacity, wherein the change of this first cross-pressure makes certainly with the change of this second cross-pressure The electric charge that this first electric capacity flows to this input node is positive and negative identical with the electric charge flowing into this testing capacitance from this input node；And

One judge module, in order to the capacitance according to this first electric capacity, the capacitance of this second electric capacity, this first cross-pressure change, The change of this second cross-pressure and the change of the 3rd cross-pressure, it is judged that the capacitance of this testing capacitance.

9. capacitance touch control system as claimed in claim 8, it is characterised in that this capacitance detecting device is saturating with this testing capacitance Crossing the connecting line being formed on a circuit board to connect, this circuit board has a screen layer, and wherein this first electric capacity comprises this company One parasitic capacitance of wiring and this shielding interlayer, and this control module control this screen layer with provide this first electric capacity this first across Buckling.

10. capacitance touch control system as claimed in claim 9, it is characterised in that this circuit board is a flexible circuit board or Printed circuit board (PCB).

11. capacitance touch control systems as claimed in claim 8, it is characterised in that this first electric capacity is connected to this input node And one controls between node, and this second electric capacity is connected between this input node and an output node；This control module is in one first time Between for should input node and this output node one first input voltage for node one first control voltage should be controlled；This control Molding block in one second the time for should input node one second input voltage and for should control node one second control voltage； This first input voltage is less than this first control voltage and the difference of this second control voltage with the difference of this second input voltage.

12. capacitance touch control systems as claimed in claim 11, it is characterised in that this control module comprises:

One operational amplifier, has a first input end, the second input and an outfan, and this first input end is this input joint Point, this outfan is this output node；

One first switch, is connected between first input end and this outfan, is path in this very first time, in this second time be Open circuit；

One second switch, is connected between this second input and one second input voltage supply, is open circuit in this very first time, It is path in this second time；

One the 3rd switch, is connected between this second input and one first input voltage supply, is path in this very first time, It is open circuit in this second time；

One the 4th switch, is connected between this control node and an earth terminal, is path in this very first time, in this second time be Open circuit；And

One the 5th switch, is connected to this control node and one first and controls between Voltage Supply Device, be open circuit in this very first time, in This second time is path.

13. capacitance touch control systems as claimed in claim 8, it is characterised in that this testing capacitance is connected to this input node And between a driving node, this first electric capacity is connected to this input node and and controls between node, and it is defeated that this second electric capacity is connected to this Between ingress and an output node；This control module in a very first time for should input node and this output node one with reference to electricity Pressure, confession should control node one first voltage, supplying should driving node one second voltage；This control module supplied in one second time Should this reference voltage of input node, for this second voltage of node should be controlled, for should this first voltage of driving node；This is years old One voltage is different from this second voltage.

14. capacitance touch control systems as claimed in claim 13, it is characterised in that this control module comprises:

One operational amplifier, has a first input end, the second input and an outfan, and this first input end is this input joint Point, this outfan is this output node, and this second input is connected to a reference voltage supplies device；

One first switch, is connected between first input end and this outfan, is path in this very first time, in this second time be Open circuit；

One second switch, is connected between this driving node and one second Voltage Supply Device, is path in this very first time, in this Two times were open circuit；

One the 3rd switch, is connected between this driving node and one first Voltage Supply Device, is path in this very first time, in this Two times were short circuit；

One the 4th switch, is connected between this control node and this first Voltage Supply Device, is path in this very first time, in this Two times were open circuit；And

One the 5th switch, is connected between this control node and this second Voltage Supply Device, is open circuit in this very first time, in this Two times were path.