CN103902123B - Self-capacitance touch sensing device capable of reducing substrate capacitance - Google Patents
Self-capacitance touch sensing device capable of reducing substrate capacitance Download PDFInfo
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- CN103902123B CN103902123B CN201410044267.0A CN201410044267A CN103902123B CN 103902123 B CN103902123 B CN 103902123B CN 201410044267 A CN201410044267 A CN 201410044267A CN 103902123 B CN103902123 B CN 103902123B
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Abstract
The invention provides a self-capacitance touch sensing device capable of reducing substrate capacitance. The self-capacitance touch sensing device capable of reducing the substrate capacitance comprises a self-capacitance touch screen and a signal processing module. The signal processing module comprises an integrated operational amplifier, a feedback capacitor, a substrate capacitor and a controlled switch. The reverse-phase input end of the integrated operational amplifier is electrically connected with a channel capacitor. By the adoption of the self-capacitance touch sensing device capable of reducing the substrate capacitance, in the pre-discharge stage, the channel capacitor is made to discharge electricity, and at least one of the substrate capacitor and the feedback capacitor is charged; in the sensing stage, the channel capacitor is charged, and the charge variable quantity, caused by touch, of a branch where the channel capacitor is located is output from the output end of the integrated operational amplifier. According to the self-capacitance touch sensing device capable of reducing the substrate capacitance, the charge mode of the substrate capacitor is changed through pre-storing of electric charge on the feedback capacitor, the quantity of electric charge which can be provided by the substrate capacitor is increased, and then the substrate capacitance is reduced; in this way, the area of a chip is reduced, process cost is reduced, and the self-capacitance touch sensing device can be lighter and thinner.
Description
Technical field
The present invention relates to the signal to collecting carries out the circuit of signal processing, more particularly to touch screen is collected
Change in electrical charge amount signal carries out the circuit of signal processing.
Background technology
Prior art capacitance touch sensing device, as shown in figure 5, causing the touching of capacitance variations to believe including for collection
The self-capacitance touch screen 4 of breath and the signal processing circuit 3 for detecting capacitance change.The self-capacitance touch screen 4 is because arranging
Electrode and to form capacitance be CSEach channel capacitor 41.Prior art signal processing circuit 3 includes integrated operational amplifier 34,
The capacitance being connected electrically between the inverting input of the integrated operational amplifier 34 and outfan is CfFeedback capacity 32, and
Its one end be connected electrically in the inverting input of integrated operational amplifier 34, the other end be transfused to voltage square wave signal, capacitance be
The substrate electric capacity 31 of Cb.The voltage square wave signal fluctuates between first voltage and second voltage, and first voltage is more than the
Two voltages.During capacitance change on the place branch road of channel capacitor 41 that is connected electrically in signal processing circuit 3 of detecting, generally
Need to experience two stages.First stage is the pre-arcing stage, as shown in figure 5, the controlled closure conducting of switch 35,36, and
The controlled shut-off of switch 37 open circuit, the basad electric capacity output voltage of the voltage square wave signal is the signal of V1, so as to passage electricity
The electric charge for holding 41 storages is released, and substrate electric capacity 31 is applied in（V1-Vref）Voltage, feedback capacity 32 storage electric charge
It is released.Second stage is reconnaissance phase, as shown in figure 5, the controlled shut-off open circuit of switch 35,36, and controlled switch 37
Closure conducting, the basad electric capacity output voltage of the voltage square wave signal is the signal of V2, in the charging to channel capacitor 41
Cheng Zhong, the feedback circuit consisted of feedback capacity 32 and integrated operational amplifier 34 detects the place branch road of channel capacitor 41
The caused change in electrical charge because of touching, and the electricity formed because of change in electrical charge from the outfan output of integrated operational amplifier 34
Stream.The current potential of the outfan of the integrated operational amplifier 34 is V3.According to quantity of electric charge conservation principle, in integrated operational amplifier
34 inverting input meets,
Cb×（V1-V2）=Cf×（Vref-V3）+CS× Vref,
And then draw,
Cb= [Cf×（Vref-V3）+CS×Vref]/ （V1-V2）（1）.
No matter the self-capacitance touch screen 4 and signal processing circuit 3 are arranged in same chip, are still separately positioned on two
In individual above chip, the size of substrate electric capacity 31 determines the area of the place chip of signal processing circuit 3.By（1）Knowable to formula, when
Channel capacitor CSDuring increase, CbAlso can therewith increase, and then cause chip area to increase, not only increase process costs, have an effect on
Self-capacitance touch sensing device to lightening direction is developed.
The content of the invention
The technical problem to be solved in the present invention is to avoid the deficiencies in the prior art part and propose a kind of substrate electric capacity
What capacitance did not changed with channel capacitor, the self-capacitance touch sensing device of substrate electric capacity can be reduced such that it is able to reduce chip
Area, saves process costs.
The present invention solves the technical problem can be realized by employing the following technical solutions：
Design, manufacture a kind of self-capacitance touch sensing device that can reduce substrate electric capacity, including for it is touched from
Capacitance touch screen, and for detecting an at least signal processing module of self-capacitance variable signal；The self-capacitance touch screen because
Electrode is set and more than one channel capacitor is formed；The signal processing module includes integrated operational amplifier, for being electrically connected
The feedback capacity being connected between the integrated operational amplifier inverting input and outfan, and substrate electric capacity；The substrate electricity
Hold one end input voltage square-wave signal, the other end of the substrate electric capacity is used to electrically connect the anti-phase defeated of the integrated operational amplifier
Enter end；The voltage square wave signal fluctuates between first voltage and second voltage, and first voltage is more than second voltage；The collection
Normal phase input end into operational amplifier is transfused to reference potential, the inverting input electrical connecting passage of the integrated operational amplifier
Electric capacity, so as to the signal processing module detects the capacitance change that the channel capacitor place branch road is formed because of touching.Especially,
The signal processing module also includes an at least controlled switch；Realized by electrically connecting each controlled switch, in pre-arcing stage, order
Channel capacitor discharges, and at least one of substrate electric capacity and feedback capacity electric capacity is charged；In reconnaissance phase, channel capacitor is filled
Electricity, by channel capacitor place branch road because the change in electrical charge amount that touching occurs is exported from the outfan of integrated operational amplifier.
A kind of scheme is that the controlled switch includes at least one electric discharge controlled switch, at least one detecting controlled switch.Pre-
Discharge regime, each electric discharge controlled switch closure conducting, each detecting controlled switch shut-off open circuit makes signal processing module institute electricity
The channel capacitor electric discharge of connection；Feedback capacity is made to disconnect the electrical connection with integrated operational amplifier, and the feedback capacity is maintained
The electric charge stored because being applied in feedback maintenance voltage；The basad electric capacity of the voltage square wave signal is input into first voltage.Detecing
Survey stage, each electric discharge controlled switch shut-off open circuit, each detecting controlled switch closure conducting, described substrate electric capacity one end is defeated
Enter the second voltage of voltage square wave signal；The feedback capacity be connected electrically in operational amplifier inverting input and outfan it
Between, and the feedback capacity is maintained applying feedback maintenance voltage；The channel capacitor is electrically charged, so as to defeated in operational amplifier
Go out to hold the output channel electric capacity place branch road electric current that caused change in electrical charge is formed because of touching.
Specifically, the controlled switch is controlled including the first to the second electric discharge controlled switch, and the first to the 5th detecting
Switch；The feedback capacity includes first end and the second end.First electric discharge controlled switch parallel connection is connected electrically in channel capacitor；Second
Electric discharge controlled switch is connected electrically between the inverting input of integrated operational amplifier and outfan.First detecting controlled switch electricity
It is connected between the first end of feedback capacity and the inverting input of integrated operational amplifier；Second detecting controlled switch electrical connection
Between the second end of feedback capacity and the outfan of operational amplifier；3rd detecting controlled switch is connected electrically in feedback capacity
Between the port of first end and output feedback maintenance voltage；4th detecting controlled switch be connected electrically in the second end of feedback capacity with
Between signal ground；It is anti-with operational amplifier that the 5th detecting controlled switch is connected electrically in the port that channel capacitor is not grounded
Between phase input.
Another kind of scheme is that the controlled switch includes at least one electric discharge controlled switch, at least one detecting controlled switch.
Pre-arcing stage, each electric discharge controlled switch closure conducting, each detecting controlled switch shut-off open circuit makes signal processing module institute
The channel capacitor electric discharge of electrical connection；Substrate electric capacity disconnects the electrical connection with integrated operational amplifier, and the substrate electric capacity two ends quilt
The first voltage of applied voltage square-wave signal and charge.In reconnaissance phase, each electric discharge controlled switch shut-off open circuit, each detecting
Controlled switch closure conducting, described substrate electric capacity one end is transfused to the second voltage of voltage square wave signal, the substrate electric capacity it is another
One end electrically connects the inverting input of integrated operational amplifier；The channel capacitor is electrically charged, so as to export in operational amplifier
The end output channel electric capacity place branch road electric current that caused change in electrical charge is formed because of touching.
Specifically, the controlled switch is controlled including the first to the 3rd electric discharge controlled switch, and the 5th to the 6th detecting
Switch；The substrate electric capacity includes the first end for electrically connecting voltage square wave signal, and puts for electrically connecting integrated computation
Second end of the end of oppisite phase of big device.First electric discharge controlled switch parallel connection is connected electrically in channel capacitor；Second electric discharge controlled switch electricity
It is connected between the inverting input of integrated operational amplifier and outfan；3rd electric discharge controlled switch is connected electrically in substrate electric capacity
The second end and signal ground between.5th detecting controlled switch is connected electrically in port and the operation amplifier that channel capacitor is not grounded
Between the inverting input of device；6th detecting controlled switch is connected electrically in the second end of substrate electric capacity and integrated operational amplifier
Between inverting input.
The combination of both the above scheme, the controlled switch includes at least one electric discharge controlled switch, and at least one detecting is controlled
Switch.In the pre-arcing stage, each electric discharge controlled switch closure conducting, each detecting controlled switch shut-off open circuit is made at signal
The channel capacitor electric discharge that reason module is electrically connected；Feedback capacity disconnects the electrical connection with integrated operational amplifier, and the feedback
Electric capacity maintains the electric charge stored because being applied in feedback maintenance voltage；The disconnection of substrate electric capacity is electrically connected with integrated operational amplifier
Connect, and the substrate electric capacity two ends are applied in the first voltage of voltage square wave signal and charge.In reconnaissance phase, each electric discharge is received
Control switch OFF open circuit, each detecting controlled switch closure conducting, described substrate electric capacity one end is transfused to the of voltage square wave signal
Two voltages, the other end of the substrate electric capacity electrically connects the inverting input of integrated operational amplifier；The feedback capacity electrical connection
Between the inverting input and outfan of operational amplifier, and the feedback capacity is maintained applying feedback maintenance voltage；Institute
State channel capacitor to be electrically charged, so as to operational amplifier output terminal output channel electric capacity place branch road because of touching caused electric charge
The electric current that change is formed.
Specifically, the controlled switch is controlled including the first to the 3rd electric discharge controlled switch, and the first to the 6th detecting
Switch；The feedback capacity includes first end and the second end；The substrate electric capacity is included for electrically connecting voltage square wave signal
First end, and for electrically connecting the second end of the end of oppisite phase of integrated operational amplifier.First electric discharge controlled switch parallel connection is electrically connected
It is connected on channel capacitor；Second electric discharge controlled switch is connected electrically between the inverting input of integrated operational amplifier and outfan；
3rd electric discharge controlled switch is connected electrically between the second end of substrate electric capacity and signal ground.First detecting controlled switch is connected electrically in
Between the first end of feedback capacity and the inverting input of integrated operational amplifier；Second detecting controlled switch is connected electrically in feedback
Between second end of electric capacity and the outfan of operational amplifier；3rd detecting controlled switch is connected electrically in the first end of feedback capacity
And the port of output feedback maintenance voltage between；4th detecting controlled switch is connected electrically in the second end and the signal ground of feedback capacity
Between；5th detecting controlled switch be connected electrically in port that channel capacitor is not grounded and operational amplifier inverting input it
Between；6th detecting controlled switch is connected electrically between the second end of substrate electric capacity and the inverting input of integrated operational amplifier.
More specifically, channel capacitor CS, substrate electric capacity Cb, feedback capacity Cf, reference potential, the first of voltage square wave signal
Voltage V1 and second voltage V2, meet between the output terminal potential V3 of integrated operational amplifier, and feedback maintenance voltage V4,
Cb×（V1-V2+Vref）+Cf×（Vref-V3-V4）=CS×Vref。
Compared with the existing technology compared with the technology effect of " the self-capacitance touch sensing device of substrate electric capacity can be reduced " of the invention
It is really：
1. the present invention reduces the quantity of electric charge that substrate electric capacity needs to provide by the quantity of electric charge that prestores in feedback capacity, so as to
In the case of same channels electric capacity, reduce substrate capacitance, in the case where channel capacitor increases, maintain substrate capacitance not
Become and even reduce substrate capacitance, and then reduce chip area, not only save process costs, additionally it is possible to make self-capacitance touch and pass
Induction device towards lighter and thinner direction is developed；
2. hinge structure of the present invention changes the charging modes of substrate electric capacity, make substrate electric capacity the pre-arcing stage just
There is certain quantity of electric charge, increase the quantity of electric charge that substrate electric capacity can be provided, so as in the case of same channels electric capacity, reduce base
Bottom capacitance, in the case where channel capacitor increases, maintains the constant even reduction substrate capacitance of substrate capacitance, and then reduces
Chip area, not only saves process costs, additionally it is possible to make self-capacitance touch sensing device develop towards lighter and thinner direction.
Description of the drawings
Fig. 1 is that the electric principle of " can reduce the self-capacitance touch sensing device of substrate electric capacity " first embodiment of the invention is shown
It is intended to；
Fig. 2 is the voltage square wave signal schematic diagram of the first embodiment；
Fig. 3 is the electric principle schematic of second embodiment of the invention；
Fig. 4 is the electric principle schematic of third embodiment of the invention；
Fig. 5 is the electric principle schematic of prior art self-capacitance touch sensing device.
Specific embodiment
It is described in further detail below in conjunction with each embodiment shown in accompanying drawing.
The present invention proposes a kind of self-capacitance touch sensing device that can reduce substrate electric capacity, as shown in Figures 1 to 4, bag
Include for touched self-capacitance touch screen 2, and for detecting an at least signal processing module 1 of self-capacitance variable signal；
It is C that the self-capacitance touch screen 2 forms more than one, capacitance because arranging electrodeSChannel capacitor 21；The signal processing
Module 1 includes integrated operational amplifier 14, for be connected electrically in the inverting input of integrated operational amplifier 14 and outfan it
Between, capacitance be CfFeedback capacity 12, and capacitance is CbSubstrate electric capacity 11.One end input voltage of the substrate electric capacity 11
Square-wave signal, the other end of the substrate electric capacity 11 is used to electrically connect the inverting input of the integrated operational amplifier 14.Such as Fig. 2
Shown, the voltage square wave signal fluctuates between first voltage and second voltage, and first voltage is more than second voltage.The collection
Normal phase input end into operational amplifier 14 is transfused to reference potential Vref, the inverting input electricity of the integrated operational amplifier 14
Interface channel electric capacity 21, so as to the signal processing module 1 detects the electric capacity that the place branch road of channel capacitor 21 is formed because of touching
Variable quantity.Especially, the signal processing module 1 also includes an at least controlled switch.Realized by electrically connecting each controlled switch,
In pre-arcing stage T1, make channel capacitor 21 discharge, at least one of substrate electric capacity 11 and feedback capacity 12 electric capacity is charged；
In reconnaissance phase T2, channel capacitor 21 is charged, by the place branch road of channel capacitor 21 because the change in electrical charge amount of touching generation is from collection
Outfan into operational amplifier 14 is exported.
A kind of preferable scheme of effect, the controlled switch includes at least one electric discharge controlled switch, and at least one detecting is controlled
Switch.In pre-arcing stage T1, each electric discharge controlled switch closure conducting, each detecting controlled switch shut-off open circuit makes signal
The channel capacitor electric discharge 21 that processing module 1 is electrically connected；Feedback capacity 12 disconnects the electrical connection with integrated operational amplifier 14, and
And the feedback capacity 12 is maintained because being applied in feedback maintenance voltage the electric charge that stores；Substrate electric capacity 11 disconnects to be put with integrated computation
The electrical connection of device 14, and the two ends of substrate electric capacity 11 greatly is applied in the first voltage of voltage square wave signal and charges.In detecting rank
Section T2, each electric discharge controlled switch shut-off open circuit, each detecting controlled switch closure conducting, described substrate electric capacity one end is transfused to
The second voltage of voltage square wave signal, the other end of the substrate electric capacity 11 electrically connects the anti-phase input of integrated operational amplifier 14
End；The feedback capacity 12 is connected electrically between the inverting input of operational amplifier 14 and outfan, and the feedback capacity
12 are maintained applying feedback maintenance voltage；The channel capacitor 21 is electrically charged, so as to logical in the output of the outfan of operational amplifier 14
The place branch road of road electric capacity 21 electric current that caused change in electrical charge is formed because of touching.
First embodiment of the invention, as shown in figure 1, in order to realize such scheme, the controlled switch includes first to the
Three electric discharge controlled switch 1511,1512,1513, and first to the 6th detecting controlled switch 1521,1522,1523,1524,
1525、1526.The feedback capacity 12 includes first end and the second end；The substrate electric capacity 11 is included for electrically connecting voltage side
The first end of ripple signal, and for electrically connecting the second end of the end of oppisite phase of integrated operational amplifier 14.First electric discharge is controlled to open
Close 1511 parallel connections and be connected electrically in channel capacitor 21.Second electric discharge controlled switch 1512 is connected electrically in the anti-of integrated operational amplifier 14
Between phase input and outfan.3rd electric discharge controlled switch 1513 be connected electrically in the second end of substrate electric capacity 11 and signal ground it
Between.First detecting controlled switch 1521 is connected electrically in the first end of feedback capacity 12 and the anti-phase input of integrated operational amplifier 14
Between end.Second detecting controlled switch 1522 be connected electrically in the second end of feedback capacity 12 and operational amplifier 14 outfan it
Between.3rd detecting controlled switch 1523 be connected electrically in the first end of feedback capacity 12 and output feedback maintenance voltage V4 port it
Between.4th detecting controlled switch 1524 is connected electrically between the second end of feedback capacity 12 and signal ground.5th detecting is controlled to open
Close 1525 to be connected electrically between the port and the inverting input of operational amplifier 14 that channel capacitor 21 is not grounded.6th detecting
Controlled switch 1526 is connected electrically between the second end of substrate electric capacity 11 and the inverting input of integrated operational amplifier 14.So as to
Realize, in pre-arcing stage T1, the described first to the 3rd electric discharge closure conducting of controlled switch 1511,1512,1513, first to the
The six detecting shut-off open circuits of controlled switch 1521,1522,1523,1524,1525,1526, make what signal processing module 1 was electrically connected
Channel capacitor electric discharge 21；The disconnection of feedback capacity 12 is connected electrically in integrated operational amplifier 14, and the feedback capacity 12 is tieed up
Hold the electric charge stored because being applied in feedback maintenance voltage V4；The disconnection of substrate electric capacity 11 is electrically connected with integrated operational amplifier 14
Connect, and the two ends of substrate electric capacity 11 are applied in first voltage V1 of voltage square wave signal and charge.In reconnaissance phase T2, described
One to the 3rd electric discharge controlled switch 1511,1512,1513 shut-off open circuit, first to the 6th detecting controlled switch 1521,1522,
1523rd, 1524,1525,1526 closure conducting, described one end of substrate electric capacity 11 is transfused to second voltage V2 of voltage square wave signal,
The other end of the substrate electric capacity 11 electrically connects the inverting input of integrated operational amplifier 14；The feedback capacity 12 is connected electrically in
Between the inverting input and outfan of operational amplifier 14, and the feedback capacity 12 is maintained applying feedback maintenance voltage
V4；The channel capacitor 21 is electrically charged, so as to the place branch road of 14 outfan output channel electric capacity of operational amplifier 21 because touching
And the electric current that caused change in electrical charge is formed.The output terminal potential of the operational amplifier 14 is V3.
According to principle of charge conservation, first embodiment of the invention is described in the inverting input of integrated operational amplifier 14
Channel capacitor CS, substrate electric capacity Cb, feedback capacity Cf, reference potential, first voltage V1 and second voltage of voltage square wave signal
Meet between V2, the output terminal potential V3 of integrated operational amplifier, and feedback maintenance voltage V4,
Cb×（V1-V2+Vref）+Cf×（Vref-V3-V4）=CS×Vref。
It can be seen that, the electric charge needed for charging process of channel capacitor 21 is provided by substrate electric capacity 11 and feedback capacity 12, Er Qieji
Bottom electric capacity 11 is because the voltage V1 being applied in the pre-arcing stage is compared with the voltage that prior art is applied in the pre-arcing stage（V1-
Vref）Increase, the electric charge that substrate electric capacity of the present invention is provided is more compared with prior art, so that in same channels electric capacity 21
In the case of, reduce substrate capacitance, in the case where channel capacitor 21 increases, maintain that substrate capacitance is constant even reduces base
Bottom capacitance, and then chip area is reduced, not only save process costs, additionally it is possible to make self-capacitance touch sensing device towards more
Light thinner direction is developed.
First embodiment of the invention is adopted simultaneously using the quantity of electric charge and the change substrate capacitor charge and discharge of prestoring for feedback capacity
Two kinds of means of mode are realized reducing substrate capacitances, then prestore for feedback capacity and quantity of electric charge means and change substrate electric capacity charge and discharge
Electrically means can also be respectively adopted and reduce the effect of substrate capacitance.
It is adopted as feedback capacity to prestore quantity of electric charge means, the controlled switch includes at least one electric discharge controlled switch, at least
One detecting controlled switch.In pre-arcing stage T1, each electric discharge controlled switch closure conducting, each detecting controlled switch shut-off is opened
Road, makes the channel capacitor 21 that signal processing module 1 is electrically connected discharge；Feedback capacity 12 is made to disconnect and integrated operational amplifier 14
Electrical connection, and the feedback capacity 12 maintained because being applied in feedback maintenance voltage the electric charge that stores；The voltage square wave letter
Number basad electric capacity 11 input first voltage.In reconnaissance phase, each electric discharge controlled switch shut-off open circuit respectively detects controlled opening
Close and close conducting, described one end of substrate electric capacity 11 is transfused to the second voltage of voltage square wave signal；The feedback capacity 12 is electrically connected
It is connected between the inverting input of operational amplifier 14 and outfan, and the feedback capacity 14 is maintained applying feedback and maintains electricity
Pressure；The channel capacitor 21 is electrically charged, so as to the place branch road of 14 outfan output channel electric capacity of operational amplifier 21 because touching
And the electric current that caused change in electrical charge is formed.
Second embodiment of the invention, as shown in figure 3, the controlled switch includes the first to the second electric discharge controlled switch
1511st, 1512, and the first to the 5th detecting controlled switch 1521,1522,1523,1524,1525.The feedback capacity 12 is wrapped
Include first end and the second end.The first electric discharge parallel connection of controlled switch 1511 is connected electrically in channel capacitor 21；Second electric discharge controlled switch
1512 are connected electrically between the inverting input of integrated operational amplifier 14 and outfan.First detecting controlled switch 1521 is electrically connected
It is connected between the inverting input of the first end of feedback capacity 12 and integrated operational amplifier 14.Second detecting controlled switch 1522
It is connected electrically between the second end of feedback capacity 12 and the outfan of operational amplifier 14.3rd detecting controlled switch 1523 is electrically connected
It is connected between the port of the first end of feedback capacity 12 and output feedback maintenance voltage V4.4th detecting controlled switch 1524 is electrically connected
It is connected between the second end of feedback capacity 12 and signal ground.The 5th detecting controlled switch 1525 is connected electrically in channel capacitor 21
Between port without ground connection and the inverting input of operational amplifier 14.In pre-arcing stage T1, described the first to the second puts
The closure conducting of electric controlled switch 1511,1512, the first to the 5th detecting controlled switch 1521,1522,1523,1524,1525 is closed
Road is disconnected, makes the channel capacitor 21 that signal processing module 1 is electrically connected discharge；Make feedback capacity 12 disconnect to amplify with integrated computation
The electrical connection of device 14, and the feedback capacity 12 maintained because being applied in feedback maintenance voltage V4 the electric charge that stores；The voltage
The basad electric capacity 11 of square-wave signal is input into first voltage V1.In reconnaissance phase T2, the first to the second electric discharge controlled switch
1511st, 1512 shut-off open circuit, the first to the 5th detecting closure conducting of controlled switch 1521,1522,1523,1524,1525 is described
The one end of substrate electric capacity 11 is transfused to second voltage V2 of voltage square wave signal；The feedback capacity 12 is connected electrically in operational amplifier
Between 14 inverting input and outfan, and the feedback capacity 14 is maintained applying feedback maintenance voltage V4；The passage
Electric capacity 21 is electrically charged, so as to the place branch road of 14 outfan output channel electric capacity of operational amplifier 21 because of touching caused electric charge
The electric current that change is formed.Second embodiment of the invention, only with prestoring quantity of electric charge means for feedback capacity 12, prestores（Cf×V4）
The quantity of electric charge, to reduce substrate capacitance.
Using substrate capacitor charge and discharge mode means are changed, the controlled switch includes at least one electric discharge controlled switch, extremely
Few detecting controlled switch.In pre-arcing stage T1, each electric discharge controlled switch closure conducting, each detecting controlled switch shut-off
Open circuit, makes the channel capacitor 21 that signal processing module 1 is electrically connected discharge；Substrate electric capacity 11 disconnects and integrated operational amplifier 14
Electrical connection, and the two ends of substrate electric capacity 11 are applied in the first voltage of voltage square wave signal and charge.In reconnaissance phase T2, institute
Each electric discharge controlled switch shut-off open circuit is stated, each to detect controlled switch closure conducting, described one end of substrate electric capacity 11 is transfused to voltage
The second voltage of square-wave signal, the other end of the substrate electric capacity 11 electrically connects the inverting input of integrated operational amplifier 14；Institute
State channel capacitor 21 to be electrically charged, so as to cause because of touching in the place branch road of 14 outfan output channel electric capacity of operational amplifier 21
Change in electrical charge formed electric current.
Third embodiment of the invention, as shown in figure 4, the controlled switch includes the first to the 3rd electric discharge controlled switch
1511st, 1512,1513, and the 5th to the 6th detecting controlled switch 1525,1526.The substrate electric capacity 11 is included for being electrically connected
The first end of voltage square wave signal is connect, and for electrically connecting the second end of the end of oppisite phase of integrated operational amplifier 14.First puts
The parallel connection of electric controlled switch 1511 is connected electrically in channel capacitor 21.Second electric discharge controlled switch 1512 is connected electrically in integrated computation amplification
Between the inverting input and outfan of device 14.3rd electric discharge controlled switch 1513 be connected electrically in the second end of substrate electric capacity 11 with
Between signal ground.5th detecting controlled switch 1525 is connected electrically in port and the operational amplifier 14 that channel capacitor 21 is not grounded
Inverting input between.6th detecting controlled switch 1526 is connected electrically in the second end of substrate electric capacity 11 and integrated computation amplifies
Between the inverting input of device 14.In pre-arcing stage T1, the described first to the 3rd electric discharge controlled switch 1511,1512,1513
Closure conducting, the 5th to the 6th detecting shut-off open circuit of controlled switch 1525,1526, make that signal processing module 1 electrically connected is logical
Road electric capacity 21 discharges；Substrate electric capacity 11 disconnects the electrical connection with integrated operational amplifier 14, and the two ends of substrate electric capacity 11 are applied
First voltage V1 of making alive square-wave signal and charge.In reconnaissance phase T2, the first to the 3rd electric discharge controlled switch 1511,
1512nd, 1513 shut-off open circuit, the 5th to the 6th detecting closure conducting of controlled switch 1525,1526, described one end of substrate electric capacity 11
Second voltage V2 of voltage square wave signal is transfused to, the other end of the substrate electric capacity 11 electrically connects the anti-of integrated operational amplifier 14
Phase input；The channel capacitor 21 is electrically charged, so as in the place branch road of 14 outfan output channel electric capacity of operational amplifier 21
The electric current that caused change in electrical charge is formed because of touching.Third embodiment of the invention, only with the discharge and recharge of change substrate electric capacity 11
Mode means, substrate electric capacity 11 is applied in compared with prior art due to the voltage V1 being applied in the pre-arcing stage in the pre-arcing stage
Voltage（V1-Vref）Increase, the electric charge that substrate electric capacity of the present invention is provided is more compared with prior art, so that in phase
In the case of channel capacitor 21, reduce substrate capacitance.
Claims (8)
1. a kind of self-capacitance touch sensing device that can reduce substrate electric capacity, including for touched self-capacitance touch screen,
And for detecting an at least signal processing module of self-capacitance variable signal；The self-capacitance touch screen is because arranging electrode and shape
Into more than one channel capacitor；The signal processing module includes integrated operational amplifier, for being connected electrically in the integrated fortune
Calculate the feedback capacity between amplifier inverting input and outfan, and substrate electric capacity；Substrate electric capacity one end input electricity
Pressure square-wave signal, the other end of the substrate electric capacity is used to electrically connect the inverting input of the integrated operational amplifier；The electricity
Pressure square-wave signal fluctuates between first voltage and second voltage, and first voltage is more than second voltage；The integrated computation amplifies
The normal phase input end of device is transfused to reference potential, the inverting input electrical connecting passage electric capacity of the integrated operational amplifier, so as to
The signal processing module detects the capacitance change that the channel capacitor place branch road is formed because of touching；It is characterized in that：
The signal processing module also includes an at least controlled switch；Realized by electrically connecting each controlled switch,
In the pre-arcing stage, make channel capacitor discharge, at least one of substrate electric capacity and feedback capacity electric capacity is charged；
In reconnaissance phase, channel capacitor is charged, the change in electrical charge amount that channel capacitor place branch road is occurred because of touching is from integrated
The outfan output of operational amplifier.
2. the self-capacitance touch sensing device that substrate electric capacity can be reduced according to claim 1, it is characterised in that：
The controlled switch includes at least one electric discharge controlled switch, at least one detecting controlled switch；
In the pre-arcing stage, each electric discharge controlled switch closure conducting, each detecting controlled switch shut-off open circuit makes signal processing
The channel capacitor electric discharge that module is electrically connected；Feedback capacity is made to disconnect the electrical connection with integrated operational amplifier, and the feedback
Electric capacity maintains the electric charge stored because being applied in feedback maintenance voltage；The basad electric capacity input first of the voltage square wave signal is electric
Pressure；
In reconnaissance phase, each electric discharge controlled switch shut-off open circuit, each detecting controlled switch closure conducting, the substrate electric capacity
One end is transfused to the second voltage of voltage square wave signal；The feedback capacity be connected electrically in operational amplifier inverting input and
Between outfan, and the feedback capacity is maintained applying feedback maintenance voltage；The channel capacitor is electrically charged, so as in computing
The amplifier out output channel electric capacity place branch road electric current that caused change in electrical charge is formed because of touching.
3. the self-capacitance touch sensing device that substrate electric capacity can be reduced according to claim 2, it is characterised in that：
The controlled switch includes the first to the second electric discharge controlled switch, and the first to the 5th detecting controlled switch；It is described anti-
Feed holds and includes first end and the second end；
First electric discharge controlled switch parallel connection is connected electrically in channel capacitor；Second electric discharge controlled switch is connected electrically in integrated computation amplification
Between the inverting input and outfan of device；
First detecting controlled switch is connected electrically between the first end of feedback capacity and the inverting input of integrated operational amplifier；
Second detecting controlled switch is connected electrically between the second end of feedback capacity and the outfan of operational amplifier；3rd detecting is controlled
Switch is connected electrically between the port of the first end of feedback capacity and output feedback maintenance voltage；4th detecting controlled switch is electrically connected
It is connected between the second end of feedback capacity and signal ground；The 5th detecting controlled switch is connected electrically in channel capacitor and is not grounded
Port and the inverting input of operational amplifier between.
4. the self-capacitance touch sensing device that substrate electric capacity can be reduced according to claim 1, it is characterised in that：
The controlled switch includes at least one electric discharge controlled switch, at least one detecting controlled switch；
In the pre-arcing stage, each electric discharge controlled switch closure conducting, each detecting controlled switch shut-off open circuit makes signal processing
The channel capacitor electric discharge that module is electrically connected；Substrate electric capacity disconnects the electrical connection with integrated operational amplifier, and the substrate electric capacity
Two ends are applied in the first voltage of voltage square wave signal and charge；
In reconnaissance phase, each electric discharge controlled switch shut-off open circuit, each detecting controlled switch closure conducting, the substrate electric capacity
One end is transfused to the second voltage of voltage square wave signal, and the other end of the substrate electric capacity electrically connects the anti-phase of integrated operational amplifier
Input；The channel capacitor is electrically charged, so as in operational amplifier output terminal output channel electric capacity place branch road because of touching
The electric current that caused change in electrical charge is formed.
5. the self-capacitance touch sensing device that substrate electric capacity can be reduced according to claim 4, it is characterised in that：
The controlled switch is put to the 3rd electric discharge controlled switch including first, and the 5th to the 6th detecting controlled switch；It is described
Substrate electric capacity includes the first end for electrically connecting voltage square wave signal, and for electrically connecting the anti-phase of integrated operational amplifier
Second end at end；
First electric discharge controlled switch parallel connection is connected electrically in channel capacitor；Second electric discharge controlled switch is connected electrically in integrated computation amplification
Between the inverting input and outfan of device；3rd electric discharge controlled switch be connected electrically in the second end of substrate electric capacity and signal ground it
Between；
5th detecting controlled switch be connected electrically in port that channel capacitor is not grounded and operational amplifier inverting input it
Between；6th detecting controlled switch is connected electrically between the second end of substrate electric capacity and the inverting input of integrated operational amplifier.
6. the self-capacitance touch sensing device that substrate electric capacity can be reduced according to claim 1, it is characterised in that：
The controlled switch includes at least one electric discharge controlled switch, at least one detecting controlled switch；
In the pre-arcing stage, each electric discharge controlled switch closure conducting, each detecting controlled switch shut-off open circuit makes signal processing
The channel capacitor electric discharge that module is electrically connected；Feedback capacity disconnects the electrical connection with integrated operational amplifier, and the feedback electricity
Hold the electric charge for maintaining to store because being applied in feedback maintenance voltage；Substrate electric capacity disconnects the electrical connection with integrated operational amplifier,
And the substrate electric capacity two ends are applied in the first voltage of voltage square wave signal and charge；
In reconnaissance phase, each electric discharge controlled switch shut-off open circuit, each detecting controlled switch closure conducting, the substrate electric capacity
One end is transfused to the second voltage of voltage square wave signal, and the other end of the substrate electric capacity electrically connects the anti-phase of integrated operational amplifier
Input；The feedback capacity is connected electrically between the inverting input of operational amplifier and outfan, and the feedback capacity
It is maintained applying feedback maintenance voltage；The channel capacitor is electrically charged, so as in operational amplifier output terminal output channel electric capacity
The place branch road electric current that caused change in electrical charge is formed because of touching.
7. the self-capacitance touch sensing device that substrate electric capacity can be reduced according to claim 6, it is characterised in that：
The controlled switch includes the first to the 3rd electric discharge controlled switch, and the first to the 6th detecting controlled switch；It is described anti-
Feed holds and includes first end and the second end；The substrate electric capacity includes the first end for electrically connecting voltage square wave signal, and
For electrically connecting the second end of the end of oppisite phase of integrated operational amplifier；
First electric discharge controlled switch parallel connection is connected electrically in channel capacitor；Second electric discharge controlled switch is connected electrically in integrated computation amplification
Between the inverting input and outfan of device；3rd electric discharge controlled switch be connected electrically in the second end of substrate electric capacity and signal ground it
Between；
First detecting controlled switch is connected electrically between the first end of feedback capacity and the inverting input of integrated operational amplifier；
Second detecting controlled switch is connected electrically between the second end of feedback capacity and the outfan of operational amplifier；3rd detecting is controlled
Switch is connected electrically between the port of the first end of feedback capacity and output feedback maintenance voltage；4th detecting controlled switch is electrically connected
It is connected between the second end of feedback capacity and signal ground；5th detecting controlled switch is connected electrically in the end that channel capacitor is not grounded
Between mouth and the inverting input of operational amplifier；6th detecting controlled switch be connected electrically in the second end of substrate electric capacity with it is integrated
Between the inverting input of operational amplifier.
8. the self-capacitance touch sensing device that substrate electric capacity can be reduced according to claim 6, it is characterised in that：
Channel capacitor CS, substrate electric capacity Cb, feedback capacity Cf, reference potential, first voltage V1 of voltage square wave signal and second electric
Meet between pressure V2, the output terminal potential V3 of integrated operational amplifier, and feedback maintenance voltage V4,
Cb×（V1-V2+Vref）+Cf×（Vref-V3-V4）=CS×Vref。
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| CN201410044267.0A CN103902123B (en) | 2014-01-30 | 2014-01-30 | Self-capacitance touch sensing device capable of reducing substrate capacitance |
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| CN201410044267.0A CN103902123B (en) | 2014-01-30 | 2014-01-30 | Self-capacitance touch sensing device capable of reducing substrate capacitance |
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Cited By (1)
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| EP3502855A4 (en) * | 2017-11-08 | 2019-09-25 | Shenzhen Goodix Technology Co., Ltd. | Capacitance detection device, touch device and terminal device |
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| CN106775143B (en) | 2015-12-31 | 2020-01-03 | 深圳市汇顶科技股份有限公司 | Integrating circuit and capacitance sensing circuit |
| CN106598370B (en) * | 2017-01-19 | 2024-03-15 | 北京集创北方科技股份有限公司 | Touch detection circuit and touch control device thereof |
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| CN111258442A (en) * | 2018-12-03 | 2020-06-09 | 陕西坤同半导体科技有限公司 | Touch sensing circuit, touch display panel, display device and electronic equipment |
| TWI693545B (en) * | 2019-04-26 | 2020-05-11 | 大陸商北京集創北方科技股份有限公司 | Touch chip, touch display device and information processing device |
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