CN101699380A - Detecting circuit for touch panel and touch panel - Google Patents
Detecting circuit for touch panel and touch panel Download PDFInfo
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- CN101699380A CN101699380A CN200910212168A CN200910212168A CN101699380A CN 101699380 A CN101699380 A CN 101699380A CN 200910212168 A CN200910212168 A CN 200910212168A CN 200910212168 A CN200910212168 A CN 200910212168A CN 101699380 A CN101699380 A CN 101699380A
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Abstract
The invention provides a detecting circuit for a touch panel, which is used for sensing the voltage of a mutual induction capacitor when an object approaches, wherein the mutual induction capacitor is formed between a first direction signal line and a second direction signal line, and the first direction signal line and the second direction signal line are separated by an isolator; and the detecting circuit is used for eliminating the parasitic capacitance effect of the second direction signal line by switching a first switcher to an eighth switcher and a first voltage switcher to a third voltage switcher, thereby the detecting circuit can quickly accumulate charge to supply the detection of an amplifier and increase the operation speed of the detecting circuit.
Description
Technical field
The invention relates to the technical field of contact panel, refer to a kind of circuit for detecting and a kind of contact panel that is used for contact panel especially.
Background technology
Fig. 1 is the synoptic diagram of one n * m contact panel.As shown in Figure 1, sense wire x1 (sensing line) 110 input waveforms (pulse) by a direction (directions X), by the sense wire y1 (sensing line) 130 of the Inductance and Capacitance 120 between directions X, the Y direction (mutual capacitance) coupling electric charge to another direction (Y direction), via the charge variation of circuit for detecting 140 detecting sense wire y1 (sensing line) 130, and then produce voltage signal Vo_1.The size variation of Inductance and Capacitance 120 is judged in variation by voltage signal Vo_1, and the size variation by Inductance and Capacitance 120 has judged whether that (x1, position y1) is in order to carry out the touch detection on the contact panel near contact panel for object again.
Fig. 2 is the calcspar of the circuit for detecting 140 of an existing contact panel, and it also can be referring to U.S. Pat 6,452, in No. 514 bulletins.As shown in Figure 2, it comprises a signal generator 210, one first drive electrode 220, one second receiving electrode 240, a sampling switch 250, a charge integrate device 260, an amplifier 270, reaches a replacement switch 280, Inductance and Capacitance 230 wherein is in order to the electric field change (changing of electric field) between the sense wire of simulation sense wire of directions X and Y direction, charge integrate device 260 mainly is an electric capacity, in order to carry out integral operation.
This signal generator 210 is in order to produce a clock signal.This first drive electrode 220 is connected to this signal generator 210, to receive this clock signal.This second receiving electrode 240 is represented Y sense of direction survey line.The principle of work of sensing circuit 140 mainly realizes via sequential control method, and utilizes Inductance and Capacitance (Cxy) 230 coupling electric charges to charge integrate device 260, and this moment, amplifier 270 utilized charge integrate device 260 to do detecting voltage again.
Yet existing circuit for detecting 140 is not considered the stray capacitance (Cy or Cx) of the sense wire of the sense wire of directions X or Y direction itself.Inductance and Capacitance (Cxy) 230 generally has only several micromicrofarads (pF), and the stray capacitance of sense wire itself (Cy or Cx) is usually up to tens micromicrofarads (pF).Because parasitic capacitance effect (Cy or Cx) produces less coupling electric charge amount in the time of will making Inductance and Capacitance 230 with charge integrate device 260 dividing potential drops, and causes the variable quantity of output voltage V out to diminish, and then makes amplifier 270 be difficult to detecting.Simultaneously, stored dividing potential drop coefficient on the charge integrate device 260
Less than 1, make institute's charges accumulated difference to increase and to reduce along with sequential (cycle) number of times, therefore being accumulate to the quantity of electric charge that amplifier 270 can detect needs sequential (cycle) more repeatedly to finish, and then reduces the sensed speed or the susceptibility of touch panel detection circuit.Therefore, the technology of existing contact panel sensing circuit still has the space of improvement.
Summary of the invention
Purpose of the present invention mainly is to be provided for the circuit for detecting of contact panel, will originally can only do the circuit that primary sample is amplified, change over a kind of circuit for detecting of add up electric charge and amplification electric charge, and make institute's charges accumulated difference to increase and rise, can avoid to get rid of in the prior art on Y direction or the directions X signal wire stray capacitance simultaneously the influence of detection signal along with sequential cycle (cycle) number of times.
According to a characteristic of the present invention, the present invention proposes a kind of circuit for detecting that is used for contact panel, when object near the time, this circuit for detecting is in order to the voltage on sensing one Inductance and Capacitance, this Inductance and Capacitance is formed between a first direction signal wire and the second direction signal wire, this first direction signal wire and the insulation of this second direction signal wire are separated, and this circuit for detecting comprises an input voltage source, one first voltage switch, one common mode voltage source, one second voltage switch, one first switch, one amplifier, one second switch, one the 3rd switch, one the 4th switch, one the 5th switches, one the 6th switch, one the 7th switch, one the 8th switch, an and tertiary voltage switch.This input voltage source is in order to produce a plurality of periodic voltage cycles that have.First end of this first voltage switch is connected to this input voltage source, and second end is connected to this first direction signal wire.This common-mode voltage source is in order to provide a direct current common mode voltage.First end of this second voltage switch is connected to this common-mode voltage source, with and second end be connected to this first direction signal wire.First end of this first switch is connected to this second direction signal wire.The reverse input end of this amplifier is connected to second end of this first switch.First end of this second switch is connected to the reverse input end of this amplifier.First end of the 3rd switch is connected to second end of this second switch, with and second end be connected to this common-mode voltage source.First end of the 4th switch is connected to the reverse input end of this amplifier.First end of this first feedback capacity is connected to second end of the 4th switch.First end of the 5th switch is connected to second end of this first feedback capacity, with and second end be connected to the output terminal of this amplifier.First end of the 6th switch is connected to this input voltage source, and its second end is connected to second end of this first feedback capacity.First end of the 7th switch is connected to second end of the 4th switch, with and second end be connected to this common-mode voltage source.First end of the 8th switch is connected to the reverse input end of this amplifier, with and second end be connected to the output terminal of this amplifier.Non-inverting input, its first contact jaw that the control end of this tertiary voltage switch is connected to this amplifier be connected to this common-mode voltage source with and second contact jaw be connected to this input voltage source.
When described circuit for detecting forms an initial period and a plurality of electric charge accumulation period, described circuit for detecting passes through described first switch to described the 8th switch, and the described first voltage switch to the switching of described tertiary voltage switch is set, and by described first feedback capacity and described second feedback capacity formation backfeed loop, in order to quicken to add up electric charge.
According to another characteristic of the present invention, the present invention proposes a kind of contact panel again, and described contact panel comprises:
Above-mentioned circuit for detecting;
The signal wire switch of first direction, in order to control one group of input voltage source and one group of common-mode voltage source, wherein, this group input voltage source is in order to provide described input voltage source, and this group common-mode voltage source is in order to provide described common-mode voltage source;
First time schedule controller is connected to described circuit for detecting, in order to control the sequential of described circuit for detecting;
Second time schedule controller, be connected to the signal wire switch of described first direction, sequential in order to the signal wire switch of controlling described first direction, so that described input voltage source and described common-mode voltage source to be provided, wherein, described circuit for detecting is carried out the voltage induced of a second direction, described first time schedule controller is controlled described first switch of described circuit for detecting to described the 8th switch and described tertiary voltage switch, described second time schedule controller is controlled the incoming level of at least one first direction signal wire, in order at least one described first direction signal wire, to produce a plurality of clock signals, and the amount of variability by the Inductance and Capacitance between described first direction and the described second direction, make described circuit for detecting can obtain most groups through the voltage varieties after adding up;
Analog to digital conversion circuit is connected to described circuit for detecting, in order to convert voltage variety to numerical code; And
Digital signal processor is connected to analog-digital conversion circuit as described, has judged whether the described contact panel of object touch-control according to described numerical code.
According to another characteristic of the present invention, the present invention proposes the circuit for detecting that another kind is used for contact panel, in order to sensing when object near the time voltage on an Inductance and Capacitance, this Inductance and Capacitance is formed between a first direction signal wire and the second direction signal wire, this first direction signal wire and the insulation of this second direction signal linear system are separated, and this circuit for detecting comprises an input voltage source, one first voltage switch, one common mode voltage source, one second voltage switch, one first switch, one amplifier, one second switch, one the 3rd switch, one the 4th switch, one first feedback capacity, one the 5th switch, one the 6th switch, one the 7th switch, one the 8th switch, one tertiary voltage switch.This input voltage source is in order to produce a plurality of periodic voltage cycles that have.First end of this first voltage switch is connected to this input voltage source, and second end is connected to this first direction signal wire.This common-mode voltage source is in order to provide a direct current common mode voltage.First end of this second voltage switch is connected to this common-mode voltage source, with and second end be connected to this first direction signal wire.First end of this first switch is connected to this second direction signal wire.The reverse input end of this amplifier is connected to second end of this first switch.First end of this second switch is connected to the reverse input end of this amplifier.First end of the 3rd switch is connected to second end of this second switch, with and second end be connected to this common-mode voltage source.First end of the 4th switch is connected to the reverse input end of this amplifier.First end of this first feedback capacity is connected to second end of the 4th switch.First end of the 5th switch is connected to second end of this first feedback capacity, with and second end be connected to an output terminal of this amplifier.First end of the 6th switch is connected to this drive electrode, with and second end be connected to second end of this first feedback capacity.First end of the 7th switch is connected to second end of the 4th switch, with and second end be connected to this common-mode voltage source.First end of the 8th switch is connected to the reverse input end of this amplifier, with and second end be connected to the output terminal of this amplifier.A non-inverting input, its first contact jaw that one control end of this tertiary voltage switch is connected to this amplifier are connected to this common-mode voltage source, with and second contact jaw be connected to this input voltage source.
When described circuit for detecting forms an initial period and a plurality of electric charge accumulation period, set by described first switch to described the 8th switch and the described first voltage switch to the switching of tertiary voltage switch, and by described first feedback capacity and described second feedback capacity formation backfeed loop, in order to quicken to add up electric charge.
According to another characteristic of the present invention, the present invention proposes a circuit for detecting that is used for contact panel, in order to sensing when object near the time voltage on an Inductance and Capacitance, this Inductance and Capacitance is formed between a first direction signal wire and the second direction signal wire, this first direction signal wire and the insulation of this second direction signal wire are separated, and this circuit for detecting comprises an input voltage source, one first voltage switch, one common mode voltage source, one second voltage switch, one first switch, one second switch, one the 3rd switch, one the 4th switch, one first feedback capacity, one the 5th switch, one the 7th switch, one the 8th switch, an and tertiary voltage switch.This input voltage source is in order to produce a plurality of periodic voltage cycles that have.First end of this first voltage switch is connected to this input voltage source, with and second end be connected to this first direction signal wire.This common-mode voltage source is in order to provide a direct current common mode voltage.First end of this second voltage switch is connected to this common-mode voltage source, with and second end be connected to this first direction signal wire.First end of this first switch is connected to this second direction signal wire.One reverse input end of this amplifier is connected to second end of this first switch.First end of this second switch is connected to the reverse input end of this amplifier.First end of the 3rd switch is connected to second end of this second switch, with and second end be connected to this common-mode voltage source.First end of the 4th switch is connected to the reverse input end of this amplifier.First end of this first feedback capacity is connected to second end of the 4th switch.First end of the 5th switch is connected to second end of this first feedback capacity, with and second end be connected to an output terminal of this amplifier.First end of the 7th switch is connected to second end of the 4th switch, with and second end be connected to this common-mode voltage source.First end of the 8th switch is connected to the reverse input end of this amplifier, with and second end be connected to the output terminal of this amplifier.A non-inverting input, one first contact jaw that one control end of this tertiary voltage switch is connected to this amplifier are connected to this common-mode voltage source, and one second contact jaw is connected to this input voltage source.
When described circuit for detecting forms an initial period and a plurality of electric charge accumulation period, set by described first switch to described the 8th switch and the described first voltage switch to the switching of tertiary voltage switch, and by described first feedback capacity and described second feedback capacity formation backfeed loop, in order to quicken to add up electric charge.
This shows that the present invention has following technique effect:
(1) the present invention utilize the first feedback capacity Cf1, the second feedback capacity Cf2, and first to the 8th switch SW1-SW8 and first to tertiary voltage switch S1-S3 switching set, can originally can only do the circuit that primary sample is amplified, change over a kind of circuit for detecting of add up electric charge and amplification electric charge.
(2) the present invention obtains higher feedback factor (feedback factor), makes institute's charges accumulated difference and to rise along with (cycle) the number of times increase of sequential cycle.
(3) the present invention is along with sequential cycle (cycle) number of times increases, and induced charge can be with the rising that adds up of multiple form.
(4) the present invention utilizes that the switching of the first feedback capacity Cf1, the second feedback capacity Cf2, first to the 8th switch SW1-SW8 and first to tertiary voltage switch S1-S3 is set, and the virtual earth of amplifier 330, when each electric charge is repeatedly long-pending, can get rid of on Y direction or the directions X signal wire stray capacitance to the influence of detection signal.
(5) the present invention first feedback capacity Cf1 and the second feedback capacity Cf2 can be designed to have than small size when manufacturing and designing, and reach to save area and reduce wafer power consumption effect.
Description of drawings
Fig. 1 is the synoptic diagram of one n * m contact panel.
Fig. 2 is the calcspar of the sensing circuit of an existing contact panel.
Fig. 3 is a kind of calcspar that is used for the circuit for detecting of contact panel of the present invention.
Fig. 4 is a kind of sequential chart that is used for the circuit for detecting of contact panel of the present invention.
Equivalent circuit diagram when Fig. 5 is a reset cycle of the present invention.
Fig. 6 is the equivalent circuit diagram of the present invention during first sample period.
Fig. 7 is the equivalent circuit diagram of the present invention's first amplification during the cycle.
Equivalent circuit diagram when Fig. 8 is a charge accumulation period of the present invention.
Fig. 9 is the equivalent circuit diagram of the present invention during second sample period.
Figure 10 is the equivalent circuit diagram of the present invention's second amplification during the cycle.
Figure 11 is the application synoptic diagram of the present invention's circuit for detecting of being used for contact panel.
Figure 12 is a kind of calcspar that is used for another embodiment of circuit for detecting of contact panel of the present invention.
Figure 13 is a kind of sequential chart that is used for another embodiment of circuit for detecting of contact panel of the present invention.
Figure 14 is a kind of calcspar that is used for the another embodiment of circuit for detecting of contact panel of the present invention.
Figure 15 is a kind of sequential chart that is used for the another embodiment of circuit for detecting of contact panel of the present invention.
[the main element symbol adds explanation]
Second receiving electrode, 240 sampling switchs 250
Charge integrate device 260 amplifiers 270
First direction signal wire 385 second direction signal wires 390
Analog to digital conversion circuit 1140 digital signal processors 1150
Circuit for detecting 1200 circuit for detecting 1400
Embodiment
Fig. 3 is the calcspar of an embodiment of a kind of circuit for detecting 300 that is used for contact panel of the present invention, it applies to a contact panel, wherein, as known to, contact panel has the signal wire of most first directions (directions X) and the signal wire of most second directions (Y direction).When an object near the time, this circuit for detecting 300 is in order to the voltage on the sensing one Inductance and Capacitance Cxy, this Inductance and Capacitance Cxy is formed between the x signal line 385 (being called for short first direction signal wire 385) of a first direction (directions X) and the y signal line 390 of a second direction (Y direction) (abbreviation second direction signal wire 390), and this first direction signal wire 385 and this second direction signal wire 390 are separated by an insulator (figure does not show).This first direction signal wire 385 and this second direction signal wire 390 have stray capacitance Cx, Cy respectively.This Inductance and Capacitance Cxy, stray capacitance Cx, Cy are not that entity exists, and it is because this first direction signal wire 385 and this second direction signal wire 390 cablings produce.This Inductance and Capacitance Cxy can be modeled to a variable capacitance, its capacitance according to an object near or push contact panel and determine.
Circuit for detecting 300 passes through the variation of voltage signal to judge the size variation of Inductance and Capacitance Cxy, judge whether the position (x of object by the size variation of Inductance and Capacitance Cxy again near y signal line 390 crossovers of the x signal line 385 of contact panel first direction and second direction, y), whereby to carry out the touch detection on the contact panel.
Circuit for detecting 300 comprises an input voltage source Vin, one first voltage switch S1, a common mode voltage source Vcm, one second voltage switch S2, one first switch SW1, an amplifier 330, one second switch SW2, one the 3rd switch SW3, one the 4th switch SW4, one first feedback capacity Cf1, one the 5th switch SW5, one the 6th switch SW6, one the 7th switch SW7, one the 8th switch SW8, a tertiary voltage switch S3, reaches one second feedback capacity Cf2.
Wherein, input voltage source Vin is in order to produce a plurality of periodic voltage cycles that have.These a plurality of voltage cycles can be periodic string ripple or periodic square wave.
The first end TS11 of the first voltage switch S1 is connected to input voltage source Vin, and the second end TS12 is connected to first direction signal wire 385.
Common-mode voltage source Vcm is in order to providing a direct current common mode voltage, and provides one to exchange ground connection (ACground).This DC common mode is biased into the working point with amplifier 330.For the purpose of convenient the analysis, DC common mode can be considered as 0 volt.
The first end TS21 of the second voltage switch S2 is connected to common-mode voltage source Vcm, and the second end TS22 is connected to first direction signal wire 385.
The first end T11 of the first switch SW1 is connected to second direction signal wire 390.One reverse input end 3301 of amplifier 330 is connected to the second end T12 of the first switch SW1.The first end T21 of the second switch SW2 is connected to the reverse input end 3301 of amplifier 330.The first end T31 of the 3rd switch SW3 is connected to the second end T22 of the second switch SW2, and the second end T32 of the second switch SW2 is connected to common-mode voltage source Vcm.
The first end T41 of the 4th switch SW4 is connected to the reverse input end 3301 of amplifier 330.First end 3501 of the first feedback capacity Cf1 is connected to the second end T42 of the 4th switch SW4.The second end T52 that the first end T51 of the 5th switch SW5 is connected to second end, 3502, the five switch SW5 of the first feedback capacity Cf1 is connected to an output terminal 3303 of amplifier 330.The first end T61 of the 6th switch SW6 is connected to input voltage source Vin, and the second end T62 of the 6th switch SW6 is connected to second end 3502 of the first feedback capacity Cf1.
The first end T71 of the 7th switch SW7 is connected to the second end T42 of the 4th switch SW4, and the second end T72 of the 7th switch SW7 is connected to common-mode voltage source Vcm.The second end T82 that the first end T81 of the 8th switch SW8 is connected to reverse input end 3301, the eight switch SW8 of amplifier 330 is connected to the output terminal 3303 of amplifier 330.A non-inverting input 3302, the one first contact jaw TS32 that the control end TS31 of tertiary voltage switch S3 is connected to amplifier 330 are connected to common-mode voltage source Vcm, and one second contact jaw TS33 is connected to input voltage source Vin.First end 3801 of the second feedback capacity Cf2 is connected to the second end T22 of the second switch SW2, and second end 3802 of the second feedback capacity Cf2 is connected to the output terminal 3303 of amplifier 330.
Switching by above-mentioned first to the 8th switch SW1-SW8 and first to tertiary voltage switch S1-S3 is set, circuit for detecting 300 of the present invention forms an initial period and a plurality of electric charge accumulation period, and, add up with accelerated charge by the first feedback capacity Cf1 and the second feedback capacity Cf2.
Fig. 4 is a kind of sequential chart that is used for the circuit for detecting 300 of contact panel of the present invention.This sequential chart comprises an initial period and a plurality of electric charge accumulation period.This initial period comprises a reset cycle, one first sample period, and one first amplification cycle, and these a plurality of electric charge accumulation periods comprise a charge accumulation period, one second sample period, and one second amplification cycle respectively.
Show that by Fig. 4 this circuit for detecting 300 is when N-1 electric charge accumulation period (N-1cycle), the output voltage of amplifier 330 output terminals 3303 is N * Δ V, in the middle of,
Vin is the voltage of input voltage source Vin, and Cf1 is the capacitance of the first feedback capacity Cf1, and Cxy is the capacitance of Inductance and Capacitance Cxy.
As shown in Figure 4, when reset cycle, the first voltage switch S1 is for opening circuit, the second voltage switch S2 is conducting, the first end TS31 of tertiary voltage switch S3 is connected to common-mode voltage source Vcm, the first switch SW1, the second switch SW2, the 4th switch SW4, the 5th switch SW5, the 7th switch SW7, and the 8th switch SW8 be conducting, the 3rd switch SW3, the 6th switch SW6 are for opening circuit.Equivalent circuit diagram when Fig. 5 is reset cycle.
For the purpose of convenient the analysis, DC common mode can be considered as 0 volt.As shown in Figure 5, when reset cycle, earlier the electric charge on Inductance and Capacitance Cxy, the first feedback capacity Cf1, the second feedback capacity Cf2 is reset.Because the 8th switch SW8 conducting forms negative feedback, so the reverse input end 3301 of this amplifier 330 and non-inverting input 3302 form virtual earth.So put on Inductance and Capacitance Cxy, the first feedback capacity Cf1, the second feedback capacity Cf2, stray capacitance Cx, the voltage on the Cy is 0 volt, and with capacitor C xy, Cf1, Cf2, Cx, the electric charge on the Cy is reset.
As shown in Figure 4, when first sample period, the first voltage switch S1 is conducting, the second voltage switch S2 is for opening circuit, the first end TS31 of tertiary voltage switch S3 is connected to common-mode voltage source Vcm, the first switch SW1, the 4th switch SW4, the 6th switch SW6, and the 8th switch SW8 be conducting, the second switch SW2, the 3rd switch SW3, the 5th switch SW5, and the 7th switch SW7 for opening circuit.
Equivalent circuit diagram when Fig. 6 was first sample period.As shown in Figure 6, utilize input voltage source Vin that Inductance and Capacitance Cxy, the first feedback capacity Cf1 are charged, and this amplifier 330 forms unity gain buffer (unit gain buffer) form, and utilize the reverse input end 3301 of amplifier 330 and non-inverting input 3302 to form virtual earth, and the state the when electric charge on the stray capacitance Cy remained reset cycle.
As shown in Figure 4, when first amplifies the cycle, the first voltage switch S1 is for opening circuit, the second voltage switch S2 is conducting, the first end TS31 of tertiary voltage switch S3 is connected to common-mode voltage source Vcm, the first switch SW1, the 3rd switch SW3, the 4th switch SW4, and the 5th switch SW5 be conducting, the second switch SW2, the 6th switch SW6, the 7th switch SW7, and the 8th switch SW8 for opening circuit.
Fig. 7 is the equivalent circuit diagram of first amplification during cycle.As shown in Figure 7, because the reverse input end 3301 of amplifier 330 and non-inverting input 3302 form the relation of virtual earth, make script will be accumulated on the first feedback capacity Cf1 across the electric charge of Inductance and Capacitance Cxy, this moment, the second feedback capacity Cf2 was connected to the output terminal 3303 of amplifier 330, made the output terminal 3303 of amplifier 330 and the last voltage of the second feedback capacity Cf2 be:
Because the reverse input end 3301 of amplifier 330 and non-inverting input 3302 form the relation of virtual earth, and the electric charge on the stray capacitance Cy of second direction signal wire 390 is remained unchanged, so the stray capacitance on the second direction signal wire 390 will can not exert an influence to detection signal.
As shown in Figure 4, when charge accumulation period, the first voltage switch S1 is for opening circuit, the second voltage switch S2 is for opening circuit, the first end TS31 of tertiary voltage switch S3 is connected to input voltage source Vin, the second switch SW2, the 5th switch SW5, the 7th switch SW7 are conducting, the first switch SW1, the 3rd switch SW3, the 4th switch SW4, the 6th switch SW6, and the 8th switch SW8 for opening circuit.
Equivalent circuit diagram when Fig. 8 is charge accumulation period.As shown in Figure 8, because capacitive feedback path exchange with the first feedback capacity Cf1 and the second feedback capacity Cf2, and non-inverting input 3302 this input voltage source of input Vin signals of amplifier 330, make the add up voltage of this input voltage source Vin of the second feedback capacity Cf2 more, this moment, the first feedback capacity Cf1 was connected to the output terminal 3303 of amplifier 330, to store the action of next sequential electric charge accumulation during the cycle.Wherein the voltage accumulated of the output terminal 3303 of amplifier 330 and the first feedback capacity Cf1 is:
In the middle of, V
0Be the voltage on the first second feedback capacity Cf2 when amplifying the cycle.
As shown in Figure 4, when second sample period, the first voltage switch S1 is conducting, the second voltage switch S2 is for opening circuit, the first end TS31 of tertiary voltage switch S3 is connected to common-mode voltage source Vcm, the first switch SW1 and the 8th switch SW8 are conducting, and the second switch SW2, the 3rd switch SW3, the 4th switch SW4, the 5th switch SW5, the 6th switch SW6, the 7th switch SW7 are for opening circuit.
Equivalent circuit diagram when Fig. 9 was second sample period.As shown in Figure 9, utilize input voltage source Vvin that this Inductance and Capacitance Cxy is charged, and amplifier 330 forms unity gain buffer (unit gainbuffer) form, and utilize the reverse input end 3301 of this amplifier 330 and non-inverting input 3302 to form virtual earth, and the electric charge on the stray capacitance Cy is remained unchanged.At this moment, the output terminal 3303 of amplifier 330 and the second feedback capacity Cf2 go up voltage V
OutBe V
Cm
As shown in Figure 4, when second amplifies the cycle, the first voltage switch S1 is for opening circuit, the second voltage switch S2 is conducting, the first end TS31 of tertiary voltage switch S3 is connected to common-mode voltage source Vcm, the first switch SW1, the 3rd switch SW3, the 4th switch SW4, and the 5th switch SW5 be conducting, the second switch SW2, the 6th switch SW6, the 7th switch SW7, and the 8th switch SW8 for opening circuit.
Figure 10 is the equivalent circuit diagram of second amplification during cycle.As shown in figure 10, because the reverse input end 3301 of amplifier 330 and non-inverting input 3302 form the relation of virtual earth, make script will be accumulated on the first feedback capacity Cf1 across the electric charge of this Inductance and Capacitance Cxy, this moment, the second feedback capacity Cf2 was connected to the output terminal 3303 of amplifier 330, made the output terminal 3303 of amplifier 330 and the second feedback capacity Cf2 go up voltage V
OutFor:
Cxy*Vin+V
1*Cf1＝Cf1*V
out
∴
Feedback factor (feedback factor) wherein
Institute's charges accumulated difference make this amplifier 330 can obtain higher feedback factor (feedback factor) when gaining, so will and rise along with (cycle) the number of times increase of sequential cycle in the closed loop.
Aforementioned be the present invention in first electric charge accumulation period, the voltage on amplifier 330 output terminals 3303.By aforementioned analysis as can be known, when the charge accumulation period of second electric charge accumulation period, the voltage V on amplifier 330 output terminals 3303
OutFor:
V
out＝Vin+V
2≡V
3。
When second sample period of second electric charge accumulation period, the voltage V on amplifier 330 output terminals 3303
OutBe V
CmWhen second of second electric charge accumulation period amplifies the cycle, the voltage V on amplifier 330 output terminals 3303
OutFor:
Cxy*Vin+V
3*Cf1＝Cf1*V
out
∴
The rest may be inferred, at N-1 electric charge accumulation period, and the voltage V on amplifier 330 output terminals
OutTo reach N * Δ V.
By aforementioned derivation and formula as can be known, circuit for detecting 300 of the present invention utilizes the first less feedback capacity Cf1 and the second feedback capacity Cf2, detects the variable quantity of Inductance and Capacitance Cxy.Promptly when object comes close to or in contact with touch control component on this contact panel, Inductance and Capacitance Cxy will change (several micromicrofarad) to some extent, and then make the output terminal 3303 of amplifier 330 produce voltage varieties.The voltage variety that is produced is by amplifying and the mode that adds up, with the reduction detecting time and simplify the flow process of digital signal processing, and then effectively promote Signal-to-Noise (Signal to Noise Ratio, SNR).Simultaneously, the virtual earth of amplifier 330 is set, is reached in switching by first to the 8th switch SW1-SW8 and first to tertiary voltage switch S1-S3, the present invention can eliminate the stray capacitance Cy effect of second direction signal wire 390, and the voltage variety after avoiding adding up for circuit for detecting 300 impacts.
The virtual earth of switching setting, the first feedback capacity Cf1, the second feedback capacity Cf2 and amplifier 330 by first to the 8th switch SW1-SW8 and first to tertiary voltage switch S1-S3, the present invention is compared to prior art stored charge more fast, when sequential cycle (cycle) number of times increases, induced charge can be with the rising that adds up of multiple form, and then increases circuit for detecting 300 execution speeds.Moreover because the present invention has adopted the first feedback capacity Cf1 and the second feedback capacity Cf2, it can be designed to have than small size when manufacturing and designing, and reaches the effect of saving area and reducing wafer power consumption.
Figure 11 is the application synoptic diagram that the present invention is used for the circuit for detecting 300 of contact panel.As shown in figure 11, one group of input voltage level Vin of signal wire switch 1110 major controls and the one group of datum Vcm (common-mode voltage source) or the earth level of directions X, and the voltage induced of Y direction mainly is made up of a plurality of circuit for detecting 300, wherein both all utilize time schedule controller 1120,1130 come control timing, in order to accumulation and amplify trickle voltage differences.
When each detecting, first to the 8th switch SW1～SW8 and tertiary voltage switch in the time schedule controller 1120 control circuit for detecting 330, and the incoming level of a directions X signal wire of time schedule controller 1130 controls, on the directions X signal wire, to produce a plurality of clock signals, and the amount of variability by the Inductance and Capacitance Cxy between directions X and the Y direction, make Y direction detecting circuit 300 can obtain the voltage variety of m group after adding up.And resulting magnitude of voltage converts numerical code to via analog to digital conversion circuit 1140, transfer to again digital signal processor 1150 judge do not have not object near or a touch control component by touch-control.Then, controlled the input signal of all directions X signal wires in regular turn, can obtain n * m voltage amount of variability, simultaneously can by voltage amount of variability Vo_1～Vo_m judge have not object near or touch control component by touch-control.
Figure 12 is a kind of second embodiment calcspar that is used for the circuit for detecting 1200 of contact panel of the present invention.Referring to Figure 12, circuit for detecting 1200 comprises an input voltage source Vin, one first voltage switch S1, a common mode voltage source Vcm, one second voltage switch S2, one first switch SW1, an amplifier 330, one second switch SW2, one the 3rd switch SW3, one the 4th switch SW4, one first feedback capacity Cf1, one the 5th switch SW5, one the 6th switch SW6, one the 7th switch SW7, one the 8th switch SW8, a tertiary voltage switch S3, reaches one second feedback capacity Cf2.
This circuit for detecting 1200 is that with Fig. 3 key distinction in the circuit for detecting 1200 of Figure 12, the first end T61 of the 6th switch SW6 is connected to first direction signal wire 385.That is referring to Figure 12, the particular circuit configurations of circuit for detecting 1200 is: the first end TS11 of the first voltage switch S1 is connected to input voltage source Vin, and the second end TS 12 is connected to first direction signal wire 385.The first end TS21 of the second voltage switch S2 is connected to this common-mode voltage source Vcm, and the second end TS22 is connected to first direction signal wire 385.The first end T11 of the first switch SW1 is connected to second direction signal wire 390.One reverse input end 3301 of amplifier 330 is connected to the second end T12 of the first switch SW1.The first end T21 of the second switch SW2 is connected to the reverse input end 3301 of amplifier 330.The first end T31 of the 3rd switch SW3 is connected to the second end T22 of the second switch SW2, and the second end T32 of the 3rd switch SW3 is connected to common-mode voltage source Vcm.The first end T41 of the 4th switch SW4 is connected to the reverse input end 3301 of amplifier 330.First end 3501 of the first feedback capacity Cf1 is connected to the second end T42 of the 4th switch SW4.The second end T52 that the first end T51 of the 5th switch SW5 is connected to second end, 3502, the five switch SW5 of this first feedback capacity Cf1 is connected to an output terminal 3303 of amplifier 330.The second end T62 that the first end T61 of the 6th switch SW6 is connected to first direction signal wire 385, the six switch SW6 is connected to second end 3502 of the first feedback capacity Cf1.The 7th switch SW7 first end T71 is connected to the second end T42 of the 4th switch SW4, and the second end T72 of the 7th switch SW7 is connected to common-mode voltage source Vcm.The second end T82 that the first end T81 of the 8th switch SW8 is connected to reverse input end 3301, the eight switch SW8 of amplifier 330 is connected to the output terminal 3303 of amplifier 330.A non-inverting input 3302, the one first control end TS32 that the control end TS31 of tertiary voltage switch S3 is connected to amplifier 330 are connected to common-mode voltage source Vcm, and one second control end TS33 is connected to input voltage source Vin.First end 3801 of the second feedback capacity Cf2 is connected to the second end T22 of the second switch SW2, and second end 3802 of this second feedback capacity Cf2 is connected to the output terminal 3303 of amplifier 330.
Figure 13 is the sequential chart of second embodiment of a kind of circuit for detecting 1200 that is used for contact panel of the present invention.Its sequential chart with Fig. 4 is identical.Referring to Figure 13, this sequential chart comprises an initial period and a plurality of electric charge accumulation period.Wherein, the initial period comprises a reset cycle, one first sample period, and one first amplification cycle, and a plurality of electric charge accumulation periods comprise a charge accumulation period, one second sample period, and one second amplification cycle respectively.When circuit for detecting 1200 amplifies the cycle at second of N-1 electric charge accumulation period, amplifier 330 output terminals output voltage be:
N×ΔV，
In the middle of,
Vin is the voltage of input voltage source Vin, and Cf1 is the capacitance of the first feedback capacity Cf1, and Cxy is the capacitance of Inductance and Capacitance Cxy.
Figure 14 is the calcspar of the 3rd embodiment of a kind of circuit for detecting 1400 that is used for contact panel of the present invention.Referring to Figure 14, circuit for detecting 1400 comprises an input voltage source Vin, one first voltage switch S1, a common mode voltage source Vcm, one second voltage switch S2, one first switch SW1, an amplifier 330, one second switch SW2, one the 3rd switch SW3, one the 4th switch SW4, one first feedback capacity Cf1, one the 5th switch SW5, one the 7th switch SW7, one the 8th switch SW8, a tertiary voltage switch S3, reaches one second feedback capacity Cf2.
This circuit for detecting 1400 is with Fig. 3 key distinction, in the circuit for detecting 1400 of Figure 14, the 6th switch SW6 is removed.That is referring to Figure 14, the particular circuit configurations of circuit for detecting 1400 is: the first end TS11 of the first voltage switch S1 is connected to input voltage source Vin, and the second end TS12 is connected to first direction signal wire 385.The first end TS21 of the second voltage switch S2 is connected to common-mode voltage source Vcm, and the second end TS22 is connected to first direction signal wire 385.The first switch SW1, the first end T11 is connected to second direction signal wire 390.One reverse input end 3301 of amplifier 330 is connected to the second end T12 of the first switch SW1.The first end T21 of the second switch SW2 is connected to the reverse input end 3301 of amplifier 330.The first end T31 of the 3rd switch SW3 is connected to the second end T22 of the second switch SW2, and the second end T32 of the 3rd switch SW3 is connected to common-mode voltage source Vcm.The first end T41 of the 4th switch SW4 is connected to the reverse input end 3301 of amplifier 330.First end 3501 of the first feedback capacity Cf1 is connected to the second end T42 of the 4th switch SW4.The second end T52 that the first end T51 of the 5th switch SW5 is connected to second end, 3502, the five switch SW5 of the first feedback capacity Cf1 is connected to an output terminal 3303 of this amplifier 330.The first end T71 of the 7th switch SW7 is connected to the second end T42 of the 4th switch SW4, and the second end T72 of the 7th switch SW7 is connected to common-mode voltage source Vcm.The second end T82 that the first end T81 of the 8th switch SW8 is connected to reverse input end 3301, the eight switch SW8 of amplifier 330 is connected to the output terminal 3303 of amplifier 330.A non-inverting input 3302, the one first contact jaw TS32 that the control end TS31 of tertiary voltage switch S3 is connected to amplifier 330 are connected to common-mode voltage source Vcm, and one second contact jaw TS33 is connected to input voltage source Vin.First end 3801 of the second feedback capacity Cf2 is connected to the second end T22 of the second switch SW2, and second end 3802 of this second feedback capacity Cf2 is connected to the output terminal 3303 of amplifier 330.
Figure 15 is the sequential chart of the 3rd embodiment of a kind of circuit for detecting 1400 that is used for contact panel of the present invention.Referring to Figure 15, the sequential chart difference of itself and Fig. 4 is that the initial period increases a sample period newly.As shown in figure 15, this sequential chart comprises an initial period and a plurality of electric charge accumulation period.Wherein, this initial period comprises a reset cycle, one first sample period, one second sample period, and one first amplification cycle, and each electric charge accumulation period comprises a charge accumulation period, one the 3rd sample period, and one second amplification cycle.When this circuit for detecting 1400 amplified the cycle at second of N-1 electric charge accumulation period, the output voltage of amplifier 330 output terminals 3303 was:
N×ΔV，
In the middle of,
Vin is the voltage of input voltage source Vin, and Cf1 is the capacitance of the first feedback capacity Cf1, and Cxy is the capacitance of Inductance and Capacitance Cxy.
The circuit working mode of aforesaid second and third embodiment of the present invention is that those skilled in the art can learn according to the sequential chart of Figure 13 and Figure 15.For example: during noble potential, represent the conducting of switch (SW1-SW8) or voltage switch (S1-S3) in the sequential chart, during electronegative potential, represent opening circuit of switch (SW1-SW8) or voltage switch (S1-S3).
In sum, characteristics of the present invention can be summarized as follows:
(1) the present invention utilize the first feedback capacity Cf1, the second feedback capacity Cf2, and first to the 8th switch SW1-SW8 and first to tertiary voltage switch S1-S3 switching set, can originally can only do the circuit that primary sample is amplified, change over a kind of circuit for detecting of add up electric charge and amplification electric charge.
(2) the present invention obtains higher feedback factor (feedback factor), makes institute's charges accumulated difference and to rise along with (cycle) the number of times increase of sequential cycle.
(3) the present invention is along with sequential cycle (cycle) number of times increases, and induced charge can be with the rising that adds up of multiple form.
(4) the present invention utilizes that the switching of the first feedback capacity Cf1, the second feedback capacity Cf2, first to the 8th switch SW1-SW8 and first to tertiary voltage switch S1-S3 is set, and the virtual earth of amplifier 330, when each electric charge is repeatedly long-pending, can get rid of on Y direction or the directions X signal wire stray capacitance to the influence of detection signal.
(5) the present invention first feedback capacity Cf1 and the second feedback capacity Cf2 can be designed to have than small size when manufacturing and designing, and reach to save area and reduce wafer power consumption effect.
From the above, no matter the present invention all shows it totally different in the feature of prior art with regard to purpose, means and effect, has practical value.Only it should be noted that above-mentioned many embodiment give an example for convenience of explanation, the interest field that the present invention advocated should be as the criterion so that claims are described certainly, but not only limits to the foregoing description.
Claims (29)
1. circuit for detecting that is used for contact panel, it is characterized in that, when object near the time, this circuit for detecting is in order to the voltage on sensing one Inductance and Capacitance, described Inductance and Capacitance is formed between a first direction signal wire and the second direction signal wire, described first direction signal wire and described second direction signal wire are that insulation is separated, and described circuit for detecting comprises:
One input voltage source is in order to produce a plurality of periodic voltage cycles that have;
One first voltage switch, its first end is connected to described input voltage source, and second end is connected to described first direction signal wire;
One common mode voltage source is in order to provide a direct current common mode voltage;
One second voltage switch, its first end is connected to described common-mode voltage source, with and second end be connected to described first direction signal wire;
One first switch, its first end is connected to described second direction signal wire;
One amplifier, its reverse input end are connected to second end of described first switch;
One second switch, its first end is connected to the reverse input end of described amplifier;
One the 3rd switch, its first end is connected to second end of described second switch, with and second end be connected to described common-mode voltage source;
One the 4th switch, its first end is connected to the reverse input end of described amplifier;
One first feedback capacity, its first end is connected to second end of described the 4th switch;
One the 5th switch, its first end is connected to second end of described first feedback capacity, with and second end be connected to the output terminal of described amplifier;
One the 6th switch, its first end is connected to described input voltage source, and its second end is connected to second end of described first feedback capacity;
One the 7th switch, its first end is connected to second end of described the 4th switch, with and second end be connected to described common-mode voltage source;
One the 8th switch, its first end is connected to the reverse input end of described amplifier, with and second end be connected to the output terminal of described amplifier; And
Non-inverting input, its first contact jaw that one tertiary voltage switch, its control end are connected to described amplifier are connected to described common-mode voltage source, with and second contact jaw be connected to described input voltage source;
When described circuit for detecting forms an initial period and a plurality of electric charge accumulation period, by described first switch to described the 8th switch, and the described first voltage switch to the switching of described tertiary voltage switch is set, and by described first feedback capacity and described second feedback capacity formation backfeed loop, in order to quicken to add up electric charge.
2. circuit for detecting as claimed in claim 1, it is characterized in that, described circuit for detecting is when the 1st electric charge accumulation period, the output voltage of described amplifier out is Δ V, and described circuit for detecting is when N-1 electric charge accumulation period, the output voltage of described amplifier out is N * Δ V, in the middle of
Vin is the voltage of input voltage source, and Cf1 is the capacitance of described first feedback capacity, and Cxy is the capacitance of described Inductance and Capacitance.
3. circuit for detecting as claimed in claim 1, it is characterized in that the described initial period comprises a reset cycle, one first sample period, and one first amplification cycle, each electric charge accumulation period comprises a charge accumulation period, one second sample period, and one second amplification cycle.
4. circuit for detecting as claimed in claim 3, it is characterized in that, when being positioned at described reset cycle, the described first voltage switch is for opening circuit, the described second voltage switch is conducting, and first end of described tertiary voltage switch is connected to described common-mode voltage source, described first switch, described second switch, described the 4th switch, described the 5th switch, described the 7th switch, and the 8th switch be conducting, described the 3rd switch and described the 6th switch are for opening circuit.
5. circuit for detecting as claimed in claim 4, it is characterized in that, when being positioned at described first sample period, the described first voltage switch is conducting, the described second voltage switch is for opening circuit, first end of described tertiary voltage switch is connected to described common-mode voltage source, described first switch, described the 4th switch, described the 6th switch, and the 8th switch be conducting, described second switch, described the 3rd switch, described the 5th switch, and described the 7th switch is for opening circuit.
6. circuit for detecting as claimed in claim 5, it is characterized in that, when being positioned at described first amplification during cycle, the described first voltage switch is for opening circuit, the described second voltage switch is conducting, first end of described tertiary voltage switch is connected to described common-mode voltage source, described first switch, described the 3rd switch, described the 4th switch, and the 5th switch be conducting, described second switch, described the 6th switch, described the 7th switch, and described the 8th switch is for opening circuit.
7. circuit for detecting as claimed in claim 6, it is characterized in that, when being positioned at described charge accumulation period, the described first voltage switch is for opening circuit, and the described second voltage switch is for opening circuit, and first end of described tertiary voltage switch is connected to described input voltage source, described second switch, described the 5th switch, and the 7th switch be conducting, described first switch, described the 3rd switch, described the 4th switch, described the 6th switch, and the 8th switch is for opening circuit.
8. circuit for detecting as claimed in claim 7, it is characterized in that, when being positioned at described second sample period, the described first voltage switch is conducting, the described second voltage switch is for opening circuit, first end of described tertiary voltage switch is connected to described common-mode voltage source, described first switch and described the 8th switch are conducting, described second switch, described the 3rd switch, described the 4th switch, described the 5th switch, described the 6th switch, and described the 7th switch is for opening circuit.
9. circuit for detecting as claimed in claim 8, it is characterized in that, when being positioned at described second amplification during cycle, the described first voltage switch is for opening circuit, the described second voltage switch is conducting, first end of described tertiary voltage switch is connected to described common-mode voltage source, described first switch, described the 3rd switch, described the 4th switch, and described the 5th switch be conducting, described second switch, described the 6th switch, described the 7th switch, and described the 8th switch is for opening circuit.
10. a contact panel is characterized in that, this contact panel comprises:
The described circuit for detecting of claim 1;
The signal wire switch of first direction, in order to control one group of input voltage source and one group of common-mode voltage source, wherein, this group input voltage source is in order to provide described input voltage source, and this group common-mode voltage source is in order to provide described common-mode voltage source;
First time schedule controller is connected to described circuit for detecting, in order to control the sequential of described circuit for detecting;
Second time schedule controller, be connected to the signal wire switch of described first direction, sequential in order to the signal wire switch of controlling described first direction, so that described input voltage source and described common-mode voltage source to be provided, wherein, described circuit for detecting is carried out the voltage induced of a second direction, described first time schedule controller is controlled described first switch of described circuit for detecting to described the 8th switch and described tertiary voltage switch, described second time schedule controller is controlled the incoming level of at least one first direction signal wire, in order at least one described first direction signal wire, to produce a plurality of clock signals, and the amount of variability by the Inductance and Capacitance between described first direction and the described second direction, make described circuit for detecting can obtain most groups through the voltage varieties after adding up;
Analog to digital conversion circuit is connected to described circuit for detecting, in order to convert voltage variety to numerical code; And
Digital signal processor is connected to analog-digital conversion circuit as described, has judged whether the described contact panel of object touch-control according to described numerical code.
11. circuit for detecting that is used for contact panel, in order to sensing when object near the time voltage on an Inductance and Capacitance, it is characterized in that, described Inductance and Capacitance is formed between a first direction signal wire and the second direction signal wire, described first direction signal wire and the insulation of described second direction signal wire are separated, and described circuit for detecting comprises:
One input voltage source is in order to produce a plurality of periodic voltage cycles that have;
One first voltage switch, its first end is connected to described input voltage source, and second end is connected to described first direction signal wire;
One common mode voltage source is in order to provide a direct current common mode voltage;
One second voltage switch, its first end is connected to described common-mode voltage source, with and second end be connected to described first direction signal wire;
One first switch, its first end is connected to described second direction signal wire;
One amplifier, its reverse input end are connected to second end of described first switch;
One second switch, its first end is connected to the reverse input end of described amplifier;
One the 3rd switch, its first end is connected to second end of described second switch, with and second end be connected to described common-mode voltage source;
One the 4th switch, its first end is connected to the reverse input end of described amplifier;
One first feedback capacity, its first end is connected to second end of described the 4th switch;
One the 5th switch, its first end is connected to second end of described first feedback capacity, with and second end be connected to an output terminal of described amplifier;
One the 6th switch, its first end is connected to described first direction signal wire, with and second end be connected to second end of described first feedback capacity;
One the 7th switch, its first end is connected to second end of described the 4th switch, with and second end be connected to described common-mode voltage source;
One the 8th switch, its first end is connected to the reverse input end of described amplifier, with and second end be connected to the output terminal of described amplifier; And
A non-inverting input, its first contact jaw that one tertiary voltage switch, one control end are connected to described amplifier are connected to described common-mode voltage source, with and second contact jaw be connected to described input voltage source;
When described circuit for detecting forms an initial period and a plurality of electric charge accumulation period, set by described first switch to described the 8th switch and the described first voltage switch to the switching of tertiary voltage switch, and by described first feedback capacity and described second feedback capacity formation backfeed loop, in order to quicken to add up electric charge.
12. circuit for detecting as claimed in claim 11, it is characterized in that, described circuit for detecting is when the 1st electric charge accumulation period, the output voltage of described amplifier out is Δ V, and described circuit for detecting is when (N-1) individual electric charge accumulation period, the output voltage of described amplifier out is N * Δ V, in the middle of
Vin is the voltage of input voltage source, and Cf1 is the capacitance of described first feedback capacity, and Cxy is the capacitance of described Inductance and Capacitance.
13. circuit for detecting as claimed in claim 12, it is characterized in that the described initial period comprises a reset cycle, one first sample period, and one first amplification cycle, each electric charge accumulation period comprises a charge accumulation period, one second sample period, and one second amplification cycle.
14. circuit for detecting as claimed in claim 13, it is characterized in that, when being positioned at described reset cycle, the described first voltage switch is for opening circuit, the described second voltage switch is conducting, and first end of described tertiary voltage switch is connected to described common-mode voltage source, described first switch, described second switch, described the 4th switch, described the 5th switch, described the 6th switch, described the 7th switch, and the 8th switch be conducting, described the 3rd switch is for opening circuit.
15. circuit for detecting as claimed in claim 14, it is characterized in that, when being positioned at described first sample period, the described first voltage switch is conducting, the described second voltage switch is for opening circuit, first end of described tertiary voltage switch is connected to described common-mode voltage source, described first switch, described the 4th switch, described the 6th switch, and the 8th switch be conducting, described second switch, described the 3rd switch, described the 5th switch, and the 7th switch is for opening circuit.
16. circuit for detecting as claimed in claim 15, it is characterized in that, when being positioned at described first amplification during cycle, the described first voltage switch is for opening circuit, the described second voltage switch is conducting, first end of described tertiary voltage switch is connected to described common-mode voltage source, described first switch, described the 3rd switch, described the 4th switch, and the 5th switch be conducting, described second switch, described the 6th switch, described the 7th switch, and the 8th switch is for opening circuit.
17. circuit for detecting as claimed in claim 16, it is characterized in that, when being positioned at described charge accumulation period, the described first voltage switch is for opening circuit, the described second voltage switch is for opening circuit, first end of described tertiary voltage switch is connected to described input voltage source, described second switch, described the 5th switch, described the 7th switch are conducting, described first switch, described the 3rd switch, described the 4th switch, described the 6th switch, and the 8th switch is for opening circuit.
18. circuit for detecting as claimed in claim 17, it is characterized in that, when being positioned at described second sample period, the described first voltage switch is conducting, the described second voltage switch is for opening circuit, first end of described tertiary voltage switch is connected to described common-mode voltage source, described first switch and described the 8th switch are conducting, described second switch, described the 3rd switch, described the 4th switch, described the 5th switch, described the 6th switch, and the 7th switch is for opening circuit.
19. circuit for detecting as claimed in claim 18, it is characterized in that, when being positioned at described second amplification during cycle, the described first voltage switch is for opening circuit, the described second voltage switch is conducting, first end of described tertiary voltage switch is connected to described common-mode voltage source, described first switch, described the 3rd switch, described the 4th switch, and described the 5th switch be conducting, described second switch, described the 6th switch, described the 7th switch, and the 8th switch is for opening circuit.
20. circuit for detecting that is used for contact panel, in order to sensing when object near the time voltage on an Inductance and Capacitance, it is characterized in that, described Inductance and Capacitance is formed between a first direction signal wire and the second direction signal wire, described first direction signal wire and the insulation of described second direction signal wire are separated, and described circuit for detecting comprises:
One input voltage source is in order to produce a plurality of periodic voltage cycles that have;
One first voltage switch, its first end is connected to described input voltage source, with and second end be connected to described first direction signal wire;
One common mode voltage source is in order to provide a direct current common mode voltage;
One second voltage switch, its first end is connected to described common-mode voltage source, with and second end be connected to described first direction signal wire;
One first switch, its first end is connected to described second direction signal wire;
One amplifier, one reverse input end are connected to second end of described first switch;
One second switch, its first end is connected to the reverse input end of described amplifier;
One the 3rd switch, its first end is connected to second end of described second switch, with and second end be connected to described common-mode voltage source;
One the 4th switch, its first end is connected to the reverse input end of described amplifier;
One first feedback capacity, its first end is connected to second end of described the 4th switch;
One the 5th switch, its first end is connected to second end of described first feedback capacity, with and second end be connected to an output terminal of described amplifier;
One the 7th switch, its first end is connected to second end of described the 4th switch, with and second end be connected to described common-mode voltage source;
One the 8th switch, its first end is connected to the reverse input end of described amplifier, with and second end be connected to the output terminal of described amplifier; And
A non-inverting input, one first contact jaw that one tertiary voltage switch, one control end are connected to described amplifier are connected to described common-mode voltage source, and one second contact jaw is connected to described input voltage source;
When described circuit for detecting forms an initial period and a plurality of electric charge accumulation period, set by described first switch to described the 8th switch and the described first voltage switch to the switching of tertiary voltage switch, and by described first feedback capacity and described second feedback capacity formation backfeed loop, in order to quicken to add up electric charge.
21. circuit for detecting as claimed in claim 20, it is characterized in that, described circuit for detecting is when the 1st electric charge accumulation period, the output voltage of described amplifier out is Δ V, and described circuit for detecting is when N-1 electric charge accumulation period, the output voltage of described amplifier out is N * Δ V, in the middle of
Vin is the voltage of input voltage source, and Cf1 is the capacitance of described first feedback capacity, and Cxy is the capacitance of described Inductance and Capacitance.
22. circuit for detecting as claimed in claim 20, it is characterized in that, the described initial period comprises a reset cycle, one first sample period, one second sample period, and one first amplification cycle, each electric charge accumulation period comprises a charge accumulation period, one the 3rd sample period, and one second amplification cycle.
23. circuit for detecting as claimed in claim 22, it is characterized in that, when being positioned at described reset cycle, the described first voltage switch is for opening circuit, the described second voltage switch is conducting, and first end of described tertiary voltage switch is connected to described common-mode voltage source, described first switch, described second switch, described the 4th switch, described the 5th switch, described the 7th switch, and the 8th switch be conducting, described the 3rd switch is for opening circuit.
24. circuit for detecting as claimed in claim 23, it is characterized in that, when being positioned at described first sample period, the described first voltage switch is conducting, the described second voltage switch is for opening circuit, and first end of described tertiary voltage switch is connected to described common-mode voltage source, and described first switch and described the 8th switch are conducting, described second switch, described the 3rd switch, described the 4th switch, described the 5th switch, and described the 7th switch is for opening circuit.
25. circuit for detecting as claimed in claim 24, it is characterized in that, when being positioned at described second sample period, the described first voltage switch is for opening circuit, the described second voltage switch is for opening circuit, first end of described tertiary voltage switch is connected to described input voltage source, and described the 5th switch, described the 7th switch and the 8th switch are conducting, and described first switch, described second switch, described the 3rd switch and described the 4th switch are for opening circuit.
26. circuit for detecting as claimed in claim 25, it is characterized in that, when being positioned at described first amplification during cycle, the described first voltage switch is for opening circuit, the described second voltage switch is conducting, and first end of described tertiary voltage switch is connected to described common-mode voltage source, described first switch, described the 3rd switch, described the 4th switch, and the 5th switch be conducting, described second switch, described the 7th switch and described the 8th switch are for opening circuit.
27. circuit for detecting as claimed in claim 26, it is characterized in that, when being positioned at described charge accumulation period, the described first voltage switch is for opening circuit, the described second voltage switch is for opening circuit, first end of described tertiary voltage switch is connected to described input voltage source, and described second switch, described the 5th switch and the 7th switch are conducting, and described first switch, described the 3rd switch, described the 4th switch and the 8th switch are for opening circuit.
28. circuit for detecting as claimed in claim 27, it is characterized in that, when being positioned at described the 3rd sample period, the described first voltage switch is conducting, the described second voltage switch is for opening circuit, first end of described tertiary voltage switch is connected to described common-mode voltage source, and described first switch and described the 8th switch are conducting, and described second switch, described the 3rd switch, described the 4th switch, described the 5th switch and described the 7th switch are for opening circuit.
29. circuit for detecting as claimed in claim 28, it is characterized in that, when being positioned at described second amplification during cycle, the described first voltage switch is for opening circuit, the described second voltage switch is conducting, first end of described tertiary voltage switch is connected to described common-mode voltage source, and described first switch, described the 3rd switch, described the 4th switch and described the 5th switch are conducting, and described second switch, described the 7th switch and described the 8th switch are for opening circuit.
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| CN102299716A (en) * | 2010-06-22 | 2011-12-28 | 君曜科技股份有限公司 | Sample-hold circuit and touch control sensing device thereof |
| CN102855035A (en) * | 2011-06-27 | 2013-01-02 | 瑞鼎科技股份有限公司 | Touch sensing device |
| CN103477316A (en) * | 2011-03-28 | 2013-12-25 | 富士胶片株式会社 | Touch panel device, display method therefor, and display program |
| CN103902123A (en) * | 2014-01-30 | 2014-07-02 | 敦泰科技有限公司 | Self-capacitance touch sensing device capable of reducing substrate capacitance |
| CN106557722A (en) * | 2015-09-25 | 2017-04-05 | 上海思立微电子科技有限公司 | Fingerprint sensing circuit and control method |
| CN109064956A (en) * | 2018-07-16 | 2018-12-21 | 深圳市华星光电半导体显示技术有限公司 | For detecting the circuit for detecting of sensing line capacitance and sensing line capacitance method for detecting and OLED display |
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| CN102299716A (en) * | 2010-06-22 | 2011-12-28 | 君曜科技股份有限公司 | Sample-hold circuit and touch control sensing device thereof |
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| CN103477316B (en) * | 2011-03-28 | 2017-03-15 | 富士胶片株式会社 | Touch-panel device and its display packing |
| CN102855035A (en) * | 2011-06-27 | 2013-01-02 | 瑞鼎科技股份有限公司 | Touch sensing device |
| CN103902123A (en) * | 2014-01-30 | 2014-07-02 | 敦泰科技有限公司 | Self-capacitance touch sensing device capable of reducing substrate capacitance |
| CN103902123B (en) * | 2014-01-30 | 2017-04-19 | 敦泰科技有限公司 | Self-capacitance touch sensing device capable of reducing substrate capacitance |
| CN106557722A (en) * | 2015-09-25 | 2017-04-05 | 上海思立微电子科技有限公司 | Fingerprint sensing circuit and control method |
| CN109064956A (en) * | 2018-07-16 | 2018-12-21 | 深圳市华星光电半导体显示技术有限公司 | For detecting the circuit for detecting of sensing line capacitance and sensing line capacitance method for detecting and OLED display |
| WO2020015335A1 (en) * | 2018-07-16 | 2020-01-23 | 深圳市华星光电半导体显示技术有限公司 | Detection circuit and detection method for detecting capacitance of sense line, and oled display apparatus |
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