CN103294297B - Signal transacting and pre-amplification circuit and touch-screen - Google Patents
Signal transacting and pre-amplification circuit and touch-screen Download PDFInfo
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- CN103294297B CN103294297B CN201210385195.7A CN201210385195A CN103294297B CN 103294297 B CN103294297 B CN 103294297B CN 201210385195 A CN201210385195 A CN 201210385195A CN 103294297 B CN103294297 B CN 103294297B
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- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
- G06F3/01—Input arrangements or combined input and output arrangements for interaction between user and computer
- G06F3/03—Arrangements for converting the position or the displacement of a member into a coded form
- G06F3/041—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
- G06F3/044—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means by capacitive means
- G06F3/0446—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means by capacitive means using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes
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- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
- G06F3/01—Input arrangements or combined input and output arrangements for interaction between user and computer
- G06F3/03—Arrangements for converting the position or the displacement of a member into a coded form
- G06F3/041—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
- G06F3/0416—Control or interface arrangements specially adapted for digitisers
- G06F3/04166—Details of scanning methods, e.g. sampling time, grouping of sub areas or time sharing with display driving
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- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
- G06F3/01—Input arrangements or combined input and output arrangements for interaction between user and computer
- G06F3/03—Arrangements for converting the position or the displacement of a member into a coded form
- G06F3/041—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
- G06F3/044—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means by capacitive means
- G06F3/0445—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means by capacitive means using two or more layers of sensing electrodes, e.g. using two layers of electrodes separated by a dielectric layer
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Abstract
The invention discloses a kind of signal transacting and pre-amplification circuit and touch-screen, signal transacting and pre-amplification circuit, for touch-screen, comprise: compensation current generating unit, be suitable for exporting compensating current signal, to eliminate at least part of background signal in the pixel output current signal of touch-screen, pixel output current signal when background signal is not for being touched; Prime amplifier, negative-phase input is suitable for receiving pixel output current signal and compensating current signal, and normal phase input end is suitable for receiving reference voltage; Feedback impedance, is suitable for the negative-phase input and the output terminal that connect prime amplifier.Employing technical solution of the present invention can reduce or remove the background signal in pixel output current, makes preamplifier circuit that the electric capacity of smaller value or resistance can be selected to obtain larger gain.Adopt technical solution of the present invention can change the feedback impedance (integrating capacitor or resistance) of preamplifier circuit, thus adjustment gain, make its realistic needed for.
Description
Technical field
The present invention relates to electronic technology field, particularly relate to a kind of signal transacting and pre-amplification circuit and touch-screen.
Background technology
Capacitive touch screen (CapacityTouchPanel, CTP) mainly contains self-capacitance induction type touch-screen and mutual capacitance induction type touch-screen two kinds.
Mutual capacitance induction type touch-screen comprises many drive wires and many lines of induction, and drive wire and the line of induction intersect to be placed, and forms mutual capacitance at the infall of drive wire and the line of induction.Mutual capacitance induction type touch-screen can comprise into the mutual capacitance of array arrangement.
Drive wire sends pulse signal, and the line of induction is by the described pulse signal generation current signal of induction.When mutual capacitance induction type touch-screen is not touched, the background signal of line of induction stable output, described background signal is converted into stable charge signal after charge amplifier circuit, and stable charge signal is converted into stable output voltage after bandpass filter.When human contact's touch-screen, due to human body grounding, finger just forms an equivalent capacity with touch-screen, the pulse signal that drive wire sends can flow into ground by this equivalent capacity, like this, line of induction generation current signal changes, and the final output voltage produced also changes, and touch operation is detected.
As shown in the above, line of induction production background signal when touch-screen is not touched of mutual capacitance induction type touch-screen, after touch-screen is touched, the line of induction produces the current signal be superimposed with described background signal.In described current signal, be only the current value of actual embodiment touch signal relative to the curent change part of background signal.
Charge amplifier circuit is actually a kind of embody rule of integrating circuit.Charge amplifier circuit can carry out Integral Processing to the current signal received, and produces corresponding charge signal.The capacitance of the integrating capacitor of charge amplifier circuit is less, and output voltage is larger, and gain is larger.
In order to increase output voltage, obtain larger gain, the integrating capacitor of charge amplifier circuit needs to arrange less capacitance.But the current value of described background signal is often comparatively large, if the capacitance of the integrating capacitor in charge amplifier circuit is less, then charge amplifier circuit is easy to saturated.After charge amplifier circuit is saturated, no matter whether touch-screen is touched, and output voltage can not change, and touch operation cannot be detected.
Summary of the invention
In view of this, the technical problem to be solved in the present invention is that existing charge amplifier circuit cannot meet needed for touch-screen detection.
For this reason, the embodiment of the present invention adopts following technical scheme:
A kind of signal transacting and pre-amplification circuit, for touch-screen, comprising:
Compensation current generating unit, is suitable for exporting compensating current signal, to eliminate at least part of background signal in the pixel output current signal of described touch-screen, and pixel output current signal when described background signal is not for being touched;
Prime amplifier, negative-phase input is suitable for receiving described pixel output current signal and compensating current signal, and normal phase input end is suitable for receiving reference voltage;
Feedback impedance, is suitable for the negative-phase input and the output terminal that connect described prime amplifier.
Optionally, described compensation current generating unit comprises:
Storage unit, is suitable for storing the background signal that in described touch-screen, all pixels are corresponding;
Current output unit, is suitable for from described storage unit, searching background signal corresponding to this pixel according to the coordinate of current pixel point, and produces compensating current signal according to the background signal found;
Electric charge feed-in impedance, is suitable for the negative-phase input described compensating current signal being exported to described prime amplifier.
Optionally, described current output unit is suitable for from the LOOKUPTABLE storage unit, searching background signal corresponding to this pixel according to the coordinate of current pixel point.
Optionally, described prime amplifier is charge amplifier, and described electric charge feed-in impedance and feedback impedance are realized by electric capacity;
Or described prime amplifier is voltage amplifier or current-voltage converter, described electric charge feed-in impedance and feedback impedance are realized by resistance.
Optionally, the waveform of the background signal that all pixels of described cell stores are corresponding or integral charge amount.
Optionally, the actual waveform of background signal that all pixels of described cell stores are corresponding or the compressed format of actual waveform.
Optionally, described prime amplifier is charge amplifier, and described compensating current signal and background signal are synchronous and phase place is contrary, and the integral charge of described compensating current signal is 0.5-1.5 times of the integral charge of described background signal.
Optionally, described prime amplifier is voltage amplifier or current-to-voltage converter, and described compensating current signal and background signal are synchronous and phase place is contrary, and compensating current signal F2i and background signal F1i is satisfied:
Optionally, described signal transacting and pre-amplification circuit also comprise: at least one road feedback branch; Between the negative-phase input that each road feedback branch in the feedback branch of described at least one road is all arranged at described prime amplifier and output terminal;
Described in each road, feedback branch comprises: the switch of serial connection and branch road feedback impedance.
A kind of signal transacting and pre-amplification circuit, for touch-screen, comprising:
Prime amplifier, negative-phase input is suitable for receiving described touch-screen pixel output current signal, and normal phase input end is suitable for receiving reference voltage;
Feedback impedance, is suitable for the negative-phase input and the output terminal that connect described prime amplifier;
At least one road feedback branch, wherein between each road feedback branch negative-phase input of being all arranged at described prime amplifier and output terminal, each road feedback branch described comprises: the switch of serial connection and branch road feedback impedance.
Optionally, described prime amplifier is charge amplifier, and described feedback impedance and branch road feedback impedance are realized by electric capacity;
Or described prime amplifier is voltage amplifier or current-voltage converter, described feedback impedance and branch road feedback impedance are realized by resistance.
Optionally, described signal transacting and pre-amplification circuit also comprise: compensation current generating unit, be suitable for exporting compensating current signal, to eliminate at least part of background signal in described pixel output current signal, pixel output current signal when described background signal is not for being touched;
The negative-phase input of described prime amplifier is also suitable for receiving described compensating current signal.
Optionally, described compensation current generating unit comprises:
Storage unit, is suitable for storing the background signal that in described touch-screen, all pixels are corresponding;
Current output unit, is suitable for from described storage unit, searching background signal corresponding to this pixel according to the coordinate of current pixel point, and produces compensating current signal according to the background signal found;
Electric charge feed-in impedance, is suitable for the negative-phase input described compensating current signal being exported to described prime amplifier.
Optionally, described current output unit is suitable for from the LOOKUPTABLE storage unit, searching background signal corresponding to this pixel according to the coordinate of current pixel point.
Optionally, described prime amplifier is charge amplifier, and described electric charge feed-in impedance and feedback impedance are realized by electric capacity;
Or described prime amplifier is voltage amplifier or current-voltage converter, described electric charge feed-in impedance and feedback impedance are realized by resistance.
Optionally, described prime amplifier is charge amplifier, and described compensating current signal and background signal are synchronous and phase place is contrary, and the integral charge of described compensating current signal is 0.5-1.5 times of the integral charge of described background signal.
Optionally, described prime amplifier is voltage amplifier or current-to-voltage converter, and described compensating current signal and background signal are synchronous and phase place is contrary, and compensating current signal F2i and background signal F1i is satisfied:
A kind of touch-screen, comprises above-mentioned signal transacting and pre-amplification circuit.
Optionally, described touch-screen comprises many drive wires and many lines of induction, and described signal transacting and pre-amplification circuit are electrically connected with the described line of induction.
Optionally, described drive wire and the described line of induction are positioned at different layers, and are separated by an insulation course therebetween.
Optionally, described drive wire and the described line of induction are positioned at same layer.
Optionally, a line of induction correspondence connects a described signal transacting and pre-amplification circuit.
Optionally, all lines of induction are connected to a described signal transacting and pre-amplification circuit jointly.
Compared with prior art, there is following advantage in technical solution of the present invention:
Employing technical solution of the present invention can reduce or remove the background signal in pixel output current, makes preamplifier circuit that the electric capacity of smaller value or resistance can be selected to obtain larger gain.
Adopt technical solution of the present invention can change the feedback impedance (integrating capacitor or resistance) of preamplifier circuit, thus adjustment gain, make its realistic needed for.
Accompanying drawing explanation
Fig. 1 is a structural representation of the embodiment of the present invention one signal transacting and pre-amplification circuit;
Fig. 2 is the schematic diagram of present invention pixel point output current signal;
Fig. 3 is another structural representation of the embodiment of the present invention one signal transacting and pre-amplification circuit;
Fig. 4 is the schematic diagram of background signal of the present invention when being stored;
Fig. 5 is the another structural representation of the embodiment of the present invention one signal transacting and pre-amplification circuit;
Fig. 6 is a relation schematic diagram of present invention pixel point output current signal and compensating signal;
Fig. 7 is another relation schematic diagram of present invention pixel point output current signal and compensating signal;
Fig. 8 is a structural representation of the process of embodiment of the present invention binary signal and pre-amplification circuit;
Fig. 9 is another structural representation of the process of embodiment of the present invention binary signal and pre-amplification circuit;
Figure 10 is a structural representation of the embodiment of the present invention three signal transacting and pre-amplification circuit;
Figure 11 is another structural representation of the embodiment of the present invention three signal transacting and pre-amplification circuit;
Figure 12 is a structural representation of inventive touch screen;
Figure 13 is another structural representation of inventive touch screen.
Embodiment
Below in conjunction with accompanying drawing, the specific embodiment of the present invention is described in detail.In the following passage, more specifically the present invention is described by way of example with reference to accompanying drawing.According to following explanation, advantages and features of the invention will be clearer.
As shown in Figure 1, the embodiment of the present invention one provides a kind of signal transacting and pre-amplification circuit, described signal transacting and pre-amplification circuit are used for touch-screen 5, comprise: compensation current generating unit 1, be suitable for exporting compensating current signal A2, to eliminate at least part of background signal in pixel output current signal A1, described background signal is the pixel output current signal of touch-screen 5 when not touching; Prime amplifier 3, negative-phase input is suitable for receiving described pixel output current signal A1 and compensating current signal A2, and normal phase input end is suitable for receiving reference voltage VF(and is generally earth terminal); Feedback impedance 4, is suitable for the negative-phase input and the output terminal that connect described prime amplifier 3.
Touch-screen 5 can be the touch-screen of mutual capacitance induction type.Mutual capacitance induction type touch-screen comprises many drive wires and many lines of induction, and drive wire and the line of induction intersect to be placed, and the infall of drive wire and the line of induction forms pixel, i.e. mutual capacitance.Concrete, so mutual capacitance induction type touch-screen comprises into the mutual capacitance of array arrangement.
Such as, the touch-screen 5 in Fig. 1 comprises first drive wire 52, second drive wire 53, first line of induction 54 and second line of induction 55.The infall of the first drive wire 52 and first line of induction 54 forms the first pixel 524; The infall of the first drive wire 52 and second line of induction 55 forms the second pixel 525; The infall of the second drive wire 53 and first line of induction 54 forms the 3rd pixel 534; The infall of the second drive wire 53 and second line of induction 55 forms the 4th pixel 535; Described first pixel 524, second pixel 525, the 3rd pixel 534 are arranged with the 4th pixel 535 one-tenth array.
Fig. 2 shows relation when not touching and touch between pixel output current signal.As can be seen from Figure 2, during touch, pixel output current signal can be larger than the amplitude of pixel output current signal when not touching, also can be less than the amplitude of pixel output current signal when not touching.
As shown in Figure 3, described compensation current generating unit 1 can comprise: storage unit 11, is suitable for storing the background signal that in described touch-screen, all pixels are corresponding; Current output unit 12, is suitable for from described storage unit, searching background signal corresponding to this pixel according to the coordinate of current pixel point, and produces compensating current signal A2 according to the background signal found; Electric charge feed-in impedance 2, is suitable for the negative-phase input described compensating current signal A2 being exported to described prime amplifier.
For each pixel, storage unit 11 stores the coordinate of this pixel, and the background signal of correspondence.That is, can find out background signal corresponding to described pixel according to the coordinate of pixel, described corresponding relation can be realized by mapping table LOOKUPTABLE.Described coordinate can define according to the drive wire at described pixel place and the line of induction.Such as, in Fig. 1, first coordinate at the first pixel 524 place is (4,2), and second coordinate at the second pixel 525 place is (5,2), and the three-dimensional at the 3rd pixel 534 place is (4,3), and the 4-coordinate at the 4th pixel 535 place is (5,3).
Storage unit 11 can store waveform or the integral charge amount of background signal corresponding to all pixels.The waveform of described background signal is the waveform of the pixel output current signal of touch-screen 5 when not being touched.Described waveform can be actual waveform, also can be the compressed format of actual waveform.Concrete compression method is the common practise of those skilled in the art, repeats no more herein.Fig. 4 shows the relation between the compressed format of the actual waveform of the actual waveform of background signal, the integral charge of background signal and background signal.Wherein, the actual waveform of described background signal and the integral charge of compressed format should be equal.
Continue with reference to figure 3, current output unit 12 can search background signal corresponding to this pixel according to the coordinate of current pixel point from the LOOKUPTABLE storage unit 11.Concrete, current output unit 12 determines the coordinate of the pixel of current generation pixel output current signal, coordinate according to this pixel searches background signal corresponding to this pixel from storage unit 11, and produces compensating current signal according to the background signal found.Current output unit 12 can determine the coordinate of the pixel of current generation pixel output current signal according to driving circuit.The scanning sequency of four pixels as described in Fig. 1 that driving circuit is arranged is respectively: the first pixel 524 and the second pixel the 525, three pixel 534 and the 4th pixel 535.After first drive wire 52 receives drive singal, the first pixel 524 is by the negative-phase input output current signal of the first line of induction 54 preamplifier 3; Second pixel 525 is by the negative-phase input output current signal of the second line of induction 55 preamplifier 3.After second drive wire 53 receives drive singal, the 3rd pixel 534 is by the negative-phase input output current signal of the first line of induction 54 preamplifier 3; 4th pixel 535 is by the negative-phase input output current signal of the second line of induction 55 preamplifier 3.When the pixel of the negative-phase input output current of current preamplifier 3 is the first pixel 524, current output unit 12 is the background signal that (4,2) search the first pixel 524 according to the first coordinate.
As shown in Figure 5, described prime amplifier 3 can be charge amplifier 31.When prime amplifier 3 is charge amplifier, electric charge feed-in impedance 2 is realized by electric charge feed-in electric capacity Cref, and feedback impedance 4 is realized by the first electric capacity Cf1.When prime amplifier 3 is charge amplifier, described compensating current signal and background signal are synchronous and phase place is contrary, and the integral charge of described compensating current signal is 0.5-1.5 times of the integral charge of described background signal.
As shown in Figure 6, when supposing to touch, pixel output current signal is larger than the amplitude of pixel output current signal when not touching, and when not touching, the integral charge of pixel output current signal is the integral charge of background signal.Compensation current generating unit 1 can produce the first compensating current signal, described first compensating current signal is a square-wave pulse signal, this square-wave pulse signal and pixel output current signal when not touching are synchronous and phase place is contrary, the integral charge of this square-wave pulse signal is 1-1.5 times of the integral charge of background signal, under this condition, at least part of background signal in pixel output current signal is eliminated, first electric capacity Cf1 can select the electric capacity that capacitance is less, thus obtains larger gain.Compensation current generating unit 1 also can produce the second compensating current signal, described second compensating current signal is the phase place opposite signal of described background signal, both are synchronous and integral charge is identical, under this condition, whole background signals in pixel output current signal are eliminated, first electric capacity Cf1 can select the electric capacity that capacitance is less equally, thus obtains larger gain.
As shown in Figure 7, when supposing to touch, pixel output current signal is less than the amplitude of pixel output current signal when not touching, and when not touching, the integral charge of pixel output current signal is the integral charge of background signal.Compensation current generating unit 1 can produce the first compensating current signal, described first compensating current signal is a square-wave pulse signal, this square-wave pulse signal and pixel output current signal when not touching are synchronous and phase place is contrary, the integral charge of this square-wave pulse signal is 0.5-1 times of the integral charge of background signal, under this condition, at least part of background signal in pixel output current signal is eliminated, first electric capacity Cf1 can select the electric capacity that capacitance is less, thus obtains larger gain.Compensation current generating unit 1 also can produce the second compensating current signal, described second compensating current signal is the phase place opposite signal of described background signal, both are synchronous and integral charge is identical, under this condition, whole background signals in pixel output current signal are eliminated, first electric capacity Cf1 can select the electric capacity that capacitance is less equally, thus obtains larger gain.
Described prime amplifier 3 can also be realized by voltage amplifier or current-voltage converter.When prime amplifier 3 is current amplifier, electric charge feed-in impedance 2 and feedback impedance 4 are realized by resistance, and compensating current signal F2i and background signal F1i are synchronous and phase place is contrary, and satisfied formula below:
Meeting under condition recited above, at least part of background signal in pixel output current signal can be eliminated.
As shown in Figure 8, the embodiment of the present invention two provides a kind of signal transacting and pre-amplification circuit, and described signal transacting and pre-amplification circuit, for touch-screen 5, comprising:
Prime amplifier 3, negative-phase input is suitable for receiving pixel output current signal, and normal phase input end is suitable for receiving reference voltage VF(and is generally earth terminal);
Feedback impedance 4, is suitable for the negative-phase input and the output terminal that connect described prime amplifier 3;
At least one road feedback branch, wherein between each road feedback branch 6 negative-phase input of being all arranged at described prime amplifier 3 and output terminal, each road feedback branch described comprises: the switch 61 of serial connection and branch road feedback impedance 62.
Touch-screen described in embodiment two can be the touch-screen of mutual capacitance induction type.Content about the touch-screen of capacitor induction type with reference to the description of embodiment one, can repeat no more herein.
Switch 61 can be realized by MOS transistor, and MOS transistor conducting and cut-off realize the open and close of switch 61.When switch 61 is opened, the negative-phase input of prime amplifier 3 connects the output terminal of prime amplifier 3 by feedback impedance 4; When switch 61 closes, branch road feedback impedance 62 and feedback impedance 4 parallel connection, the negative-phase input of prime amplifier 3 is connected the output terminal of prime amplifier 3 with feedback impedance 4 by branch road feedback impedance 62 in parallel.Closing and opening and can arrange according to actual needs of described switch 61, such as, arranges, or arranges according to the state of described prime amplifier 3 needed for described touch-screen, if switch 61 closes when prime amplifier 3 is saturated.
This sentences feedback branch and is one and schematically illustrates, but is understandable that, the quantity of described feedback branch can be one, two, three or more.Branch road feedback impedance 62 in feedback branch can be identical, also can be different.As shown in Figure 9, described prime amplifier 3 can be charge amplifier 31, and switch 61 can be the first MOS transistor S1.When prime amplifier 3 is charge amplifier, feedback impedance 4 is realized by the first electric capacity Cf1, and branch road feedback impedance 62 is realized by the second electric capacity Cf2.
During the first MOS transistor S1 cut-off, the negative-phase input of prime amplifier 3 connects the output terminal of prime amplifier 3 by means of only the first electric capacity Cf1, in this situation, charge amplifier 31 and the first electric capacity Cf1 form the first charge amplifier circuit.
During the first MOS transistor S1 conducting, second electric capacity Cf2 and the first electric capacity Cf1 is in parallel, the negative-phase input of prime amplifier 3 is connected the output terminal of prime amplifier 3 with the first electric capacity Cf1 by the second electric capacity Cf2 in parallel, in this situation, charge amplifier 31, first electric capacity Cf1 and the second electric capacity Cf2 forms the second charge amplifier circuit.The integrating capacitor of the second charge amplifier circuit changes compared with the capacitance of the integrating capacitor of the first charge amplifier circuit.Gain and signal to noise ratio (S/N ratio) can be adjusted by the integrating capacitor of change, make it meet actual design.
As shown in Figure 10, the embodiment of the present invention three provides a kind of signal transacting and pre-amplification circuit, described signal transacting and pre-amplification circuit are used for touch-screen 5, comprising: compensation current generating unit 1, prime amplifier 3, feedback impedance 4 and at least one road feedback branch.Between the negative-phase input that each road feedback branch 6 in the feedback branch of described at least one road is all arranged at described prime amplifier 3 and the output terminal of prime amplifier 3; Described in each road, feedback branch 6 comprises: the switch 61 of serial connection and branch road feedback impedance 62.
The specific descriptions of compensation current generating unit 1, prime amplifier 3, feedback impedance 4 and touch-screen 5 can reference example one, and the specific descriptions about feedback branch 6 can reference example two, repeats no more herein.
As shown in figure 11, compensation current generating unit 1 comprises: storage unit 11, is suitable for storing the background signal that in described touch-screen, all pixels are corresponding; Current output unit 12, is suitable for from described storage unit, searching background signal corresponding to this pixel according to the coordinate of current pixel point, and produces compensating current signal according to the background signal found; Electric charge feed-in impedance 2, is suitable for the negative-phase input described compensating current signal being exported to described prime amplifier.Described prime amplifier 3 is charge amplifier 31, and switch 61 is the first MOS transistor S1, and electric charge feed-in impedance 2, feedback impedance 4 and branch road feedback impedance 62 are electric capacity.
When described prime amplifier be voltage amplifier or current-voltage converter time, electric charge feed-in impedance 2, feedback impedance 4 and branch road feedback impedance 62 are resistance.
It should be noted that, in above all embodiments, the output terminal of pre-amplification circuit can also be connected in series a bandpass filter.
Technical solution of the present invention also provides a kind of touch-screen, comprises the signal transacting described in above-described embodiment and pre-amplification circuit.
Optionally, described touch-screen comprises many drive wires and many lines of induction, and described signal transacting and pre-amplification circuit are electrically connected with the described line of induction.Concrete, the negative-phase input of the prime amplifier of signal transacting and pre-amplification circuit is electrically connected with the line of induction by the current output terminal of pixel.
Optionally, described drive wire and the described line of induction are positioned at different layers, and are separated by an insulation course therebetween.Described drive wire and the described line of induction are positioned at same layer.
Optionally, described signal transacting and pre-amplification circuit can be positioned at the substrate at drive wire and line of induction place, also can outside described substrate.
Optionally, all lines of induction can be connected to a described signal transacting and pre-amplification circuit jointly, as shown in figure 12.Wherein, every root line of induction is connected with signal transacting and pre-amplification circuit by a switch 51, and during line of induction output current signal, switch 51 closes.Now, the scan mode of all pixels is: drive wire is lined by line scan, and the line of induction is output current signal by column.
Optionally, a line of induction correspondingly can connect a described signal transacting and pre-amplification circuit, as shown in figure 13.Now, the scan mode of all pixels is: drive wire is lined by line scan, line of induction parallel output current signal.
The above is only the preferred embodiment of the present invention; it should be pointed out that for those skilled in the art, under the premise without departing from the principles of the invention; can also make some improvements and modifications, these improvements and modifications also should be considered as protection scope of the present invention.
Claims (20)
1. signal transacting and a pre-amplification circuit, for touch-screen, is characterized in that, comprising:
Compensation current generating unit, is suitable for exporting compensating current signal, to eliminate at least part of background signal in the pixel output current signal of described touch-screen, and pixel output current signal when described background signal is not for being touched;
Prime amplifier, negative-phase input is suitable for receiving described pixel output current signal and compensating current signal, and normal phase input end is suitable for receiving reference voltage;
Feedback impedance, is suitable for the negative-phase input and the output terminal that connect described prime amplifier;
Wherein, described compensation current generating unit comprises:
Storage unit, is suitable for storing the background signal that in described touch-screen, all pixels are corresponding;
Current output unit, is suitable for from described storage unit, searching background signal corresponding to this pixel according to the coordinate of current pixel point, and produces compensating current signal according to the background signal found;
Electric charge feed-in impedance, is suitable for the negative-phase input described compensating current signal being exported to described prime amplifier.
2. signal transacting as claimed in claim 1 and pre-amplification circuit, it is characterized in that, described current output unit is suitable for from the LOOKUPTABLE storage unit, searching background signal corresponding to this pixel according to the coordinate of current pixel point.
3. signal transacting as claimed in claim 1 and pre-amplification circuit, it is characterized in that, described prime amplifier is charge amplifier, and described electric charge feed-in impedance and feedback impedance are realized by electric capacity;
Or described prime amplifier is voltage amplifier or current-voltage converter, described electric charge feed-in impedance and feedback impedance are realized by resistance.
4. signal transacting as claimed in claim 1 and pre-amplification circuit, is characterized in that, the waveform of the background signal that all pixels of described cell stores are corresponding or integral charge amount.
5. signal transacting as claimed in claim 4 and pre-amplification circuit, is characterized in that, the actual waveform of the background signal that all pixels of described cell stores are corresponding or the compressed format of actual waveform.
6. signal transacting as claimed in claim 1 and pre-amplification circuit, it is characterized in that, described prime amplifier is charge amplifier, described compensating current signal and background signal are synchronous and phase place is contrary, and the integral charge of described compensating current signal is 0.5-1.5 times of the integral charge of described background signal.
7. signal transacting as claimed in claim 1 and pre-amplification circuit, it is characterized in that, described prime amplifier is voltage amplifier or current-to-voltage converter, and described compensating current signal and background signal are synchronous and phase place is contrary, and compensating current signal F2i and background signal F1i is satisfied:
8. signal transacting as claimed in claim 1 and pre-amplification circuit, is characterized in that, also comprise: at least one road feedback branch; Between the negative-phase input that each road feedback branch in the feedback branch of described at least one road is all arranged at described prime amplifier and output terminal;
Described in each road, feedback branch comprises: the switch of serial connection and branch road feedback impedance.
9. signal transacting and a pre-amplification circuit, for touch-screen, is characterized in that, comprising:
Prime amplifier, negative-phase input is suitable for receiving described touch-screen pixel output current signal, and normal phase input end is suitable for receiving reference voltage;
Feedback impedance, is suitable for the negative-phase input and the output terminal that connect described prime amplifier;
At least one road feedback branch, wherein between each road feedback branch negative-phase input of being all arranged at described prime amplifier and output terminal, each road feedback branch described comprises: the switch of serial connection and branch road feedback impedance;
Compensation current generating unit, is suitable for exporting compensating current signal, to eliminate at least part of background signal in described pixel output current signal, and pixel output current signal when described background signal is not for being touched;
The negative-phase input of described prime amplifier is also suitable for receiving described compensating current signal;
Wherein, described compensation current generating unit comprises:
Storage unit, is suitable for storing the background signal that in described touch-screen, all pixels are corresponding;
Current output unit, is suitable for from described storage unit, searching background signal corresponding to this pixel according to the coordinate of current pixel point, and produces compensating current signal according to the background signal found;
Electric charge feed-in impedance, is suitable for the negative-phase input described compensating current signal being exported to described prime amplifier.
10. signal transacting as claimed in claim 9 and pre-amplification circuit, it is characterized in that, described prime amplifier is charge amplifier, and described feedback impedance and branch road feedback impedance are realized by electric capacity;
Or described prime amplifier is voltage amplifier or current-voltage converter, described feedback impedance and branch road feedback impedance are realized by resistance.
11. signal transacting as claimed in claim 9 and pre-amplification circuits, is characterized in that, described current output unit is suitable for from the LOOKUPTABLE storage unit, searching background signal corresponding to this pixel according to the coordinate of current pixel point.
12. signal transacting as claimed in claim 9 and pre-amplification circuits, it is characterized in that, described prime amplifier is charge amplifier, and described electric charge feed-in impedance and feedback impedance are realized by electric capacity;
Or described prime amplifier is voltage amplifier or current-voltage converter, described electric charge feed-in impedance and feedback impedance are realized by resistance.
13. signal transacting as claimed in claim 9 and pre-amplification circuits, it is characterized in that, described prime amplifier is charge amplifier, described compensating current signal and background signal are synchronous and phase place is contrary, and the integral charge of described compensating current signal is 0.5-1.5 times of the integral charge of described background signal.
14. signal transacting as claimed in claim 10 and pre-amplification circuits, it is characterized in that, described prime amplifier is voltage amplifier or current-to-voltage converter, and described compensating current signal and background signal are synchronous and phase place is contrary, and compensating current signal F2i and background signal F1i is satisfied:
15. 1 kinds of touch-screens, is characterized in that, comprise the signal transacting described in any one of claim 1 to 14 and pre-amplification circuit.
16. touch-screens as claimed in claim 15, described touch-screen comprises many drive wires and many lines of induction, and described signal transacting and pre-amplification circuit are electrically connected with the described line of induction.
17. touch-screens as claimed in claim 16, described drive wire and the described line of induction are positioned at different layers, and are separated by an insulation course therebetween.
18. touch-screens as claimed in claim 16, described drive wire and the described line of induction are positioned at same layer.
19. touch-screens as claimed in claim 16, a line of induction correspondence connects a described signal transacting and pre-amplification circuit.
20. touch-screens as claimed in claim 16, all lines of induction are connected to a described signal transacting and pre-amplification circuit jointly.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210385195.7A CN103294297B (en) | 2012-10-11 | 2012-10-11 | Signal transacting and pre-amplification circuit and touch-screen |
| PCT/CN2013/073800 WO2014056313A1 (en) | 2012-10-11 | 2013-04-07 | Signal processing and preamplifier circuit and touch screen |
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| Application Number | Priority Date | Filing Date | Title |
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| CN201210385195.7A CN103294297B (en) | 2012-10-11 | 2012-10-11 | Signal transacting and pre-amplification circuit and touch-screen |
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| CN103294297A CN103294297A (en) | 2013-09-11 |
| CN103294297B true CN103294297B (en) | 2016-04-20 |
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| CN201210385195.7A Active CN103294297B (en) | 2012-10-11 | 2012-10-11 | Signal transacting and pre-amplification circuit and touch-screen |
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| CN105677119A (en) * | 2014-11-18 | 2016-06-15 | 敦泰科技有限公司 | Capacitive touch screen and detection circuit thereof, electronic equipment |
| CN105447439B (en) * | 2015-02-13 | 2017-05-03 | 比亚迪股份有限公司 | Fingerprint detection circuit and electronic device |
| 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 |
| DE102016124555A1 (en) | 2016-12-15 | 2018-06-21 | Nora Systems Gmbh | Flooring and process for its production |
| KR102596607B1 (en) * | 2016-12-20 | 2023-11-01 | 엘지디스플레이 주식회사 | Touch circuit, touch sensing device, and touch sensing method |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1635541A (en) * | 2003-12-26 | 2005-07-06 | 北京汇冠新技术有限公司 | Photoelectric detection positioning system and method for computer touch screen |
| CN101937662A (en) * | 2008-10-30 | 2011-01-05 | 三星电子株式会社 | Touch controller, and display driving circuit and display device and system having the touch controller |
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| KR20110091380A (en) * | 2010-02-05 | 2011-08-11 | 삼성전자주식회사 | Method and apparatus for noise compensation in touch panel |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1635541A (en) * | 2003-12-26 | 2005-07-06 | 北京汇冠新技术有限公司 | Photoelectric detection positioning system and method for computer touch screen |
| CN101937662A (en) * | 2008-10-30 | 2011-01-05 | 三星电子株式会社 | Touch controller, and display driving circuit and display device and system having the touch controller |
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| WO2014056313A1 (en) | 2014-04-17 |
| CN103294297A (en) | 2013-09-11 |
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