CN102999236B - Touch panel sensor integrated circuit, its operational approach and system - Google Patents

Abstract

The invention discloses a kind of touch panel sensor integrated circuit and its operational approach, and including the capacitive touch systems of the touch panel sensor integrated circuit.The touch panel sensor integrated circuit can be according to the level of the first input signal being input into by sense wire, level for example according to noise signal, by performing the demodulation paths process of demodulation operation via the second input signal of sense wire input or processing second input signal by not performing the non-demodulated path of the demodulation operation.

Description

Touch panel sensor integrated circuit, its operational approach and system

Technical field

Self adaptation touch-sensing scheme based on noise measuring is related to according to the embodiment of present inventive concept, more specifically, It is related to for sensing the touch panel sensor integrated circuit of real multiple point touching（IC）, operate this touch panel sensor IC's Method and the system including this touch panel sensor IC.

Background technology

Recently, capacitive touch systems are widely used in such as smart phone and tablet personal computer（PC）Mobile device In, because they are durable in use and light transmittance is high, and there is multiple point touching feature and soft touch feature.

Meanwhile, capacitive touch systems require the multiple performance of touch controller, for example, real multiple point touching detection, Strong noise immunity and low-power consumption.

Recently, in " the A Mobile-Display-Driver IC Embedding a of Hyoung-Rae Kim etc. Capacitive-Touch-Screen Controller System”（ISSCC Dig.Tech.Papers,pp.114-115, 2 months 2010）In describe in the Capacitive touch screen controller built in display driver IC.

Capacitive touch systems can be reduced including the one chip solution of display driver and touch screen controller Manufacturing cost.However, the touch controller only supports single-touch or two virtual touch for using gesture, because the touch Controller is based upon the projection-type electricity of each the independent one-dimensional distribution of offer in the signal of the signal and drives line of sense wire Hold touch-sensing.

Further, since signal to noise ratio（SNR）Low, under strong noise environment, the touch controller is unable to accurate sense touch point.

Therefore, for the research of the touch controller of the strict demand for meeting present capacitive touch systems is necessary 's.

The content of the invention

【Technical problem to be solved】

The technical problem to be solved in the present invention is to provide based on the detection of real multiple point touching, strong noise immunity The touch panel sensor integrated circuit and its operational approach of the mutual capacitance detection with the characteristic such as low-power consumption and including the touch The device of screen sensor IC.

【The means of solve problem】

Touch panel sensor integrated circuit according to an embodiment of the invention（IC）Operational approach include step：In noise During detection operation, judged from the first input signal of capacitive touch screen panel output whether in the range of noise window it Afterwards, a path in demodulation paths and non-demodulated path is selected according to judged result；And, during sensing operation, pass through During the noise measuring is operated, selected path processes the second input letter from capacitive touch screen panel output Number.

In the selection step, the non-solution is selected if first input signal is in the range of the noise window Path is adjusted, and the demodulation paths is selected if first input signal is outside the noise window scope.

In the process step, if selected for the non-demodulated path, then by the non-demodulated path detection institute State the peak value of the second input signal and keep detected peak value, if selected for the demodulation paths, then by described Demodulation paths demodulate second input signal.

The step of second input signal is demodulated by the demodulation paths includes step：Removal is included in described second Noise in input signal；Demodulation removes the second input signal of noise；And remove the second input signal for being included in demodulation In noise.

The operational approach of the touch panel sensor integrated circuit also includes using shifted signal adjusting by selected Path process signal skew.

Touch panel sensor integrated circuit according to an embodiment of the invention, including：Sense respectively and amplify from condenser type Multiple unit senses circuits of the signal of each output in a plurality of sense wire of touch panel.

Each in the plurality of unit senses circuit includes：First selector, which will be in institute in response to selection signal Demodulation paths or non-demodulated path are sent to from the input signal of corresponding sense wire output in stating a plurality of sense wire；Second choosing Device is selected, which exports from the demodulation paths or the non-demodulated path signal for exporting in response to the selection signal；And Noise detector, its noise measuring operation during judge from the sense wire output noise signal whether in noise window scope It is interior, and the selection signal is exported according to judged result, and the selection signal is kept during sensing operation.

The demodulation paths include：First wave filter, its removal are included in the output signal of the first selector Noise signal；Demodulator, the output signal of its demodulation first wave filter；And low pass filter, which is to the demodulator Output signal perform low-pass filtering.

First wave filter is anti-harmonic filter, and the demodulator is square wave demodulator.

The non-demodulated path includes peak detector, the peak value of the output signal of its detection first selector and Keep detected peak value.

The touch panel sensor integrated circuit, also including offset adjusting circuit, which is described in response to shifted signal adjustment The skew of the output signal of second selector.

It is additionally included between the sense wire and the first selector in the touch panel sensor integrated circuit and connects Charge amplifier in the case of, the noise detector the noise measuring operation during judge from the charge amplifier Whether the noise signal of output is in the range of the noise window, and exports the selection signal according to judged result.

System includes according to an embodiment of the invention：The touch panel sensor integrated circuit and can be with the touch screen The console controller communicated by sensor IC.

【The effect of invention】

Touch panel sensor IC can accurately sense real multiple point touching according to an embodiment of the invention, and have Strong noise immunity and the effect of low-power consumption.

Description of the drawings

Figure 1A is shown including touch panel sensor integrated circuit according to an embodiment of the invention（IC）System show Meaning property block diagram；

Figure 1B shows the monolayer capacitive touch screen panel shown in Figure 1A, and the monolayer capacitive touch screen panel has Pedicellus et Pericarpium Trapae Shape pattern；

Fig. 2 shows the schematic block diagram of the touch panel sensor IC shown in Figure 1A；

Fig. 3 shows the schematic block diagram of the drive circuit block shown in Fig. 2；

Fig. 4 shows one embodiment of the oscillogram of the shielding control signal shown in Fig. 3；

Fig. 5 shows the schematic block diagram of the sensor circuit block shown in Fig. 2；

Fig. 6 shows the block diagram of one embodiment of the cell sensor circuit shown in Fig. 5；

Fig. 7 shows the waveform of the input signal of the circuit diagram and the noise detector of the noise detector shown in Fig. 6 Figure；

Fig. 8 shows the input/output signal of the circuit diagram and the peak detector of the peak detector shown in Fig. 6 Oscillogram；

Fig. 9 shows the circuit diagram and the square wave of the square wave demodulator with built-in anti-harmonic filter shown in Fig. 6 The oscillogram of the input/output signal of demodulator；

Figure 10 shows the block diagram of the delay tracker shown in Fig. 6；

Figure 11 is shown for explaining the oscillogram of the input signal of the operation of the delay tracker shown in Figure 10；

Figure 12 is the block diagram of another embodiment of the cell sensor circuit shown in Fig. 5；

Figure 13 shows the circuit diagram of the charge amplifier shown in Figure 12；

Figure 14 shows the oscillogram of the output signal of the sensor circuit block shown in Fig. 2；

Figure 15 is shown for explaining using frequency displacement function according to an embodiment of the invention come the method for adjusting source frequency One embodiment；

Figure 16 is shown for explaining using frequency displacement function according to an embodiment of the invention come the method for adjusting source frequency Another embodiment；

Figure 17 is the method that the cell sensor processing of circuit sensor signal shown in Fig. 6 or Figure 12 is used for explanation Flow chart；And

Figure 18 is the flow chart of the method for the embodiment adjustment source frequency for explanation according to Figure 16 or Figure 17.

Specific embodiment

Figure 1A is shown including touch panel sensor integrated circuit according to an embodiment of the invention（IC）30 system 10 Schematic block diagram.Figure 1B shows the monolayer capacitive touch screen panel shown in Figure 1A, the monolayer capacitive touch screen panel With argyle design.

With reference to Figure 1A, system 10 includes touch panel 20, touch panel sensor IC 30 and console controller（Or application Program processor（AP））40.In figure ia, for the ease of explanation, not separately shown display floater and for driving the display surface The display panel drive IC of plate.

System 10 can be such as mobile phone, smart phone, tablet PC, personal digital assistant（PDA）, portable many matchmakers Body player（PMP）Or the mobile device of MP3 player.

With reference to Figure 1B, touch panel 20 can come real using the monolayer capacitive touch screen panel with argyle design It is existing.The monolayer capacitive touch screen panel includes a plurality of drives line X0 to Xn（Wherein n represents natural number, for example, n=18）And A plurality of sense wire Y0 to Ym（Wherein m represents natural number, for example, m=11）.Drives line X0 to Xn is properly termed as horizontal line, sense wire Y0 to Ym is properly termed as vertical line.

According to embodiment, some in drives line X0 to Xn, for example, the drives line of odd-numbered can be respectively transmitted offer To the drive signal in the left side of touch panel 20, the other drives lines in drives line X0 to Xn, for example, the drive of even-numbered Moving-wire, can be respectively transmitted the drive signal on the right side for being supplied to touch panel 20.However, according to another embodiment, driving Line X0 to Xn can be arranged to the multiple drive signals for being respectively transmitted the left side or right side that are supplied to touch panel 20.

Connect based on the bridging similar to the via process in CMOS technology, drives line X0 to Xn can be with electrically separated from each other, sense Survey line Y0 to Ym can be with electrically separated from each other.In drives line X0 to Xn each in each and sense wire Y0 to Ym between friendship Mutual capacitance node M C is formed at crunode, as shown in Figure 1A and 1B.Therefore, (n+1) * (m+1) can be obtained from touch panel 20 Two dimension mutual capacitance distribution.

When finger or conductive material contacts capacitive touch screen panel 20, the mutual capacitance point of capacitive touch screen panel 20 Cloth changes.Therefore, touch panel sensor IC 30 can accurately find according to the change of mutual capacitance distribution or sense touch Point.

In other words, touch panel sensor IC 30 provides drive signal respectively, processes respectively from sense to drives line X0 to Xn Survey line Y0 to Ym output read output signal and signal corresponding with the result of the process is sent to into console controller 40.

Touch panel sensor IC 30 will be described in detail structurally and operationally referring to figs. 2 to Figure 18.

Fig. 2 shows the schematic block diagram of the touch panel sensor IC shown in Figure 1A.

With reference to Fig. 2, touch panel sensor IC 30 includes power generator 31, drive circuit block 100, sensor circuit block 200th, control logic circuit 300, agitator 301, delay table 400（More properly, the memorizer of storage delay table）, skew occur Device 410, analogue-to-digital converters（ADC）Block 510, digital finite impulse response（FIR）Wave filter 520 and micro controller unit （MCU）530.

Power generator 31 is by using the multiple voltages from outside input（That is, voltage AVDD and VDD）Produce touch screen Electric energy or voltage needed for sensor IC 30.For example, power generator 31 can include for produce each part 100,200, The DC-DC converter of the voltage needed for 410 and 510 work, and for producing the voltage needed for control logic circuit 300 works Low voltage difference（LDO）Manostat.

Drive circuit block 100 can be in response to shielding control signal MSK that exports from control logic circuit 300 and from control Multiple drive signal DRV of the output of logic circuit processed 300, provide drive signal to drives line X0 to Xn respectively, or prevent to drive Dynamic signal enters drives line X0 to Xn.

Fig. 3 shows the schematic block diagram of the drive circuit block 100 shown in Fig. 2, and Fig. 4 shows the shielding control shown in Fig. 3 One embodiment of the oscillogram of signal MSK processed.

Referring to figs. 2 to Fig. 4, the drive circuit block 100 for performing transmitter function includes multiple screened circuit 110_1 to 110_ N and multiple driver 120_1 to 120_n.

Screened circuit 110_1 to 110_n can be in response to shielding control signal MSK, by multiple drive signal DRV0 extremely DRVn is respectively transmitted to driver 120_1 to 120_n, or shielding（Or prevent）Drive signal DRV0 to DRVn enters driver 120_1 to 120_n.

For example, as shown in figure 3, drive signal DRV0 to DRVn can be the square wave that order is produced and do not overlapped each other.Drive Dynamic signal DRV includes drive signal DRV0 to DRVn.

For example, each in screened circuit 110_1 to 110_n can be implemented as AND-gate.Therefore, when shielding control letter Number MSK is logic 1 or second electrical level（Such as high level）When, AND-gate transmits drive signal to driver.When shielding control signal MSK is logical zero or is in the first level（Such as low level）When, AND-gate shielding（Or prevent）Drive signal is sent to the drive Dynamic device.

For example, each in driver 120_1 to 120_n can be implemented as inverter chain.Driver 120_1 to 120_ Each outfan of n can be connected respectively to drives line X0 to Xn.

For example, drive circuit block 100 is in response to being in shielding control signal MSK of second electrical level in sensing operation interval SI Period provides drive signal DRV0 to DRVn to drives line X0 to Xn orders respectively.

On the other hand, drive circuit block 100 is grasped in noise measuring in response to shielding control signal MSK in the first level Drive signal DRV0 to DRVn is prevented to be provided to drives line X0 to Xn during making interval NDI.

As shown in figure 4, each unit interval UI1 and UI2 includes sensing operation interval SI and noise measuring operating range NDI.For example, in the UI1 and UI2 of unit interval, each can be a frame.

During noise measuring operating range NDI, the noise detector 211 shown in Fig. 6 and Figure 12 is in response to shielding control Signal MSK processed（For instance in shielding control signal MSK of the first level）And be activated./ MSK is shielding control signal MSK Anti-phase form.

Therefore, during noise measuring operating range NDI, noise detector 211 can detect the signal of each sense wire The level of level, such as noise signal, and it is corresponding with testing result to first selector 212 and the output of second selector 230 Selection signal SEL.During the SI of sensing operation interval, selection signal SEL can be kept constant.

Fig. 5 shows the schematic block diagram of the sensor circuit block 200 shown in Fig. 2.

With reference to Fig. 5, sensor circuit block 200 includes multiple cell sensor circuits, i.e. the 1st to m cell sensors electricity Road 210_1 to 210_m, its number correspond to the 1st to m sense wire Y0 to Ym number.Perform the 1st to the of receptor function the Delay table 400 and offset generator 410 shown in the shared Fig. 2 of m cell sensor circuits 210_1 to 210_m.

Fig. 6 shows the block diagram of one embodiment of the cell sensor circuit shown in Fig. 5.As multiple units are sensed The structure of each in device circuit 210_1 to 210_m is identical, so will pass to first module below for convenience of description Sensor circuit 210_1A's structurally and operationally illustrates.

With reference to Fig. 6, according to the first module sensor of one embodiment of the first module sensor circuit 210_1 of Fig. 5 Circuit 210_1A include two for process via the first sense wire Y0 input input signal V_INPath, for example, demodulation path Footpath（DP）With peakvalue's checking path（PDP）.PDP is referred to as non-demodulated path.According to embodiment, for processing input signal V_INPath can also be three or more a plurality of.The path can represent path circuit.

First module sensor circuit 210_1A includes noise detector 211, first selector 212, peak detector 214th, anti-harmonic filter 220, square wave demodulator 222, delay tracker 224, low pass filter 226, second selector 230, Subtractor 232 and amplifier 234.

During noise measuring operating range NDI, noise detector 211 is in response in the first level（Such as low level） Shielding control signal MSK or the inverted masks control signal/MSK in second electrical level and be activated.

Above with reference to described in Fig. 3 and Fig. 4, during noise measuring operating range NDI, screened circuit 110_1 to 110-n rings Shielding control signals MSK of the Ying Yu in the first level prevents drive signal DRV0 to DRVn to be sent to driver 120_1 respectively To 120-n.

In response to the inverted masks control signal/MSK in second electrical level, noise detector 211 is detected via the first sense The signal V of survey line Y0 inputs_IN(such as noise signal V_IN) level, and export corresponding to testing result selection signal SEL。

For example, when noise signal V_INLevel in Fig. 7 noise window NW in the range of when, noise detector 211 is exported In selection signal SEL of the first level.Therefore, during the SI of sensing operation interval, as shown in fig. 7, in the first level Selection signal SEL keeps constant, therefore the signal of the first sense wire Y0 is processed by PDP.

On the other hand, when the level of noise signal exceedes noise window NW, the output of noise detector 211 is in second electrical level （For example, high level）Selection signal SEL.Therefore, during the SI of sensing operation interval, as shown in fig. 7, in second electrical level Selection signal SEL keeps constant, therefore the signal of the first sense wire Y0 is processed by DP.Noise detector 211 is according to being detected Noise signal V_INLevel output can control first selector 212 and second selector 230 operation selection signal SEL。

Fig. 7 shows the input signal of the circuit diagram and the noise detector 211 of the noise detector 211 shown in Fig. 6 V_IN（That is, noise signal）Oscillogram.

With reference to Fig. 7, noise detector 211 include first comparator 211_1, second comparator 211_2, OR door 211_3, AND-gate 211_4 and inverter latch device.

Noise signal V that first comparator 211_1 will be input into via the first sense wire Y0_INLevel and the first reference signal The level of VREFT compares.For example, noise signal V_INFirst comparator 211_1 can be input to（+）Input, the first ginseng Examine signal V_REFTFirst comparator 211_1 can be input to（-）Input.

Noise signal V that second comparator 211_2 will be input into via the first sense wire Y0_INLevel and the second reference signal V_REFBLevel compare.For example, noise signal V_INCan be input to the second comparator 211_2's（-）Input, the second reference Signal V_REFBCan be input to the second comparator 211_2's（+）Input.

Can be according to the first reference signal V_REFTLevel and the second reference signal V_REFBThe difference of level determine the noise Window NW.In the figure 7, V_CMIt can be common mode voltage level.Therefore, the first reference signal V_REFTLevel and the second reference signal V_REFBLevel can be with regard to common mode voltage level V_CMSymmetrically.

The output signal of the output signal of 2113 pairs of first comparators 211_1 of OR doors and the second comparator 211_2 is performed and is patrolled Collect or operate.AND-gate 211_4 can to the output signal execution logic of inverted masks control signal/MSK and OR door 211_3 with Operation, and it is corresponding with the result of the AND operation to each output in first selector 212 and second selector 230 Selection signal SEL.

Inverter latch device includes phase inverter 211_5 and 211_6 and latches from AND-gate 211_4 the selection signal for exporting SEL。

During the SI of sensing operation interval, first selector 212 can be according to the choosing latched by the inverter latch device The level of signal SEL is selected, and the signal of the first sense wire Y0 is transmitted via PDP or DP.

First selector 212 can be demultiplexer（DEMUX）.Therefore, the DEMUX can be according in the first level Selection signal SEL to peak detector 214 transmit the first sense wire Y0 signal V_IN.Additionally, DEMUX can be according in the Selection signal SEL of two level transmits the signal V of the first sense wire Y0 to anti-harmonic filter 220_IN。

During the SI of sensing operation interval, as shown in figure 8, peak detector 214 can detect the of first selector 212 Output signal V of one outfan_IN1Peak value V_OUT1, and peak value V can be kept_OUT1。

Fig. 8 shows the input/output of the circuit diagram and the peak detector 214 of the peak detector 214 shown in Fig. 6 The oscillogram of signal.

With reference to Fig. 6 and Fig. 8, peak detector 214 includes comparator 214_1, capacitor C_CMP, current source 214_3, first Switch 214_4, buffer amplifier 214_5 and second switch 214_6.For the ease of explaining, it is assumed that first switch 214_4 and second Switch 214_6 is respectively according to reset signal RST and comparison signal V in second electrical level_CMPAnd connect.First switch 214_4 and Each in second switch 214_6 can be realized using nmos pass transistor.

During the SI of sensing operation interval, comparator 214_1 is by the output signal of the first outfan of first selector 212 V_IN1Level and buffer amplifier 214_5 output signal V_OUT1Level compare, and export with the result of the comparison pair The comparison signal V for answering_CMP。

Current source 214_3 is connected to offer operating voltage AV_DDPower line 214_2 and first switch 214_4 between.When Output signal V of the first outfan of one selector 212_IN1Level higher than buffer amplifier 214_5 output signal V_OUT1's During level, comparison signal V of the comparator 214_1 outputs in second electrical level_CMP。

First switch 214_4 is based on the comparison signal V in second electrical level_CMPAnd connect, and by current source 214_3's Electric current I_REFIt is supplied to capacitor C_CMP.Therefore, capacitor C_CMPAccording to the electric current I for being received_REFIt is electrically charged, therefore buffer amplifier 214_5's（+）The voltage of input increases.

When output signal V of the first outfan of first selector 212_IN1Level it is defeated less than buffer amplifier 214_5 Go out signal V_OUT1Level when, comparator 214_1 output in the first level comparison signal V_CMP.Due to first switch 214_4 According to the comparison signal V in the first level_CMPShut-off, in capacitor C_CMPThe electric charge of middle charging is kept intact.

Second switch 2146 is connected to capacitor C_CMPTwo terminals between, and in response to from control logic circuit 300 Reset signal RST in second electrical level of output is in capacitor C_CMPThe electric charge of middle charging is substantially discharged.With pulse Reset signal RST of shape only need to be produced before sensing operation interval SI starts.

Fig. 9 shows the circuit diagram of the square wave demodulator 222 with built-in anti-harmonic filter shown in Fig. 6 and the party The oscillogram of the input/output signal of ripple demodulator 222.

The anti-harmonic filter 220 of Fig. 6 removes output signal V of the second outfan for being included in first selector 212_IN2 In noise signal, the noise signal being for example included in harmonic band.The square wave demodulator 222 of Fig. 6 demodulates anti-harmonic filter 220 output signal.

The square wave demodulator 222 of Fig. 9 has built-in anti-harmonic filter, and including multiple capacitors（That is capacitor C1 And C2）, multiple resistors（That is, resistor R1, R2 and R3）, multiple operational amplifiers（That is, the first operational amplifier 222_1 and Second operational amplifier 222_2）With selector 222_3.

According to embodiment, capacitor C1 and C2 can be designed with identical electric capacity, and resistor R1, R2 and R3 can set Count into identical or different resistance.

When output signal V of the second outfan via first resistor device R1 incoming first selector 212_IN2When, the first fortune Calculate amplifier 222_1 and produce positive Buffer output voltage V_POS.When second via resistor R2 incoming first selectors 212 it is defeated Go out output signal V at end_IN2When, the second operational amplifier 222_2 produces negative Buffer output voltage V_NEG.Positive Buffer output electricity Pressure V_POSExport delay tracker 224.

In this process, resistor R1 and capacitor C1 perform the function of anti-harmonic filter, and resistor for this pair R2 and capacitor C2 perform the function of anti-harmonic filter for this pair.The cut-off frequency of each anti-harmonic filter can With the resistance according to resistor R1 and the resistance and the electric capacity of capacitor C2 of the product or resistor R2 of the electric capacity of capacitor C1 Product determining.

Second operational amplifier 222_2, resistor R2 and capacitor C2 form negative unit gain feedback or negative unit Gain feedback loop, and the first operational amplifier 222_1, resistor R1 and capacitor C1 form unit gain feedback or unit Gain feedback loop.The unit gain is fed back or unit gain feedback circuit is for prolonging in the first operational amplifier 222_1 And the delay of the second operational amplifier 222_2 between carry out delay matching and be additionally inserted late.

Selector 222_3 is in response to selection signal DM1 that exports from control logic circuit 300, defeated to low pass filter 226 Go out positive Buffer output voltage V_POSOr negative Buffer output voltage V_NEGAs demodulation voltage V_OUT2.Selector 222_3 can make Use multiplexer（MUX）To realize.Selection signal DM1 represents that the selection for being supplied to first module sensor circuit 210_1 is believed Number.Therefore, the DM shown in Fig. 2 represents the group selection for being respectively supplied to the 1st to m cell sensor circuit 210_1 to 210_m Signal.

226 couples of demodulation voltage V from selector 222_3 outputs of low pass filter_OUT2Low-pass filtering is carried out, to remove bag It is contained in demodulation voltage V_OUT2In noise signal.

Low pass filter 226 can use 4 rank Butterworth filters.The 4 rank Butterworth filter can be with Sallen-Key topologys or Sallen-Key structures are used together.

As shown in figure 9, due to touch panel 20 and the first sense wire Y0, input signal V_IN2With unknown propagation phase Postpone.In order that power consumption is minimized, input signal V_IN2Homophase is needed with selection signal DM1.

When input signal V_IN2Phase contrast and selection signal DM1 between is θ, input signal V_IN2It is modeled into Acos (2 π Ft+ θ), when selection signal DM1 is modeled into cos (2 π ft), input signal V_IN2With product such as 1 institute of equation of selection signal DM1 Show.

【Equation 1】

V_OUT2(t)={cosθ+cos(4πft+θ)}A/2

With reference to equation 1, Phase delay be the zero DC signal levels with maximum be θ function.Therefore, input signal V_IN2Phase contrast and selection signal DM1 between needs adjustment.Delay tracker 224 can adjust input signal V_IN2With selection letter The phase place of number DM1 so that input signal V_IN2With selection signal DM1 homophase.

Figure 10 shows the block diagram of the delay tracker 224 shown in Fig. 6, and Figure 11 is shown for explaining prolonging shown in Figure 10 The waveform input signal figure of the operation of slow tracker 224.

It is included in delay trackers 224 of the 1st to the m cell sensor circuit 210_1 to 210_m in each and receives the One drive signal DRV0, positive Buffer output voltage V_POSWith fast clock signal FCLK.Here, it is assumed that the first drive signal DRV0 Phase place it is identical with the phase place of the output signal of the source driving signal realized in control logic circuit 300.

Postpone to be present in the first drive signal DRV0 by the propagation phase that touch panel 20 and the first sense wire Y0 cause With positive Buffer output voltage V_POSBetween.Therefore, delay tracker 224 counts first using fast clock signal FCLK and drives letter Number DRV0 and positive Buffer output voltage V_POSBetween Phase delay D, and export corresponding to the meter to control logic circuit 300 Phase delay information DLI1 of number result.Control logic circuit 300 stores the Phase delay information in delay table 400 DLI1。

According to embodiment, delay tracker 224 produces phase place in real time or when touch panel sensor IC 30 is initialized Delay information DLI1, and by the output of Phase delay information DLI1 to control logic circuit 300.

In other words, it is included in delay tracking of the cell sensor circuit 210_1 to 210_m shown in Fig. 5 in each Device produces Phase delay information DLI1 in real time or when touch panel sensor IC 30 is initialized, and Phase delay is believed Breath DLI1 outputs are to control logic circuit 300.Therefore, control logic circuit 300 will be for cell sensor circuit 210_1 extremely In 210_m, the Phase delay information DLI1 storage of each is in delay table 400.

Control logic circuit 300 prolongs from each phase place of 400 reading unit sensor circuit 210_1 to 210_m of delay table Slow information, and each selection signal corresponding to each Phase delay information for being read is respectively transmitted to into cell sensor The selector 222_3 of each square wave demodulator 222 of circuit 210_1 to 210_m.Selection signal DM of Fig. 2 includes being respectively transmitted To each selection signal of the selector 222_3 of each square wave demodulator 222 of cell sensor circuit 210_1 to 210_m.

Therefore, in cell sensor circuit 210_1 to 210_m, the square wave demodulator 222 of each can receive homophase Input signal V_IN2With selection signal DM.

With reference to Fig. 6, level of the second selector 230 based on selection signal SEL is included in PDP to the transmission of subtractor 232 Peak detector 214 output signal V_OUT1Or the output signal of the low pass filter 226 being included in DP.Subtractor 232 is an example of the offset adjusting circuit of the skew of the output signal that can adjust second selector 230.

Subtractor deducts the voltage V of the first shifted signal OFS1 from the output signal of second selector 230_OFFSET1, and Signal corresponding to subtraction result is sent to into amplifier 234.Subtractor 232 can be had（-）The adder generation of input Replace.

The signal exported from subtractor 232 is amplified with gain A and will be the signal OUT0 for amplifying defeated by amplifier 234 Go out to ADC blocks 510.

With reference to Fig. 2, the overall operation of the control touch panel sensor of control logic circuit 300 IC 30.Control logic circuit 300 operations that can control at least one of multiple parts 31,100,200,301,400,410,510,520 and 530.

Control logic circuit 300 can be produced for the peak of each in control unit sensor circuit 210_1 to 210_m Reset signal RST of the switching manipulation of the second switch 214_6 of value detector 214, and it is used for control unit sensor circuit Each selection signal DM of the operation of the selector 222_3 of the square wave demodulator 222 of each in 210_1 to 210_m.

Control logic circuit 300 can synchronously be worked with vertical synchronizing signal VSYNC from outside input, or can be with Independently work with vertical synchronizing signal VSYNC.

Agitator 301 can provide oscillator signal OSC to control logic circuit 300.Control logic circuit 300 can be used Oscillator signal OSC produces multiple drive signal DRV0 to DRVn（It is referred to as DRV）.

Delay table 400 can be stored for the Phase delay of each in adjustment unit sensor circuit 210_1 to 210_m The Phase delay information of D, as above with reference to described by Figure 10 and Figure 11.The Phase delay information being stored in delay table 400 Can be referred to by control logic circuit 300.Delay table 400 can be stored in the nonvolatile memory or is stored in such as static Random access memory（SRAM）Volatile memory in.

Offset generator 410 can produce the subtraction of each in cell sensor circuit 210_1 to 210_m is supplied to Shifted signal OFS of device.

ADC blocks 510 include multiple ADC, each ADC by multiple cell sensor circuit 210_1 to 210_m each Analog output signal is converted into digital signal.Each ADC can use successive approximation analog to digital C（SAR ADC）To realize.

Digital FIR filter 520 removes the residual noise being included in the digital signal of the output of ADC blocks 510.

After the sensing operation of all sense wire Y0 to Ym terminates, from the Two-Dimensional Moment formation of the output of digital FIR filter 510 Initial data is sent to MCU 530.

MCU 530 extracts X-coordinate and Y-coordinate for true multiple point touching and by X-coordinate and Y from the initial data Coordinate is sent to console controller 40.For example, MCU 530 can pass through internal integrated circuit（I²C）X-coordinate and Y-coordinate are passed It is sent to console controller 40.

Figure 12 shows the block diagram of another embodiment of the cell sensor circuit shown in Fig. 5.

In addition to charge amplifier CA, the shown in first module sensor circuit 210_1A shown in Fig. 6 and Figure 12 One cell sensor circuit 210_1B is substantially the same.

AC current signals with noise current signal are sent to first module sensor circuit by the first sense wire Y0 210_1B.The AC current signals received by the first sense wire Y0 are converted into AC voltage signals by charge amplifier CA.Therefore, electricity Lotus amplifier CA is an example of current-voltage converter.

During noise measuring operating range NDI, noise of the detection of noise detector 211 by the first sense wire Y0 transmission Signal V_INLevel, and produce corresponding to testing result selection signal SEL.Therefore, during the SI of sensing operation interval, base Pass through output signal V that PDP or DP processes charge amplifier CA in the level of selection signal SEL_IN。

Charge amplifier CA includes operational amplifier CA-AMP, the input for being connected to operational amplifier CA-AMP and output Feedback resistor R between end_FB, and be parallel-connected to the feedback condenser CFB of feedback resistor RFB.

Figure 14 shows the oscillogram of the output signal of the sensor circuit block 200 shown in Fig. 2.

Figure 14 shows the waveform of the waveform and demodulation modes of peak detection mode, used in the peak detection mode PDP is the output signal of each the first sense wire Y0 of process in drives line X3 to X18, and used in the demodulation modes, DP is The output signal of each the first sense wire Y0 of process in drives line X3 to X18.

The readout time of peak detection mode is considerably shorter than the readout time of demodulation modes.Further, since narrow-band low pass filter Ripple, the setup time of demodulation modes are longer than the setup time of peak detection mode.

In the region Untouched not touched, mutual capacitance change is observed by the processing variation of touch panel 20.Due to Near the wiring of the first sense wire Y0（routing）The extra mutual capacitance for causing, the mutual capacitance caused by drives line X3 and X4 More than the electric capacity caused by other drives lines X18 to X5.

Each Xi in Figure 14（Wherein i is 3 to 18）Represent the amplification of first module sensing circuit 210_1A or 210_1B The output signal of device 234.In other words, each Xi in Figure 14 is corresponding to the output signal from 234 Sequential output of amplifier OUT0。

Figure 15 is shown for explaining using frequency displacement function according to an embodiment of the invention come the method for adjusting source frequency One embodiment.

In demodulation modes, in order to perform frequency displacement function, drive signal is prevented under the control of control logic circuit 300 DRV0 to DRVn is respectively supplied to drives line X0 to Xn.For example, control of the control logic circuit 300 in response to control frequency displacement function Signal output is in low level shielding control signal MSK.Therefore, each sense in cell sensor circuit 210_1 to 210_m Survey and amplify noise signal present in signal band.

ADC blocks 510 are supplied to from the signal of the output of sensor circuit block 200, and it is defeated from the signal of the output of ADC blocks 510 Go out the noise analyzer 310 to control logic circuit 300.Noise analyzer 310 analyzes the noise present in the signal band Signal is producing the frequency change signal FCS corresponding to analysis result.Frequency source 320 is in response to frequency change signal FCS point Each frequency of analysis drive signal DRV0 to DRVn.

For example, in demodulation modes, if frequency source 320 produces the first drive signal DRV0 with first frequency F1, The first drive signal DRV0 is being prevented to provide to after the first sense wire Y0, noise detector 211 or noise analyzer 310 are from letter Number band detect with noise signal NOISE of first frequency F1 same frequencys (F1), then noise analyzer 310 will be used for changing Become the frequency change signal FCS outputs of first frequency F1 to frequency source 320.

So as to, in demodulation modes, frequency source 320 can produce the first drive signal DRV0 with second frequency F2, And the first drive signal DRV0 with second frequency F2 is supplied to into the first sense wire Y0.Therefore, control logic circuit 300 May determine that and whether there is noise in the signal band.

Figure 16 is shown for explaining using frequency displacement function according to an embodiment of the invention come the method for adjusting source frequency Another embodiment.

In demodulation modes, in order to perform frequency displacement function, drive signal is prevented under the control of control logic circuit 300 DRV0 to DRVn is respectively supplied to drives line X0 to Xn.For example, control of the control logic circuit 300 in response to control frequency domain function Signal output is in low level shielding control signal MSK.Therefore, each cell sensor circuit 210_1 to 210_m read and Amplification is present in the noise signal in signal band.

For example, the noise point from the signal OUT0 outputs of first module sensor circuit output to control logic circuit 300 Parser 310.Noise analyzer 310 analyzes the noise signal present in the signal band to produce the frequency corresponding to analysis result Rate changes signal FCS.

Frequency source 320 analyzes the frequency of the first drive signal DRV0 in response to frequency change signal FCS.

For example, in demodulation modes, if frequency source 320 produces the first drive signal DRV0 with first frequency F1, After preventing the first drive signal DRV0 from being supplied to the first sense wire Y0, by noise detector 211 or 511 from the signal band Detect with noise signal NOISE of first frequency F1 same frequencys (F1), then 310 Analyze noise of noise analyzer detection The output signal of device 511, and frequency will be arrived for the frequency change signal FCS outputs for changing first frequency F1 according to analysis result Source 320.

Therefore, in demodulation modes, frequency source 320 can produce the first drive signal DRV0 with second frequency F2, And the first drive signal DRV0 with second frequency F2 is supplied to into the first sense wire Y0.Therefore, control logic circuit 300 May determine that and whether there is noise in the signal band.

Figure 17 is to use cell sensor circuit 210_1A or 210_B shown in Fig. 6 or Figure 12 to process sensing for explanation The flow chart of the method for device signal.

With reference to Fig. 3, Fig. 4, Fig. 6, Figure 12 and Figure 17, during noise measuring operating range NDI, in the operation s 10, noise Detector 211 detects the signal V of the first sense wire Y0_INLevel or charge amplifier CA output signal V_INLevel, That is, detected noise signal V_INLevel, and export corresponding to testing result selection signal SEL.

In operation S20, based on the level of selection signal SEL, the signal V of the first sense wire Y0 is processed by PDP or DP_IN Or output signal V of charge amplifier CA_IN.In other words, in operation S20, based on being present in making an uproar on the first sense wire Y0 The level of acoustical signal, it is determined that for the signal V of the first sense wire Y0_INOr output signal V of charge amplifier CA_INTransmission path Footpath.

During the SI of sensing operation interval, in operation S30, subtractor 232 is from the signal processed by PDP or passes through DP The signal of process deducts shifted signal.In other words, the inclined of the signal by PDP or by DP process is adjusted by subtractor 232 Move.

Figure 18 is the flow chart of the method for the embodiment adjustment source frequency for explanation according to Figure 16 or Figure 17.

With reference to Fig. 3, Figure 16, Figure 17 and Figure 18, in order to perform frequency displacement function, in operation sl 10, drive signal is prevented DRV0 to DRVn is respectively supplied to drives line X0 to Xn.According to embodiment, can disable every in driver 120_1 to 120_n One.

In operation s 120, select DP.Therefore, only noise signal NOISE (F1) is present in the letter of the first sense wire Y0 Number V_INOr output signal V of charge amplifier CA_IN.In operation S130, ADC block of the noise analyzer 310 in response to Figure 15 The output signal of 510 output signal or the noise detector 511 of Figure 16, detection and analysis are included in the first sense wire Y0's Signal V_INSignal band or charge amplifier CA output signal V_INSignal band in noise signal NOISE (F1).

Noise analyzer 310 exports the frequency change signal FCS corresponding to analysis result.Therefore, in operation S140, frequency Rate source 320 first frequency F1 is changed into into second frequency F2.After frequency displacement function is completed, in operation S150, each Drive signal DRV0 to DRVn with the second frequency exported from frequency source 320 is respectively supplied to drives line X0 to Xn.Now, In operation S150, each in driver 120_1 to 120_n can be enabled.

Touch panel sensor IC can accurately sense real multiple point touching according to an embodiment of the invention, and have Strong noise immunity and the effect of low-power consumption.

Claims (15)

1. a kind of operational approach of touch panel sensor integrated circuit, the method comprising the steps of：

Noise measuring operate during, judged from capacitive touch screen panel output the first input signal whether in noise After in the range of window, a path in demodulation paths and non-demodulated path is selected according to judged result；And

During sensing operation, processed from the capacitance touch by the selected path during the noise measuring is operated Second input signal of panel plate output.

2. the operational approach of touch panel sensor integrated circuit according to claim 1, wherein in the selection step,

The non-demodulated path is selected if first input signal is in the range of the noise window,

The demodulation paths are selected if first input signal is outside the noise window scope.

3. the operational approach of touch panel sensor integrated circuit according to claim 1, wherein in the process step,

If selected for the non-demodulated path, then by the peak value of the second input signal described in the non-demodulated path detection simultaneously And the peak value detected by keeping,

If selected for the demodulation paths, then second input signal is demodulated by the demodulation paths.

4. the operational approach of touch panel sensor integrated circuit according to claim 3, wherein by the demodulation paths The step of demodulating second input signal includes step：

Removal is included in the noise in second input signal；

Demodulation removes the second input signal of noise；And

Removal is included in the noise in the second input signal of demodulation.

5. the operational approach of touch panel sensor integrated circuit according to claim 4, wherein demodulating the removal noise The second input signal the step of include step：

Positive Buffer output voltage is produced from second input signal for removing noise using unit gain feedback circuit, and made Negative Buffer output voltage is produced from second input signal for removing noise with negative unit gain feedback circuit；And

The positive Buffer output voltage or the negative Buffer output voltage are exported as the demodulation in response to selection signal Second input signal.

6. the operational approach of touch panel sensor integrated circuit according to claim 1 also includes step：

The skew of the signal processed by selected path is adjusted using shifted signal.

7. a kind of touch panel sensor integrated circuit, including：

Sense and amplify multiple lists of each signal for exporting from a plurality of sense wire of capacitive touch screen panel respectively First sensing circuit；

Each in wherein the plurality of unit senses circuit includes：

First selector, the input from the output of corresponding sense wire in a plurality of sense wire is believed by which in response to selection signal Number it is sent to demodulation paths or non-demodulated path；

Second selector, which exports from the demodulation paths or the non-demodulated path what is exported in response to the selection signal Signal；And

Noise detector, its noise measuring operation during judge from the sense wire output noise signal whether in noise window In the range of, and the selection signal is exported according to judged result, and the selection signal is kept during sensing operation.

8. touch panel sensor integrated circuit according to claim 7, wherein the demodulation paths include：

First wave filter, its removal are included in the noise signal in the output signal of the first selector；

Demodulator, the output signal of its demodulation first wave filter；And

Low pass filter, its output signal to the demodulator perform low-pass filtering.

9. touch panel sensor integrated circuit according to claim 8, wherein first wave filter is anti-harmonic Device, and the demodulator is square wave demodulator.

10. touch panel sensor integrated circuit according to claim 7, wherein the non-demodulated path includes peakvalue's checking Device, the peak value and the detected peak value of holding of the output signal of its detection first selector.

11. touch panel sensor integrated circuits according to claim 7, also include：

Offset adjusting circuit, which adjusts the skew of the output signal of the second selector in response to shifted signal.

12. touch panel sensor integrated circuits according to claim 7, wherein in the touch panel sensor integrated circuit In the case of being additionally included in the charge amplifier connect between the sense wire and the first selector,

The noise detector is judged during noise measuring operation It is no in the range of the noise window, and the selection signal is exported according to judged result.

A kind of 13. capacitive touch systems, including：

The touch panel sensor integrated circuit of claim 7；And

The console controller communicated with the touch panel sensor integrated circuit.

14. capacitive touch systems according to claim 13, wherein the demodulation paths include：

First wave filter, its removal are included in the noise signal in the output signal of the first selector；

Demodulator, the output signal of its demodulation first wave filter；And

Low pass filter, its output signal to the demodulator perform low-pass filtering.

15. capacitive touch systems according to claim 13, wherein the non-demodulated path includes peak detector, its Detect the peak value of the output signal of the first selector and keep detected peak value.