CN201956996U - Capacitive sensing key - Google Patents
Capacitive sensing key Download PDFInfo
- Publication number
- CN201956996U CN201956996U CN2011200102384U CN201120010238U CN201956996U CN 201956996 U CN201956996 U CN 201956996U CN 2011200102384 U CN2011200102384 U CN 2011200102384U CN 201120010238 U CN201120010238 U CN 201120010238U CN 201956996 U CN201956996 U CN 201956996U
- Authority
- CN
- China
- Prior art keywords
- button
- key
- value
- capacitance
- capacitance touch
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Images
Landscapes
- Electronic Switches (AREA)
Abstract
The utility model relates to a capacitive sensing key, which comprises a capacitive touch key (20) and a microprocessor (21), wherein the capacitive touch key (20) is provided with a sensing electrode (201); the sensing electrode (201) is connected with the microprocessor (21); and the microprocessor (21) is connected with the capacitive touch key (20) through an input/output port (210) to charge and discharge the capacitive touch key (20) repeatedly and detect a touch sensing capacitance (Cf) of the sensing electrode (201) to generate key detecting signals (AD0 and ADf). The capacitive sensing key and a key detecting method thereof adopt a working principle of 'capacitance charge transfer', so that the circuit structure is simplified, the product reliability is improved, the cost is lowered, the sensitivity is high, and the capacitive sensing key is anti-jamming and is applicable to various electronic and electric products.
Description
Technical field
The utility model relates to the contactless electronic button, more specifically, relates to a kind of capacitive induction button.
Background technology
The capacitive induction button is a kind of contactless electronic button commonly used, than traditional mechanical key, and advantage such as have waterproof, life-span length, stable performance, be quick on the draw, thereby be widely used in the middle of the control panel of various electric equipment productss.
The capacitive induction button of prior art adopts the detection of the operation principle realization of " relaxation oscillator " to human finger or felt pen contact induction button as shown in Figure 1.As shown in Figure 1, existing capacitive induction button comprises: capacitance touch button 10, N road multidiameter option switch 11 (N be generally 4,6,8,16 etc.), comparator 12 and timer conter 13; Wherein, capacitance touch button 10 has induction electrode, and corresponding touch sensible capacitor C fn (n=1～N), and outside distribution stray capacitance Con (n=1～N) is arranged; Capacitance touch button 10 is connected to the input of N road multidiameter option switch 11; The output of N road multidiameter option switch 11 is connected to the negative input of comparator 12, and the electrode input end of comparator 12 connects the threshold level (not marking the automatic electric-level setting device among the figure) that is provided with automatically; The output of comparator 12 connects timer conter 13, and connects the negative input of comparator 12 as feedback loop.The operation principle of existing capacitive induction button is: electric capacity in the described capacitance touch button 10 and the comparator 12 common oscillating circuits that constitute a continuous charging and discharge; If human finger or felt pen be the induction electrode of touch sensible capacitance touch button 10 not, then this oscillating circuit keeps discharging and recharging the cycle of a fixed frequency, and its fixing frequency of oscillation is timed 13 count detection of counter.When the induction electrode of human finger or felt pen contact touch sensible capacitance touch button 10, itself and induction electrode form an inductance capacitance Cf1 by medium, the capacity (Cf1 and Co1) that is external capacitive has increased, thereby make the cycle that discharges and recharges of described oscillating circuit elongated, frequency of oscillation changes.Timer conter 13 is measured the variation of frequencies of oscillation, just can detect the touch action of button, reaches the purpose of touch key-press detection.
The shortcoming of existing capacitive induction button is the circuit structure complexity, needs to adopt the induced signal that forms between special-purpose chip detection human finger or felt pen and the induction electrode, and product reliability is lower, the cost height.Thereby, press for a kind of improved capacitance key in the prior art, replace existing " relaxation oscillator " capacitive induction button.
The utility model content
At the above-mentioned defective of existing " relaxation oscillator " capacitive induction button, the utility model provides a kind of improved capacitive induction button, and it adopts the working method of " capacitance charge transfer " to replace traditional " relaxation oscillator ".
Capacitive induction button of the present utility model comprises capacitance touch button (20) and microprocessor (21); Wherein said capacitance touch button (20) has induction electrode (201); Induction electrode (201) connects described microprocessor (21); Microprocessor (21) connects capacitance touch button (20) by input/output end port (210), to described capacitance touch button (20) repeated charge and detect the touch sensible electric capacity (Cf) of described induction electrode (201), generation button detection signal (AD0, ADf).
Wherein, described microprocessor (21) further comprises: capacitance charge carry circuit (211), to parasitic capacitance (Ch) repeated charge and the electric charge transfer of described capacitance touch button (20) and microprocessor (21); Analog to digital converter (212), repeatedly sampling obtain that electric charge shifts back capacitance touch button (20) some to input signal values (ADl, ADh); Digital signal processing module (213), keep analog to digital converter (212) to change described some that the back is obtained to sampling repeatedly to input signal values (ADl, ADh) deposit, difference comparison operation, digital filtering and dual threshold relatively, obtain the button detection signal (AD0, ADf).
Further preferably, wherein, described charge transfer circuit (211) comprises that first discharges and recharges terminal (RA0), first control switch (K1), and second discharges and recharges terminal (RA1), second control switch (K2) and charge transfer switch (K0); Wherein first discharge and recharge terminal (RA0) by described first control switch (K1) connection described capacitance touch button (20); Second discharges and recharges terminal (RA1) connects microprocessor by second control switch (K2) parasitic capacitance (Ch); Charge transfer switch (K0) connects described capacitance touch button (20) and described parasitic capacitance (Ch) and controls the electric charge transfer of the two.
Further preferably, wherein, described digital signal processing module (213) comprises register (2131), deposit through sampling repeatedly keep the described input signal values of analog to digital converter (212) conversion back acquisition (ADl, ADh); Differential ratio is than computing module (2132), to sampling repeatedly keep that analog to digital converter (212) conversion back obtains some (ADl ADh) carries out the difference comparison operation and obtains several differential signals (ADn) to described input signal values; Digital filtering and button judge module (2133), to described several differential signals (ADn) carry out digital filtering and dual threshold relatively obtain described button detection signal (AD0, ADf).
Further preferably, wherein, (ADh ADl) carries out the difference comparison operation and obtains several differential signals (ADn) described differential ratio to the input signal after analog to digital converter (212) conversion to some than computing module (2132).
Still more preferably, described digital filtering and button judge module (2133) comprise first order digital filter (2133a), second level digital filter (2133b), third level digital filter (2133c), induced key fiducial value computing module (2133d) and button judge module (2133e), wherein:
First order digital filter (2133a) goes maximum, minimum value and mean value computing to interior at interval several differential signals (ADn) of the very first time, obtains first order digital filtering value;
Second level digital filter (2133b) goes maximum, minimum value and mean value computing to a plurality of first order digital filtering values that obtain in second time interval, obtains second level digital filtering value;
A plurality of second level digital filtering value the average value computing of third level digital filter (2133c) to obtaining in the 3rd time interval obtains third level digital filtering value, as key induced signal value (AD
KEY);
Induced key fiducial value computing module (2133d) calculates the induced key fiducial value (AD of capacitance touch button (20) when not being pressed
Ben);
The more described key induced signal value (AD of button judge module (2133e)
KEY) and induced key fiducial value (AD
Ben), judge whether described capacitance touch button (20) is pressed, generate button detection signal (AD0, ADf).
In sum, capacitive induction button of the present utility model and key detecting method thereof have adopted the operation principle of " capacitance charge transfer ", compare with traditional " relaxation oscillator " capacitive induction button, abandon special-purpose induced signal detection chip, simplified circuit structure greatly, increased product reliability, reduced product cost, button is highly sensitive, and antijamming capability is strong, can be widely used in various electric equipment productss.
Description of drawings
Fig. 1 is the structural representation of the capacitive induction button of prior art;
Fig. 2 is the structural representation of the capacitive induction button of the utility model embodiment;
Fig. 3 is the structural representation of the digital signal processing module of the utility model embodiment;
Fig. 4 is the digital filtering of the utility model embodiment and the structural representation of button judge module.
Embodiment
By describing technology contents of the present utility model, structural feature in detail, realized purpose and effect, give explanation below in conjunction with embodiment and conjunction with figs. are detailed.
Fig. 2 is the structural representation of the capacitive induction button of the utility model embodiment.Capacitive induction button of the present utility model adopts " capacitance charge transfer " working method, directly linked to each other with induction electrode 201 in the capacitance touch button 20 by microprocessor 21 (CPU), described microprocessor 21 has I/O (I/O) port of analog to digital converter 212 (A/D) function.The touch sensible capacitor C f that is produced when microprocessor CPU human body finger or felt pen contact induction electrode, thus the button detection signal of expression actuation of keys produced.Owing to have outside distribution stray capacitance Co at the capacitance touch button, and microprocessor chip inside has parasitic capacitance Ch, the touch sensible capacitor C f that is produced when human finger or felt pen contact induction electrode and outside distribution stray capacitance Co and parasitic capacitance Ch differ little, in order to eliminate Ch and Co influence to detecting, microprocessor adopts difference A/D comparison operation method to come senses touch inductance capacitance Cf, thereby reaches the purpose of detecting actuation of keys.
As shown in Figure 2, capacitive induction button of the present utility model comprises capacitance touch button 20 and microprocessor 21; Wherein said capacitance touch button 20 has induction electrode 201; Induction electrode 201 connects described microprocessor 21.When human finger or felt pen contacted with induction electrode 201, the two formed described touch sensible capacitor C f by medium; If human finger or felt pen do not contact with induction electrode 201, then be equivalent to touch sensible capacitor C f=0.Capacitance touch button 20 also has outside distribution stray capacitance Co.As Fig. 2, microprocessor 21 connects capacitance touch button 20 by its input/output end port 210.Microprocessor 21 charges repeatedly, discharges by 210 pairs of described capacitance touch buttons 20 of its input/output end port, and detects the touch sensible capacitor C f of described induction electrode 201, according to variation generation button detection signal AD0 or the ADf of touch sensible capacitor C f.
Wherein, the structure of described microprocessor 21 further comprises: capacitance charge carry circuit 211, and analog to digital converter 212 and digital signal processing module 213, and the chip internal of microprocessor 21 also has parasitic capacitance Ch.
Capacitance charge carry circuit 211 is connected to outside described capacitance touch button 20 by input/output end port 210, and control to the parasitic capacitance Ch of described capacitance touch button 20 and microprocessor 21 charge repeatedly, discharge and electric charge shift.Particularly, described charge transfer circuit 211 comprises that first discharges and recharges terminal RA0, the first control switch K1, and second discharges and recharges terminal RA1, the second control switch K2 and charge transfer switch K0; Wherein first discharge and recharge terminal RA0 and connect described capacitance touch button 20 by the described first control switch K1; Second discharges and recharges terminal RA1 connects microprocessor by the second control switch K2 parasitic capacitance Ch; Charge transfer switch K0 connects touch sensible capacitor C f and the outside distribution stray capacitance Co and the described parasitic capacitance Ch of described capacitance touch button 20, and the electric charge of controlling the two shifts, thereby makes touch sensible capacitor C f and outside distribution stray capacitance Co and described parasitic capacitance Ch reach charge balance.
Analog to digital converter 212 is sampled repeatedly, maintenance, analog-to-digital conversion (A/D conversion), obtaining the transfer of process electric charge reaches after the charge balance, capacitance touch button 20 some to input signal values ADl and ADh also are the input signal values on touch sensible capacitor C f and the outside distribution stray capacitance Co.
Digital signal processing module 213, to sampling repeatedly keep that analog to digital converter (212) conversion back obtains described some to input signal values ADl and ADh deposit, difference comparison operation, digital filtering and dual threshold relatively, obtain button detection signal AD0 or ADf.
Describe the key detecting method of above-mentioned capacitive induction button of the present utility model below in detail:
When operate as normal, the charge transfer switch K0 in the charge transfer circuit 211 disconnects, the first control switch K1 and the second control switch K2 closure; First level that discharges and recharges terminal RA0 is changed to " 0 ", makes touch sensible capacitor C f and outside distribution stray capacitance Co discharge; Second level that discharges and recharges terminal RA1 is changed to " 1 ", makes parasitic capacitance Ch charging.Then, the first control switch K1 and the second control switch K2 disconnect, charge transfer switch K0 closure, parasitic capacitance Ch is charged to touch sensible capacitor C f and outside distribution stray capacitance Co, behind three's charge balance, analog to digital converter 212 is sampled, maintenance, A/D conversion, obtains the first input signal values ADh on touch sensible capacitor C f and the outside distribution stray capacitance Co.
Afterwards, the charge transfer switch K0 in the charge transfer circuit 211 disconnects, the first control switch K1 and the second control switch K2 closure; First level that discharges and recharges terminal RA0 is changed to " 1 ", makes touch sensible capacitor C f and outside distribution stray capacitance Co charging; Second level that discharges and recharges terminal RA1 is changed to " 0 ", makes parasitic capacitance Ch discharge.Then, the first control switch K1 and the second control switch K2 disconnect, charge transfer switch K0 closure, touch sensible capacitor C f and outside distribution stray capacitance Co are charged to parasitic capacitance Ch, behind three's charge balance, analog to digital converter 212 is sampled once more, maintenance, A/D conversion, obtains the second input signal values ADl on touch sensible capacitor C f and the outside distribution stray capacitance Co.
Carry out the process of above-mentioned charging, discharge and charge balance repeatedly, and analog to digital converter 212 is with fixing sampling holding frequency, sample repeatedly, maintenance, A/D conversion, obtain the transfer of process electric charge and reach charge balance input signal values afterwards, thereby in very first time interval, obtain some first and second input signal values ADl and the ADh.For example, at present embodiment, analog to digital converter 212 carries out 12 samplings in every 10ms, promptly gather 6 ADl and 6 ADh respectively, thereby obtains 6 couples of ADl and ADh in every 10ms, is expressed as ADln and ADhn (n=1～6).
The structure of digital signal processing module 213 comprises register 2131 as shown in Figure 3, and differential ratio is than computing module 2132 and digital filtering and button judge module 2133.Register 2131 deposit through sample repeatedly, maintenance, A/D conversion, the described input signal values ADh and the ADl that are obtained; Differential ratio is somely carried out the difference comparison operation to the first and second input signal values ADh and ADl than what computing module obtained more than 2132 pairs after over-sampling keeps analog to digital converter (212) conversion, obtain several differential signals ADn.In the present embodiment, differential ratio carries out the difference comparison operation respectively than 2132 couples of 6 couples of ADl of computing module and ADh in every 10ms, i.e. ADn=ADhn-ADln (n=1～6), thus in every 10ms, obtain 6 ADn values.Digital filtering and button judge module 2133, again to through sample repeatedly, maintenance, A/D conversion, several differential signals ADn that is obtained carries out digital filtering and dual threshold comparison process, filtering common mode, differential mode interference, and obtain final button detection signal AD0 or ADf.
Fig. 4 shows in detail the structure of digital filtering and button judge module 2133.Described digital filtering and button judge module 2133 comprise first order digital filter 2133a, second level digital filter 2133b, third level digital filter 2133c, induced key fiducial value computing module 2133d and button judge module 2133e.Specifically introduce described digital filtering and dual threshold below in conjunction with Fig. 4 and relatively wait the step of handling.
First order digital filter 2133a goes maximum, minimum value and mean value computing to interior at interval several differential signals ADn of the very first time, obtains first order digital filtering value.As indicated above, differential ratio is than 6 ADn values of computing module 2132 outputs in every 10ms.First order digital filter 2133a carries out first order digital filtering, removes maximum ADnmax and the minimum value ADnmin of 6 ADn in worthwhile, gets remaining 4 ADn value and averages, and the first order digital filtering value as in this 10ms is designated as AD
10ms, thereby just export a first order digital filtering value every 10ms first order digital filter 2133a.
Second level digital filter 2133b goes maximum, minimum value and mean value computing to a plurality of first order digital filtering values that obtain in second time interval, obtains second level digital filtering value.As indicated above, will export under the situation of a first order digital filtering value every 10ms first order digital filter 2133a, obtain 4 first order digital filtering values every 40ms second level digital filter 2133b, be designated as AD
10msN(N=1-4).Above 4 first order digital filtering values are removed wherein maximum AD
10msmaxWith minimum value AD
10msmin, all the other 2 first order digital filtering values are averaged, the second level digital filtering value as in this 40ms is designated as AD
40ms, promptly obtain a second level digital filtering value every 40ms.
A plurality of second level digital filtering value the average value computing of third level digital filter 2133c to obtaining in the 3rd time interval obtains third level digital filtering value, and this filter value is promptly as key induced signal value ADKEY.As indicated above, obtain a second level digital filtering value every 40ms, then every 120ms obtains 3 second level digital filtering values, is designated as AD
40msN(N=1-3).To 3 second level digital filtering value value of averaging computings, mean value is to export as third level digital filtering value.This filter value is also as key induced signal value AD
KEY
In order to realize to key induced signal value AD
KEYDynamic tracking, can adopt the method for sliding window dynamic tracking.As indicated above, every 10ms carries out 12 secondary data collections, and utilizes the data of gathering in the 120ms can calculate an AD
KEYBy sliding window dynamic tracking method, every 10ms, the data of gathering among first 10ms are removed, the data that the data of gathering among the next 10ms are gathered as a 10ms again, the rest may be inferred rearranges the data of gathering before, and the data that nearest 10ms is gathered enter as the data of gathering in last 10ms, recomputate AD
KEYCarry out dynamic tracking like this, guaranteed the reliability, real-time and the accuracy that detect, farthest avoid and reduced and disturbed the influence that key induced signal value is detected.
Induced key fiducial value AD when induced key fiducial value computing module 2133d calculating capacitance touch button 20 is not pressed
Ben, with induced key fiducial value AD
BenAs the benchmark of judging whether capacitance touch button 20 is pressed.Concrete computational methods are: when electrification reset, also be capacitance touch button 20 when not being pressed, gather 16 second level digital filtering values, be designated as AD
40msN(N=1-16).The mean value that calculates these 16 second level digital filtering values is as initial baseline value AD
640ms0Determining initial baseline value AD
640ms0Afterwards, promptly along with the increase of running time, every 40ms, with the second level digital filtering value of up-to-date acquisition as AD
40msnew, be calculated as follows AD
Ben:
AD
ben＝(AD
40ms1+AD
40ms2+AD
40ms3+......AD
40msN+AD
40msnew-AD
640ms0)/16(N＝1～16)
Wherein, to AD
BenCalculating also utilize the method for sliding window dynamic tracking to follow the tracks of; Promptly every 40ms, the second level digital filtering value of first 40ms is removed, the data that the second level digital filtering value of next 40ms is gathered as a 40ms again, the rest may be inferred rearranges the data of gathering before, and the data that nearest 40ms is gathered enter as last second level digital filtering value, recomputate AD
BenPass through dynamic tracking, induced key fiducial value computation's reliability, accuracy and real-time have also been guaranteed, at utmost avoided disturbing the influence that the induced key fiducial value is calculated, also can eliminate simultaneously because after long-time the use, factors such as the surface dirt accumulation of capacitance touch button 20 and the variation of circuit stray capacitance value are to the influence of induced key sensitivity.
The more described key induced signal value AD of button judge module 2133e
KEYWith induced key fiducial value AD
Ben, judge whether described capacitance touch button 20 is pressed, thereby generate button detection signal AD0 or ADf.Described key induced signal value AD
KEYThe capacitance that has reflected capacitance touch button 20.Wherein, if human finger or felt pen contact induction electrode not, promptly Cf is 0, and Co remains unchanged, and the key induced signal value that obtain this moment is designated as AD
KEY0, AD at this moment
KEY0With induced key fiducial value AD
BenBe more or less the same.If human finger or felt pen contact induction electrode 201 generate touch sensible capacitor C f, will change the value of (Cf+Co), the key induced signal value that generate this moment is designated as AD
KEYf, meeting and induced key fiducial value AD
BenBigger difference is arranged.Thereby, by more key induced signal value AD
KEYWith induced key fiducial value AD
BenCan reach the purpose of detecting actuation of keys.
Button judge module 2133e is to key induced signal value AD
KEYWith induced key fiducial value AD
BenCarry out dual threshold relatively, specifically comprise:
If continuous 8 key induced signal value AD
KEYThan induced key fiducial value AD
BenMore than 1 A/D conversion unit value, judge that then capacitance touch button 20 do not press, button judge module 2133e generates button detection signal AD0;
If continuous 8 key induced signal value AD
KEYThan induced key fiducial value AD
BenMore than 5 A/D conversion unit values, judge that then capacitance touch button 20 presses, button judge module 2133e generates button detection signal Adf;
After capacitance touch button 20 is pressed, if continuous 8 key induced signal value AD
KEYThan induced key fiducial value AD
BenLess than 3 A/D conversion units of less than value, judge that then capacitance touch button 20 has discharged, button judge module 2133e regenerates button detection signal AD0.
In sum, capacitive induction button of the present utility model and key detecting method thereof have utilized
The operation principle of " capacitance charge transfer ", circuit structure is simple, good reliability, filtering interfering has reached the purpose of detecting button, can be widely used in various electric equipment productss.
The above only is embodiment of the present utility model; be not so limit claim of the present utility model; every equivalent structure or equivalent flow process conversion that utilizes the utility model specification and accompanying drawing content to be done; or directly or indirectly be used in other relevant technical fields, all in like manner be included in the scope of patent protection of the present utility model.
Claims (6)
1. a capacitive induction button is characterized in that, comprises capacitance touch button (20) and microprocessor (21); Wherein said capacitance touch button (20) has induction electrode (201); Induction electrode (201) connects described microprocessor (21); Microprocessor (21) connects capacitance touch button (20) by input/output end port (210), to described capacitance touch button (20) repeated charge and detect the touch sensible electric capacity (Cf) of described induction electrode (201), generation button detection signal (AD0, ADf).
2. capacitive induction button according to claim 1, it is characterized in that, described microprocessor (21) further comprises: capacitance charge carry circuit (211), to parasitic capacitance (Ch) repeated charge and the electric charge transfer of described capacitance touch button (20) and microprocessor (21); Analog to digital converter (212), repeatedly sampling obtain that electric charge shifts back capacitance touch button (20) some to input signal values (ADl, ADh); Digital signal processing module (213), keep analog to digital converter (21) to change described some that the back is obtained to sampling repeatedly to input signal values (ADl, ADh) deposit, difference comparison operation, digital filtering and dual threshold relatively, obtain the button detection signal (AD0, ADf).
3. capacitive induction button according to claim 2, it is characterized in that: described charge transfer circuit (211) comprises that first discharges and recharges terminal (RA0), first control switch (K1), second discharges and recharges terminal (RA1), second control switch (K2) and charge transfer switch (K0); Wherein first discharge and recharge terminal (RA0) by described first control switch (K1) connection described capacitance touch button (20); Second discharges and recharges terminal (RA1) connects microprocessor by second control switch (K2) parasitic capacitance (Ch); Charge transfer switch (K0) connects described capacitance touch button (20) and described parasitic capacitance (Ch) and controls the electric charge transfer of the two.
4. capacitive induction button according to claim 2, it is characterized in that, described digital signal processing module (213) comprises register (2131), deposit the described input signal values that keeps being obtained after analog to digital converter (212) conversion through sampling repeatedly (ADl, ADh); Differential ratio is than computing module (2132), and keep back obtained some of analog to digital converter (212) conversion (ADl ADh) carries out the difference comparison operation and obtains several differential signals (ADn) to described input signal values to sampling repeatedly; Digital filtering and button judge module (2133), to described several differential signals (ADn) carry out digital filtering and dual threshold relatively obtain described button detection signal (AD0, ADf).
5. capacitive induction button according to claim 4, it is characterized in that, (ADh ADl) carries out the difference comparison operation and obtains several differential signals (ADn) described differential ratio to the input signal after analog to digital converter (212) conversion to some than computing module (2132).
6. capacitive induction button according to claim 4, it is characterized in that, described digital filtering and button judge module (2133) comprise first order digital filter (2133a), second level digital filter (2133b), third level digital filter (2133c), induced key fiducial value computing module (2133d) and button judge module (2133e), wherein:
First order digital filter (2133a) goes maximum, minimum value and mean value computing to interior at interval several differential signals (ADn) of the very first time, obtains first order digital filtering value;
Second level digital filter (2133b) goes maximum, minimum value and mean value computing to a plurality of first order digital filtering values that obtain in second time interval, obtains second level digital filtering value;
A plurality of second level digital filtering value the average value computing of third level digital filter (2133c) to obtaining in the 3rd time interval obtains third level digital filtering value, as key induced signal value (AD
KEY);
Induced key fiducial value computing module (2133d) calculates the induced key fiducial value (AD of capacitance touch button (20) when not being pressed
Ben);
The more described key induced signal value (AD of button judge module (2133e)
KEY) and induced key fiducial value (AD
Ben), judge whether described capacitance touch button (20) is pressed, generate button detection signal (AD0, ADf).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011200102384U CN201956996U (en) | 2011-01-14 | 2011-01-14 | Capacitive sensing key |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011200102384U CN201956996U (en) | 2011-01-14 | 2011-01-14 | Capacitive sensing key |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN201956996U true CN201956996U (en) | 2011-08-31 |
Family
ID=44501097
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2011200102384U Expired - Lifetime CN201956996U (en) | 2011-01-14 | 2011-01-14 | Capacitive sensing key |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN201956996U (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102497191A (en) * | 2011-12-27 | 2012-06-13 | 深圳Tcl新技术有限公司 | Key protection circuit and realization method thereof |
| CN102594327A (en) * | 2011-01-14 | 2012-07-18 | 苏州路之遥科技股份有限公司 | Capacitive sensing key and key detection method |
| CN103049154A (en) * | 2012-11-21 | 2013-04-17 | 温州长江汽车电子有限公司 | Touch signal acquisition method for capacitive touch switch |
| CN110224695A (en) * | 2019-05-22 | 2019-09-10 | 长沙景美集成电路设计有限公司 | A kind of hardware waterproof capacitance touch button circuit |
| CN111813277A (en) * | 2020-07-10 | 2020-10-23 | 温州长江汽车电子有限公司 | Double-layer pressure touch signal acquisition method of capacitive touch switch |
| CN114285398A (en) * | 2022-03-04 | 2022-04-05 | 南京沁恒微电子股份有限公司 | Capacitive charging type touch key detection circuit and detection method |
-
2011
- 2011-01-14 CN CN2011200102384U patent/CN201956996U/en not_active Expired - Lifetime
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102594327A (en) * | 2011-01-14 | 2012-07-18 | 苏州路之遥科技股份有限公司 | Capacitive sensing key and key detection method |
| CN102594327B (en) * | 2011-01-14 | 2015-04-15 | 苏州路之遥科技股份有限公司 | Capacitive sensing key and key detection method |
| CN102497191A (en) * | 2011-12-27 | 2012-06-13 | 深圳Tcl新技术有限公司 | Key protection circuit and realization method thereof |
| CN102497191B (en) * | 2011-12-27 | 2015-09-30 | 深圳Tcl新技术有限公司 | A kind of key protection circuit and its implementation |
| CN103049154A (en) * | 2012-11-21 | 2013-04-17 | 温州长江汽车电子有限公司 | Touch signal acquisition method for capacitive touch switch |
| CN110224695A (en) * | 2019-05-22 | 2019-09-10 | 长沙景美集成电路设计有限公司 | A kind of hardware waterproof capacitance touch button circuit |
| CN111813277A (en) * | 2020-07-10 | 2020-10-23 | 温州长江汽车电子有限公司 | Double-layer pressure touch signal acquisition method of capacitive touch switch |
| CN114285398A (en) * | 2022-03-04 | 2022-04-05 | 南京沁恒微电子股份有限公司 | Capacitive charging type touch key detection circuit and detection method |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102594327B (en) | Capacitive sensing key and key detection method | |
| CN201956996U (en) | Capacitive sensing key | |
| CN102667690B (en) | Methods and apparatus for performing capacitive touch sensing and proximity detection | |
| US9268441B2 (en) | Active integrator for a capacitive sense array | |
| CN101419522B (en) | Capacitance touch detection device and detection method thereof | |
| CN203117298U (en) | Capacitance detection circuit | |
| CN109245754A (en) | A kind of capacitance touch button circuit for detecting and method | |
| CN101685364B (en) | Device and method for sensing touch panel | |
| CN102193032A (en) | Self-capacitance change measuring circuit with high precision and high stability | |
| CN201523371U (en) | Human body touch key control circuit | |
| CN102749525B (en) | Capacitor detection method and capacitor detection circuit | |
| CN201594117U (en) | Capacitance detection device | |
| CN105700757A (en) | fingerprint sensing device and finger touch detection method thereof | |
| CN102346607B (en) | Touch control sensing circuit and method | |
| CN103823598A (en) | Touch sensing circuit and touch sensing method | |
| CN201302712Y (en) | Capacity type touch detector | |
| CN114487784A (en) | Capacitance detection circuit, touch chip and electronic equipment | |
| CN110224695A (en) | A kind of hardware waterproof capacitance touch button circuit | |
| CN203535119U (en) | Capacitance detection circuit | |
| CN202033322U (en) | High-precision digital and intelligent cotton moisture detector | |
| CN112161673B (en) | Accurate capacitive liquid level detection circuit and adjustment mode | |
| CN207321225U (en) | A kind of double RC touch key-press circuits | |
| CN217085101U (en) | Capacitance detection circuit, touch control chip and electronic equipment | |
| CN116203411A (en) | Touch key capacitance detection method and system applied to MCU | |
| CN103049154A (en) | Touch signal acquisition method for capacitive touch switch |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| AV01 | Patent right actively abandoned |
Granted publication date: 20110831 Effective date of abandoning: 20150415 |
|
| RGAV | Abandon patent right to avoid regrant |