CN108139840A - The device of capacitance detecting - Google Patents

The device of capacitance detecting Download PDF

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Publication number
CN108139840A
CN108139840A CN201680000579.9A CN201680000579A CN108139840A CN 108139840 A CN108139840 A CN 108139840A CN 201680000579 A CN201680000579 A CN 201680000579A CN 108139840 A CN108139840 A CN 108139840A
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China
Prior art keywords
capacitor
switch
phase inverter
circuit
control
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CN201680000579.9A
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Chinese (zh)
Inventor
吕凤铭
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Shenzhen Goodix Technology Co Ltd
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Shenzhen Goodix Technology Co Ltd
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Publication of CN108139840A publication Critical patent/CN108139840A/en
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    • HELECTRICITY
    • H03ELECTRONIC CIRCUITRY
    • H03KPULSE TECHNIQUE
    • H03K17/00Electronic switching or gating, i.e. not by contact-making and –breaking
    • H03K17/94Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the way in which the control signals are generated
    • H03K17/96Touch switches

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Abstract

The invention discloses a kind of devices of capacitance detecting, can reduce power consumption.The device includes:First oscillating circuit (110), for generating the first oscillator signal of preset frequency;Second oscillating circuit (120), including the first capacitance (121), for generating the second oscillator signal, the frequency of the second oscillator signal changes second oscillating circuit (120) according to the variation of the capacitance of the first capacitance (121);Control module (130), for generating switch control signal according to the first oscillator signal and the second oscillator signal, switch control signal is used to control the connection and disconnection of charge circuit (140);Charge circuit (140), including the second capacitance (141), for charging under connected state to the second capacitance (141);Output module (150), for by the voltage output on the second capacitance (141) to processing module (160);Processing module (160), the variable quantity of the voltage for being exported according to output module (150) determine whether the capacitance of the first capacitance (121) changes.

Description

The device of capacitance detecting Technical field
The present invention relates to information technology fields, and more particularly, to a kind of device of capacitance detecting.
Background technique
Pursuit with consumer to appearance with the development of science and technology, on more and more household electrical appliances, consumer electronics product, manufacturer gradually uses capacitance type touch control keys instead of traditional mechanical key.The basic principle of capacitance type touch control keys is an electrode the conductive material of key area as capacitor, and assign being used as the finger face touched as another electrode of capacitor, and the changing for capacitance by detecting this capacitor detects the touching signals of finger.
Currently, the scheme for detecting inductance capacitance mainly has two kinds of induction modes of Approach by inchmeal (CapSense Successive Approximation, CSA) and capacitance modulation (CapSense Sigma-Delta, CSD).A kind of scheme of CSA is to determine whether key is in touch-control state by the variation for reaching the time of threshold voltage;The scheme always of CSD is to determine whether key is in touch-control state by the variation of the ratio of high level state and low level state.The structure of current detection device is more complex, and power consumption is higher.
Summary of the invention
The embodiment of the invention provides a kind of devices of capacitance detecting, can reduce power consumption.
In a first aspect, providing a kind of device of capacitance detecting, comprising:
First oscillating circuit 110, for generating the first oscillator signal of preset frequency;
The capacitance of second oscillating circuit 120, including first capacitor 121, first capacitor 121 is variable, and the second oscillating circuit 120 changes for generating the second oscillator signal, the frequency of the second oscillator signal according to the variation of the capacitance of first capacitor 121;
Control module 130, for generating switch control signal according to the first oscillator signal and the second oscillator signal, switch control signal is used to control the connection and disconnection of charge circuit 140;
Charge circuit 140, including the second capacitor 141, for charging under connected state to the second capacitor 141;
Output module 150, for by the voltage output on the second capacitor 141 to processing module 160;
Processing module 160, the variable quantity of the voltage for being exported according to output module 150 determine whether the capacitance of first capacitor 121 changes.
The device of the capacitance detecting of the embodiment of the present invention, the variation of capacitance is converted to the deviation of frequency of oscillation, and deviation is summed into capacitor charging time, the variable quantity that the charging time of capacitor is converted to voltage determines whether capacitance changes according to the variable quantity of voltage, and used device is simple, and there is no quiescent dissipation, therefore, the structure of the device of the capacitance detecting of the embodiment of the present invention is simple, and power consumption is lower.
In some possible implementations, first capacitor 121 is touch controlled key capacitor;
Whether the variable quantity for the voltage that processing module 160 is used to be exported according to output module 150 determines first capacitor 121 by touch-control.
In some possible implementations, when first capacitor 121 is not by touch-control, the frequency of the second oscillator signal is identical as the frequency of the first oscillator signal;When first capacitor 121 is by touch-control, the frequency of the second oscillator signal is different from the frequency of the first oscillator signal.
In some possible implementations, device further include:
First counter 170, for generating the first count signal according to the first oscillator signal;
Second counter 175, for generating the second count signal according to the second oscillator signal;
Control module 130 is specifically used for generating switch control signal according to the first count signal and the second count signal.
The delay difference of two-way oscillating circuit can be added up by counter.
In some possible implementations, control module 130 is exclusive or processing module, such as XOR gate.
In some possible implementations, the second oscillating circuit 120 further includes the first charging paths 1211, the first comparison circuit 1212, the second comparison circuit 1213 and the first charge-discharge control circuit 1214;
The output end of first charging paths 1211 is connect with the input terminal of the first comparison circuit 1212, and one end of first capacitor 121 is connect with the input terminal of the output end of the first comparison circuit 1212 and the second comparison circuit 1213, the other end ground connection of first capacitor 121;
First charge-discharge control circuit 1214, which is used to control the first charging paths 1211 according to the output signal of the second comparison circuit 1213, switches charging and discharging state.
In some possible implementations, the first oscillating circuit 110 includes the 5th capacitor 111, the second charging paths 1111, third comparison circuit 1112, the 4th comparison circuit 1113 and the second charge-discharge control circuit 1114;
The output end of second charging paths 1111 is connect with the input terminal of third comparison circuit 1112, and one end of the 5th capacitor 111 is connect with the input terminal of the output end of third comparison circuit 1112 and the 4th comparison circuit 1113, the other end ground connection of the 5th capacitor 111;
Second charge-discharge control circuit 1114 is used to be controlled according to the output signal of the 4th comparison circuit 1113 Second charging paths 1111 switch charging and discharging state.
In some possible implementations, the second oscillating circuit 120 further includes the first current source 122, first switch 123, third capacitor 124, the first phase inverter 125, the second phase inverter 126, first resistor 127, third phase inverter 128, the 4th phase inverter 129 and second switch 1210;
First phase inverter 125, the second phase inverter 126, first resistor 127, third phase inverter 128 and the 4th phase inverter 129 are sequentially connected in series, one end of first capacitor 121 is connect with the input terminal of third phase inverter 128, the other end of first capacitor 121 is grounded, one end of third capacitor 124 is grounded, and the other end of third capacitor 124 is connect with the input terminal of the first phase inverter 125;
The output signal of third phase inverter 128 is for controlling turning on and off for first switch 123, the output signal of 4th phase inverter 129 is for controlling turning on and off for second switch 1210, when first switch 123 is opened and second switch 1210 turns off, first current source 122 charges to third capacitor 124, when first switch 123 turns off and second switch 1210 is opened, third capacitor 124 discharges.
In some possible implementations, the first oscillating circuit 110 includes the second current source 112, third switch 113, the 4th capacitor 114, the 5th phase inverter 115, hex inverter 116, second resistance 117, the 7th phase inverter 118, the 8th phase inverter 119, the 4th switch 1110 and the 5th capacitor 111;
5th phase inverter 115, hex inverter 116, second resistance 117, the 7th phase inverter 118 and the 8th phase inverter 119 are sequentially connected in series, one end of 5th capacitor 111 is connect with the input terminal of the 7th phase inverter 118, the other end of 5th capacitor 111 is grounded, one end of 4th capacitor 114 is grounded, and the other end of the 4th capacitor 114 is connect with the input terminal of the 5th phase inverter 115;
The output signal of 7th phase inverter 118 is for controlling turning on and off for third switch 113, the output signal of 8th phase inverter 119 is for controlling turning on and off for the 4th switch 1110, when third switch 113 is opened and the 4th switch 1110 turns off, second current source 112 charges to the 4th capacitor 114, when third switch 113 turns off and the 4th switch 1110 is opened, the electric discharge of the 4th capacitor 114.
In some possible implementations, the first oscillating circuit 110 is oscillator.
In some possible implementations, charge circuit 140 further includes third current source 142 and the 5th switch 143;
Switch control signal is for controlling turning on and off for the 5th switch 143, and when the 5th switch 143 is opened, third current source 142 charges to the second capacitor 141.
In some possible implementations, charge circuit 140 further includes the 6th switch 144, when the 6th switch 144 is opened, the electric discharge of the second capacitor 141.
In some possible implementations, output module 150 can be analog-digital converter.
Second aspect provides a kind of touch controlled key equipment, the device of the capacitance detecting in any possible implementation including first aspect or first aspect.
Detailed description of the invention
To describe the technical solutions in the embodiments of the present invention more clearly, attached drawing needed in the embodiment of the present invention will be briefly described below, apparently, drawings in the following description are only some embodiments of the invention, for those of ordinary skill in the art, without creative efforts, it is also possible to obtain other drawings based on these drawings.
Fig. 1 is the schematic block diagram of the device of the capacitance detecting of one embodiment of the invention.
Fig. 2 is the schematic block diagram of the device of the capacitance detecting of another embodiment of the present invention.
Fig. 3 is the schematic block diagram of the device of the capacitance detecting of further embodiment of this invention.
Fig. 4 is the schematic diagram of the waveform of the first counter of the embodiment of the present invention and the input terminal of the second counter.
Fig. 5 is the schematic block diagram of the device of the capacitance detecting of further embodiment of this invention.
Specific embodiment
Following will be combined with the drawings in the embodiments of the present invention, and technical scheme in the embodiment of the invention is clearly and completely described, it is clear that described embodiment is a part of the embodiments of the present invention, rather than whole embodiments.Based on the embodiments of the present invention, those of ordinary skill in the art's every other embodiment obtained without creative labor, all should belong to the scope of protection of the invention.
The technical solution of the embodiment of the present invention can be applied in the various equipment using capacitance type touch control keys (Touch Key), such as mobile terminal, computer, household electrical appliances etc..Whether the equipment determines touch controlled key by touch-control by the variation of the capacitance of touch controlled key capacitor.The device of the capacitance detecting of the embodiment of the present invention can be set in the equipment, and whether the capacitance for detecting touch controlled key capacitor changes, and further determine that touch controlled key by touch-control.
Fig. 1 shows the schematic block diagram of the device 100 of the capacitance detecting of the embodiment of the present invention.As shown in Figure 1, the device 100 may include the first oscillating circuit 110, the second oscillating circuit 120, control module 130, charge circuit 140, output module 150 and processing module 160.
First oscillating circuit 110 is used to generate the first oscillator signal of preset frequency.
The preset frequency can be preset before detection, and be remained unchanged in the detection process.In this way, the second oscillating circuit 120 can generate frequency and the identical or different vibration of the preset frequency by variable capacitance Swing signal.
Optionally, the first oscillating circuit 110 can use the structure similar with the second oscillating circuit 120.
Optionally, the first oscillating circuit 110 or oscillator.The frequency of the oscillator is preset frequency.
Second oscillating circuit 120 includes first capacitor 121, and the capacitance of first capacitor 121 is variable, and the second oscillating circuit 120 changes for generating the second oscillator signal, the frequency of the second oscillator signal according to the variation of the capacitance of first capacitor 121.
First capacitor 121 is capacitor to be detected.That is, whether the capacitance that the device 100 is used to detect first capacitor 121 changes.
When first capacitor 121 does not change, the frequency of the second oscillator signal is identical as the frequency of the first oscillator signal, i.e., is all preset frequency;When first capacitor 121 changes, the frequency of the second oscillator signal is different from the frequency of the first oscillator signal.
Optionally, first capacitor 121 is touch controlled key capacitor.When first capacitor 121 is by touch-control, the capacitance of first capacitor 121 changes.That is, the frequency of the second oscillator signal is identical as the frequency of the first oscillator signal when first capacitor 121 is not by touch-control;When first capacitor 121 is by touch-control, the frequency of the second oscillator signal is different from the frequency of the first oscillator signal.
Control module 130 is used to generate switch control signal according to the first oscillator signal and the second oscillator signal, and switch control signal is used to control the connection and disconnection of charge circuit 140.
The second oscillator signal that the first oscillator signal and the second oscillating circuit 120 that first oscillating circuit 110 generates generate is for generating switch control signal, to control the connection and disconnection of charge circuit 140.
Optionally, control module 130 can be exclusive or processing module, such as XOR gate.In this way, the first oscillator signal and the second oscillator signal are identical when first capacitor 121 does not change, 130 output signal of control module is zero, and charge circuit 140 is off-state;When first capacitor 121 changes, the first oscillator signal and the second oscillator signal are different, and 130 output signal of control module is 1, and charge circuit 140 is connected state.
Optionally, counter can also be set between the first oscillating circuit 110 and the second oscillating circuit 120 and control module 130, for adding up to oscillator signal, i.e., adds up in time to the difference of two-way oscillator signal.As shown in Fig. 2, in another embodiment, which can also include the first counter 170 and the second counter 175.
First counter 170 is used to generate the first count signal according to the first oscillator signal.
Second counter 175 is used to generate the second count signal according to the second oscillator signal.
For example, the first counter 170 and the second counter 175 can export high level signal (or low level signal) afterwards in the rising edge signal (or failing edge signal) for counting on predetermined quantity respectively.In this way, in two-way oscillation signal frequency difference, for example, counter can add up delay difference when the second oscillator signal has delay difference relative to the first oscillator signal.
In this case, control module 130 is specifically used for generating switch control signal according to the first count signal and the second count signal.
For example, the first oscillator signal and the second oscillator signal are identical when first capacitor 121 does not change, the first count signal and the second count signal are identical, and 130 output signal of control module is zero, and charge circuit 140 is off-state;When first capacitor 121 changes, first oscillator signal and the second oscillator signal are different, first counter 170 counts on different at the time of rising edge signal (or failing edge signal) of predetermined quantity with the second counter 175, the output signal of control module 130 is 1 in time between two moment, and charge circuit 140 is connected state.
Charge circuit 140 includes the second capacitor 141, for charging under connected state to the second capacitor 141.
As previously mentioned, the connection and disconnection of the switch control signal control charge circuit 140 that control module 130 exports.Charge circuit 140 charges to the second capacitor 141 under connected state, does not charge in the off state to the second capacitor 141 then.
Output module 150 is used for the voltage output on the second capacitor 141 to processing module 160.
Output module 150 detects the voltage on the second capacitor 141, it can the second capacitor 141 of detection is in charging or the not voltage change under charged state, by the voltage output on the second capacitor 141 to processing module 160.Optionally, output module 150 can be analog-digital converter (Analog to Digital Converter, ADC).
The variable quantity for the voltage that processing module 160 is used to be exported according to output module 150 determines whether the capacitance of first capacitor 121 changes.
Processing module 160 is handled according to the voltage that output module 150 exports, and determines whether the capacitance of first capacitor 121 changes according to the variable quantity of voltage.For example, determining that the capacitance of first capacitor 121 does not change if voltage does not have variation or variable quantity to be less than predetermined threshold;Determine that the capacitance of first capacitor 121 changes if voltage changes or variable quantity is not less than predetermined threshold.
When first capacitor 121 is touch controlled key capacitor, whether the variable quantity for the voltage that processing module 160 is exported according to output module 150 determines first capacitor 121 by touch-control.For example, determining first capacitor 121 not by touch-control if voltage does not change or variable quantity is less than predetermined threshold;If voltage changes or variable quantity Then determine first capacitor 121 by touch-control not less than predetermined threshold.
Optionally, as shown in Figure 3, in another embodiment, the second oscillating circuit 120 may include first capacitor 121, the first current source 122, first switch 123, third capacitor 124, the first phase inverter 125, the second phase inverter 126, first resistor 127, third phase inverter 128, the 4th phase inverter 129 and second switch 1210.
First phase inverter 125, the second phase inverter 126, first resistor 127, third phase inverter 128 and the 4th phase inverter 129 are sequentially connected in series, one end of first capacitor 121 is connect with the input terminal of third phase inverter 128, the other end of first capacitor 121 is grounded, one end of third capacitor 124 is grounded, and the other end of third capacitor 124 is connect with the input terminal of the first phase inverter 125.
The output signal of third phase inverter 128 is for controlling turning on and off for first switch 123, the output signal of 4th phase inverter 129 is for controlling turning on and off for second switch 1210, when first switch 123 is opened and second switch 1210 turns off, first current source 122 charges to third capacitor 124, when first switch 123 turns off and second switch 1210 is opened, third capacitor 124 discharges.
Optionally, the first oscillating circuit 110 can use the structure similar with the second oscillating circuit 120.Specifically, the first oscillating circuit 110 may include the second current source 112, third switch 113, the 4th capacitor 114, the 5th phase inverter 115, hex inverter 116, second resistance 117, the 7th phase inverter 118, the 8th phase inverter 119, the 4th switch 1110 and the 5th capacitor 111.
5th phase inverter 115, hex inverter 116, second resistance 117, the 7th phase inverter 118 and the 8th phase inverter 119 are sequentially connected in series, one end of 5th capacitor 111 is connect with the input terminal of the 7th phase inverter 118, the other end of 5th capacitor 111 is grounded, one end of 4th capacitor 114 is grounded, and the other end of the 4th capacitor 114 is connect with the input terminal of the 5th phase inverter 115.
The output signal of 7th phase inverter 118 is for controlling turning on and off for third switch 113, the output signal of 8th phase inverter 119 is for controlling turning on and off for the 4th switch 1110, when third switch 113 is opened and the 4th switch 1110 turns off, second current source 112 charges to the 4th capacitor 114, when third switch 113 turns off and the 4th switch 1110 is opened, the electric discharge of the 4th capacitor 114.
By taking the second oscillating circuit 120 as an example, its working principles are as follows:
When first switch 123 is opened and second switch turns off 1210, first current source 122 charges to third capacitor 124, the voltage of the input end of first phase inverter 125 increases, by the delay (CU/I of certain time, wherein C is the capacitance of third capacitor 124, I and U is respectively charging current and voltage) after, the voltage of the output of second phase inverter 126 is high level, to charge to first capacitor 121, the voltage of the input end of third phase inverter 128 increases, by the delay (RC of certain timeTP, In, R is the resistance value of first resistor 127, CTPFor the capacitance of first capacitor 121) after, the voltage of the output of third phase inverter 128 is low level, and the voltage of the output of the 4th phase inverter 129 is high level, and such first switch 123 turns off, second switch 1210 is open-minded, so that third capacitor 124 discharges;The voltage of the input end of first phase inverter 125 reduces, after the delay of certain time, the voltage of the output of second phase inverter 126 is low level, first capacitor 121 is discharged, the voltage of the input end of third phase inverter 128 reduces, after the delay of certain time, the voltage of the output of third phase inverter 128 is high level, the voltage of the output of 4th phase inverter 129 is low level, first switch 123 is open-minded in this way, second switch 1210 turns off, so that the first current source 122 charges to third capacitor 124, and so on.
The working principle of first oscillating circuit 110 is identical as the working principle of the second oscillating circuit 120.
In addition to the capacitance C of the 5th capacitor 111inWith the capacitance C of first capacitor 121TPCan be different outer, the first oscillating circuit 110 is identical as the parameter value of other parts of the second oscillating circuit 120.After the capacitance of the 5th capacitor 111 is fixed, the difference of the first oscillating circuit 110 and the second oscillating circuit 120 is determined by the variation of the capacitance of first capacitor 121.
When working on power, the value of the 5th capacitor 111 of adjustment can be first passed through, also the value of adjustable second resistance 117 and the 5th capacitor 111, so that the frequency of two oscillating circuits is identical or close to (difference on the frequency be less than certain threshold value), the switch control signal that control module 130 exports in this way is zero, charge circuit 140 does not charge to the second capacitor 141, and the output of output module 150 is a fixed value.If the capacitance of first capacitor 121 changes, for example, touch-control occurs, the delay difference of two-way oscillating circuit will be made to become larger, the time of the cumulative corresponding output of control module 130 1 of the delay difference, also correspond to the time that charge circuit 140 charges to the second capacitor 141.Again:
I2Δ t=C2·ΔV               (1)
Wherein, C2Indicate the capacitance of the second capacitor 141, I2Indicate the charging current of the second capacitor 141.
Whether delay difference is converted to voltage value variable quantity by the voltage value that can detect capacitor by output module 150 in this way, then changed by the processing of processing module 160 with the capacitance for confirming first capacitor 121, for example whether by touch-control.
By taking Fig. 3 as an example, the delay accumulation of the first oscillating circuit 110 be may be expressed as:
Σtin=Σ [CU/I+RCin]          (2)
The delay accumulation of second oscillating circuit 120 may be expressed as:
Σttp=Σ [CU/I+R (CTP+ΔCTP)]      (3)
Wherein, Δ CTPIndicate the variable quantity of the capacitance of first capacitor 121.
Formula (3) and formula (2) are subtracted each other and can be obtained, the second oscillating circuit 120 and 110 delay difference of the first oscillating circuit are cumulative are as follows:
ΣΔtdelay=Σ R (CTP+ΔCTP-Cin)        (4)
The variation delta C of the capacitance of first capacitor 121 it can be seen from formula (4)TPCorresponding delay difference is cumulative, further according to formula (1), the variable quantity of further corresponding voltage.Therefore, whether the variable quantity for the voltage that processing module 160 can be exported according to output module 150 determines first capacitor 121 by touch-control.
For example, Fig. 4 shows the schematic diagram that touch-control does not occur and the waveform of 175 input terminal of the first counter 170 and the second counter when touch-control occurs.As shown in figure 4, the first counter 170 is identical with the waveform of 175 input terminal of the second counter when touch-control does not occur.When first capacitor 121 is by touch-control, there is delay difference between two-way oscillating circuit.Further the delay difference in multiple periods can be added up by counter.For example, it is assumed that the first counter 170 and the second counter 175 are 10 digit counters, and the period of the first oscillating circuit 110 is T1, and the first counter 170 exports high level signal after 10 T1 periods;Since touch-control leads to the capacitance variation of first capacitor 121 in the second oscillating circuit 120, so that the period of the second oscillating circuit 120 becomes T2, similarly, after 10 T2 periods, the second counter 175 exports high level signal.Assuming that T1 is Δ T with the difference of T2, so by 10 digit counters it is cumulative after, the delay difference that counter 170 and counter 175 export high level is 10 Δ T, therefore, in the delay difference of 10 Δ T, first counter 170 is different with the output signal of the second counter 175, the output signal of control module 130 is 1, charge circuit 140 charges to the second capacitor 141, the voltage change that output module 150 exports, the variable quantity for the voltage that processing module 160 is exported according to output module 150 determine first capacitor 121 by touch-control.
It should be understood that, other than above-mentioned first oscillating circuit 110 is using the design of the structure similar with the second oscillating circuit 120, first oscillating circuit 110 can also use internal oscillator, as long as the first oscillator signal that i.e. the first oscillating circuit 110 can produce preset frequency, the present invention do not limit this.
Optionally, as shown in figure 3, in another embodiment, charge circuit 140 may include the second capacitor 141, third current source 142 and the 5th switch 143.
The switch control signal that control module 130 exports is for controlling turning on and off for the 5th switch 143.When 5th switch 143 is opened, third current source 142 charges to the second capacitor 141.
Optionally, in another embodiment, charge circuit 140 can also include the 6th switch 144.When 6th switch 144 is opened, the electric discharge of the second capacitor 141.
Specifically, can periodically be discharged the second capacitor 141 by the circuit 144 structural reconstruction of the 6th switch (reset).
It should be understood that the specific example in the embodiment of the present invention is intended merely to that those skilled in the art is helped to more fully understand the embodiment of the present invention, the range for the embodiment that is not intended to limit the present invention.
For example, the structure of the first oscillating circuit 110 and the second oscillating circuit 120 is only a kind of example in Fig. 3, the two oscillating circuits can also use other mapped structures.It illustrates as one, the first oscillating circuit 110 and the second oscillating circuit 120 can use structure shown in fig. 5.
As shown in figure 5, optionally, in an embodiment of the invention, the second oscillating circuit 120 may include first capacitor 121, the first charging paths 1211, the first comparison circuit 1212, the second comparison circuit 1213 and the first charge-discharge control circuit 1214;
The output end of first charging paths 1211 is connect with the input terminal of the first comparison circuit 1212, and one end of first capacitor 121 is connect with the input terminal of the output end of the first comparison circuit 1212 and the second comparison circuit 1213, the other end ground connection of first capacitor 121;
First charge-discharge control circuit 1214, which is used to control the first charging paths 1211 according to the output signal of the second comparison circuit 1213, switches charging and discharging state.
Such as, first charge-discharge control circuit 1214 controls the first charging paths 1211 into charged state when can be low level according to the output signal of the second comparison circuit 1213, the first charging paths 1211 are controlled when high level into discharge condition according to the output signal of the second comparison circuit 1213.
Optionally, in an embodiment of the invention, the first oscillating circuit 110 may include the 5th capacitor 111, the second charging paths 1111, third comparison circuit 1112, the 4th comparison circuit 1113 and the second charge-discharge control circuit 1114;
The output end of second charging paths 1111 is connect with the input terminal of third comparison circuit 1112, and one end of the 5th capacitor 111 is connect with the input terminal of the output end of third comparison circuit 1112 and the 4th comparison circuit 1113, the other end ground connection of the 5th capacitor 111;
Second charge-discharge control circuit 1114, which is used to control the second charging paths 1111 according to the output signal of the 4th comparison circuit 1113, switches charging and discharging state.
Such as, second charge-discharge control circuit 1114 controls the second charging paths 1111 into charged state when can be low level according to the output signal of the 4th comparison circuit 1113, the second charging paths 1111 are controlled when high level into discharge condition according to the output signal of the 4th comparison circuit 1113.
The device of the capacitance detecting of the embodiment of the present invention, the variation of capacitance is converted to the deviation of frequency of oscillation, and deviation is summed into capacitor charging time, the variable quantity that the charging time of capacitor is converted to voltage determines whether capacitance changes according to the variable quantity of voltage, and used device is simple, and there is no quiescent dissipation, therefore, the structure of the device of the capacitance detecting of the embodiment of the present invention is simple, and power consumption is lower.
Those of ordinary skill in the art may be aware that, unit and algorithm steps described in conjunction with the examples disclosed in the embodiments of the present disclosure, it can be realized with electronic hardware, computer software, or a combination of the two, in order to clearly illustrate the interchangeability of hardware and software, each exemplary composition and step are generally described according to function in the above description.These functions are implemented in hardware or software actually, the specific application and design constraint depending on technical solution.Professional technician can use different methods to achieve the described function each specific application, but such implementation should not be considered as beyond the scope of the present invention.
In several embodiments provided herein, it should be understood that disclosed device may be implemented in other ways.Such as, the apparatus embodiments described above are merely exemplary, such as, the division of the unit, only a kind of logical function partition, there may be another division manner in actual implementation, such as multiple units or components can be combined or can be integrated into another system, or some features can be ignored or not executed.In addition, shown or discussed mutual coupling, direct-coupling or communication connection can be through some interfaces, the indirect coupling or communication connection of device or unit, be also possible to electricity, the connection of mechanical or other forms.
The unit as illustrated by the separation member may or may not be physically separated, and component shown as a unit may or may not be physical unit, it can and it is in one place, or may be distributed over multiple network units.It can select some or all of unit therein according to the actual needs to realize the purpose of the embodiment of the present invention.
In addition, the functional units in various embodiments of the present invention may be integrated into one processing unit, it is also possible to each unit and physically exists alone, is also possible to two or more units and is integrated in one unit.Above-mentioned integrated unit both can take the form of hardware realization, can also realize in the form of software functional units.
If the integrated unit is realized in the form of SFU software functional unit and when sold or used as an independent product, can store in a computer readable storage medium.Based on this understanding, technical solution of the present invention substantially the part that contributes to existing technology in other words, or all or part of the technical solution can be embodied in the form of software products, the computer software product is stored in a storage medium, it uses including some instructions so that a computer equipment (can be personal computer, server or the network equipment etc.) it performs all or part of the steps of the method described in the various embodiments of the present invention.And storage medium above-mentioned includes: USB flash disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), the various media that can store program code such as magnetic or disk.
It is described above; only a specific embodiment of the invention; but scope of protection of the present invention is not limited thereto; anyone skilled in the art is in the technical scope disclosed by the present invention; various equivalent modifications or substitutions can be readily occurred in, these modifications or substitutions should be covered by the protection scope of the present invention.Therefore, protection scope of the present invention should be subject to the protection scope in claims.

Claims (11)

  1. A kind of device of capacitance detecting characterized by comprising
    First oscillating circuit (110), for generating the first oscillator signal of preset frequency;
    Second oscillating circuit (120), including first capacitor (121), the capacitance of the first capacitor (121) is variable, second oscillating circuit (120) changes for generating the second oscillator signal, the frequency of second oscillator signal according to the variation of the capacitance of the first capacitor (121);
    Control module (130), for generating switch control signal according to first oscillator signal and second oscillator signal, the switch control signal is used to control the connection and disconnection of charge circuit (140);
    Charge circuit (140), including the second capacitor (141), for charging when the charge circuit (140) are connected to second capacitor (141);
    Output module (150) is used for the voltage output on second capacitor (141) to processing module (160);
    The variable quantity of processing module (160), the voltage for being exported according to the output module (150) determines whether the capacitance of the first capacitor (121) changes.
  2. The apparatus according to claim 1, which is characterized in that the first capacitor (121) is touch controlled key capacitor;
    Whether the variable quantity for the voltage that the processing module (160) is used to be exported according to the output module (150) determines the first capacitor (121) by touch-control.
  3. The apparatus of claim 2, which is characterized in that when the first capacitor (121) is not by touch-control, the frequency of second oscillator signal is identical as the frequency of first oscillator signal;When the first capacitor (121) is by touch-control, the frequency of second oscillator signal is different from the frequency of first oscillator signal.
  4. Device according to any one of claim 1 to 3, which is characterized in that described device further include:
    First counter (170), for generating the first count signal according to first oscillator signal;
    Second counter (175), for generating the second count signal according to second oscillator signal;
    The control module (130) is specifically used for generating the switch control signal according to first count signal and second count signal.
  5. Device according to any one of claim 1 to 4, which is characterized in that the control module (130) is exclusive or processing module.
  6. Device according to any one of claim 1 to 5, which is characterized in that described second Oscillating circuit (120) further includes the first charging paths (1211), the first comparison circuit (1212), the second comparison circuit (1213) and the first charge-discharge control circuit (1214);
    The output end of first charging paths (1211) is connect with the input terminal of first comparison circuit (1212), one end of the first capacitor (121) is connect with the input terminal of the output end of first comparison circuit (1212) and second comparison circuit (1213), the other end ground connection of the first capacitor (121);
    First charge-discharge control circuit (1214), which is used to control first charging paths (1211) according to the output signal of second comparison circuit (1213), switches charging and discharging state.
  7. Device according to any one of claim 1 to 6, it is characterized in that, first oscillating circuit (110) includes the 5th capacitor (111), the second charging paths (1111), third comparison circuit (1112), the 4th comparison circuit (1113) and the second charge-discharge control circuit (1114);
    The output end of second charging paths (1111) is connect with the input terminal of the third comparison circuit (1112), one end of 5th capacitor (111) is connect with the input terminal of the output end of the third comparison circuit (1112) and the 4th comparison circuit (1113), the other end ground connection of the 5th capacitor (111);
    Second charge-discharge control circuit (1114), which is used to control second charging paths (1111) according to the output signal of the 4th comparison circuit (1113), switches charging and discharging state.
  8. Device according to any one of claim 1 to 5, it is characterized in that, second oscillating circuit (120) further includes the first current source (122), first switch (123), third capacitor (124), the first phase inverter (125), the second phase inverter (126), first resistor (127), third phase inverter (128), the 4th phase inverter (129) and second switch (1210);
    First phase inverter (125), second phase inverter (126), the first resistor (127), third phase inverter (128) and the 4th phase inverter (129) are sequentially connected in series, one end of the first capacitor (121) is connect with the input terminal of the third phase inverter (128), the other end of the first capacitor (121) is grounded, one end of the third capacitor (124) is grounded, and the other end of the third capacitor (124) is connect with the input terminal of first phase inverter (125);
    The output signal of the third phase inverter (128) is for controlling turning on and off for the first switch (123), the output signal of 4th phase inverter (129) is for controlling turning on and off for the second switch (1210), when the first switch (123) is opened and the second switch (1210) turns off, first current source (122) charges to the third capacitor (124), when the first switch (123) turns off and the second switch (1210) is opened, third capacitor (124) electric discharge.
  9. According to claim 1 to 6, device described in any one of 8, it is characterized in that, first oscillating circuit (110) includes the second current source (112), third switch (113), the 4th capacitor (114), the 5th phase inverter (115), hex inverter (116), second resistance (117), the 7th phase inverter (118), the 8th phase inverter (119), the 4th switch (1110) and the 5th capacitor (111);
    5th phase inverter (115), the hex inverter (116), the second resistance (117), the 7th phase inverter (118) and the 8th phase inverter (119) are sequentially connected in series, one end of 5th capacitor (111) is connect with the input terminal of the 7th phase inverter (118), the other end of 5th capacitor (111) is grounded, one end of 4th capacitor (114) is grounded, and the other end of the 4th capacitor (114) is connect with the input terminal of the 5th phase inverter (115);
    The output signal of 7th phase inverter (118) is used to control turning on and off for the third switch (113), the output signal of 8th phase inverter (119) is used to control turning on and off for the 4th switch (1110), when the third switch (113) is opened and the 4th switch (1110) turns off, second current source (112) charges to the 4th capacitor (114), when the third switch (113) turns off and the 4th switch (1110) is opened, the 4th capacitor (114) electric discharge.
  10. Device according to any one of claim 1 to 9, the charge circuit (140) further include third current source (142) and the 5th switch (143);
    The switch control signal is used to control turning on and off for the 5th switch (143), and when the 5th switch (143) is opened, the third current source (142) charges to second capacitor (141).
  11. Device according to claim 10, which is characterized in that the charge circuit (140) further includes the 6th switch (144), when the 6th switch (144) is opened, the second capacitor (141) electric discharge.
CN201680000579.9A 2016-05-17 2016-05-17 The device of capacitance detecting Pending CN108139840A (en)

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CN112906954A (en) * 2021-02-04 2021-06-04 优方科技(东莞)有限公司 Large-area capacitance induction system
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