CN116317545A - Negative-pressure charge transfer circuit and capacitive touch detection circuit - Google Patents
Negative-pressure charge transfer circuit and capacitive touch detection circuit Download PDFInfo
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- CN116317545A CN116317545A CN202310527506.7A CN202310527506A CN116317545A CN 116317545 A CN116317545 A CN 116317545A CN 202310527506 A CN202310527506 A CN 202310527506A CN 116317545 A CN116317545 A CN 116317545A
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- 238000001514 detection method Methods 0.000 title claims abstract description 71
- 239000003990 capacitor Substances 0.000 claims abstract description 233
- 239000004973 liquid crystal related substance Substances 0.000 claims description 20
- 101000868045 Homo sapiens Uncharacterized protein C1orf87 Proteins 0.000 description 76
- 102100032994 Uncharacterized protein C1orf87 Human genes 0.000 description 76
- 238000010586 diagram Methods 0.000 description 4
- 238000005259 measurement Methods 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 238000007599 discharging Methods 0.000 description 1
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R27/00—Arrangements for measuring resistance, reactance, impedance, or electric characteristics derived therefrom
- G01R27/02—Measuring real or complex resistance, reactance, impedance, or other two-pole characteristics derived therefrom, e.g. time constant
- G01R27/26—Measuring inductance or capacitance; Measuring quality factor, e.g. by using the resonance method; Measuring loss factor; Measuring dielectric constants ; Measuring impedance or related variables
- G01R27/2605—Measuring capacitance
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- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
- G06F3/01—Input arrangements or combined input and output arrangements for interaction between user and computer
- G06F3/03—Arrangements for converting the position or the displacement of a member into a coded form
- G06F3/041—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
- G06F3/0416—Control or interface arrangements specially adapted for digitisers
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- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
- G06F3/01—Input arrangements or combined input and output arrangements for interaction between user and computer
- G06F3/03—Arrangements for converting the position or the displacement of a member into a coded form
- G06F3/041—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
- G06F3/044—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means by capacitive means
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M3/00—Conversion of dc power input into dc power output
- H02M3/02—Conversion of dc power input into dc power output without intermediate conversion into ac
- H02M3/04—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters
- H02M3/06—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using resistors or capacitors, e.g. potential divider
- H02M3/07—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using resistors or capacitors, e.g. potential divider using capacitors charged and discharged alternately by semiconductor devices with control electrode, e.g. charge pumps
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T10/00—Road transport of goods or passengers
- Y02T10/60—Other road transportation technologies with climate change mitigation effect
- Y02T10/70—Energy storage systems for electromobility, e.g. batteries
Abstract
The application provides a negative-pressure charge transfer circuit, which comprises a charging branch, a charge transfer branch, a capacitance module and a reference capacitance; the first end of the charging branch is electrically connected with the first end of the capacitor module, the second end of the capacitor module is grounded, the second end of the charging branch is electrically connected with the second end of the reference capacitor, the third end of the charging branch is electrically connected with the first end of the reference capacitor, the input end of the charging branch is connected with a voltage source, and the fourth end of the charging branch is grounded; the first end of the charge transfer branch is electrically connected with the first end of the capacitor module, and the second end of the charge transfer branch is electrically connected with the first end of the reference capacitor; therefore, the reference capacitor can be charged in a negative pressure manner in the charging stage, so that the electric charge quantity transferred in the charge transfer stage is more, namely, the capacitor with a lower capacitance value can be selected as the reference capacitor, and the volume of the reference capacitor can be reduced, namely, the negative pressure charge transfer circuit has a smaller volume, so that the volume of the capacitive touch detection circuit can be reduced.
Description
Technical Field
The embodiment of the application relates to the technical field of touch measurement, in particular to a negative pressure charge transfer circuit and a capacitive touch detection circuit.
Background
The capacitive touch detection circuit requires a reference capacitor in addition to the capacitive module. In the capacitance detection process, the charge on the capacitance module needs to be transferred to the reference capacitance. At present, an external capacitor of a chip is used as a reference capacitor, which results in larger volume of the capacitive touch detection circuit.
Disclosure of Invention
In view of the above, the embodiments of the present application provide a negative-pressure charge transfer circuit and a capacitive touch detection circuit, which have the effect of reducing the volume of a reference capacitor, so that the reference capacitor can be integrated into the capacitive touch detection circuit, and the volume of the capacitive touch detection circuit is reduced.
In a first aspect of embodiments of the present application, a negative-pressure charge transfer circuit is provided, including a charging branch, a charge transfer branch, a capacitance module, and a reference capacitance; wherein, the liquid crystal display device comprises a liquid crystal display device,
the first end of the charging branch is electrically connected with the first end of the capacitor module, the second end of the capacitor module is grounded, the second end of the charging branch is electrically connected with the second end of the reference capacitor, the third end of the charging branch is electrically connected with the first end of the reference capacitor, the input end of the charging branch is connected with a voltage source, and the fourth end of the charging branch is grounded; the first end of the charge transfer branch is electrically connected with the first end of the capacitor module, and the second end of the charge transfer branch is electrically connected with the first end of the reference capacitor; the third end of the charge transfer branch is electrically connected with the second end of the reference capacitor, and the fourth end of the charge transfer branch is grounded;
the charging branch is used for respectively charging the capacitor module and the reference capacitor in a charging stage;
the charge transfer branch is used for moving the charge in the capacitor module to the reference capacitor in the charge transfer stage.
In the above scheme, the charging branch comprises a first charging branch and a second charging branch; wherein, the liquid crystal display device comprises a liquid crystal display device,
the output end of the first charging branch is electrically connected with the first end of the capacitor module, and the input end of the first charging branch is connected with a first voltage source; the output end of the second charging branch is electrically connected with the second end of the reference capacitor, the first end of the second charging branch is electrically connected with the first end of the reference capacitor, the input end of the second charging branch is connected with a second voltage source, and the second end of the second charging branch is grounded; the voltage of the first voltage source is the same as the voltage of the second voltage source, or the first voltage source is multiplexed into the second voltage source;
the first charging branch is used for charging the capacitor module in a charging stage;
and the second charging branch is used for charging the reference capacitor in the charging stage.
In the above scheme, the first charging branch comprises a first switch; wherein, the liquid crystal display device comprises a liquid crystal display device,
the first end of the first switch is electrically connected with the first end of the capacitor module, and the second end of the first switch is connected with the first voltage source.
In the above scheme, the second charging branch comprises a second switch and a third switch; wherein, the liquid crystal display device comprises a liquid crystal display device,
the first end of the second switch is electrically connected with the second end of the reference capacitor, the second end of the second switch is connected with the second voltage source, the first end of the third switch is electrically connected with the first end of the reference capacitor, and the second end of the third switch is grounded.
In the above scheme, the charge transfer branch includes a resistor, a fourth switch and a fifth switch; wherein, the liquid crystal display device comprises a liquid crystal display device,
the first end of the fourth switch is electrically connected with the first end of the capacitor module, the second end of the fourth switch is electrically connected with the first end of the resistor, the second end of the resistor is electrically connected with the first end of the reference capacitor, the second end of the reference capacitor is electrically connected with the first end of the fifth switch, and the second end of the fifth switch is grounded;
the charge transfer branch is used for conducting the first end of the capacitor module and the first end of the reference capacitor in the charge transfer stage, and conducting the second end of the reference capacitor and the ground.
In the above scheme, the charge transfer branch is further configured to conduct the second end of the reference capacitor and ground in the charge emptying stage;
the charging branch is also used for conducting the first end of the reference capacitor and the ground in the charge emptying stage.
In the above scheme, the capacitive module further comprises a sixth switch, wherein the first end of the sixth switch is electrically connected with the first end of the capacitive module, and the second end of the sixth switch is grounded;
and a sixth switch for conducting the first terminal of the capacitor module and the ground during the charge-draining period.
In a second aspect of the embodiments of the present application, a capacitive touch detection circuit is provided, including the negative-pressure charge transfer circuit of the foregoing embodiments, where, in a detection phase, the second end of the reference capacitor is turned on with ground.
In the scheme, the device further comprises a detection module;
the first input end of the detection module is electrically connected with the first end of the reference capacitor, and the second input end of the detection module is electrically connected with the second end of the reference capacitor;
the detection module is used for receiving the voltages at the two ends of the reference capacitor in the detection stage and detecting the touch control signal based on the voltages at the two ends of the reference capacitor.
In the scheme, the switch further comprises a seventh switch and an eighth switch;
the first end of the seventh switch is electrically connected with the first end of the reference capacitor, and the first end of the eighth switch is electrically connected with the second end of the reference capacitor; the second end of the seventh switch is electrically connected with the first input end of the detection module, and the second end of the eighth switch is electrically connected with the second input end of the detection module;
a seventh switch for conducting the first end of the reference capacitor and the first input end of the detection module in the detection stage;
and the eighth switch is used for conducting the second end of the reference capacitor and the second input end of the detection module in the detection stage.
The embodiment of the application provides a negative-pressure charge transfer circuit, which comprises a charging branch, a charge transfer branch, a capacitor module and a reference capacitor; the first end of the charging branch is electrically connected with the first end of the capacitor module, the second end of the capacitor module is grounded, the second end of the charging branch is electrically connected with the second end of the reference capacitor, the third end of the charging branch is electrically connected with the first end of the reference capacitor, the input end of the charging branch is connected with a voltage source, and the fourth end of the charging branch is grounded; the first end of the charge transfer branch is electrically connected with the first end of the capacitor module, and the second end of the charge transfer branch is electrically connected with the first end of the reference capacitor; the charging branch is used for respectively charging the capacitor module and the reference capacitor in a charging stage; the charge transfer branch is used for moving the charge in the capacitor module to the reference capacitor in the charge transfer stage, so that the reference capacitor can be subjected to negative-pressure charging in the charging stage, the charge quantity transferred in the charge transfer stage is more, namely, the capacitor with a lower capacitance value can be selected as the reference capacitor, and the volume of the reference capacitor can be reduced, namely, the negative-pressure charge transfer circuit has a smaller volume; therefore, the negative-pressure charge transfer circuit is integrated into the capacitive touch detection circuit, so that the volume of the capacitive touch detection circuit can be reduced.
The foregoing description is only an overview of the technical solutions of the embodiments of the present application, and may be implemented according to the content of the specification, so that the technical means of the embodiments of the present application can be more clearly understood, and the following detailed description of the present application will be presented in order to make the foregoing and other objects, features and advantages of the embodiments of the present application more understandable.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the description of the embodiments will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present application, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
Fig. 1 is a schematic structural diagram of a negative-pressure charge transfer circuit according to an embodiment of the present disclosure;
fig. 2 is a schematic structural diagram of a capacitive touch detection circuit according to an embodiment of the present application.
Detailed Description
For the purposes of making the objects, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions of the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is apparent that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which can be made by one of ordinary skill in the art based on the embodiments herein without making any inventive effort, are intended to be within the scope of the present application.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used in the description of the applications herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application; the terms "comprising" and "having" and any variations thereof in the description and claims of the present application and in the description of the drawings are intended to cover a non-exclusive inclusion.
Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the present application. The appearances of the phrase "an embodiment" in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Those of skill in the art will explicitly and implicitly appreciate that the embodiments described herein may be combined with other embodiments.
The term "and/or" is herein merely an association relationship describing an associated object, meaning that there may be three relationships, e.g., a and/or B, may represent: there are three cases, a, B, a and B simultaneously. In addition, the character "/" herein generally indicates that the front and rear associated objects are an "or" relationship.
Furthermore, the terms first, second and the like in the description and in the claims of the present application or in the above-described figures, are used for distinguishing between different objects and not for describing a particular sequential order, and may be used to expressly or implicitly include one or more such features.
In the description of the present application, unless otherwise indicated, the meaning of "plurality" means two or more (including two), and similarly, "plural sets" means two or more (including two).
In order to better understand the technical solutions of the present application, the following description will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the accompanying drawings.
Fig. 1 is a schematic structural diagram of a negative-pressure charge transfer circuit according to an embodiment of the present application, as shown in fig. 1, the negative-pressure charge transfer circuit includes a charging branch, a charge transfer branch 103, a capacitor module CS, and a reference capacitor CREF.
The first end of the charging branch is electrically connected with the first end of the capacitor module CS, the second end of the capacitor module CS is grounded, the second end of the charging branch is electrically connected with the second end of the reference capacitor CREF, the third end of the charging branch is electrically connected with the first end of the reference capacitor CREF, the input end of the charging branch is connected with a voltage source, and the fourth end of the charging branch is grounded; the first terminal of the charge transfer branch 103 is electrically connected to the first terminal of the capacitor module CS, and the second terminal of the charge transfer branch 103 is electrically connected to the first terminal of the reference capacitor CREF.
The charging branch is used for respectively charging the capacitor module CS and the reference capacitor CREF in a charging stage; the charge transfer branch 103 is configured to move the charge in the capacitor module CS into the reference capacitor CREF during the charge transfer phase.
The capacitance module CS may be a capacitance sensor, for example. In practical applications, the input end of the charging branch and the first end of the charging branch, the input end of the charging branch and the second end of the charging branch, and the fourth end of the charging branch and the third end of the charging branch, that is, the first end of the voltage source and the capacitor module CS, the second end of the reference capacitor CREF, and the first end of the reference capacitor CREF and the ground may be turned on, so that the charge provided by the voltage source is stored to the first end of the capacitor module CS and the second end of the reference capacitor CREF. At this time, the negative-pressure charge transfer circuit is in a charging stage, and can charge the capacitor module CS and the reference capacitor CREF through the charging branch, and after the charging is completed, the voltage of the capacitor module CS is a positive voltage, and the voltage of the reference capacitor CREF is a negative voltage. For example, the voltage provided by the voltage source is VDD, and after the charging is completed, the voltage of the capacitor module CS is VDD, and the voltage of the reference capacitor CREF is-VDD.
Thereafter, the connection between the voltage source and the first terminal of the capacitor module CS, the connection between the voltage source and the second terminal of the reference capacitor CREF, and the connection between the first terminal of the reference capacitor CREF and ground are disconnected, and the first terminal of the charge transfer branch 103 and the second terminal of the charge transfer branch 103 are turned on, and the third terminal of the charge transfer branch 103 and the fourth terminal of the charge transfer branch 103, i.e., the first terminal of the capacitor module CS and the first terminal of the reference capacitor CREF are turned on, and the second terminal of the reference capacitor CREF and ground are turned on. At this time, the piezo-electric charge transfer circuit enters the charge transfer stage, and the charge transfer between the capacitor module CS and the reference capacitor CREF can be performed through the charge transfer branch 103, that is, the positive charge at the first end of the capacitor module CS is transferred to the first end of the reference capacitor CREF until the charges of the capacitor module CS and the reference capacitor CREF are balanced, and the charge transfer is stopped. After the charge transfer is stopped, the voltage across the capacitor module CS is equal to the voltage across the reference capacitor CREF, which can be denoted as Vm, that is, vdd×cs-vdd×cref=vm (cs+cref), so that vm=vdd×cs-CREF)/(cs+cref) can be obtained. At this time, assuming Vm is VDD/4, the reference capacitance cref=0.6cs in negative charge transfer.
It should be noted that, until the capacitance module CS and the reference capacitance CREF are balanced, the voltage at both ends of the capacitance module CS and the voltage of the reference capacitance CREF are both VDD/4, in the prior art, only the voltage charged to both ends of the capacitance module CS is VDD, when the capacitance module CS and the reference capacitance CREF are balanced, the voltage at both ends of the capacitance module CS and the voltage at both ends of the reference capacitance CREF are equal, and may be denoted as Vc, that is, vdd×cs=vc (cs+cref), so that vc=vdd×cs/(cs+cref) can be obtained, and thus, if Vc is equal to Vm, the voltage at both ends of the capacitance module CS is VDD/4, the capacitance value of the reference capacitance CREF in the negative-pressure charge transfer provided in the application is smaller than the capacitance value of the reference capacitance CREF in the prior art.
In the embodiment of the application, the negative-pressure charge transfer comprises a charging branch, a charge transfer branch, a capacitance module and a reference capacitance; the first end of the charging branch is electrically connected with the first end of the capacitor module, the second end of the capacitor module is grounded, the second end of the charging branch is electrically connected with the second end of the reference capacitor, the third end of the charging branch is electrically connected with the first end of the reference capacitor, the input end of the charging branch is connected with a voltage source, and the fourth end of the charging branch is grounded; the first end of the charge transfer branch is electrically connected with the first end of the capacitor module, and the second end of the charge transfer branch is electrically connected with the first end of the reference capacitor; the charging branch is used for respectively charging the capacitor module and the reference capacitor in a charging stage; the charge transfer branch is used for moving the charge in the capacitor module to the reference capacitor in the charge transfer stage, so that the reference capacitor can be subjected to negative-pressure charging in the charging stage, the charge quantity transferred in the charge transfer stage is more, namely, the capacitor with a lower capacitance value can be selected as the reference capacitor, and the volume of the reference capacitor can be reduced, namely, the negative-pressure charge transfer circuit has a smaller volume; therefore, the negative-pressure charge transfer circuit is integrated into the capacitive touch detection circuit, so that the volume of the capacitive touch detection circuit can be reduced.
In some embodiments, with continued reference to fig. 1, the charging branch includes a first charging branch 101 and a second charging branch 102.
The output end of the first charging branch circuit 101 is electrically connected with the first end of the capacitor module CS, and the input end of the first charging branch circuit 101 is connected with a first voltage source; the output end of the second charging branch 102 is electrically connected with the second end of the reference capacitor CREF, the first end of the second charging branch 102 is electrically connected with the first end of the reference capacitor CREF, the input end of the second charging branch 102 is connected with a second voltage source, and the second end of the second charging branch 102 is grounded; the voltage of the first voltage source is the same as the voltage of the second voltage source, or the first voltage source is multiplexed into the second voltage source.
A first charging branch 101 for charging the capacitive module CS during a charging phase; the second charging branch 102 is configured to charge the reference capacitor CREF during a charging phase.
The first voltage source and the second voltage source are different voltage sources with the same specification, and then the voltage provided by the first voltage source is the same as the voltage provided by the second voltage source, for example, the voltage provided by the first voltage source and the voltage provided by the second voltage source are VDD. The output end of the first charging branch 101 is a first end of a charging branch, the input end of the first charging branch 101 and the input end of the second charging branch 102 are both input ends of the charging branch, the output end of the second charging branch 102 is a second end of the charging branch, the first end of the second charging branch 102 is a third end of the charging branch, and the second end of the second charging branch 102 is a fourth end of the charging branch.
In the charging stage, the input terminal of the first charging branch 101 is conducted with the output terminal of the first charging branch 101, that is, the first voltage source is conducted with the first terminal of the capacitor module CS, the second terminal of the capacitor module CS is grounded, and positive charges provided by the first voltage source can be stored in the first terminal of the capacitor module CS. In this way, the first charging branch 101 may charge the capacitor module CS in the charging stage, and after the charging is completed, the voltage across the capacitor module CS is a positive voltage.
In the charging stage, the input terminal of the second charging branch 102 and the output terminal of the second charging branch 102 are turned on, and the first terminal of the second charging branch 102 and the second terminal of the second charging branch 102 are turned on, i.e. the first terminal of the reference capacitor CREF is turned on with ground, the second terminal of the reference capacitor CREF is turned on with the second voltage source, and the positive charge provided by the second voltage source can be stored in the second terminal of the reference capacitor CREF. In this way, the second charging branch 102 can charge the reference capacitor CREF in the charging stage, and after the charging is completed, the voltage across the reference capacitor CREF is a negative voltage.
In other embodiments, the first voltage source is multiplexed to the second voltage source, i.e., the first voltage source and the second voltage source are the same voltage source.
In some embodiments, with continued reference to fig. 1, the first charging branch 101 includes a first switch K1. The first end of the first switch K1 is electrically connected to the first end of the capacitor module CS, and the second end of the first switch K1 is connected to the first voltage source.
Illustratively, the first end of the first switch K1 is an output end of the first charging branch 101, and the second end of the first switch K1 is an input end of the first charging branch 101. When the first switch K1 is closed, the first voltage source is turned on to the first end of the capacitor module CS, and the charging phase is entered.
As shown in fig. 1, the second charging branch 102 includes a second switch K2 and a third switch K3. The first end of the second switch K2 is electrically connected to the second end of the reference capacitor CREF, the second end of the second switch K2 is connected to the second voltage source, the first end of the third switch K3 is electrically connected to the first end of the reference capacitor CREF, and the second end of the third switch K3 is grounded.
The first end of the second switch K2 is an output end of the second charging branch 102, the second end of the second switch K2 is an input end of the second charging branch 102, the first end of the third switch K3 is a first end of the second charging branch 102, and the second end of the third switch K3 is a second end of the second charging branch 102.
When the second switch K2 is turned on, the second voltage source is turned on with the second end of the reference capacitor CREF, and when the third switch K3 is turned on, the first end of the reference capacitor CREF is turned on with the ground, at this time, the second charging branch 102 enters a charging stage, and the second voltage source charges the reference capacitor CREF, that is, when both the second switch K2 and the third switch K3 are turned on, the second voltage source charges negative charges the reference capacitor CREF.
As shown in fig. 1, the charge transfer branch 103 includes a resistor R1, a fourth switch K4, and a fifth switch K5. The first end of the fourth switch K4 is electrically connected to the first end of the capacitor module CS, the second end of the fourth switch K4 is electrically connected to the first end of the resistor R1, the second end of the resistor R1 is electrically connected to the first end of the reference capacitor CREF, the second end of the reference capacitor CREF is electrically connected to the first end of the fifth switch K5, and the second end of the fifth switch K5 is grounded.
Illustratively, the first terminal of the fourth switch K4 is the first terminal of the charge transfer branch 103, the second terminal of the resistor R1 is the second terminal of the charge transfer branch 103, the first terminal of the fifth switch K5 is the third terminal of the charge transfer branch 103, and the second terminal of the fifth switch K5 is the fourth terminal of the charge transfer branch 103.
When the fourth switch K4 is closed, the first end of the capacitor module CS is turned on with the first end of the resistor R1, while the second end of the resistor R1 is turned on with the first end of the reference capacitor CREF, and when the fifth switch K5 is closed, the second end of the reference capacitor CREF is turned on with the ground.
When the first switch K1, the second switch K2 and the third switch K3 are all closed and the fourth switch K4 and the fifth switch K5 are opened, the negative-pressure charge transfer circuit enters a charging stage, and the first voltage source and the second voltage source charge the capacitor module CS and the reference capacitor CREF respectively. When the first switch K1, the second switch K2 and the third switch K3 are all turned off, and the fourth switch K4 and the fifth switch K5 are turned on, the negative-pressure charge transfer circuit enters a charge transfer stage, and charge transfer is performed between the capacitor module CS and the reference capacitor CREF through the resistor R1, that is, the charge transfer branch 103 can conduct the first end of the capacitor module CS and the first end of the reference capacitor CREF and conduct the second end of the reference capacitor CREF and ground in the charge transfer stage.
In some embodiments, the charge transfer branch 103 is further configured to conduct the second terminal of the reference capacitor CREF and ground during the charge draining phase; the charging branch is also used to conduct the first terminal of the reference capacitor CREF and ground during the charge-draining phase.
Illustratively, the charge draining phase refers to draining of the charge in the capacitor module CS and the reference capacitor CREF. After the charge transfer is finished, the voltages at the two ends of the reference capacitor CREF are connected to a later-stage detection circuit, so that the later-stage detection circuit measures the voltages at the two ends of the reference capacitor CREF; after the measurement is finished, the negative pressure charge transfer circuit enters a charge emptying stage. At this time, the charge transfer branch 103 may conduct the third terminal of the charge transfer branch 103 to ground, that is, conduct the second terminal of the reference capacitor CREF to ground, so that the charge at the second terminal of the reference capacitor CREF is released to ground; meanwhile, the third end of the charging branch circuit and the fourth end of the charging branch circuit can be conducted, namely, the first end of the reference capacitor CREF and the ground are conducted, so that the electric charge at the first end of the reference capacitor CREF is released to the ground, and the electric charge in the reference capacitor CREF can be emptied.
In some embodiments, with continued reference to fig. 1, the negative voltage charge transfer circuit further includes a sixth switch K6, a first terminal of the sixth switch K6 is electrically connected to the first terminal of the capacitor module CS, and a second terminal of the sixth switch K6 is grounded.
The sixth switch K6 is configured to conduct the first terminal of the capacitor module CS and ground during the charge draining period.
In an exemplary charge discharging phase, the sixth switch K6 is closed to conduct the first end of the capacitor module CS and the ground, so that the charge at the first end of the capacitor module CS is discharged to the ground, and the second end of the capacitor module CS is always conducted to the ground, so that the charge at the second end of the capacitor module CS is continuously discharged to the ground, and the charge in the capacitor module CS can be discharged.
Fig. 2 is a schematic structural diagram of a capacitive touch detection circuit provided in an embodiment of the present application, where, as shown in fig. 2, the capacitive touch detection circuit includes a negative-pressure charge transfer circuit according to any one of the above embodiments.
Wherein, during the detection phase, the second terminal of the reference capacitor CREF is conducted with the ground.
Illustratively, opening the fourth terminal of the charging branch at the second terminal of the charging branch and turning on the third terminal of the charge transfer branch 103 and the fourth terminal of the charge transfer branch 103, for example, as shown in fig. 2, opening the fourth switch K4 and closing the fifth switch K5 may turn on the second terminal of the reference capacitor CREF and ground.
In some embodiments, with continued reference to fig. 2, the capacitive touch detection circuit further includes a detection module. The first input end of the detection module is electrically connected with the first end of the reference capacitor CREF, and the second input end of the detection module is electrically connected with the second end of the reference capacitor CREF.
The detection module is used for receiving the voltages at two ends of the reference capacitor CREF in the detection stage and detecting the touch control signal based on the voltages at two ends of the reference capacitor CREF.
Illustratively, the charge transfer is completed between the capacitor module CS and the reference capacitor CREF, and after the third terminal of the charge transfer branch 103 and the fourth terminal of the charge transfer branch 103 are turned on, the first terminal of the reference capacitor CREF and the first input terminal of the detection module are turned on, the second terminal of the reference capacitor CREF and the second input terminal of the detection module are turned on, and the voltages at the two terminals of the reference capacitor CREF are transmitted to the detection module. The detection module can measure the voltages at two ends of the received reference capacitor CREF to realize detection of the touch signal.
In some embodiments, with continued reference to fig. 2, the capacitive touch detection circuit further includes a seventh switch K7 and an eighth switch K8. The first end of the seventh switch K7 is electrically connected to the first end of the reference capacitor CREF, and the first end of the eighth switch K8 is electrically connected to the second end of the reference capacitor CREF; the second end of the seventh switch K7 is electrically connected with the first input end of the detection module, and the second end of the eighth switch K8 is electrically connected with the second input end of the detection module.
A seventh switch K7, configured to conduct the first end of the reference capacitor CREF and the first input end of the detection module in the detection phase; the eighth switch K8 is configured to conduct the second terminal of the reference capacitor CREF and the second input terminal of the detection module during the detection phase.
Illustratively, the charge transfer is completed between the capacitor module CS and the reference capacitor CREF, and after the third terminal of the charge transfer branch 103 and the fourth terminal of the charge transfer branch 103 are turned on, the seventh switch K7 and the eighth switch K8 are closed, and the detection phase is entered. At this time, the first terminal of the reference capacitor CREF is conducted with the first input terminal of the detection module, and the second terminal of the reference capacitor CREF is conducted with the second input terminal of the detection module.
In this embodiment of the present application, the capacitive touch detection circuit includes the negative-pressure charge transfer circuit of the foregoing embodiment, and since the negative-pressure charge transfer circuit uses the capacitor with a smaller volume as the reference capacitor, the negative-pressure charge transfer circuit has a smaller volume, so that the volume of the capacitive touch detection circuit can be reduced.
The apparatus embodiments described above are merely illustrative, wherein the elements illustrated as separate elements may or may not be physically separate, and the elements shown as elements may or may not be physical elements, may be located in one place, or may be distributed over a plurality of network elements. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of this embodiment. Those of ordinary skill in the art will understand and implement the present invention without undue burden.
From the above description of the embodiments, it will be apparent to those skilled in the art that the embodiments may be implemented by means of software plus necessary general hardware platforms, or of course may be implemented by means of hardware. Based on this understanding, the foregoing technical solution may be embodied essentially or in a part contributing to the prior art in the form of a software product, which may be stored in a computer readable storage medium, such as ROM/RAM, a magnetic disk, an optical disk, etc., including several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute the method described in the respective embodiments or some parts of the embodiments.
Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present application, and are not limiting thereof; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the corresponding technical solutions.
Claims (10)
1. The negative-pressure charge transfer circuit is characterized by comprising a charging branch, a charge transfer branch, a capacitor module and a reference capacitor; wherein, the liquid crystal display device comprises a liquid crystal display device,
the first end of the charging branch is electrically connected with the first end of the capacitor module, the second end of the capacitor module is grounded, the second end of the charging branch is electrically connected with the second end of the reference capacitor, the third end of the charging branch is electrically connected with the first end of the reference capacitor, the input end of the charging branch is connected with a voltage source, and the fourth end of the charging branch is grounded; the first end of the charge transfer branch is electrically connected with the first end of the capacitor module, and the second end of the charge transfer branch is electrically connected with the first end of the reference capacitor; the third end of the charge transfer branch is electrically connected with the second end of the reference capacitor, and the fourth end of the charge transfer branch is grounded;
the charging branch is used for respectively charging the capacitor module and the reference capacitor in a charging stage;
the charge transfer branch is used for moving the charge in the capacitor module to the reference capacitor in a charge transfer stage.
2. The negative-pressure charge transfer circuit of claim 1, wherein the charging branch comprises a first charging branch and a second charging branch; wherein, the liquid crystal display device comprises a liquid crystal display device,
the output end of the first charging branch is electrically connected with the first end of the capacitor module, and the input end of the first charging branch is connected with a first voltage source; the output end of the second charging branch is electrically connected with the second end of the reference capacitor, the first end of the second charging branch is electrically connected with the first end of the reference capacitor, the input end of the second charging branch is connected with a second voltage source, and the second end of the second charging branch is grounded; the voltage of the first voltage source is the same as the voltage of the second voltage source, or the first voltage source is multiplexed into the second voltage source;
the first charging branch is used for charging the capacitor module in the charging stage;
the second charging branch is used for charging the reference capacitor in the charging stage.
3. The negative-pressure charge transfer circuit of claim 2, wherein the first charging branch comprises a first switch; wherein, the liquid crystal display device comprises a liquid crystal display device,
the first end of the first switch is electrically connected with the first end of the capacitor module, and the second end of the first switch is connected with the first voltage source.
4. The negative-pressure charge transfer circuit of claim 2, wherein the second charging branch comprises a second switch and a third switch; wherein, the liquid crystal display device comprises a liquid crystal display device,
the first end of the second switch is electrically connected with the second end of the reference capacitor, the second end of the second switch is connected with the second voltage source, the first end of the third switch is electrically connected with the first end of the reference capacitor, and the second end of the third switch is grounded.
5. The negative pressure charge transfer circuit of any one of claims 1-4, wherein the charge transfer leg comprises a resistor, a fourth switch, and a fifth switch; wherein, the liquid crystal display device comprises a liquid crystal display device,
the first end of the fourth switch is electrically connected with the first end of the capacitor module, the second end of the fourth switch is electrically connected with the first end of the resistor, the second end of the resistor is electrically connected with the first end of the reference capacitor, the second end of the reference capacitor is electrically connected with the first end of the fifth switch, and the second end of the fifth switch is grounded;
the charge transfer branch is used for conducting the first end of the capacitor module and the first end of the reference capacitor in the charge transfer stage, and conducting the second end of the reference capacitor and ground.
6. The negative-pressure charge transfer circuit of claim 5, wherein the charge transfer branch is further configured to conduct the second terminal of the reference capacitor to ground during a charge dump phase;
the charging branch is further configured to conduct the first end of the reference capacitor and ground during the charge draining stage.
7. The negative-pressure charge transfer circuit of any one of claims 1-6, further comprising a sixth switch, a first end of the sixth switch being electrically connected to the first end of the capacitive module, a second end of the sixth switch being grounded;
the sixth switch is used for conducting the first end of the capacitor module and the ground in a charge emptying stage.
8. A capacitive touch detection circuit comprising the negative-pressure charge transfer circuit of any one of claims 1-7, wherein during a detection phase, the second terminal of the reference capacitor is conductive to ground.
9. The capacitive touch detection circuit of claim 8, further comprising a detection module;
the first input end of the detection module is electrically connected with the first end of the reference capacitor, and the second input end of the detection module is electrically connected with the second end of the reference capacitor;
the detection module is used for receiving the voltages at the two ends of the reference capacitor in the detection stage and detecting a touch signal based on the voltages at the two ends of the reference capacitor.
10. The capacitive touch detection circuit of claim 9, further comprising a seventh switch and an eighth switch;
the first end of the seventh switch is electrically connected with the first end of the reference capacitor, and the first end of the eighth switch is electrically connected with the second end of the reference capacitor; the second end of the seventh switch is electrically connected with the first input end of the detection module, and the second end of the eighth switch is electrically connected with the second input end of the detection module;
the seventh switch is used for conducting the first end of the reference capacitor and the first input end of the detection module in the detection stage;
the eighth switch is configured to conduct the second end of the reference capacitor and the second input end of the detection module in the detection stage.
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| CN116317545B (en) | 2023-08-08 |
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