CN111625110A - Touch sensing circuit, touch display panel, display device and electronic equipment - Google Patents
Touch sensing circuit, touch display panel, display device and electronic equipment Download PDFInfo
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- 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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- 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
- G06F3/0412—Digitisers structurally integrated in a display
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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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- G06—COMPUTING; CALCULATING OR COUNTING
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Abstract
The invention relates to a touch sensing circuit, a touch display panel, a display device and an electronic device. The touch sensing circuit includes: the driving voltage circuit is used for generating two preset voltage signals with equal amplitude and opposite phase, and the two preset voltage signals are simultaneously provided to adjacent equivalent capacitors in a plurality of equivalent capacitors on the touch panel; the comparator, connect the first electric capacity between negative input end and carry-out terminal of the comparator, the first electric capacity connects a first switch in parallel; the inverting input end of the comparator is connected with the equivalent capacitors; and the conversion circuit is connected to the output end of the comparator and used for converting the analog voltage signal output by the comparator into a digital voltage signal. The invention can improve the accuracy of touch position detection, avoid failure of a touch detection mechanism, improve the sensitivity of touch detection and reduce misjudgment of touch behaviors.
Description
Technical Field
The present invention relates to the field of display technologies, and in particular, to a touch sensing circuit for sensing touch operations on a touch display panel, a touch display panel including the touch sensing circuit, a display device, and an electronic apparatus including the display device.
Background
With the rapid development and application of electronic information technology, touch display panels with both touch and display functions have been widely applied to various electronic products, such as Global Positioning System (GPS), Personal Digital Assistant (PDA), cellular phone (cellular phone), and Hand-held PC, in recent years, to replace conventional input devices (e.g., keyboard and mouse). The great change in the design not only improves the human-computer interface affinity of the electronic devices, but also saves more space for installing a display panel with larger size and is convenient for users to browse data because the traditional input equipment is omitted.
In the related art, the touch panel can be roughly classified into a resistive type, a capacitive type, a sonic type, an optical type, an electromagnetic type, and the like, wherein the capacitive type touch panel is the most common product. The capacitive touch panel usually adopts a switched capacitor technology, and by using a charge redistribution principle, the capacitance can be converted into a corresponding voltage, and the converted voltage is converted by an analog-digital converter to obtain a digital signal which can be analyzed by a signal processing unit.
However, when the capacitive touch panel is applied, the touch operation behavior on the touch panel often only generates a small equivalent capacitance variation, so that a corresponding small voltage variation is caused, which is easy to cause difficulty in signal reading and judgment, and further causes problems such as reduced accuracy of touch point position detection, reduced touch sensitivity, and even failure of touch detection mechanism. Therefore, there is a need to provide a new technical solution to improve one or more of the problems in the above solutions.
It is noted that this section is intended to provide a background or context to the embodiments of the invention that are recited in the claims. The description herein is not admitted to be prior art by inclusion in this section.
Disclosure of Invention
An object of the present invention is to provide a touch sensing circuit, which overcomes at least some of the problems caused by the limitations and disadvantages of the related art.
According to a first aspect of embodiments of the present invention, there is provided a touch sensing circuit, including:
the driving voltage circuit is used for generating two preset voltage signals with equal amplitude and opposite phase, and the two preset voltage signals are simultaneously provided to adjacent equivalent capacitors in a plurality of equivalent capacitors on the touch panel;
the comparator, connect the first electric capacity between negative input end and carry-out terminal of the comparator, the first electric capacity connects a first switch in parallel; the inverting input end of the comparator is connected with the equivalent capacitors;
and the conversion circuit is connected to the output end of the comparator and used for converting the analog voltage signal output by the comparator into a digital voltage signal.
In an embodiment of the invention, the first switch is connected to a timing signal generating circuit for generating a predetermined timing signal and providing the predetermined timing signal to the first switch.
In the embodiment of the invention, the non-inverting input end of the comparator is connected with a reference voltage providing circuit.
In an embodiment of the invention, the two preset voltage signals are differential scanning signals.
In an embodiment of the invention, the two preset voltage signals are sequentially and cyclically provided to adjacent equivalent capacitors in the plurality of equivalent capacitors.
In an embodiment of the present invention, the conversion circuit is an analog-to-digital converter.
According to a second aspect of the embodiments of the present invention, a touch display panel is provided, which includes the touch sensing circuit of any one of the embodiments.
In the embodiment of the invention, the equivalent capacitors are formed by equivalent upper and lower electrodes corresponding to pixel points on the touch panel.
According to a third aspect of the embodiments of the present invention, there is provided a display device, including the touch display panel according to any one of the embodiments.
According to a fourth aspect of the embodiments of the present invention, there is provided an electronic apparatus including the display device according to the above embodiments.
The technical scheme provided by the embodiment of the invention can have the following beneficial effects:
in the embodiment of the invention, two preset voltage signals with equal amplitude and opposite phase are provided for adjacent equivalent capacitors in a plurality of equivalent capacitors on the touch panel, so that the charge storage effect of the equivalent capacitors can be eliminated, and only the capacitance variation of the equivalent charge variation is captured, so that the voltage variation which is effectively amplified can be obtained at the output end of the comparator, the position detection accuracy of the touch point is further improved, the failure of a touch detection mechanism is avoided, the touch detection sensitivity is improved, and the misjudgment of the touch behavior is reduced.
Drawings
FIG. 1 illustrates a prior art switched capacitor circuit;
FIG. 2 is a schematic diagram of a conventional touch panel touch detection system;
FIG. 3 is a schematic diagram of a touch detection circuit of a conventional touch panel;
FIG. 4 is a schematic diagram of another prior art switched capacitor circuit;
FIG. 5 is a schematic diagram of a touch sensing circuit according to an embodiment of the invention;
FIG. 6 is a schematic diagram illustrating a touch sensing circuit according to an embodiment of the invention.
Detailed Description
Example embodiments will now be described more fully with reference to the accompanying drawings. Example embodiments may, however, be embodied in many different forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of example embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.
Furthermore, the drawings are merely schematic illustrations of the invention and are not necessarily drawn to scale. The same reference numerals in the drawings denote the same or similar parts, and thus their repetitive description will be omitted. Some of the block diagrams shown in the figures are functional entities and do not necessarily correspond to physically or logically separate entities.
Capacitive input devices such as touch panels usually employ a switched capacitor technology, and the principle of charge redistribution is used to convert capacitance into a voltage, and the converted voltage is converted by an analog-to-digital converter to obtain data that can be analyzed by a signal processing system.
As shown in fig. 1, in the exemplary switched capacitor circuit, based on the charge principle Q ═ C × V (Q represents the charge amount, C represents the capacitance value, and V represents the voltage value), the corresponding capacitor can obtain the corresponding voltage under the condition that the charge is not changed, so that the corresponding capacitance variation can be converted into the corresponding voltage variation.
In an electronic device having a capacitive touch panel, as shown in fig. 2, a processor unit sends a detection signal to detect whether a touch operation is generated in a touch panel area, a pixel point of the touch panel corresponding to an upper electrode 200 and a lower electrode 200 is regarded as an equivalent capacitor, and when the equivalent capacitor value in the corresponding area changes during the touch operation, the capacitance of the equivalent capacitor can be converted into a readable voltage value.
As shown in fig. 3, the driving voltage circuit sequentially sends out the scan signal (tx ckt) to inject charges into the equivalent capacitor Cxy, the converting circuit converts the amount of charges to be detected into a readable voltage signal, and the readable voltage signal is converted into an interpretable digital signal (rx ckt) by the converter, and according to the obtained digital signal, it can be determined whether there is a touch behavior.
In conjunction with the switched capacitor circuit shown in fig. 4, the equivalent capacitance Ct to be detected is converted into a readable voltage signal VO, and can be converted into a readable Digital signal by an Analog-to-Digital Converter (ADC). For example, the processor unit generates the output voltage signal Vdrv to inject charges into the equivalent capacitor Ct, and transfers the charges stored in the equivalent capacitor Ct to the capacitor Cfb through the timing control of the switch S1, thereby generating the corresponding output voltage signal VO.
Specifically, the capacitance-to-voltage conversion is shown in formula one.
The formula I is as follows: vdrv Ct ═ Cfb ═ Vref-VO, 0 ≦ VO ≦ Vref.
To obtain a reasonable voltage value, the minimum value of the capacitor Cfb is selected as shown in equation two.
The formula II is as follows: cfb _ min Vdrv Ct/Vref.
When a touch behavior mechanism occurs, the equivalent capacitance changes due to the movement of the charge, for example, the equivalent capacitance Ct changes to Ct (1-), which represents the capacitance variation (usually less than or equal to 10%) of the equivalent capacitance Ct, and at this time, the corresponding voltage change can be obtained, as shown in formula three and formula four.
The formula III is as follows: vdrv Ct (1- (1-))) Cfb ((Vref-VO)1)-(Vref-VO2))
The formula four is as follows: dV _ max ═ Vdrv Ct/Cfb _ min; .
Substituting the formula two into the formula four to obtain the formula five: dV _ max ═ Vref.
For example, when Vdrv is 3V, Vref is 1.5V, Ct is 5pF and is 10%, Cfb is 10pF, the maximum voltage variation dV _ max is 150mV, and the voltage variation is small, so that it is easily covered by the interference voltage, and it is impossible to effectively determine whether a touch operation occurs, resulting in a failure of the touch detection mechanism.
In summary, when applied to a capacitance detection input device such as a capacitive touch panel, since the touch operation (such as clicking, pressing, sliding, etc.) on the touch panel usually generates only a small equivalent capacitance variation, the corresponding small voltage variation is liable to cause difficulty in signal reading and determining.
To solve the above problems or disadvantages, a touch sensing circuit is first provided in the present exemplary embodiment. As shown in fig. 5, the touch sensing circuit includes: a driving voltage circuit 1, a comparator 3, and a conversion circuit 6; the driving voltage circuit 1 is configured to generate two preset voltage signals with equal amplitude and opposite phase, and the two preset voltage signals are simultaneously provided to adjacent equivalent capacitors of a plurality of equivalent capacitors 2 on the touch panel; a first capacitor 4 is connected between the inverting input end and the output end of the comparator 3, and the first capacitor 4 is connected with a first switch 5 in parallel; the inverting input end of the comparator 3 is connected with the equivalent capacitors 2; the conversion circuit 6 is connected to the output end of the comparator 3, and is configured to convert the analog voltage signal output by the comparator 3 into a digital voltage signal.
In this embodiment, as shown in fig. 5, two preset voltage signals with equal amplitude and opposite phase are provided to adjacent equivalent capacitors of a plurality of equivalent capacitors on the touch panel, so that the charge storage effect of the equivalent capacitors can be eliminated, and only the capacitance variation of the equivalent charge variation is captured, so that the voltage variation can be effectively amplified at the output terminal Dout. The scheme of the embodiment provides two preset voltage signals with equal amplitude and opposite phase, and a complementary capacitance elimination mode is adopted, so that the corresponding voltage variation dV can be effectively increased under the same equivalent capacitance variation.
Specifically, in the embodiment of the present invention, the first switch is connected to a timing signal generating circuit for generating a predetermined timing signal and providing the predetermined timing signal to the first switch, and the first switch S1 may be a CMOS transistor switch, but is not limited thereto.
In the embodiment of the invention, the non-inverting input end of the comparator is connected with a reference voltage providing circuit. The reference voltage providing circuit is used for providing a reference voltage signal to the non-inverting input terminal of the comparator, wherein the reference voltage signal is the voltage signal Vref shown in fig. 6.
In the embodiment of the present invention, the two preset voltage signals are Differential scanning signals, i.e. Differential signals, in general, the driving end sends two signals (such as V + and V-) with equal amplitude and opposite phase.
In an embodiment of the invention, the two preset voltage signals are sequentially and cyclically provided to adjacent equivalent capacitors in the plurality of equivalent capacitors. As shown in fig. 6, after the two preset voltage signals Vdrvp and Vdrvn with equal and opposite phases are simultaneously supplied to C1 and C2 and scanned, the two preset voltage signals Vdrvp and Vdrvn … … with equal and opposite phases are simultaneously supplied to C2 and C3, and thus the preset voltage signals are sequentially and cyclically supplied to the plurality of equivalent capacitors C1 to Cn.
In an embodiment of the invention, the conversion circuit may be an analog-to-digital converter ADC for converting an analog voltage signal output by the comparator into a digital voltage signal, and providing the digital voltage signal to a processor unit of the touch panel, so as to facilitate, for example, determining a position of a touch point.
In the scheme provided in this embodiment, as shown in fig. 6, it is assumed that the equivalent capacitance C1 ═ C2 … ═ Ct ═ Cn ═ Cu, | Vdrvp | ═ Vdrvn | > -Vdrv,
specifically, the capacitance-to-voltage conversion is shown in formula one.
Formula six: vdrv Cu (1- (1-))) ═ Cfb | Vref-VO |, and | Vref-VO | ≦ Vref.
To obtain a reasonable voltage value, the minimum value of the capacitor Cfb is selected as shown in equation two.
The formula seven: cfb _ min Vdrv Cu/Vref.
When a touch behavior mechanism occurs, the equivalent capacitance changes due to the movement of charges, for example, the equivalent capacitance Cu changes to Cu (1-), which represents the capacitance variation (usually less than or equal to 10%) of the equivalent capacitance Ct, and then corresponding voltage changes can be obtained, as shown in formula three and formula four.
The formula eight: vdrv Ct (1- (1-))) Cfb (| Vref-VO)1|-|Vref-VO2|)
The formula is nine: dV _ max ═ VO1-VO2|＝*Vdrv*Cu/Cfb_min；。
Substituting the formula seven into the formula nine can obtain the formula ten: dV _ max is Vref.
For example, when Vdrv is 3V, Vref is 1.5V, Ct is 5pF and 10%, Cfb is 10pF, the maximum voltage change amount dV _ max is 1.5V, which effectively amplifies the voltage change amount, and thus, whether a touch operation occurs can be effectively determined, and at the same time, the area of the metal plate of the capacitor Cfb can be reduced.
In one exemplary experiment:
in the touch sensing circuit, each parameter value is Vdrv ═ 3V, Vref ═ 1.5V, Ct ═ 5pF, ═ 1% to 10%, Cfb ═ 10 pF; performing a touch operation experiment on the display panel using the touch sensing circuit to obtain the following experimental data:
VO output value before touch behavior occurs:
VO output value after touch behavior occurs:
| rx1 | rx2 | rx3 | rx4 | rx5 | rx6 | rx7 | rx8 | rx9 | rx10 | rx11 | rx12 | rx13 | rx14 | |
| VO1 | 1.496 | 1.496 | 1.496 | 1.496 | 1.496 | 1.496 | 1.496 | 1.496 | 1.496 | 1.496 | 1.496 | 1.496 | 1.496 | 1.496 |
| VO2 | 1.496 | 1.496 | 1.496 | 1.496 | 1.496 | 1.421 | 1.271 | 1.271 | 1.421 | 1.496 | 1.496 | 1.496 | 1.496 | 1.496 |
| VO3 | 1.496 | 1.496 | 1.496 | 1.421 | 1.271 | 1.197 | 1.197 | 1.197 | 1.197 | 1.271 | 1.421 | 1.496 | 1.496 | 1.496 |
| VO4 | 1.496 | 1.496 | 1.346 | 1.271 | 1.271 | 1.271 | 1.271 | 1.271 | 1.271 | 1.271 | 1.271 | 1.346 | 1.496 | 1.496 |
| VO5 | 1.496 | 1.496 | 1.496 | 1.496 | 1.496 | 1.496 | 1.496 | 1.496 | 1.496 | 1.496 | 1.496 | 1.496 | 1.496 | 1.496 |
| VO6 | 1.496 | 1.496 | 1.646 | 1.721 | 1.721 | 1.721 | 1.721 | 1.721 | 1.721 | 1.721 | 1.721 | 1.646 | 1.496 | 1.496 |
| VO7 | 1.496 | 1.496 | 1.496 | 1.571 | 1.721 | 1.795 | 1.795 | 1.795 | 1.795 | 1.721 | 1.571 | 1.496 | 1.496 | 1.496 |
| VO8 | 1.496 | 1.496 | 1.496 | 1.496 | 1.496 | 1.571 | 1.721 | 1.721 | 1.571 | 1.496 | 1.496 | 1.496 | 1.496 | 1.496 |
| VO9 | 1.496 | 1.496 | 1.496 | 1.496 | 1.496 | 1.496 | 1.496 | 1.496 | 1.496 | 1.496 | 1.496 | 1.496 | 1.496 | 1.496 |
| VO10 | 1.496 | 1.496 | 1.496 | 1.496 | 1.496 | 1.496 | 1.496 | 1.496 | 1.496 | 1.496 | 1.496 | 1.496 | 1.496 | 1.496 |
Δ VO values before and after occurrence of the touch behavior:
| rx1 | rx2 | rx3 | rx4 | rx5 | rx6 | rx7 | rx8 | rx9 | rx10 | rx11 | rx12 | rx13 | rx14 | |
| ΔVO1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| ΔVO2 | 0 | 0 | 0 | 0 | 0 | -0.075 | -0.075 | -0.075 | -0.075 | 0 | 0 | 0 | 0 | 0 |
| ΔVO3 | 0 | 0 | 0 | -0.075 | -0.225 | -0.299 | -0.299 | -0.299 | -0.299 | -0.225 | -0.075 | 0 | 0 | 0 |
| ΔVO4 | 0 | 0 | -0.15 | -0.225 | -0.225 | -0.225 | -0.225 | -0.225 | -0.225 | -0.225 | -0.225 | -0.15 | 0 | 0 |
| ΔVO5 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| ΔVO6 | 0 | 0 | 0.15 | 0.225 | 0.225 | 0.225 | 0.225 | 0.225 | 0.225 | 0.225 | 0.225 | 0.15 | 0 | 0 |
| ΔVO7 | 0 | 0 | 0 | 0.075 | 0.225 | 0.299 | 0.299 | 0.299 | 0.299 | 0.225 | 0.075 | 0 | 0 | 0 |
| ΔVO8 | 0 | 0 | 0 | 0 | 0 | 0.075 | 0.225 | 0.225 | 0.225 | 0 | 0 | 0 | 0 | 0 |
| ΔVO9 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| ΔVO10 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
ADC output difference before and after touch behavior occurs:
| rx1 | rx2 | rx3 | rx4 | rx5 | rx6 | rx7 | rx8 | rx9 | rx10 | rx11 | rx12 | rx13 | rx14 | |
| Δdout1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Δdout2 | 0 | 0 | 0 | 0 | 0 | -94 | -281 | -281 | -94 | 0 | 0 | 0 | 0 | 0 |
| Δdout3 | 0 | 0 | 0 | -94 | -281 | -374 | -374 | -374 | -374 | -281 | -94 | 0 | 0 | 0 |
| Δdout4 | 0 | 0 | -188 | -281 | -281 | -281 | -281 | -281 | -281 | -281 | -281 | -188 | 0 | 0 |
| Δdout5 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Δdout6 | 0 | 0 | 188 | 281 | 281 | 281 | 281 | 281 | 281 | 281 | 281 | 188 | 0 | 0 |
| Δdout7 | 0 | 0 | 0 | 94 | 281 | 374 | 374 | 374 | 374 | 281 | 94 | 0 | 0 | 0 |
| Δdout8 | 0 | 0 | 0 | 0 | 0 | 94 | 281 | 281 | 94 | 0 | 0 | 0 | 0 | 0 |
| Δdout9 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Δdout10 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
before and after the touch action occurs, the interpretable ADC outputs a difference value:
it can be seen from the above experimental data that, by using the differential signal capacitance detection technology, two preset voltage signals with equal amplitude and opposite phase are provided to adjacent equivalent capacitors of a plurality of equivalent capacitors on the touch panel, and after the touch operation is performed, an obviously amplified voltage variation is obtained, so that an obviously amplified interpretable ADC output difference is obtained.
In summary, the technical solution provided by the embodiment of the present invention has at least the following technical advantages:
1) providing two preset voltage signals with equal amplitude and opposite phase to adjacent equivalent capacitors in a plurality of equivalent capacitors on a touch panel, eliminating partial charges on the equivalent capacitor Ct to capture effective capacitance variation, so that amplified voltage variation dV can be obtained correspondingly at an output end, that is, the voltage variation of a touch behavior can be effectively amplified, the accuracy of touch point position detection can be improved, failure of a touch detection mechanism is avoided, and the touch detection sensitivity is improved; 2) because the voltage variation of the touch behavior can be effectively amplified, the signal-to-noise ratio can be improved, the requirement of a signal processing circuit in the touch panel can be reduced, the cost is reduced, meanwhile, the misjudgment of the touch operation behavior can be reduced, and the touch detection accuracy and sensitivity are improved; 3) the capacitance detection technology of differential signal scanning is adopted, so that the use area of the capacitor can be reduced, and the device is favorable for lightness, thinness, miniaturization and the like.
According to a second aspect of the embodiments of the present invention, a touch display panel is provided, which includes the touch sensing circuit of any one of the embodiments.
In the embodiment of the invention, the equivalent capacitors are formed by equivalent upper and lower electrodes corresponding to pixel points on the touch panel. Reference may be made in particular to the prior art, which is not described in detail herein.
According to a third aspect of the embodiments of the present invention, there is provided a display device, including the touch display panel according to any one of the embodiments.
According to a fourth aspect of the embodiments of the present invention, there is provided an electronic apparatus including the display device according to the above embodiments.
In the touch display panel, the display device and the electronic device of the embodiment of the invention, in the capacitor circuit during switching, the two preset voltage signals with equal amplitude and opposite phase are provided for the adjacent equivalent capacitors in the plurality of equivalent capacitors on the touch panel, so that the charge storage effect of the equivalent capacitors can be eliminated, and only the capacitance variation of the equivalent charge variation is captured, so that the effectively amplified voltage variation can be obtained at the output end of the comparator, the accuracy of detecting the position of the touch point is further improved, the failure of a touch detection mechanism is avoided, and the touch detection sensitivity is improved.
In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", and the like, indicate orientations and positional relationships based on those shown in the drawings, and are used only for convenience of description and simplicity of description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be considered as limiting the present invention.
Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.
In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.
In the present invention, unless otherwise expressly stated or limited, "above" or "below" a first feature means that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact with each other via another feature therebetween. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.
In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples described in this specification can be combined and combined by those skilled in the art.
Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the invention and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims.
Claims (10)
1. A touch sensing circuit, comprising:
the driving voltage circuit is used for generating two preset voltage signals with equal amplitude and opposite phase, and the two preset voltage signals are simultaneously provided to adjacent equivalent capacitors in a plurality of equivalent capacitors on the touch panel;
the comparator, connect the first electric capacity between negative input end and carry-out terminal of the comparator, the first electric capacity connects a first switch in parallel; the inverting input end of the comparator is connected with the equivalent capacitors;
and the conversion circuit is connected to the output end of the comparator and used for converting the analog voltage signal output by the comparator into a digital voltage signal.
2. The touch sensing circuit of claim 1, wherein the first switch is connected to a timing signal generating circuit for generating a predetermined timing signal and providing the predetermined timing signal to the first switch.
3. The touch sensing circuit of claim 1, wherein a non-inverting input of the comparator is connected to a reference voltage providing circuit.
4. The touch sensing circuit according to any one of claims 1 to 3, wherein the two preset voltage signals are differential scanning signals.
5. The touch sensing circuit of claim 4, wherein the two preset voltage signals are sequentially provided to adjacent equivalent capacitors of the equivalent capacitors in a cyclic manner.
6. The touch sensing circuit of claim 4, wherein the conversion circuit is an analog-to-digital converter.
7. A touch display panel comprising the touch sensing circuit of any one of claims 1 to 6.
8. The touch display panel of claim 7, wherein the equivalent capacitors are equivalent to upper and lower electrodes corresponding to pixel points on the touch panel.
9. A display device comprising the touch display panel according to claim 7 or 8.
10. An electronic device characterized by comprising the display device according to claim 9.
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| CN201910148697.XA CN111625110A (en) | 2019-02-28 | 2019-02-28 | Touch sensing circuit, touch display panel, display device and electronic equipment |
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| CN201910148697.XA CN111625110A (en) | 2019-02-28 | 2019-02-28 | Touch sensing circuit, touch display panel, display device and electronic equipment |
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