CN203720826U - Capacitive touch screen detection circuit and capacitive touch control equipment - Google Patents
Capacitive touch screen detection circuit and capacitive touch control equipment Download PDFInfo
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- CN203720826U CN203720826U CN201420087680.0U CN201420087680U CN203720826U CN 203720826 U CN203720826 U CN 203720826U CN 201420087680 U CN201420087680 U CN 201420087680U CN 203720826 U CN203720826 U CN 203720826U
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- capacitive touch
- touch screen
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Abstract
The utility model is applicable to the technical field of touch control and provides a capacitive touch screen detection circuit. The capacitive touch screen detection circuit is arranged in capacitive touch control equipment and comprises a core detection module and a data processing and communication module, the core detection module is electrically connected with the data processing and communication module through a communication interface, and the data processing and communication module and the communication interface are electrically connected with a system circuit; and the core detection module is provided with an internal power supply and an internal ground, the capacitive touch control equipment is provided with a system power supply and a system ground, the internal power supply is connected with the system power supply through a first switch, and the internal ground and the system ground are connected through a second switch and are closed after the completion of detection. The capacitive touch screen detection circuit and the capacitive touch control equipment have the benefit that as the isolation from the power supply ground is carried out, inaccurate detection, misinformation and other situations cannot be generated when a touch screen is heavily pressed; the interference of the system power supply is avoided; as the data processing and communication module and the system circuit are positioned in a same power supply domain, the interface error or damage and other risks are eliminated, so that the reliability of the detection circuit is improved.
Description
Technical field
The utility model relates to touch technology field, relates in particular to a kind of capacitive touch screen testing circuit and capacitance touching control equipment.
Background technology
Capacitance touching control equipment is a kind of electronic equipment with capacitive touch screen, and it at least comprises capacitive touch screen and display device, comparatively commonly LCD.As Fig. 1, in the time having LCD equipment near capacitive touch screen, between LCD screen and capacitive touch screen, can produce stray capacitance, as the Clm in figure and Cln, can exert an influence to the Electric Field Distribution of capacitive touch screen, can siphon away the electric induced line sending on detecting electrode M and detecting electrode N.As Fig. 2, when slight touch, there is deformation in capacitance touch screen hardly, stray capacitance becomes Clm ' and Cln ', and its change amount is very little, now Clm ' ≈ Clm, Cln ' ≈ Cln, therefore almost constant when the relative no touch of this impact, touch-screen is detected and coordinates computed does not exert an influence substantially.With further reference to Fig. 3, in the time that touch-screen is subject to weight and deformation occurs, the amplitude of variation of stray capacitance is larger, now, stray capacitance Clm " with Cln " change when relative no touch a lot, thereby affect touch-screen testing result and coordinate precision, even can there is situation about reporting by mistake.
For the problems referred to above, prior art has proposed following several solution:
The first, structurally improves, and strengthen the hardness of touch-screen, or between touch-screen and LCD, fill other solid matter, the deformation amplitude of touch-screen when reducing weight, or increase the distance of touch-screen and LCD, reduce the electric field change that deformation brings.In the complete machine application that this scheme has been determined in a lot of structures, be not attainable, the method that strengthens cover plate hardness also can increase cost, and cannot deal with problems at all.
The second, solves by data processing, analyzes feature, trend and amplitude that touch-screen deformation exerts an influence to data, repairs and make up on software.This scheme also can only be improved to a certain extent, for serious still cannot the solving of deformation comparison, and has increased the complexity of software debugging, also likely accuracy of detection is brought to harmful effect.
The third, adopt ground isolation method, and which specifically has following two kinds:
1, as Chinese patent application 201310253774.0, simultaneously with reference to figure 4, testing circuit 401 and machine system 402 adopt different electrical power and ground, the ground of the ground of testing circuit 401 and system 402 is isolated from each other, testing circuit 401 adopts GND1, in system 402, other parts adopt GND2, now LCD will become incoherent conductor for touch-screen, the i.e. conductor of a suspension, can evade by prior art (Chinese patent application 201210212641.4) harmful effect that LCD brings completely.Meanwhile, for solve between testing circuit and system cannot communication problem, magnetic coupling or optocoupler can be set and realize communication.
2, as Chinese patent application 201310253774.0, simultaneously with reference to figure 5, testing circuit 501 and machine system 502 adopt different electrical power and ground, testing circuit and systematically between add a K switch 1, in detection time section, K1 is disconnected, detect after finishing K1 closure to supplement electric charge and to complete and the communication of system.
Said method 1 need to be set up magnetic coupling or Light Coupled Device, has improved cost; Method 2 is in the time that switch disconnects, and communication interface, can bring the extra risk such as interface error or damage, and need docking port to do special processing in different power domain from system complete machine, has also increased cost.Meanwhile, above two kinds of methods all cannot shield some extra interference relevant with system power supply, and accuracy of detection is brought to certain impact.
Utility model content
The purpose of this utility model is to provide a kind of capacitive touch screen testing circuit, is intended to effectively avoid weight on touching the impact detecting, and eliminates the interference relevant with system power supply simultaneously, improves accuracy of detection.
The utility model is to realize like this, a kind of capacitive touch screen testing circuit, be arranged in capacitance touching control equipment, comprise: core detection module and data processing and communication module, described core detection module is electrically connected with described data processing and communication module by communication interface, and described data processing and communication module and communication interface are all electrically connected with the circuit system of described capacitance touching control equipment;
Described core detection module has internal electric source and internally, and described capacitance touching control equipment has system power supply and systematically, and described internal electric source is connected by the first switch with system power supply, describedly internally with is systematically connected by second switch.
As optimal technical scheme of the present utility model:
Described the 3rd switch that systematically also passes through is connected with the output terminal of one drive circuit, and the output terminal current potential of described driving circuit equates with the output terminal current potential of the capacitor charging circuit in described capacitive touch screen testing circuit.
Described internal electric source is condenser type energy storage device.
Described the first switch comprises the first system gauge tap parallel with one another and the first testing circuit gauge tap; Described second switch comprises second system gauge tap parallel with one another and the second testing circuit gauge tap.
Another object of the present utility model is to provide a kind of capacitance touching control equipment, comprises display screen and capacitive touch screen that lamination arranges, also comprises described capacitive touch screen testing circuit.
Preferably, described display screen is LCDs.
The testing circuit that the utility model provides the power supply of core detection module, and the power supply of system, between respectively establish a switch, and in testing process, carry out power supply and isolate, make the display screen of touch control device is only an incoherent conductor for capacitance touch screen, makes capacitive touch screen that situation inaccurate or that misrepresent deliberately can not occur to detect in the time being subject to weight; Owing to having carried out isolated from power, avoid the interference of system power supply simultaneously, further improved accuracy of detection; In addition, this scheme is only core detection module to be carried out to the isolation on power supply ground, and other parts of testing circuit do not have and system power supply is isolated with ground, data processing wherein and communication module are still connected with system power supply and ground, that is to say data processing and communication module with circuit system in identical power domain, therefore eliminated interface error or damage equivalent risk, do not need docking port to carry out special processing yet, and then improved the reliability of testing circuit, and reduce cost.
Brief description of the drawings
Fig. 1 is the part-structure schematic diagram of capacitance touching control equipment in prior art;
Fig. 2 is the light pressure condition schematic diagram of capacitance touch screen in prior art;
Fig. 3 is the stress condition schematic diagram of capacitance touch screen in prior art;
Fig. 4 is the schematic diagram of capacitance touch screen isolation detection scheme one in prior art;
Fig. 5 is the schematic diagram of capacitance touch screen isolation detection scheme two in prior art;
Fig. 6 is the capacitive touch screen testing circuit schematic diagram that the utility model embodiment provides;
Fig. 7 is the partial circuit figure () of the capacitive touch screen testing circuit that provides of the utility model embodiment;
Fig. 8 is the partial circuit figure (two) of the capacitive touch screen testing circuit that provides of the utility model embodiment.
Embodiment
In order to make the purpose of this utility model, technical scheme and advantage clearer, below in conjunction with drawings and Examples, the utility model is further elaborated.Should be appreciated that specific embodiment described herein is only in order to explain the utility model, and be not used in restriction the utility model.
Fig. 6 shows the capacitive touch screen testing circuit schematic diagram that the utility model embodiment provides, and for convenience of explanation, only shows the part relevant to the present embodiment.
In conjunction with Fig. 6, the capacitive touch screen testing circuit that the utility model embodiment provides is arranged in capacitance touching control equipment, for touch event is detected.This capacitive touch screen testing circuit comprises: core detection module 1 and data processing and communication module 2, core detection module 1 carries out information interaction by communication interface 3 according to preset protocol and data processing and communication module 2, and data processing and communication module 2 and communication interface 3 are all electrically connected with the circuit system of capacitance touching control equipment 4.Further, core detection module 1 has internal electric source 11 and internally 12, and capacitance touching control equipment 4 has system power supply 41 and systematically 42, and system power supply 41 and internal electric source 11 are two separate power supplys, equally, systematically 42 and internally 12 is also separate.Internal electric source 11 is connected by the first switch 5 with system power supply 41, internally 12 with systematically 42 be connected by second switch 6, in touch event detection process, the first switch 5 and second switch 6 disconnect simultaneously, after detection finishes, the first switch 5 and second switch 6 are simultaneously closed, ensure testing circuit and system normal communication.Whole testing circuit is divided into several modules by the present embodiment, only make testing circuit a part-core detection module 1 internal electric source 11 with internally 12 be connected with ground 42 with the system power supply 41 of complete machine, and other parts of testing circuit are still connected with the circuit system of complete machine as data processing and communication module 2, simultaneously, core detection module 1 carries out communication by newly-increased communication interface 3 according to the agreement of new regulation and data processing and communication module 2, data processing and communication module 2 and the proper communication of system complete machine simultaneously, and then ensure core detection module 1 power supply can carry out normal communication by homologous ray while being isolated.
The principle of work of this capacitive touch screen testing circuit is: in testing process, the first switch 5 and second switch 6 disconnect simultaneously, the internal electric source 11 of core detection module 1 and the system power supply 41 of capacitance touching control equipment 4 are isolated, make the ground of core detection module 1 and the isolation of the ground of machine system, core detection module 1 is powered by internal electric source 11.Core detection module 1 is exported to data processing and communication module 2 according to the agreement of new definition by the communication interface 3 of new definition detecting data, and this information exchange is crossed the circuit system output of interface element to complete machine by data processing and communication module 2.After detection finishes, the first switch 5 and second switch 6 are simultaneously closed, and recovery core detection module 1 is communicated by letter with circuit system, and the internal electric source 11 that can be simultaneously core detection module 1 by system power supply 41 charges.The testing circuit that the embodiment of the present invention provides is owing to having carried out VDD-to-VSS isolation in testing process, make the display screen (as LCD) of touch control device is only an incoherent conductor for capacitance touch screen, makes capacitive touch screen that situation inaccurate or that misrepresent deliberately can not occur to detect in the time being subject to weight; Owing to having carried out isolated from power, avoid the interference of system power supply simultaneously, further improved accuracy of detection; In addition, this scheme is only core detection module to be carried out to the isolation on power supply ground, and other parts of testing circuit do not have and system power supply is isolated with ground, data processing wherein and communication module are still connected with system power supply and ground, that is to say data processing and communication module with circuit system in identical power domain, therefore eliminated interface error or damage equivalent risk, do not need docking port to carry out special processing yet, and then improved the reliability of testing circuit, and reduce cost.
Further, this testing circuit is realized connection and the disconnection on the power supply ground of core detection module 1 and capacitance touching control equipment 4 by paralleling switch.Specifically with reference to figure 7, the first above-mentioned switch 5 is included in the first system gauge tap 51 and the first testing circuit gauge tap 52 that between system power supply 41 and the internal electric source 11 of core detection module 1, are connected in parallel, and above-mentioned second switch 6 is included in systematically 42 and the second system gauge tap 61 being internally connected in parallel between 12 and the second testing circuit gauge tap 62 of core detection module 1.Wherein, system control the first system gauge tap 51 and second system gauge tap 61 closures, realize system power supply 41 and ground 42 and the internal electric source 11 of core detection module 1 and 12 be connected internally, for testing circuit powers on, after having powered on, touching detection-phase, system disconnects the first system gauge tap 51 and second system gauge tap 61, by testing circuit according to the disconnection that touches situation control the first testing circuit gauge tap 52 and the second testing circuit gauge tap 62 be connected.Be that testing circuit powers on by system, the disconnection by testing circuit control the first switch and second switch be connected.Can make testing circuit complete fast and effectively by paralleling switch and power on and enter normal operating conditions, circuit structure is simple, and good reliability is easy to implement.
With further reference to Fig. 7, systematically 42 can also be connected with the output terminal of one drive circuit by the 3rd switch 7, the output terminal current potential of this driving circuit equates with the output terminal current potential of the capacitor charging circuit in capacitive touch screen testing circuit, and the 3rd switch 7 is closure in the time that the first switch 5 and second switch 6 disconnect simultaneously.With further reference to Fig. 8, at power supply, when ground isolates, by closed the 3rd switch 7, the systematically GND_S of touch-screen system complete machine is received to the output terminal of the capacitor C tm charging circuit in capacitance touch screen testing circuit, the voltage on this output terminal output relative interior ground is Vch, the voltage that is capacitor C tm is Vch, systematically connect a pole plate of stray capacitance Clm and testing circuit capacitor C tm simultaneously, in the time being systematically connected to the output terminal of Ctm charging circuit, by the voltage signal Vch drive system ground of testing circuit, now the voltage of the upper bottom crown of stray capacitance Clm is also Vch, be equivalent to make detecting electrode M and LCD voltage in Fig. 1 to equate, △ V=0, be equivalent to mask the impact of Clm, further improve accuracy of detection.
The capacitive touch screen testing circuit that the utility model provides is applicable in various capacitance touching control equipment, is therefore provided with the capacitance touching control equipment of this testing circuit also in protection scope of the present invention.
The foregoing is only preferred embodiment of the present utility model; not in order to limit the utility model; all any amendments of doing within spirit of the present utility model and principle, be equal to and replace and improvement etc., within all should being included in protection domain of the present utility model.
Claims (6)
1. a capacitive touch screen testing circuit, be arranged in capacitance touching control equipment, it is characterized in that, comprise: core detection module and data processing and communication module, described core detection module is electrically connected with described data processing and communication module by communication interface, and described data processing and communication module and communication interface are all electrically connected with the circuit system of described capacitance touching control equipment;
Described core detection module has internal electric source and internally, and described capacitance touching control equipment has system power supply and systematically, and described internal electric source is connected by the first switch with system power supply, describedly internally with is systematically connected by second switch.
2. capacitive touch screen testing circuit as claimed in claim 1, it is characterized in that, described the 3rd switch that systematically also passes through is connected with the output terminal of one drive circuit, and the output terminal current potential of described driving circuit equates with the output terminal current potential of the capacitor charging circuit in described capacitive touch screen testing circuit.
3. capacitive touch screen testing circuit as claimed in claim 1, is characterized in that, described internal electric source is condenser type energy storage device.
4. the capacitive touch screen testing circuit as described in claim 1,2 or 3, is characterized in that, described the first switch comprises the first system gauge tap parallel with one another and the first testing circuit gauge tap; Described second switch comprises second system gauge tap parallel with one another and the second testing circuit gauge tap.
5. a capacitance touching control equipment, comprises display screen and capacitive touch screen that lamination arranges, it is characterized in that, also comprises the capacitive touch screen testing circuit described in claim 1 to 4 any one.
6. capacitance touching control equipment as claimed in claim 5, is characterized in that, described display screen is LCDs.
Priority Applications (1)
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CN201420087680.0U CN203720826U (en) | 2014-02-27 | 2014-02-27 | Capacitive touch screen detection circuit and capacitive touch control equipment |
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CN201420087680.0U CN203720826U (en) | 2014-02-27 | 2014-02-27 | Capacitive touch screen detection circuit and capacitive touch control equipment |
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CN203720826U true CN203720826U (en) | 2014-07-16 |
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CN201420087680.0U Withdrawn - After Issue CN203720826U (en) | 2014-02-27 | 2014-02-27 | Capacitive touch screen detection circuit and capacitive touch control equipment |
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Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN104881186A (en) * | 2014-02-27 | 2015-09-02 | 敦泰科技有限公司 | Capacitive touch screen detection circuit and capacitive touch control equipment |
CN109564485A (en) * | 2016-07-29 | 2019-04-02 | 苹果公司 | Touch sensor panel with the configuration of multi-power domain chip |
US11353985B2 (en) | 2015-02-02 | 2022-06-07 | Apple Inc. | Flexible self-capacitance and mutual capacitance touch sensing system architecture |
US11662867B1 (en) | 2020-05-30 | 2023-05-30 | Apple Inc. | Hover detection on a touch sensor panel |
-
2014
- 2014-02-27 CN CN201420087680.0U patent/CN203720826U/en not_active Withdrawn - After Issue
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN104881186A (en) * | 2014-02-27 | 2015-09-02 | 敦泰科技有限公司 | Capacitive touch screen detection circuit and capacitive touch control equipment |
CN104881186B (en) * | 2014-02-27 | 2017-11-03 | 敦泰科技有限公司 | A kind of capacitive touch screen detection circuit and capacitance touch equipment |
US11353985B2 (en) | 2015-02-02 | 2022-06-07 | Apple Inc. | Flexible self-capacitance and mutual capacitance touch sensing system architecture |
US12014003B2 (en) | 2015-02-02 | 2024-06-18 | Apple Inc. | Flexible self-capacitance and mutual capacitance touch sensing system architecture |
CN109564485A (en) * | 2016-07-29 | 2019-04-02 | 苹果公司 | Touch sensor panel with the configuration of multi-power domain chip |
CN109564485B (en) * | 2016-07-29 | 2022-04-01 | 苹果公司 | Touch sensor panel with multi-power domain chip configuration |
US11662867B1 (en) | 2020-05-30 | 2023-05-30 | Apple Inc. | Hover detection on a touch sensor panel |
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C14 | Grant of patent or utility model | ||
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AV01 | Patent right actively abandoned |
Granted publication date: 20140716 Effective date of abandoning: 20171103 |
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AV01 | Patent right actively abandoned |