CN102193695A - Touch panel test equipment and detecting device thereof - Google Patents
Touch panel test equipment and detecting device thereof Download PDFInfo
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- CN102193695A CN102193695A CN2010101344056A CN201010134405A CN102193695A CN 102193695 A CN102193695 A CN 102193695A CN 2010101344056 A CN2010101344056 A CN 2010101344056A CN 201010134405 A CN201010134405 A CN 201010134405A CN 102193695 A CN102193695 A CN 102193695A
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Abstract
The invention provides touch panel test equipment and a detecting device thereof. The test equipment is used for testing the function of a touch panel; the test equipment and the detecting device thereof are used for detecting micro capacitance signals on the touch panel by using a special circuit; and the detecting device can be used for accurately sensing the micro capacitance signals and is not interfered by a peripheral circuit. The test equipment comprises a plurality of sensors, a detecting module and a judging module, wherein the detecting module is used for receiving and processing a plurality of micro capacitance signals to generate a plurality of output signals; the detecting module comprises a plurality of detecting units; and each detecting unit is coupled with a sensor and comprises an input node, a computing unit, at least one compensating unit and at least one electrostatic discharging protection unit.
Description
Technical field
The invention relates to a kind of testing apparatus, refer to a kind of equipment of testing contact panel especially, it is to utilize special circuit to detect the testing apparatus of small capacitance signal on the contact panel.
Background technology
At present touch technology comprises resistance-type, condenser type, infrared-type, sound wave type, optical profile type, induction and digital etc.Wherein resistance-type has advantage because of simple in structure and cost, enjoy the highest city for a long time and account for rate, and the surface capacitance type technology is that resistance-type is unrivaled in tolerance, optic advantage, though but the past is subject to patent limitation, add that cost is higher,, and use for society owing to these patent limitation are out of date in recent years so its city accounts for rate all the time not as good as resistance-type, and be indebted to the progress of optical technology, therefore the new opportunity that will bring condenser type to popularize.
Comprehensively above-mentioned, the demand of testing capacitor formula contact panel has the trend that increases gradually.Yet the capacitance signal output stage of capacitance type touch-control panel small (fF grade) and be subjected to noise easily is so the Circuits System that needs to resist the stray capacitance in noise and the buffer circuit is come this small capacitance signal of sensing exactly.
The existing desire that is used for contact panel that shows Fig. 1 detects the synoptic diagram of the circuit that tiny signal amplifies; this circuit is to use an amplifier that the small capacitance signal Vin that desire detects is amplified, and couples two PN diodes as the Electrostatic Discharge holding circuit in amplifier input terminal again.But the PN diode is a cavity type junction rectifier, itself can form small capacitance (for example stray capacitance (Parasitic Capacitor)), so output signal Vout can't learn reliable capacitance from input small capacitance signal Vin, and is subjected to direct current (DC) the voltage/current interference that input signal Vin carries secretly easily because the influence of PN diode small capacitance will cause output signal Vout to change.Fig. 2 shows the synoptic diagram of another available circuit, uses a capacitor C bias, makes the voltage of node voltage Vg and direct current (DC) voltage/current irrelevant, gets rid of influence of direct current, and can detect the variation of input signal Vin exactly.But the PN diode still can produce small capacitance, and circuit still can't obtain reliable capacitance.
In view of this, still be necessary to develop the pick-up unit of new detection small capacitance signal, can resist the stray capacitance in noise and the buffer circuit, exactly this small capacitance signal of sensing and be applicable to the function that measures capacitance type touch-control panel.
Summary of the invention
At the problems referred to above, in order to meet the requirement on the industry, the purpose of this invention is to provide a kind of testing apparatus and pick-up unit thereof, exactly this small capacitance signal of sensing and be applicable to the function of measuring capacitance type touch-control panel.
In order to achieve the above object, provide a kind of testing apparatus according to an aspect of the present invention, in order to test the function of a contact panel.This testing apparatus includes a plurality of sensors, a detection module and a judge module.These sensors are in order to a plurality of small capacitance signals of this contact panel of sensing.This detection module receives also handles these a plurality of small capacitance signals, and producing a plurality of output signals, and this detection module includes a plurality of detecting units.Each this detecting unit couples this sensor.This detecting unit includes an input node (Ng), an arithmetic element, at least one compensating unit and at least one electrostatic discharge (ESD) protection unit.This input node (Ng) receives this small capacitance signal.This arithmetic element couples this input node (Ng), and handles or amplify small capacitance signal after this filtration, to produce this output signal.First end of this compensating unit couples this input node, and second end is in order to receive a compensating signal.This electrostatic discharge (ESD) protection unit, in order to this testing apparatus and this contact panel are carried out electrostatic discharge (ESD) protection, and its first end couples a power supply, and second end couples second end of this compensating unit and forms a first node.Wherein, this compensating signal equals this small capacitance signal and produces voltage level in this input node in the voltage level that this first node produces.This judge module couples this detection module, and judges that according to these a plurality of output signals whether this contact panel is by test.
In an embodiment of the present invention, this at least one compensating unit can include: one first compensating unit, its first end couple this input node and second end in order to receive a compensating signal; With one second compensating unit, its first end couples this input node and second end in order to receive a compensating signal; And this at least one electrostatic discharge (ESD) protection unit can include: one first electrostatic discharge (ESD) protection unit, and its first end couples one first power supply, and second end couples second end of this first compensating unit and forms a first node; With one second electrostatic discharge (ESD) protection unit, its first end couples a second source, and second end couples second end of this second compensating unit and forms a Section Point.
Provide a kind of according to a further aspect of the invention, include a sensor and a detecting unit in order to detect the pick-up unit of contact panel.This sensor is in order to a small capacitance signal of this contact panel of sensing, and this detecting unit couples this sensor.This detecting unit includes: an input node (NG), receive this small capacitance signal, and produce a node voltage in this input node; One arithmetic element is handled or is amplified this small capacitance signal, to produce an output signal; At least one electrostatic discharge (ESD) protection unit couples this input node, to carry out electrostatic discharge protection; And at least one compensating unit provides at least one other end that equals the feedback voltage of this node voltage to this electrostatic discharge (ESD) protection unit, the influence that this node voltage is caused with the stray capacitance that compensates this electrostatic discharge (ESD) protection unit.
Useful technique effect of the present invention is: testing apparatus of the present invention and pick-up unit, this small capacitance signal of sensing and be applicable to the function of measuring capacitance type touch-control panel exactly.
Description of drawings
Fig. 1 shows the synoptic diagram of existing signal amplification technique.
Fig. 2 shows the synoptic diagram of the existing signal amplification technique of improveing Fig. 1.
Fig. 3 shows the synoptic diagram according to the testing apparatus of one embodiment of the invention.
Fig. 4 shows the synoptic diagram of detecting unit according to an embodiment of the invention.
Fig. 5 shows the synoptic diagram of detecting unit according to another embodiment of the present invention.
Fig. 6 shows the synoptic diagram of detecting unit according to another embodiment of the present invention.
Fig. 7 A and Fig. 7 B show the synoptic diagram of arithmetic element according to an embodiment of the invention.
Embodiment
Below, describe enforcement aspect of the present invention in detail.
One embodiment of the invention disclose a testing apparatus 100.Fig. 3 shows the synoptic diagram according to the testing apparatus 100 of one embodiment of the invention.This testing apparatus 100 includes a plurality of sensors 200, a detection module 300 and a judge module 400.
These sensors 200 are in order to a plurality of small capacitance signal Vin of this determinand 10 (contact panel) of sensing.Must note, be the complexity of simplified illustration, sensor 200 is to draw with simple line segment in the icon, and the operator who is familiar with this area should be able to understand according to icon and explanation, and adopts the various present existing or future sensors that develop to implement.This detection module 300 receives also handles these a plurality of small capacitance signal Vin, and producing a plurality of output signal Vout, and this detection module 300 includes a plurality of detecting units 310.Each this detecting unit 310 couples this sensor 200.For example this testing apparatus 100 can comprise the individual sensor 200 of 12 (4x3) and 12 detecting units 310.Fig. 4 shows the synoptic diagram of detecting unit 310 according to an embodiment of the invention.This detecting unit 310 includes an input node (Ng), an arithmetic element 340, two compensating units 321,322, two electrostatic discharge (ESD) protection unit 331,332 and filter unit Cbias.This filter unit Cbias couples this input node (Ng), in order to filter the direct current composition of this small capacitance signal.
As shown in Figure 4, wherein first end of compensating unit 321 couples this input node and second end in order to receiving a compensating signal, and first end of compensating unit 322 couples this input node (Ng) and second end in order to receive a compensating signal.Wherein, the voltage level that this compensating signal produces in this first node (N1); equal this small capacitance signal and import node (Ng) in this and produce voltage level (Vg), with so that this small capacitance signal, be not subjected to the interference of the stray capacitance that this electrostatic discharge (ESD) protection unit produced.In the example as this figure, this compensating signal is this output (negative feedback) signal.And behind the compensating unit 322 reception compensating signals, the voltage level V2 that produces in Section Point (N2) also can equal voltage level (Vg).Therefore; between node N1, the Ng with node Ng, N1 between current potential identical; no current circulate in first power supply (+Vdd) and second source (Vdd); so the stray capacitance (Parasitic Capacitor) that electrostatic discharge (ESD) protection unit 331,332 forms does not just have effect, and can't the small capacitance signal Vin by node Ng be impacted.
Electrostatic discharge (ESD) protection unit 331,332 provides the function of circuit electrostatic discharge (ESD) protection.First end of this electrostatic discharge (ESD) protection unit 331 couple one first power supply (+Vdd), second end couples second end of this compensating unit 321 and forms a first node (N1); And electrostatic discharge (ESD) protection unit 332, its first end couples a second source (Vdd or ground connection), and second end couples second end of this compensating unit 322 and forms a Section Point (N2).
This judge module 400 couples this detection module 300, and whether judges this contact panel by test (GO/NG) according to these a plurality of output signals, if classify as non-defective unit by test (GO), if do not classify as defective products by (NG).
Design according to this mode; the small capacitance signal Vin that the detecting unit 310 of the embodiment of the invention is detected; to can not be subjected to electrostatic discharge (ESD) protection unit 331,332 formed stray capacitances and disturb, and can solve prior art problems, reach the effect of accurate detection signal.
In addition, in another embodiment (not icon), this compensating signal can be provided by a power supply or other external device (ED), and the voltage level that this first node (N1) is produced equals this small capacitance signal and imports node (Ng) generation voltage level (Vg) in this.This mode also can reach identical effect, solves electrostatic discharge (ESD) protection unit 331,332 formed stray capacitance interference problems.
Fig. 5 shows the synoptic diagram of detecting unit 310 according to another embodiment of the present invention.Simultaneously with reference to Fig. 4 and Fig. 5; present embodiment (Fig. 5) and the foregoing description (Fig. 4) difference; this detecting unit that is Fig. 5 also comprises two RC low-pass filters (a RC low-pass filter and the 2nd RC low-pass filter); first end of the one this first node of RC low pass filter coupled (N1), this electrostatic discharge (ESD) protection unit 331 and the output terminal of this arithmetic element 340; and first end of the 2nd this Section Point of RC low pass filter coupled (N2), this electrostatic discharge (ESD) protection unit 332 and the output terminal of this arithmetic element 340, in order to this compensating signal stably to be provided.Must notice that RC low-pass filter herein only is an example, the present invention can adopt existing at present or be that the various wave filters that develop are implemented.
Fig. 6 shows the synoptic diagram of detecting unit 310 according to another embodiment of the present invention.Simultaneously with reference to Fig. 4 and Fig. 6, present embodiment (Fig. 6) and the foregoing description (Fig. 4) difference, this detecting unit that is Fig. 6 also comprises two arithmetical unit G1 and G2, the input end of G1 couples the output terminal of this arithmetic element 340 and the output terminal of arithmetical unit G1 couples this first node (N1), the input end of arithmetical unit G2 couples the output terminal of this arithmetic element 340 and the output terminal of arithmetical unit G2 couples this Section Point (N2), in order to this compensating signal stably to be provided.
In the foregoing description, this compensating unit can be a PN junction rectifier.And this arithmetic element can be an amplifier, for example the mos field effect transistor (MOSFET) of the anti-phase closed loop amplifier of Fig. 7 A or Fig. 7 B.In the above embodiments, the capacitance that this small capacitance signal comprises is less than or equal to 1pF, and certainly, these data only are example, and the present invention is not limited to this data.Moreover this judge module can be implemented by an interface and a disposal system that receives this output signal, and for example this disposal system can be a computing machine.
In sum, according to pick-up unit of the present invention and testing apparatus, can detect the small capacitance signal and provide the pick-up unit avoiding disturbing and testing apparatus that the test contact panel is used, sensing small capacitance signal exactly is specially adapted to testing capacitor formula contact panel or with the various electronic products of capacitance type touch-control panel.
Though more than with specific embodiment explanation the present invention; but therefore do not limit scope of the present invention; only otherwise break away from main idea of the present invention; being familiar with present technique person understands not breaking away under the intent of the present invention and the scope and can carry out various distortion or change; for example can comprise 2,4 or 6 compensating units, perhaps can comprise 2,4 or 6 electrostatic discharge (ESD) protection unit in detecting unit.For example this determinand can be various electronic products with contact panel again.
Claims (11)
1. a testing apparatus in order to test the function of a contact panel, is characterized in that, this testing apparatus includes:
A plurality of sensors are in order to a plurality of small capacitance signals of sensing one determinand;
One detection module receives and these a plurality of small capacitance signals of processing, and to produce a plurality of output signals, wherein this detection module includes:
A plurality of detecting units, each this detecting unit couples this sensor, and this detecting unit includes:
One input node (Ng) receives this small capacitance signal;
One arithmetic element couples this input node (Ng), and the small capacitance signal after processing or the amplification filtration, to produce this output signal;
At least one compensating unit, its first end couples this input node, and second end is in order to receive a compensating signal;
At least one electrostatic discharge (ESD) protection unit, in order to this testing apparatus and this contact panel are carried out electrostatic discharge (ESD) protection, and its first end couples a power supply, and second end couples second end of this compensating unit and forms a first node;
Wherein this compensating signal equals this small capacitance signal and produces voltage level in this input node in the voltage level that this first node produces;
One judge module couples this detection module, judges that according to these a plurality of output signals whether this contact panel is by test.
2. testing apparatus according to claim 1 is characterized in that, this at least one compensating unit includes:
One first compensating unit, its first end couple this input node and second end in order to receive a compensating signal; With
One second compensating unit, its first end couple this input node and second end in order to receive a compensating signal; And
This at least one electrostatic discharge (ESD) protection unit pack contains:
One first electrostatic discharge (ESD) protection unit, its first end couples one first power supply, and second end couples second end of this first compensating unit and forms a first node; With
One second electrostatic discharge (ESD) protection unit, its first end couples a second source, and second end couples second end of this second compensating unit and forms a Section Point.
3. testing apparatus according to claim 1 is characterized in that, this compensating signal is this output signal, and this output is negative feedback.
4. testing apparatus according to claim 1 is characterized in that this detecting unit also includes a filter unit, couples this input node (Ng), in order to filter the direct current composition of this small capacitance signal.
5. testing apparatus according to claim 1 is characterized in that, this compensating signal is provided by a power supply.
6. testing apparatus according to claim 1; it is characterized in that; this detecting unit also includes at least one low-pass filter, couples first end of this first node, this electrostatic discharge (ESD) protection unit and the output terminal of this arithmetic element, in order to this compensating signal stably to be provided.
7. testing apparatus according to claim 1 is characterized in that this detecting unit also includes at least one amplifier, and output terminal and output terminal that its input end couples this arithmetic element couple this first node, in order to this compensating signal stably to be provided.
8. testing apparatus according to claim 1 is characterized in that, this compensating unit is a PN junction rectifier, and this arithmetic element is an amplifier.
9. testing apparatus according to claim 1 is characterized in that, this arithmetic element is an anti-phase closed loop amplifier or a mos field effect transistor.
10. testing apparatus according to claim 1 is characterized in that, this determinand is a contact panel or the various electronic products of having contact panel.
11. a pick-up unit in order to detect the function of contact panel, is characterized in that, includes:
One sensor is in order to a small capacitance signal of this contact panel of sensing; And
One detecting unit couples this sensor, and this detecting unit includes:
One input node (NG) receives this small capacitance signal, produces a node voltage in this input node;
One arithmetic element is handled or is amplified this small capacitance signal, to produce an output signal;
At least one electrostatic discharge (ESD) protection unit couples this input node, to carry out electrostatic discharge protection;
At least one compensating unit provides at least one other end that equals the feedback voltage of this node voltage to this electrostatic discharge (ESD) protection unit, the influence that this node voltage is caused with the stray capacitance that compensates this electrostatic discharge (ESD) protection unit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2010101344056A CN102193695A (en) | 2010-03-05 | 2010-03-05 | Touch panel test equipment and detecting device thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2010101344056A CN102193695A (en) | 2010-03-05 | 2010-03-05 | Touch panel test equipment and detecting device thereof |
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| Publication Number | Publication Date |
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| CN102193695A true CN102193695A (en) | 2011-09-21 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN2010101344056A Pending CN102193695A (en) | 2010-03-05 | 2010-03-05 | Touch panel test equipment and detecting device thereof |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103092397A (en) * | 2011-11-03 | 2013-05-08 | 群康科技(深圳)有限公司 | Touch panel for electrostatic discharge protection and electronic device using the same |
| CN103207713A (en) * | 2012-01-16 | 2013-07-17 | 晨星软件研发(深圳)有限公司 | Signal processing method of touch panel and touch panel system |
| CN105677119A (en) * | 2014-11-18 | 2016-06-15 | 敦泰科技有限公司 | Capacitive touch screen and detection circuit thereof, electronic equipment |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA2165631A1 (en) * | 1995-01-18 | 1996-07-19 | Carlo Gavazzi Services Ag | Capacitive sensor |
| CN1826534A (en) * | 2003-08-06 | 2006-08-30 | 东京毅力科创株式会社 | Capacitance determining circuit and capacitance determining method |
| CN101315287A (en) * | 2007-06-01 | 2008-12-03 | 凌通科技股份有限公司 | Condenser type contact sensor |
-
2010
- 2010-03-05 CN CN2010101344056A patent/CN102193695A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA2165631A1 (en) * | 1995-01-18 | 1996-07-19 | Carlo Gavazzi Services Ag | Capacitive sensor |
| CN1826534A (en) * | 2003-08-06 | 2006-08-30 | 东京毅力科创株式会社 | Capacitance determining circuit and capacitance determining method |
| CN101315287A (en) * | 2007-06-01 | 2008-12-03 | 凌通科技股份有限公司 | Condenser type contact sensor |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103092397A (en) * | 2011-11-03 | 2013-05-08 | 群康科技(深圳)有限公司 | Touch panel for electrostatic discharge protection and electronic device using the same |
| US9134858B2 (en) | 2011-11-03 | 2015-09-15 | Innolux Corporation | Touch panel for electrostatic discharge protection and electronic device using the same |
| CN103092397B (en) * | 2011-11-03 | 2016-04-27 | 群康科技(深圳)有限公司 | The contact panel of tool electrostatic discharge (ESD) protection and use its electronic installation |
| CN103207713A (en) * | 2012-01-16 | 2013-07-17 | 晨星软件研发(深圳)有限公司 | Signal processing method of touch panel and touch panel system |
| CN103207713B (en) * | 2012-01-16 | 2016-06-22 | 晨星软件研发(深圳)有限公司 | The signal processing method of contact panel and touch panel system |
| CN105677119A (en) * | 2014-11-18 | 2016-06-15 | 敦泰科技有限公司 | Capacitive touch screen and detection circuit thereof, electronic equipment |
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Application publication date: 20110921 |