CN205374654U - Touch -sensitive screen defect detecting system - Google Patents
Touch -sensitive screen defect detecting system Download PDFInfo
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- CN205374654U CN205374654U CN201620135375.3U CN201620135375U CN205374654U CN 205374654 U CN205374654 U CN 205374654U CN 201620135375 U CN201620135375 U CN 201620135375U CN 205374654 U CN205374654 U CN 205374654U
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Abstract
The utility model relates to a touch -sensitive screen defect detecting system, this touch -sensitive screen detecting system include that electric capacity changes voltage module CV, resistance commentaries on classics voltage module RV, analog -to -digital conversion module ADC and DSP&MCU module, electric capacity is connected respectively to analog -to -digital conversion module ADC one end changes voltage module CV and resistance commentaries on classics voltage module RV, and the other end is connected the DSP&MCU module, electric capacity changes voltage module CV and is used for turning into voltage with sensor channel's on the touch -sensitive screen several to ground parasitic capacitance's electric capacity, and resistance commentaries on classics voltage module RV is used for turning into voltage with sensor channel's on the touch -sensitive screen several to ground parasitic capacitance's resistance, the DSP&MCU module is used for the control capacitance to change voltage module CV, resistance commentaries on classics voltage module RV and processing analog -to -digital conversion module ADC's output result. The utility model discloses a scheme does not need additionally to increase the hardware cost, utilizes touch -control chip itself can accomplish the detection of touch screen module's defect, the utility model discloses a test procedure of scheme accomplishes and realizes the automation, and efficiency of software testing is high, and test reliability is high.
Description
Technical field
This utility model relates to a kind of touch screen defect detecting system.
Background technology
Touch screen is widely used at present in the portable sets such as various mobile terminals, particularly smart mobile phone.Current type of touch screens mainly has capacitive touch screen, and the transparent thin-film material being wherein fabricated by by ITO (indium tin oxide or title oxide indium stannum) is the critical material manufacturing capacitive touch screen.Before touch screen manufacture is dispatched from the factory, it is necessary to its electrical characteristic is tested, to detect touch screen for non-defective unit or defective products, thus avoiding defective products to put goods on the market use.Owing to touch screen production exists yield issues and process deviation, also have some touch screens can cause damage because of factors such as mechanical damages, therefore to ensure that touch screen module is consistent with requirement before dispatching from the factory, it is necessary to touch screen module is tested.
The method of testing of the touch screen that prior art provides is completed by test man's touch screen stippled line, and this kind of method of testing length consuming time, test result is directly perceived, and test result reliability is poor.
Utility model content
nullIn order to solve above-mentioned technical problem，This utility model provides a kind of touch screen defect detecting system on the one hand，Described touch screen detection system includes electric capacity and turns voltage module CV、Resistance turns voltage module RV、Analog-to-digital conversion module ADC and DSP&MCU module，Described analog-to-digital conversion module ADC one end connects electric capacity respectively and turns voltage module CV and resistance turns voltage module RV，The other end connects described DSP&MCU module，Described electric capacity turns voltage module CV for the several of sensor passage on touch screen are converted into voltage to ground parasitic capacitance，Resistance turns voltage module RV for the several of sensor passage on touch screen are converted into voltage to ground short circuit resistance，Described DSP&MCU module is used for controlling electric capacity and turns voltage module CV、Resistance turns voltage module RV and processes the output result of analog-to-digital conversion module ADC.
Described electric capacity turns voltage module and includes several first switch, and described several first switches connect the several to ground parasitic capacitance of touch panel sensor passage respectively.
Described resistance turns voltage module and includes several second switch, and described several second switches connect the several to ground parasitic capacitance of touch panel sensor passage respectively,
Described resistance turns voltage module RV and includes several second switch, resistance Rp and power supply, one end of described power supply output reference voltage VREF and resistance Rp is connected, the other end of resistance Rp is connected with one end of second switch, the other end of second switch is connected with to ground parasitic capacitance, and described resistance turns voltage module RV and exports the pressure drop Vx that signal is resistance Rp.
Described resistance turns voltage module RV and includes several second switch, amplifier, resistance Rfb and power supply, described power supply output reference voltage VREF is connected with the first input end of amplifier, one end of described second switch is connected with the second input of amplifier, the other end of second switch is connected with to ground parasitic capacitance, one end of resistance Rfb connects the second input of amplifier, the other end of resistance Rfb connects the outfan of amplifier, and described resistance turns voltage module RV and exports the output voltage Vx that signal is amplifier.
This utility model additionally provides a kind of touch screen defect inspection method on the other hand, and described touch screen defect inspection method includes resistance detection step:
Closing electric capacity and turn voltage module CV, opening resistor turns voltage module RV；
Test sensor passage connects resistance and turns voltage module RV, non-test sensor passage ground connection, voltage module RV conversion is turned through resistance, analog-to-digital conversion module ADC samples, after DSP&MCU resume module and calculating, obtain the parallel value of sensor passage and the short-circuit impedance of other all non-test sensor passages；
Test sensor passage connects resistance and turns voltage module RV, the non-test sensor passage that non-test sensor passage only one of which is adjacent draws ground, other non-test sensor passage floatings, voltage module RV conversion is turned through resistance, analog-to-digital conversion module ADC samples, after DSP&MCU resume module and calculating, obtain the short-circuit impedance of test sensor passage and adjacent non-test sensor passage；
Judge touch panel sensor whether short circuit or micro-short circuit.
Described touch screen defect inspection method also includes capacitance detecting step:
Open electric capacity and turn voltage module CV, close resistance and turn voltage module RV；
Non-test sensor passage ground connection, test sensor passage on add driving signal, turn voltage module C V conversion through electric capacity, analog-to-digital conversion module ADC sample, DSP&MCU resume module and calculate after, obtain the first capacitance of each sensor passage；
TCH test channel adds driving signal, non-test passage adds contrary driving signal, turn voltage module C V conversion through electric capacity, analog-to-digital conversion module ADC sample, DSP&MCU resume module and calculate after, obtain the second capacitance of each sensor passage；
Analytical calculation the first capacitance and the second capacitance, it is judged that whether sensor path exists open circuit.
Calculate the first capacitance and the difference of the second capacitance, judge whether sensor path exists open circuit according to difference.
During touch chip normal operation, resistance turns voltage module RV and does not work, and only when carrying out defects detection, resistance turns voltage module RV just can start work.During normal operation, DSP&MCU module can control the switch being connected with sensor passage, allows sensor passage be sequentially ingressed into electric capacity and turns voltage module CV, and is obtained the touch sensible data value of each sensor passage by follow-up analog-to-digital conversion module ADC and filtering.
Touch panel sensor passage due to process deviation, defect main manifestations in electrical characteristic that the problem such as yield causes is: different sensors passage (or sensor passage and ground) forms short circuit or micro-short circuit；Sensor passage is opened a way.
The short circuit of different sensors passage, shows as interchannel and there is an only small resistance, be typically in this case, and it is saturated that the electrical characteristic of tested passage can cause that electric capacity turns the output valve of voltage module CV and analog-to-digital conversion module ADC.Now, it is easy to judge that touch screen occurs by the output initial data of touch chip abnormal.There is micro-short circuit in different sensors passage, shows as interchannel and there is a bigger resistance, is typically in this case, and the output initial data performance of touch chip is substantially not abnormal.But touch screen performance (such as the linearity/coordinate precision/anti-noise jamming ability) can be caused in this case to be deteriorated.
This utility model mainly utilizes upper layer software (applications) to send order control touch chip and enters specific duty；Touch chip obtains data under particular job state and submits to upper layer software (applications) process；Upper layer software (applications) is by processing data and judging each passage of touch screen sensor whether existing defects.Scheme of the present utility model need not additionally increase hardware cost, utilizes touch chip itself can complete the detection of defect of touch screen module；The test process of scheme of the present utility model completes to realize automatization, and testing efficiency is high, and testing reliability is high.
It is more readily understood the above-mentioned of the application and other features, aspect and advantage with reference to described further below.
Accompanying drawing explanation
Fig. 1 is the fundamental block diagram that touch screen defect detecting system of the present utility model realizes.
Fig. 2 is that resistance of the present utility model turns voltage module RV circuit diagram.
Fig. 3 is that resistance of the present utility model turns voltage module RV another kind circuit diagram.
Fig. 4 opens step 1 circuit diagram when electric capacity turns voltage module CV
Fig. 5 opens step 2 circuit diagram when electric capacity turns voltage module CV
Fig. 6 opens step 1 circuit diagram (there is sensor passage open circuit in schematic diagram) when electric capacity turns voltage module CV
Fig. 7 opens step 2 circuit diagram (there is sensor passage open circuit in schematic diagram) when electric capacity turns voltage module CV
Detailed description of the invention
For making the purpose of this utility model embodiment, technical scheme and advantage clearly, below in conjunction with the accompanying drawing of this utility model embodiment, the technical scheme of this utility model embodiment is clearly and completely described.Obviously, described embodiment is a part of embodiment of the present utility model, rather than whole embodiments.Based on described embodiment of the present utility model, all other embodiments that those of ordinary skill in the art obtain under the premise without creative work, broadly fall into the scope of this utility model protection.
Unless otherwise defined, technical term used herein or scientific terminology should be and have the ordinary meaning that the personage of general technical ability understands in this utility model art." first ", " second " that use in this utility model patent application specification and claims and similar word are not offered as any order, quantity or importance, and are used only to distinguish different ingredients.Equally, the similar word such as " " or " " does not indicate that quantity limits yet, and indicates that and there is at least one.
nullIf Fig. 1 is the fundamental block diagram that touch screen defect detecting system of the present utility model realizes，This touch screen detection system includes electric capacity and turns voltage module CV、Resistance turns voltage module RV、Analog-to-digital conversion module ADC and DSP&MCU module，Described analog-to-digital conversion module ADC one end connects electric capacity respectively and turns voltage module CV and resistance turns voltage module RV，The other end connects described DSP&MCU module，Described electric capacity turns voltage module CV for the several of sensor passage on touch screen are converted into voltage to ground parasitic capacitance value，Resistance turns voltage module RV for several short-circuit resistance values of sensor passage on touch screen are converted into voltage，Described DSP&MCU module is used for controlling electric capacity and turns voltage module CV、Resistance turns voltage module RV and processes the output result of analog-to-digital conversion module ADC.Described electric capacity turns voltage module and includes several first switch, and described several first switches connect the several to ground parasitic capacitance of touch panel sensor passage respectively.Described resistance turns voltage module and includes several second switch, and described several second switches connect the several to ground parasitic capacitance of touch panel sensor passage respectively,
Voltage module RV implementation is turned as resistance of the present utility model, as shown in Figure 2, resistance turns voltage module RV and includes several second switch, resistance Rp and power supply, one end of described power supply output reference voltage VREF and resistance Rp is connected, the other end of resistance Rp is connected with one end of second switch, the other end of second switch is connected with to ground parasitic capacitance, and described resistance turns voltage module RV and exports the pressure drop Vx that signal is resistance Rp.
As Fig. 2, Cm be tested passage to ground parasitic capacitance, Rx is the short-circuit resistance between tested passage m and adjacency channel m+1.Tested passage is pulled upward to voltage VREF by beginning Pm and resistance Rp, and other non-test passages (only depict Cm+1 here) and draw ground by switch.Obtain according to simple electric resistance partial pressure relation:
Voltage module RV implementation is turned as resistance of the present utility model, as shown in Figure 3, resistance turns voltage module RV and includes several second switch, amplifier, resistance Rfb and power supply, described power supply output reference voltage VREF is connected with the first input end of amplifier, one end of described second switch is connected with the second input of amplifier, the other end of second switch is connected with to ground parasitic capacitance, one end of resistance Rfb connects the second input of amplifier, the other end of resistance Rfb connects the outfan of amplifier, described resistance turns voltage module RV and exports the output voltage Vx that signal is amplifier.
According to simple analysis, it is possible to the Vx output voltage obtaining Fig. 3 is:
Vx is directly connected to the input of analog-to-digital conversion module ADC, the output result of analog-to-digital conversion module ADC be readily available the input voltage value of analog-to-digital conversion module ADC, through the simple computation of upper layer software (applications), just can obtain the resistance of Rx.Thus obtaining the short-circuit impedance value of sensor passage m.
This utility model additionally provides a kind of touch screen defect inspection method on the other hand, and described touch screen defect inspection method includes resistance detection step:
Closing electric capacity and turn voltage module CV, opening resistor turns voltage module RV；
Test sensor passage connects resistance and turns voltage module RV, non-test sensor passage ground connection, voltage module RV conversion is turned through resistance, analog-to-digital conversion module ADC samples, after DSP&MCU resume module and calculating, obtain the parallel value of sensor passage and the short-circuit impedance of other all non-test sensor passages；
Test sensor passage connects resistance and turns voltage module RV, the non-test sensor passage that non-test sensor passage only one of which is adjacent draws ground, other non-test sensor passage floatings, voltage module RV conversion is turned through resistance, analog-to-digital conversion module ADC samples, after DSP&MCU resume module and calculating, obtain the short-circuit impedance of test sensor passage and adjacent non-test sensor passage；
Judge touch panel sensor whether short circuit or micro-short circuit.
As shown in Figure 2 or Figure 3, upper layer software (applications) sends instruction allows touch chip enter resistance test pattern, short-circuit resistance between n sensor passage is sampled by chip, and the data that sampling obtains are uploaded upper layer software (applications), and upper layer software (applications) calculates the short-circuit resistance value obtaining between each sensor passage.Under normal circumstances, the short-circuit resistance between sensor passage is infinitely great, if calculated resistance value is substantially less than normal, then it is assumed that touch panel sensor short circuit or micro-short circuit.
When sensor passage m is tested, if other all non-test passages all draw ground, then calculated Rx is the parallel value of sensor passage m and the short-circuit impedance of other all non-test passages.When sensor passage m is tested, if other non-test passages only have m+1 to draw ground, other non-test passage floatings, then calculated Rx is the short-circuit impedance between passage m and passage m+1.Draw ground successively and individually to non-test passage, measure and repeatedly can be obtained by interchannel short-circuit impedance value between two.
Described touch screen defect inspection method also includes capacitance detecting step:
Open electric capacity and turn voltage module CV, close resistance and turn voltage module RV；
Non-test sensor passage ground connection, test sensor passage on add driving signal, turn voltage module C V conversion through electric capacity, analog-to-digital conversion module ADC sample, DSP&MCU resume module and calculate after, obtain the first capacitance of each sensor passage；
TCH test channel adds driving signal, non-test passage adds contrary driving signal, turn voltage module C V conversion through electric capacity, analog-to-digital conversion module ADC sample, DSP&MCU resume module and calculate after, obtain the second capacitance of each sensor passage；
Analytical calculation the first capacitance and the second capacitance, it is judged that whether sensor path exists open circuit.
Upper layer software (applications) control chip enters capacity measurement pattern, test point the 3: the 1st step, non-test passage ground connection, adds driving signal on TCH test channel, and through C V conversion, ADC samples, and DSP Filtering Processing and software analysis obtain the capacitance of each passage after calculating；2nd step, adds driving signal on TCH test channel, adds contrary driving signal on non-test passage, and through C V conversion, ADC samples, and after DSP Filtering Processing and software analysis calculate, obtains another group capacitance of each passage；3rd step, to these two groups of capacitance analytical calculations, it is judged that whether sensor path exists open circuit.
As shown in Figure 4, when sensor passage i is tested, other non-test passage all draws ground by switch.In figure, CVCORE represents that electric capacity turns the core circuit (such as electric charge amplification module) of voltage module CV.Ci represents that sensor passage i's arrives ground parasitic capacitance, and Cij represents the parasitic capacitance between passage i and passage j.Fig. 4 test obtains capacitance and is actually:
As it is shown in figure 5, when sensor passage i is tested, non-test passage is plus the driving signal contrary with TCH test channel.
Upper figure test obtains capacitance and is actually:
Above-mentioned 2 test results being subtracted each other, the value obtained is:
As shown in Fig. 6 Fig. 7, owing to passage i opens a way, driving signal can not pass to Ci, reverse drive signals can not pass to CVCORE by parasitic capacitance between sensor passage simultaneously.Therefore twice test obtains electric capacity and does not include Ci, Cij(j=1 ~ n), test only includes the pin trace portions parasitic capacitance (not drawing this partition capacitance in above-mentioned circuit diagram) to screen body of touch screen of chip sensor passage i and the parasitic capacitance (not drawing this partition capacitance in above-mentioned circuit diagram) between different sensors passage cabling.Sensor passage cabling is general relatively thin, therefore between sensor passage cabling, parasitic capacitance value is generally much smaller than touch panel sensor interchannel parasitic capacitance.Therefore twice test result subtracts each other the value that obtains much smaller than sensor passage value time normal during sensor passage open circuit.By what data prepared, upper layer software (applications) can judge whether sensor path opens a way.
The above, be only preferred embodiment of the present utility model, is not intended to limit protection domain of the present utility model.Every equalization done according to this utility model content changes and modifies, and is encompassed by the scope of the claims of the present utility model.
Claims (5)
1. a touch screen defect detecting system, described touch screen defect detecting system includes electric capacity and turns voltage module CV, resistance turns voltage module RV, analog-to-digital conversion module ADC and DSP&MCU module, described analog-to-digital conversion module ADC one end connects electric capacity respectively and turns voltage module CV and resistance turns voltage module RV, the other end connects described DSP&MCU module, described electric capacity turns voltage module CV for the several of sensor passage on touch screen are converted into voltage to ground parasitic capacitance, resistance turns voltage module RV for several short-circuit resistances of sensor passage on touch screen are converted into voltage, described DSP&MCU module is used for controlling electric capacity and turns voltage module CV, resistance turns voltage module RV and processes the output result of analog-to-digital conversion module ADC.
2. a kind of touch screen defect detecting system according to claim 1, it is characterised in that described electric capacity turns voltage module and includes several first switch, and described several first switches connect the several to ground parasitic capacitance of touch panel sensor passage respectively.
3. a kind of touch screen defect detecting system according to claim 1, it is characterised in that described resistance turns voltage module and includes several second switch, described several second switches connect the several to ground parasitic capacitance of touch panel sensor passage respectively.
4. a kind of touch screen defect detecting system according to claim 1, it is characterized in that, described resistance turns voltage module RV and includes several second switch, resistance Rp and power supply, one end of described power supply output reference voltage VREF and resistance Rp is connected, the other end of resistance Rp is connected with one end of second switch, the other end of second switch is connected with to ground parasitic capacitance, and described resistance turns voltage module RV and exports the pressure drop Vx that signal is resistance Rp.
5. a kind of touch screen defect detecting system according to claim 1, it is characterized in that, described resistance turns voltage module RV and includes several second switch, amplifier, resistance Rfb and power supply, described power supply output reference voltage VREF is connected with the first input end of amplifier, one end of described second switch is connected with the second input of amplifier, the other end of second switch is connected with to ground parasitic capacitance, one end of resistance Rfb connects the second input of amplifier, the other end of resistance Rfb connects the outfan of amplifier, described resistance turns voltage module RV and exports the output voltage Vx that signal is amplifier.
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| CN201620135375.3U CN205374654U (en) | 2016-02-23 | 2016-02-23 | Touch -sensitive screen defect detecting system |
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| CN201620135375.3U CN205374654U (en) | 2016-02-23 | 2016-02-23 | Touch -sensitive screen defect detecting system |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105676053A (en) * | 2016-02-23 | 2016-06-15 | 上海芯什达电子技术有限公司 | Touch screen defect detection system |
| CN107462273A (en) * | 2017-07-17 | 2017-12-12 | 江苏邦融微电子有限公司 | A kind of mass production test device and its method of capacitance type sensor module |
-
2016
- 2016-02-23 CN CN201620135375.3U patent/CN205374654U/en active Active
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105676053A (en) * | 2016-02-23 | 2016-06-15 | 上海芯什达电子技术有限公司 | Touch screen defect detection system |
| CN105676053B (en) * | 2016-02-23 | 2018-09-25 | 上海芯什达电子技术有限公司 | A kind of touch screen defect detecting system |
| CN107462273A (en) * | 2017-07-17 | 2017-12-12 | 江苏邦融微电子有限公司 | A kind of mass production test device and its method of capacitance type sensor module |
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