TW202240246A - Detection method and detection device - Google Patents

Abstract

The present disclosure provides a detection method. The detection method includes the following steps. During a first time period, a voltage is applied to a touch sensing electrode of an capacitive touch panel screen. At the end of the first time period, the voltage is stop applying to the touch sensing electrode of the capacitive touch panel screen, and the touch sensing electrode is electric coupled to a variable capacitor and an operational amplifier, wherein a noninverting input terminal of the operational amplifier is configured to receive a reference voltage. The capacitance of the variable capacitor is adjusted to an output voltage of the operational amplifier roughly equal to zero. Whether the capacitance of the variable capacitor is at predicted capacitance value is determined.

Description

Detection method and detection device

This case relates to a detection method and detection device, in particular to a detection method and detection device suitable for capacitive touch display panels.

Today's capacitive touch display panel technologies include plug-in touch display panels and built-in touch display panels. Among them, the variation of capacitance and resistance in the manufacturing process of capacitive touch display panels is more likely to cause touch display Defective panel, how to distinguish the variation of capacitance and resistance of capacitive touch display panel is a necessary issue.

This disclosed document provides a detection method, which includes the following steps. A voltage is applied to the touch sensing electrodes of the capacitive touch panel for a first time period. When the first time length ends, stop applying voltage to the touch sensing electrodes of the capacitive touch panel, and electrically couple the touch sensing electrodes to the variable capacitor and the operational amplifier, wherein the non-inverting input of the operational amplifier The terminal is used to receive the reference voltage. Adjust the capacitance value of the variable capacitor so that the output voltage of the operational amplifier is approximately zero. Determine whether the capacitance value of the variable capacitor is within the expected capacitance value.

The disclosed document provides a detection device, which includes: a variable capacitor and an operational amplifier. The detection device is used to apply a voltage to the touch sensing electrodes of the capacitive touch panel within the first time length, and the detection device connects the touch sensing electrodes to the variable capacitor and the operational amplifier after the first time length is over, Wherein the detection device adjusts the variable capacitor until the output of the operational amplifier is substantially zero, and the detection device judges whether the adjusted value of the variable capacitor is within the expected capacitance value.

To sum up, the disclosed document utilizes the variable capacitance in the detection device to determine whether the capacitance of the capacitive touch panel varies.

The following is a detailed description of the embodiments in conjunction with the attached drawings, but the provided embodiments are not intended to limit the scope of this disclosure, and the description of the structure and operation is not intended to limit the execution sequence. Any recombination of components Structures and devices with equivalent functions are all within the scope of this disclosure. In addition, the illustrations are for illustration purposes only and are not drawn in original size. To facilitate understanding, the same elements or similar elements will be described with the same symbols in the following description.

The terms (terms) used throughout the specification and claims, unless otherwise specified, generally have the ordinary meaning of each term used in the field, in the disclosed content and in the special content.

In addition, the words "comprising", "including", "having", "containing", etc. used in this article are all open terms, meaning "including but not limited to". In addition, "and/or" used herein includes any one and all combinations of one or more items in the relevant listed items.

Herein, when an element is referred to as "coupled" or "coupled", it may mean "electrically coupled" or "electrically coupled". "Coupling" or "coupling" can also be used to indicate that two or more elements cooperate or interact with each other. In addition, although terms such as "first", "second", ..., etc. are used herein to describe different elements, these terms are only used to distinguish elements or operations described with the same technical terms.

Please refer to FIG. 1 , which is a schematic diagram of a capacitive touch panel 100 according to an embodiment of the present disclosure. As shown in FIG. 1 , the capacitive touch panel 100 includes packaging glass 110 , touch sensing electrodes 120 , common electrodes 140 , light emitting elements 150 , an array 160 and a display glass substrate 170 . The light emitting elements 150 can be implemented by organic photodiodes, and the array 160 is used to drive the light emitting elements 150 . The touch sensing electrodes 120 , the common electrodes 140 , the light emitting elements 150 , and the array 160 are encapsulated between the packaging glass 110 and the display glass substrate 170 . Moreover, there is a gap 130 between the touch sensing electrode 120 and the common electrode 140 . In this way, the touch sensing electrodes 120 , the gaps 130 and the common electrodes 140 can be regarded as the capacitance of the capacitive touch panel 100 . In the subsequent embodiments, for a better understanding, how the method provided in this disclosure document detects the variation of the capacitance and resistance of the capacitive touch panel 100 respectively. The capacitive touch panel 100 in the first figure is an in-cell Take the touch panel as an example. However, the detection method provided in this disclosure can also be applied to other touch panels with capacitive structures, for example, plug-in touch panels and the like. Therefore, this disclosure document is not limited thereto.

In the capacitive touch panel technology, the capacitance of the capacitive touch panel 100 is composed of the touch sensing electrode 120 , the common electrode 140 and the gap 130 between the touch sensing electrode 120 and the common electrode 140 . Therefore, in the manufacturing process of the capacitive touch panel 100 , the gap 130 between the touch sensing electrodes 120 and the common electrodes 140 may vary. On the other hand, since the capacitance of the in-cell touch panel is larger than that of the external touch panel, the tolerance of the resistance of the touch sensing electrode 120 in the manufacturing process is lower.

That is, the variation of the gap 130 of the capacitive touch panel 100 will cause the capacitance deviation of the capacitive touch panel 100, and the variation of the touch sensing electrodes 120 of the capacitive touch panel 100 will cause the touch in the capacitive touch panel 100. Control the resistance deviation of the sensing electrode 120. The aforesaid capacitance deviation and resistance deviation may cause the capacitive touch panel 100 to fail or delay determining the correct touch sensing position. Therefore, a detection device and a detection method for detecting the capacitive touch panel 100 are provided in this disclosure document.

Please refer to FIG. 2 . FIG. 2 is a schematic diagram of an inspection device 200 for inspecting the capacitive touch panel 100 in FIG. 1 according to an embodiment of the present disclosure. In the embodiment of FIG. 2, the touch sensing electrode 120 of the capacitive touch panel 100 can be regarded as the first end of the capacitor Cpanel, and the common electrode 140 of the capacitive touch panel 100 can be regarded as the second end of the capacitor Cpanel. The terminal and the gap 130 of the capacitive touch panel 100 are regarded as the gap of the capacitor Cpanel.

Moreover, the touch sensing electrodes 120 of the capacitive touch panel 100 can be regarded as a resistor Rpanel, and the detection pads of the touch sensing electrodes 120 can be regarded as a node Vpad. That is to say, the first terminal of the resistor Rpanal is electrically coupled to the node Vpad, the second terminal of the resistor Rpanal is electrically coupled to the first terminal of the capacitor Cpanel, and the second terminal of the capacitor Cpanel is electrically coupled to the system voltage terminal Vcom. Wherein, the voltage level of the system voltage terminal Vcom may be equal to or similar to the voltage level of the ground terminal GND.

The detection device 200 includes a variable capacitor CC, an operational amplifier AMP, a capacitor Cbase, and switches S1 and S2. In detail, the first end of the switch S1 is used to receive the voltage Vtx, and the second end of the switch S1 is electrically coupled to the first end of the resistor Rpanel and the node Vpad. A first end of the switch S2 is electrically coupled to the node Vpad, and a second end of the switch S2 is electrically coupled to the first end of the variable capacitor CC and the inverting input end of the operational amplifier AMP. The second terminal of the variable capacitor CC is electrically coupled to the ground terminal GND. The non-inverting input terminal of the operational amplifier AMP is used for receiving the reference voltage Vref. The operational amplifier AMP is used to operate in a differential mode, so as to output the voltage difference between its two input terminals.

Please refer to FIG. 3 . FIG. 3 is a flow chart S300 of a detection method for detecting the capacitance Cpanel of the capacitive touch panel 100 according to an embodiment of the present disclosure. The flowchart S300 includes steps S310 , S320 , S330 , S340 , S342 and S344 . Step S310 is to charge the capacitor Cpanel of the capacitive touch panel 100 within a period of time. Step S320 is to connect the detection pad Pad of the capacitive touch panel 100 to the detection device 200 . Step S330 is to adjust the variable capacitor CC in the detection device 200 . Step S340 is to determine whether the capacitance value of the variable capacitor CC is within the expected capacitance value. In step S342, the capacitance Cpanel of the capacitive touch panel 100 is at a standard capacitance value. Step S344 is that the capacitance Cpanel of the capacitive touch panel 100 is different from the standard capacitance. Wherein, steps S310 to S340 can be executed by the detection device 200 .

In step S310 , the voltage Vtx is applied to the touch sensing electrodes 120 of the capacitive touch panel 100 within a period of time. In other words, within a period of time, the switch S1 is turned on and the switch S2 is turned on, so that the voltage Vtx at the first terminal of the switch S1 is transmitted to the capacitor Cpanel of the capacitive touch panel 100 through the resistor Rpanel of the capacitive touch panel 100 , To charge the capacitor Cpanel of the capacitive touch panel 100 . And, when the time length ends, the switch S1 is turned off to stop applying the voltage Vtx to the touch sensing electrodes 120 of the capacitive touch panel 100 . That is, the charging of the capacitor Cpanel of the capacitive touch panel 100 is stopped. It is worth noting that since the charging capacity of the RC circuit is related to the time constant (that is, the resistance value on the RC circuit multiplied by the capacitance value), and when the charging time reaches five times the time constant, the charging capacity of the RC circuit is approximately equal to 99.3%.

Therefore, in step S310, in order to fully charge the capacitor Cpanel of the capacitive touch panel 100, the aforementioned time length may be more than five times the time constant (that is, the value of the resistor Rpanel multiplied by the capacitor Cpanel), thereby charging the capacitor The capacitor Cpanel of the type touch panel 100 is charged to approximately the maximum power value. In some embodiments, in order to ensure that the capacitor Cpanel of the capacitive touch panel 100 is fully charged, the aforementioned time length can be set at eight times the time constant (value of the resistor Rpanel multiplied by the capacitor Cpanel).

For a better understanding of the relationship between the time constant and the charging capacity, please also refer to Figure 4. FIG. 4 is a waveform diagram of charging the touch sensing electrodes 120 of the capacitive touch panel 100 according to step S310 in FIG. 3 . In the embodiment shown in FIG. 4 , the vertical axis represents the charging power ratio, and the unit is percentage (%). The horizontal axis represents time in microseconds (μs). As shown in FIG. 4, regardless of whether the capacitance Cpanel of the capacitive touch panel 100 varies, the capacitive touch panel can be turned on after providing a charging time eight times the first standard time constant (for example, 4.8 μs). The capacitor Cpanel of 100 is charged to a power ratio of more than 99.9%. In other words, the potential of the first end of the capacitor Cpanel of each capacitive touch panel 100 should be able to reach the level of the voltage Vtx after sufficient charging time. Wherein, the first standard time constant mentioned in step S310 may be the standard capacitance multiplied by the standard resistance value of the ideal capacitive touch panel 100 .

The aforementioned power ratio is the power ratio obtained by converting the total power that can be charged by the respective capacitors Cpanel of each capacitive touch panel 100 . Therefore, if the capacitance Cpanel of one capacitive touch panel 100 is larger, there will be a larger capacitance, and the stored electricity will be relatively large under sufficient charging time; if the capacitance Cpanel of another capacitive touch panel 100 Smaller, there will be a smaller capacity, and the stored power is relatively small under sufficient charging time. And in subsequent embodiments, it will be determined whether the capacitance Cpanel of the capacitive touch panel 100 has variation through the electric quantity stored in the capacitance Cpanel of each capacitive touch panel 100 in step S310 .

In step S320, in order to check whether the capacitance Cpanel of the capacitive touch panel 100 varies, the switch S2 is turned on to connect the detection pad of the capacitive touch panel 100 to the detection device 200, so that the touch pad of the capacitive touch panel 100 The sensing electrode 120 is connected to the inverting input terminal of the operational amplifier AMP and the first terminal of the variable capacitor CC in the detection device 200 . In step S320 , sufficient charging time is provided so that the potential of the capacitor Cpanel of the capacitive touch panel 100 is transmitted to the variable capacitor CC through the resistor Rpanel and the switch S2 , so that the potentials of the capacitor Cpanel and the variable capacitor CC are balanced.

Similarly, the time stated in step S320 may also be more than eight times the charging time of the second standard time constant (eg, about 4.8 μs). Further, the second standard time constant in step S320 may be the first standard time constant of the capacitive touch panel 100 (the value of the resistor Rpanel multiplied by the capacitor Cpanel) plus the time constant of the detection device 200 itself.

In actual situations, in steps S310 and S320, it is only necessary to ensure that the capacitor Cpanel of the capacitive touch panel 100 has enough time to charge/discharge to achieve potential balance in the current circuit structure, and then the variable The capacitance value of the capacitor CC determines the relative size of the capacitance Cpanel of the capacitive touch panel 100 , so as to determine whether the capacitance Cpanel varies.

Since in step S320, sufficient discharge time has been provided to balance the potentials of the capacitor Cpanel and the variable capacitor CC, the variable capacitor CC in the detection device 200 is adjusted in step S330 so that the voltage of the output terminal Vout of the operational amplifier AMP is approximately above is zero, that is, the variable capacitor CC is adjusted to the node Vpad, the voltages of the first terminal of the variable capacitor CC and the capacitor Cpanel are substantially equal to the reference voltage Vref. Wherein, the level of the reference voltage Vref is higher than the voltage level of the ground terminal GND. Moreover, the voltage Vtx is greater than the reference voltage Vref and the voltage of the ground terminal GND.

Since the capacitors Cpanel of each capacitive touch panel 100 are charged to approximately the maximum power in step S310 . Therefore, in step S320, for the capacitive touch panel 100 with a larger capacitance Cpanel, the detection device 200 will adjust the variable capacitor CC to a larger capacitance value, so as to make the output terminal Vout of the operational amplifier AMP The voltage is approximately zero; for a capacitive touch panel 100 with a small capacitance Cpanel, the detection device 200 will adjust the variable capacitance CC to a small capacitance value, so that the output terminal Vout of the operational amplifier AMP The voltage is approximately zero.

In step S340, since the capacitance value of the capacitor Cpanel of the capacitive touch panel 100 is positively correlated with the adjusted capacitance value of the variable capacitor CC, by judging whether the capacitance value of the variable capacitor CC is within the expected capacitance value, It can be known whether the capacitance Cpanel of the capacitive touch panel 100 is at the standard capacitance value.

In this way, the relative size of the capacitance Cpanel of each capacitive touch panel 100 can be determined through the capacitance value of the variable capacitor CC, and can be compared with the capacitance Cpanel of the capacitive touch panel 100 produced in the same batch. , so as to determine whether the capacitance Cpanel of the capacitive touch panel 100 varies.

In some embodiments, after steps S340-S360 are performed on the known standard capacitive touch panel 100, the capacitance value of the variable capacitor CC in the detection device 200 can be recorded, and the capacitance value can be set as expected capacitance value.

In some embodiments, the capacitance values of the variable capacitors CC obtained through steps S310-S330 of the same batch of capacitive touch panels 100 can be compared to determine whether the capacitance Cpanel of the capacitive touch panel 100 varies. .

In step S342, if the capacitance value of the variable capacitor CC is at the expected capacitance value, it is determined that the capacitance Cpanel of the capacitive touch panel 100 is at the standard capacitance value. Wherein, the standard capacitance value may be known as the capacitance value of the capacitance Cpanel of the standard capacitive touch panel 100 .

In step S344, if the capacitance value of the variable capacitor CC is different from the expected capacitance value, it is determined that the capacitance Cpanel of the capacitive touch panel 100 is different from the standard capacitance value.

Please refer to FIG. 5 . FIG. 5 is a flow chart S300 of a detection method for detecting the resistance Rpanel of the capacitive touch panel 100 according to an embodiment of the present disclosure. The flowchart S300 further includes steps S340 , S350 , S360 , S370 , S372 and S374 . Step S340 is to maintain the variable capacitor CC in the detection device. Step S350 is to charge the touch sensing electrodes 120 of the capacitive touch panel 200 within a period of time. Step S360 is to connect the detection pads of the capacitive touch panel 100 to the detection device within a period of time. Step S370 is to determine whether the output voltage of the operational amplifier AMP is at the expected voltage value. In step S372, the resistance Rpanel of the capacitive touch panel 100 is at a standard resistance value. Step S374 is that the resistance Rpanel of the capacitive touch panel is different from the standard resistance value. Wherein, steps S340 - S370 may be executed by the detection device 200 .

Step S340 is a continuation of step S330 in FIG. 3 . In step S340, the capacitance value of the variable capacitor CC adjusted in step S330 is maintained.

In step S350 , the voltage Vtx is applied to the touch sensing electrodes 120 of the capacitive touch panel 100 within a period of time. In other words, within a period of time, the switch S1 is turned on and the switch S2 is turned off, so that the switch S1 transmits the voltage Vtx at its first terminal to the capacitor of the capacitive touch panel 100 through the resistor Rpanel of the capacitive touch panel 100 Cpanel, to charge the capacitor Cpanel of the capacitive touch panel 100 . And, when the time length ends, the switch S1 is turned off to stop applying the voltage Vtx to the touch sensing electrodes 120 of the capacitive touch panel 100 . That is, when the time length ends, the charging of the capacitor Cpanel of the capacitive touch panel 100 is stopped. It should be noted that the time length in step S350 may be double the first standard time length, for example, the value of the resistor Rpanel multiplied by the capacitor Cpanel.

For a better understanding of the relationship between the time constant and the potential of the capacitor Cpanel, please also refer to Figure 6. FIG. 6 is a voltage waveform diagram of charging the touch sensing electrodes 120 of the capacitive touch panel 100 according to step S350 in FIG. 5 . In the embodiment shown in FIG. 6 , the vertical axis represents the charging voltage, and the unit is volts (V). The horizontal axis represents time in microseconds (μs). As shown in FIG. 6, if the resistance Rpanel of some capacitive touch panels 100 is relatively large, after a charging time of twice the first standard time constant (for example, 0.6 μs) is provided, the capacitive touch panel with a small resistance Rpanel The capacitor Cpanel of the control panel 100 can be charged to a higher potential; if the resistance Rpanel of a part of the capacitive touch panel 100 is larger, after providing a charging time of twice the first standard time constant (for example, 0.6 μs), the resistance The capacitor Cpanel of the capacitive touch panel 100 with larger Rpanel is charged to a lower potential.

In other words, the capacitor Cpanel of the capacitive touch panel 100 with a smaller resistance Rpanel will store a relatively large amount of electricity after providing a charging time of twice the first standard time constant (for example, 0.6 μs); the capacitor with a larger resistance Rpanel The capacitor Cpanel of the touch panel 100 stores relatively little power.

In step S360, in order to detect whether the resistance Rpanel of the capacitive touch panel 100 varies, the detection pad (that is, the node Vpad) of the capacitive touch panel 100 is connected to the detection device 200, and the switch S2 is turned on, so that The touch sensing electrodes 120 of the capacitive touch panel 100 are connected to the inverting input terminal of the operational amplifier AMP and the first terminal of the variable capacitor CC in the detection device 200 . In step S360 , sufficient time is provided for the potential of the capacitor Cpanel of the capacitive touch panel 100 to be transmitted to the variable capacitor CC through the resistor Rpanel and the switch S2 , so that the potentials of the capacitor Cpanel and the variable capacitor CC are balanced. Similarly, the time stated in step S360 may also be more than eight times the charging time of the second standard time constant (for example, about 4.8 μs). Furthermore, under this circuit connection relationship, the second standard time constant is substantially equal to the first time constant (the resistance Rpanel multiplied by the capacitance Cpanel) of the capacitive touch panel 100 plus the time constant of the circuit of the detection device 200 itself.

In actual situations, in steps S350 and S3360, it is only necessary to ensure that the resistance Rpanel of the capacitive touch panel 100 is charged and discharged within a set period of time, and the charging time must be different from the discharging time, and the following steps S330~S340 can be used. The relative magnitude of the resistance Rpanel of the capacitive touch panel 100 is determined to determine whether the resistance Rpanel varies.

Since the capacitance value of the variable capacitor CC in the detection device 200 is adjusted in step S330, it is maintained until step S370. Therefore, after the detection pad (and node Vpad) of the capacitive touch panel 100 is connected to the detection device 200 in step S360, the capacitance value of the variable capacitor CC in the detection device 200 can be regarded as a capacitive touch panel 100 of compensation capacitor. In other words, regardless of whether the capacitance Cpanel of the capacitive touch panel 100 is larger or smaller at this time, the capacitance Cpanel of each capacitive touch panel 100 plus the variable capacitance CC adjusted by the detection device 200 in step S330 The capacitor value should be a fixed value.

Therefore, in step S370, by judging whether the output voltage of the operational amplifier AMP is at the expected voltage value, it can be known whether the resistance Rpanel of the capacitive touch panel 100 is at the standard resistance value.

For example, the capacitance Cpanel of the capacitive touch panel 100 with a smaller resistance Rpanel will store more electricity in step S350, so in step S360, the detection pad (that is, the node Vpad) is connected to the detection device 200 Afterwards, the node Vpad, the first terminal of the capacitor Cpanel, and the first terminal of the variable capacitor CC will be at a higher potential, so that the voltage difference between the two input terminals of the operational amplifier OPA will be smaller, and the output voltage of the operational amplifier AMP will have a higher potential. Small voltage amplitude. On the other hand, the capacitance Cpanel of the capacitive touch panel 100 with a larger resistance Rpanel will store less electricity in step S350, so the detection pad (ie, the node Vpad) is connected to the detection device 200 in step S360 Afterwards, the node Vpad, the first terminal of the capacitor Cpanel, and the first terminal of the variable capacitor CC will be at a lower potential, so that the voltage difference between the two input terminals of the operational amplifier OPA will be larger, so that the output voltage of the operational amplifier AMP will have Larger voltage amplitude.

In this way, the relative size of the resistance Rpanel of each capacitive touch panel 100 can be determined through the output voltage of the operational amplifier AMP, and can be compared with the resistance Rpanel of the capacitive touch panel 100 produced in the same batch. Therefore, it is determined whether the resistance Rpanel of the capacitive touch panel 100 varies.

In some embodiments, it is possible to record the output voltage of the operational amplifier AMP in the detection device 200 after performing steps S340-S360 on the known standard capacitive touch panel 100, and set the output voltage as the expected voltage value.

In step S372, if the output voltage of the operational amplifier AMP is at the expected voltage value, it is determined that the resistance Rpanel of the capacitive touch panel 100 is at the standard resistance value. Wherein, the standard resistance value may be a resistance value known as the resistance Rpanel of the ideal capacitive touch panel 100 .

In step S374, if the output voltage of the operational amplifier AMP is different from the expected voltage value, it is determined that the resistance Rpanel of the capacitive touch panel 100 is different from the standard resistance value.

It should be noted that by setting the time length described in step S360 to be greater than the time length described in step S350, the effect of charging/discharging the capacitance Cpanel of the capacitive touch panel 100 at different time lengths can be achieved, so that through step S310 ~S370 can also determine whether the capacitance Cpanel and the resistance Rpanel of the capacitive touch panel 100 vary. Moreover, in this case, the time length in step S310 is also greater than the time length in step S350. Therefore, the time length described in step S360 may be set to be five times or more than the time length described in step S350. In addition, the time length described in step S310 may be set to be five times or more than the time length described in step S350.

In some other embodiments of this disclosure document, the time length described in step S350 in Fig. 5 can also be set to be five times or more the time constant, and the time length described in step S360 can be set to be more than double the time The constant can also achieve the effect of charging/discharging the capacitance Cpanel of the capacitive touch panel 100 at different time lengths, so that whether the capacitance Cpanel and the resistance Rpanel of the capacitive touch panel 100 have variation can also be determined through steps S310-S370. That is, setting the time length in step S350 to be longer than the time length in step S360 can achieve the effect of charging/discharging the capacitance Cpanel of the capacitive touch panel 100 at different time lengths. Moreover, in this case, the time length in step S310 is also greater than the time length in step S360. Therefore, the time length described in step S350 may be set to be five times or more than the time length described in step S360. In addition, the time length in step S310 may be set to be five times or more than the time length in step S360.

To sum up, the disclosed document utilizes the variable capacitor CC in the detection device 200 to determine whether the capacitance Cpanel of the capacitive touch panel 100 has changed, and maintains the detection device 200 during the detection stage of detecting the resistance Rpanel of the capacitive touch panel 100 The capacitance value of the variable capacitor CC is used to determine whether the resistance Rpanel of the capacitive touch panel 100 varies.

Although the present disclosure has been disclosed above in terms of implementation, it is not intended to limit this disclosure. Any person with ordinary knowledge in the field may make various changes and modifications without departing from the spirit and scope of this disclosure. Therefore, this disclosure The scope of protection disclosed shall be subject to what is defined in the scope of the appended patent application.

In order to make the above and other purposes, features, advantages and embodiments of the present disclosure more obvious and easy to understand, the descriptions of the attached symbols are as follows: 100: capacitive touch panel 120: Touch sensing electrode 130: Gap 140: common electrode 150: light emitting element 160: array 170: display glass substrate 200: detection device Cpanel: capacitance Rpanel: resistance Vcom: system voltage terminal S1, S2: switch CC: variable capacitance Vpad: node AMP: operational amplifier Cbase: Capacitance Vout: output terminal Vref: reference voltage GND: ground terminal Vtx: Voltage

In order to make the above and other purposes, features, advantages and embodiments of the present disclosure more comprehensible, the accompanying drawings are described as follows: FIG. 1 is a schematic diagram of a capacitive touch panel according to an embodiment of the present disclosure. FIG. 2 is a schematic diagram of a testing device for testing the capacitive touch panel in FIG. 1 according to an embodiment of the present disclosure. FIG. 3 is a flowchart of a detection method for detecting capacitance of a capacitive touch panel according to an embodiment of the present disclosure. FIG. 4 is a waveform diagram of charging the touch sensing electrodes of the capacitive touch panel according to step S310 in FIG. 3 . FIG. 5 is a flowchart of a detection method for detecting resistance of a capacitive touch panel according to an embodiment of the present disclosure. FIG. 6 is a voltage waveform diagram of charging the touch sensing electrodes of the capacitive touch panel according to step S350 in FIG. 5 .

Domestic deposit information (please note in order of depositor, date, and number) none Overseas storage information (please note in order of storage country, institution, date, and number) none

200: detection device

Cpanel: capacitance

Rpanel: resistance

Vcom: system voltage terminal

S1, S2: switch

CC: variable capacitance

Vpad: node

AMP: operational amplifier

Cbase: Capacitance

Vout: output terminal

Vref: reference voltage

GND: ground terminal

Vtx: Voltage

Claims (10)

A detection method comprising: Applying a voltage to a touch sensing electrode of a capacitive touch panel for a first time length; When the first time length ends, stop applying the voltage to the touch sensing electrode of the capacitive touch panel, and electrically couple the touch sensing electrode to a variable capacitor and an operational amplifier, wherein The non-inverting input terminal of the operational amplifier is used to receive a reference voltage; adjusting a capacitance value of the variable capacitor so that the output voltage of the operational amplifier is substantially zero; and It is judged whether the capacitance value of the variable capacitor is within an expected capacitance value. The detection method as described in request item 1 further includes: If the capacitance value of the variable capacitor is equal to the expected capacitance value, it is determined that the capacitance of the capacitive touch panel is within a standard capacitance value; and If the capacitance value of the variable capacitor is different from the expected capacitance value, it is determined that the capacitance of the capacitive touch panel is different from the standard capacitance value. The detection method as described in request item 2 further includes: maintaining a capacitance value of the variable capacitor; applying the voltage to the touch-sensing electrodes of the capacitive touch panel for a second length of time; stopping applying the voltage to the touch-sensing electrodes of the capacitive touch panel at the end of the second length of time; electrically coupling the touch sensing electrode to the variable capacitor and the operational amplifier during a third duration; and When the third time period ends, the touch sensing electrode is disconnected from the variable capacitor and the operational amplifier, and it is determined whether the output voltage of the operational amplifier is at a desired voltage value. The detection method according to claim 3, wherein the first time length is longer than the second time length, and the third time length is longer than the second time length. The detection method according to claim 3, wherein the first time length is greater than the third time length, and the second time length is greater than the third time length. The detection method as described in claim item 3 further includes: If the output voltage of the operational amplifier is equal to the expected voltage value, it is determined that the resistance of the touch sensing electrode is at a standard resistance value; and If the output voltage of the operational amplifier is different from the expected voltage value, it is determined that the resistance of the touch sensing electrode is different from the standard resistance value. A detection device comprising: a variable capacitor; and An operational amplifier, wherein the detection means applies a voltage to a touch sensing electrode of a capacitive touch panel within a first time length, and the detection means senses the touch sense electrode after the first time length ends. The measuring electrode is connected to the variable capacitance and the operational amplifier, the detection device adjusts the variable capacitance until the output of the operational amplifier is substantially zero, and the detection device judges whether the adjusted value of the variable capacitance is in the expected capacitance value. The detection device as claimed in claim 7, wherein the detection device applies the voltage to the touch sensing electrode for a second time length, and connects the touch sensing electrode to the detection device for a third time length The variable capacitor and the operational amplifier, and the detection device judges whether the output of the operational amplifier is at the expected resistance value. The detecting device according to claim 8, wherein the first time length is longer than the second time length, and the third time length is longer than the second time length. The detecting device as claimed in claim 8, wherein the first time length is longer than the third time length, and the second time length is longer than the third time length.

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