Display panel edge crack detection method and device

Abstract

The invention provides a display panel edge crack detection method and device, and belongs to the technical field of display panel detection, and the method comprises the steps: firstly, obtaining an initial impedance value of a crack detection line of a display panel in a module processing stage; then, in the crack detection stage, resistance detection is carried out on the crack detection wire, and a detection impedance value is obtained. And finally, obtaining a crack detection result of the display panel according to the initial impedance value and the detection impedance value. The detection impedance value is obtained in the crack detection stage, the initial impedance value is compared with the detection impedance value, and the initial impedance value is used as a reference, so that the influence on the crack detection result caused by the difference of the resistance values of the crack detection wires of different display panels can be avoided, and the detection accuracy is improved. And the accuracy of crack detection of the display panel is improved.

Description

Technical Field

[0001] The present application relates to the technical field of display panel detection, and particularly relates to a method and device for detecting edge cracks of a display panel. Background Art

[0002] AMOLED (Active-Matrix Organic Light-Emitting Diode) display panels are widely used due to their many advantages such as high contrast, wide viewing angle, fast response, and the ability to achieve flexible display. During the production process of AMOLED display panels, various complex process operations and external environmental factors are faced. The screen edge of the display panel is relatively fragile and is prone to generating micro-cracks due to external forces during the production process, resulting in subsequent use. Due to various factors (such as temperature changes, mechanical stress, etc.), the cracks will gradually expand, ultimately leading to functional abnormalities such as abnormal display and local black screen in the display panel. Therefore, it is necessary to detect cracks in the display panel and timely discover and screen out products with crack defects.

[0003] Currently, a circle of crack detection traces (Printed-Circuit for Detection, PCD) is usually built-in at the edge of the display panel, and then the resistance value of the crack detection traces is measured to determine whether there are cracks in the display panel. If there are cracks, the resistance value of the crack detection traces will change due to open circuit or the change of the connection cross-sectional area.

[0004] However, the resistance values of the crack detection traces of different-sized display panels vary greatly, and the resistance values of the crack detection traces of the same type of display panel also vary due to factors such as manufacturing processes, resulting in low accuracy of detecting cracks in the display panel by the resistance values of the crack detection traces. Summary of the Invention

[0005] Aiming at the deficiencies in the prior art, the present application provides a method and device for detecting edge cracks of a display panel.

[0006] In a first aspect, a method for detecting edge cracks of a display panel provided by the present application includes:

[0007] Obtaining an initial impedance value of the crack detection traces of the display panel in the module manufacturing process stage;

[0008] In the crack detection stage, detecting the resistance value of the crack detection traces to obtain a detected impedance value;

[0009] Obtaining a crack detection result of the display panel according to the initial impedance value and the detected impedance value.

[0010] Optionally, before obtaining the initial impedance value of the crack detection trace in the module manufacturing process stage of the display panel, the method further includes:

[0011] In the module manufacturing process stage of the display panel, performing impedance detection on the crack detection trace to obtain the initial impedance value, and storing the initial impedance value in the display panel.

[0012] Optionally, performing resistance value detection on the crack detection trace to obtain a detected impedance value includes:

[0013] Taking a preset initial range as the measurement range, and performing resistance value detection on the crack detection trace according to the measurement range to obtain a resistance value measurement result;

[0014] If the ratio between the resistance value measurement result and the measurement range is within a preset range, taking the resistance value measurement result as the detected impedance value;

[0015] If the ratio between the resistance value measurement result and the measurement range is not within the preset range, adjusting the measurement range, and re-performing resistance value detection on the crack detection trace until the ratio between the resistance value measurement result and the measurement range is within the preset range.

[0016] Optionally, performing resistance value detection on the crack detection trace according to the measurement range to obtain a resistance value measurement result includes:

[0017] According to the measurement range, outputting a range switching signal to a detection device to enable the detection device to switch to a measurement gear; wherein, the detection device is used to measure the resistance value of the crack detection trace;

[0018] Controlling each resistor corresponding to the measurement gear in the detection device to be sequentially selected until the detection device feeds back a test completion signal;

[0019] Obtaining the resistance value measurement result according to the resistance value of the resistor selected when the test completion signal is fed back.

[0020] Optionally, obtaining the crack detection result of the display panel according to the initial impedance value and the detected impedance value includes:

[0021] If the difference between the initial impedance value and the detected impedance value exceeds a preset difference threshold, determining that the crack detection result of the display panel is that there is a crack;

[0022] If the difference between the initial impedance value and the detected impedance value does not exceed the preset difference threshold, determining that the crack detection result of the display panel is that there is no crack.

[0023] Optionally, the method further includes:

[0024] If the difference between the initial impedance value and the detected impedance value does not exceed a preset difference threshold, determine whether the detected impedance value is greater than a preset resistance threshold;

[0025] If the detected impedance value is greater than or equal to the preset resistance threshold, it is determined that there is a crack in the crack detection result of the display panel;

[0026] If the detected impedance value is less than the preset resistance threshold, it is determined that there is no crack in the crack detection result of the display panel.

[0027] In a second aspect, in one embodiment, the present application provides a display panel edge crack detection device, including:

[0028] A connection end, connected to a crack detection trace in the display panel;

[0029] A resistor array circuit, including a plurality of resistors;

[0030] A gear selection circuit, connected to the resistor array circuit, for sequentially selecting the resistors in the resistor array circuit, so that the selected resistor and the crack detection trace divide the first reference voltage to obtain a divided voltage signal;

[0031] A resistance value detection circuit, connected to the gear selection circuit and connected to a second reference voltage, for obtaining the detected impedance value of the crack detection trace according to the divided voltage signal and the second reference voltage;

[0032] Wherein, the detected impedance value is used to obtain the crack detection result of the display panel.

[0033] Optionally, the resistor array circuit includes a plurality of resistor sub-circuits;

[0034] Each of the resistor sub-circuits is connected to the gear selection circuit and connected to the first reference voltage; the resistors in each of the resistor sub-circuits are connected in series in sequence, and each of the resistors is respectively connected to the gear selection circuit, so that the gear selection circuit sequentially selects each of the resistors.

[0035] Optionally, the gear selection circuit includes a gear adjustment sub-circuit and a selection sub-circuit;

[0036] The gear adjustment sub-circuit includes gear adjustment switches corresponding to the resistor sub-circuits one by one. Each of the gear adjustment switches includes a control pole for accessing a range switching signal, a first end connected to the corresponding selection sub-circuit, and a second end connected to the resistance value detection circuit;

[0037] The gating sub-circuit includes gating switches corresponding one by one to the resistors in the resistor sub-circuit. Each gating switch includes a control electrode for receiving a gating control signal, a first end connected to the resistor, and a second end connected to the corresponding gear adjustment switch.

[0038] Optionally, the resistance value detection circuit includes a comparator and a controller;

[0039] The comparator includes a first input terminal for receiving the second reference voltage, a second input terminal connected to the gear selection circuit, and an output terminal connected to the controller. The comparator is configured to output a test completion signal according to the voltage division signal and the second reference voltage;

[0040] The controller is configured to obtain the resistance value measurement result according to the resistance value of the selected resistor in the resistor array circuit corresponding to the test completion signal.

[0041] In summary, in the present application, first, by obtaining the initial impedance value in the module manufacturing process stage, an independent resistance value standard for each display panel is established. Secondly, in the crack detection stage, the detected impedance value is obtained. By comparing the initial impedance value and the detected impedance value, with the initial impedance value as a reference, the influence on the crack detection result caused by the difference in the resistance values of the crack detection traces of different display panels can be avoided. In this way, the accuracy of the crack detection of the display panel is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present application. For those skilled in the art, without creative efforts, other drawings can be obtained according to these drawings.

[0043] Figure 1 It is a schematic diagram of a crack detection trace in an embodiment of the present application;

[0044] Figure 2 It is a flowchart of a crack detection method for a display panel in an embodiment of the present application;

[0045] Figure 3 It is a flowchart of a method for measuring a resistance value detection result in an embodiment of the present application;

[0046] Figure 4 It is a schematic diagram of a crack detection device for a display panel in an embodiment of the present application;

[0047] Figure 5 It is a circuit connection diagram of a crack detection device for a display panel in an embodiment of the present application. Detailed implementation manners

[0048] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Apparently, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present application.

[0049] In the description of the present application, it should be understood that the terms "first" and "second" are only used for descriptive purposes, and cannot be construed as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of the described features. In the description of the present application, "a plurality" means two or more, unless otherwise specifically defined. In the present application, the term "exemplary" is used to mean "serving as an example, illustration, or description". Any embodiment described as "exemplary" in the present application is not necessarily to be construed as being more preferred or having more advantages than other embodiments. In order for any person skilled in the art to implement and use the present application, the following description is given. In the following description, details are set forth for the purpose of explanation. It should be understood that those of ordinary skill in the art can recognize that the present application can be implemented without the use of these specific details. In other instances, well-known structures and processes are not described in detail to avoid unnecessary details from obscuring the description of the present application. Therefore, the present application is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed in the present application.

[0050] In a first aspect, as Figure 1 and Figure 2 shown, in one embodiment, the present application provides a method for detecting edge cracks of a display panel, including the following steps S100 to S300, which will be introduced in detail below.

[0051] Step S100: Obtain the initial impedance value of the crack detection trace of the display panel in the module manufacturing process stage.

[0052] Generally, in the manufacturing process of a display panel, it needs to go through the array process stage, the cell process stage, and the module process stage. The array process stage is the starting stage of display panel manufacturing. Thin film transistors and other circuit elements are fabricated on a glass substrate through processes such as photolithography, etching, and thin film deposition to construct a circuit array for driving pixels. In the cell process stage, the substrate that has completed the array process is bonded to the color filter substrate, and an organic light-emitting material is evaporated. Combining Figure 1, in the module manufacturing process stage, the crack detection trace is connected to the substrate driving chip (Display Driver Integrated Circuit, DDIC), and the display panel after the cell manufacturing process stage is assembled with the substrate driving chip, polarizer, etc., so as to obtain the display module.

[0053] As an example, the initial impedance value can be the resistance value of the crack detection trace measured at the beginning of the module manufacturing process stage. On the one hand, at the beginning of the module manufacturing process, the main structure of the display panel has been basically completed, and the physical state of the crack detection trace is relatively stable. On the other hand, during the assembly of the driving chip and the polarizer with the substrate of the display panel, certain stress will be generated on the display panel, thus interfering with the measurement result of the resistance value of the crack detection trace.

[0054] Step S200: In the crack detection stage, perform a resistance value detection on the crack detection trace to obtain a detected impedance value.

[0055] As an example, after the display panel is manufactured, there will also be processing stages such as housing assembly and function testing, and then the manufacturing of the whole machine product of the display panel will be completed. For example, the whole machine product can be a display device such as a mobile phone or a TV. The crack detection stage can be any stage after the module manufacturing process stage, which can be the housing assembly stage, the testing stage or the detection stage after the whole machine manufacturing is completed. For example, performing a resistance value detection on the crack detection trace during the housing assembly stage can timely detect that cracks may occur at the edge of the screen due to external forces such as extrusion and collision during the housing assembly process. Another example is that when the display panel completes the manufacturing of the whole machine product, the whole machine product may also be affected by external forces during transportation, storage and use, which will also cause cracks at the edge of the display panel. Therefore, it is also necessary to perform crack detection on the display panel after the whole machine manufacturing is completed to improve the quality of the whole machine product of the display panel.

[0056] Step S300: Obtain the crack detection result of the display panel according to the initial impedance value and the detected impedance value.

[0057] As an example, the lengths of the crack detection traces of display panels of different sizes are different, and for the same type of display panels produced in different batches, the resistance values of their crack detection traces may also be different due to material batches, minor differences in production equipment, etc. By using the initial impedance value measured by the display panel itself as a reference and judging whether there are cracks in the display panel by comparing the differences between the initial impedance value and the detected impedance value, the crack detection result is not affected by the differences in the resistance values of the crack detection traces of each display panel.

[0058] In the above embodiments, first, by obtaining the initial impedance value in the module manufacturing process stage, an independent resistance value standard for each display panel is established. Second, in the crack detection stage, the detected impedance value is obtained. By comparing the initial impedance value with the detected impedance value and using the initial impedance value as a reference, the influence on the crack detection result caused by the difference in the resistance value of the crack detection trace of different display panels can be avoided. In this way, the accuracy of the crack detection of the display panel is improved.

[0059] In some embodiments, before step S100, it may further include: in the module manufacturing process stage of the display panel, performing impedance detection on the crack detection trace to obtain an initial impedance value, and storing the initial impedance value in the display panel.

[0060] Among them, the initial impedance value can be stored in the substrate driver chip of the display panel.

[0061] As an example, by setting a preset resistance value threshold, the display panel can be first detected according to the initial impedance value. The preset resistance value threshold can be a fixed value set in advance. When the initial impedance value exceeds the preset resistance value threshold, it can be determined that there is a crack phenomenon in the display panel in the module manufacturing process stage. At this time, the crack detection result of the display panel can be directly obtained as having a crack, and the display panel can be directly obtained as having a crack, and this display panel can be not required to continue the subsequent process or be repaired in time.

[0062] In this way, the display panel in the module manufacturing process stage has not experienced great stress and is in a relatively stable state. At this time, measuring the resistance value of the crack detection trace can obtain a relatively accurate initial impedance value and store the initial impedance value. Then, in the subsequent crack detection stage, there is no need to detect the initial impedance value again, and the initial impedance value of the stored crack detection trace can be directly read from the display panel.

[0063] As an implementation manner of step S200, step S200 may include steps S210 - S230, which will be introduced in detail below.

[0064] Step S210: Use the preset initial range as the measurement range, and perform resistance value detection on the crack detection trace according to the measurement range to obtain a resistance value measurement result.

[0065] As an example, the preset initial range can be set according to experience or according to the result of the resistance value of the crack detection trace of the same model display panel. For example, for the same model display panel, according to production data and test experience, it is estimated that the order of magnitude of the resistance value of its crack detection trace may be in the range of several thousand ohms, then the initial range can be set to 1000K.

[0066] Step S220: If the ratio between the resistance value measurement result and the measurement range is within the preset range, use the resistance value measurement result as the detected impedance value.

[0067] As an example, by comparing the resistance measurement result with the measurement range, it is possible to determine whether the current measurement range is appropriate. If the ratio between the resistance measurement result and the measurement range is within a preset range, it can be considered that the current measurement range is appropriate; otherwise, the current measurement range is inappropriate. The preset range can be set to 50%-100%. For example, when the measurement range is 1000 KΩ and the measured resistance measurement result is 600 KΩ, the ratio between the resistance measurement result and the measurement range is 60%, which is within the preset range of 50%-100%. At this time, the resistance detection result of 600 KΩ can be used as the detected impedance value.

[0068] Step S230: If the ratio between the resistance measurement result and the measurement range is not within the preset range, adjust the measurement range and re-measure the resistance of the crack detection trace until the ratio between the resistance measurement result and the measurement range is within the preset range.

[0069] As an example, if the ratio between the resistance measurement result and the measurement range is not within the preset range, it indicates that the current range is inappropriate and needs to be adjusted. For example, when the resistance measurement result obtained using a measurement range of 1000 KΩ is 300 KΩ, the ratio between the resistance measurement result and the measurement range is 30%, indicating that the current measurement range is too large and the measurement is not precise enough. At this time, the measurement range needs to be adjusted. For example, the measurement range can be adjusted from 1000 KΩ to 500 KΩ, and the resistance of the crack detection trace is re-measured. When re-measuring, the resistance measurement operation is performed again according to the measurement range of 500 KΩ to obtain the resistance measurement result again, and it is re-determined whether the ratio between the re-obtained resistance measurement result and the measurement range of 500 KΩ is within the preset range. If it is still not within the range, continue to adjust the range and re-measure until the ratio between the resistance measurement result and the measurement range is within the preset range.

[0070] In the above embodiments, by presetting the initial range and adjusting the measurement range according to the ratio relationship between the measurement result and the range, it is possible to automatically adjust the measurement range in the case of a large span of the resistance value range of the crack detection trace, avoiding the decrease in measurement accuracy caused by an inappropriate measurement range.

[0071] Referring to Figure 3 , as an embodiment of step 210, step S210 may include steps S211 - S213, which will be introduced in detail below.

[0072] Step S211: Output a range switching signal to the detection device according to the measurement range so that the detection device switches to the measurement gear.

[0073] Among them, the detection device is used to measure the resistance value of the crack detection trace. As an example, different measurement ranges will output different range switching signals. The detection device includes several resistor sub-circuits, each resistor sub-circuit includes several resistors, and the resistance values of the resistors in the grouped resistor sub-circuits are different. The range switching signal is used to select and enable the resistor sub-circuit, so as to determine the measurement gear of the detection device.

[0074] Step S212: Control each resistor corresponding to the measurement gear in the detection device to be sequentially selected and enabled until the detection device feeds back a test completion signal.

[0075] As an example, during the selection and enabling process, the selected resistor and the crack detection trace share the voltage. As the resistors are connected one by one, the voltage division relationship changes continuously until a combination of selected resistors that can reflect the resistance value of the crack detection trace is determined, a feedback test completion signal is output, and the currently selected resistors are recorded, so as to calculate the resistance value of the crack detection trace according to the currently selected resistors.

[0076] For example, the resistor sub-circuit corresponding to the 10K measurement gear contains 10 resistors. When the detection device starts to work, first select and enable the first resistor, so that the resistor is connected in series with the crack detection trace to share the voltage and obtain a voltage division signal. Then judge whether the current voltage division signal meets the conditions. If not, select and enable the first resistor and the second resistor until the detection device detects a signal that meets the test completion conditions and outputs a test completion signal.

[0077] Step S213: Obtain a resistance value measurement result according to the resistance value of the resistor selected when the feedback test completion signal is received.

[0078] Among them, when the detection device feeds back a test completion signal, it means that the voltage division signal obtained by sharing the voltage between the selected resistor and the crack detection trace meets the conditions. By calculating according to the voltage division relationship and the resistance value of the selected resistor, the resistance value measurement result of the crack detection trace can be obtained.

[0079] In the above embodiment, by combining the range switching signal and the operation of sequentially selecting and enabling the resistors in the detection device, it is possible to traverse the resistance values formed by various resistor combinations in the detection device to select a combination of selected resistors suitable for the crack detection trace, so as to calculate the resistance value detection result of the crack detection trace.

[0080] As an implementation manner of step S300, step S300 may include steps S310 - S320, which will be introduced in detail below.

[0081] Step S310: If the difference between the initial impedance value and the detected impedance value exceeds a preset difference threshold, it is determined that the crack detection result of the display panel is that there is a crack.

[0082] Step S320: If the difference between the initial impedance value and the detected impedance value does not exceed the preset difference threshold, it is determined that the crack detection result of the display panel is that there is no crack.

[0083] Among them, the preset difference threshold can be set according to the initial impedance value. For example, the preset difference threshold can be set to 10%, 15%, 20%, 25% or 30% of the initial impedance value. Taking the preset difference threshold set to 15% of the initial impedance value as an example, if the initial impedance value of the display panel is 120 KΩ, then the preset difference threshold is 120 KΩ × 15% = 18 K. If during the crack detection stage of the display panel, the measured detected impedance value is 140 KΩ, then the difference between the initial impedance value and the detected impedance value is 20 KΩ. At this time, it can be determined that the crack detection result of the display panel is that there is a crack. If during the crack detection stage of the display panel, the measured detected impedance value is 130 KΩ, then the difference between the initial impedance value and the detected impedance value is 10 KΩ, which is less than the preset difference threshold. At this time, it can be determined that the crack detection result of the display panel is that there is no crack.

[0084] In the above embodiments, by using the initial impedance value of the display panel itself in the module manufacturing process stage as the comparison reference, compared with setting a fixed threshold, it can effectively eliminate the individual differences in the crack detection trace impedance of different display panels caused by factors such as manufacturing process fluctuations and raw material batch differences, reduce the missed detection or false detection of the crack situation of the display panel caused by individual differences, and thus can more accurately reflect the impedance change of the display panel due to cracks, improving the accuracy of crack detection.

[0085] In some embodiments, the crack inspection method further includes Step S400 - Step S600, which will be introduced in detail below.

[0086] Step S400: If the difference between the initial impedance value and the detected impedance value does not exceed the preset difference threshold, determine whether the detected impedance value is greater than the preset resistance threshold. If the detected impedance value is greater than or equal to the preset resistance threshold, then execute Step S500. If the detected impedance value is less than the preset resistance threshold, then execute Step S600.

[0087] Step S500: Determine that the crack detection result of the display panel is that there is a crack.

[0088] Step S600: Determine that the crack detection result of the display panel is that there is no crack.

[0089] Among them, the preset resistance threshold value can be a fixed value set according to the size or model of the display panel. As an example, the impedance change of the crack detection trace caused by the tiny crack existing in the display panel is small, which is not enough to make the difference between the initial impedance value and the detected impedance value exceed the preset difference threshold. However, the detected impedance value at this time is at a relatively high abnormal level. By adding the judgment of the fixed resistance threshold value, such potential crack situations can be captured to avoid missed detection.

[0090] In the above-mentioned implementation manner, for the situation where the difference between the initial impedance value and the detected impedance value does not exceed the preset difference threshold, a re-judgment is made through the preset difference threshold. If the detected impedance value is greater than or equal to the preset resistance threshold value, even if the difference between the initial impedance value and the detected value does not exceed the preset difference threshold, the crack detection result of the display panel is also determined to have a crack, thereby reducing the situation of missed detection of cracks.

[0091] Refer to Figure 4 Second, in one embodiment, the present application provides a display panel edge crack detection device, including a connection end 1, a resistor array circuit 2, a gear selection circuit 3, and a resistance value detection circuit 4. Among them, the connection end 1 is connected to the crack detection trace in the display panel. The resistor array circuit 2 includes a plurality of resistors. The gear selection circuit 3 is connected to the resistor array circuit 2 and is used to sequentially select the resistors in the resistor array circuit 2 so that the selected resistor and the crack detection trace divide the first reference voltage to obtain a divided voltage signal. The resistance value detection circuit 4 is connected to the gear selection circuit 3 and is connected to the second reference voltage, and is used to obtain the detected impedance value of the crack detection trace according to the divided voltage signal and the second reference voltage.

[0092] Among them, the detected impedance value is used to obtain the crack detection result of the display panel. For the specific method of obtaining the crack detection result of the display panel according to the detected impedance value, reference can be made to the foregoing method embodiments, which will not be elaborated here. In addition, the initial impedance value of the display panel can also be measured by using the connection end 1, the resistor array circuit 2, the gear selection circuit 3, and the resistance value detection circuit 4 in the above-mentioned manner of measuring the detected impedance value.

[0093] Among them, as Figure 5 shown, the connection end may include a first connection terminal V1 and a second connection terminal V2. The first connection terminal V1 is connected to the gear selection circuit 3 and is used to connect one end of the crack detection trace; the second connection terminal V2 is grounded and is used to connect the other end of the crack detection trace.

[0094] In the above-described embodiments, through the connection between the connection end 1 and the crack detection trace, the crack detection trace can form a voltage dividing circuit with the resistor array circuit 2. The resistor array circuit 2 includes a plurality of resistors. Each resistor in the resistor array circuit 2 is selected by the gear selection circuit 3 to enable combinations of different numbers of resistors to provide different voltage division ratios. Then, based on the resistors sequentially selected by the gear selection circuit 3, the selected resistor and the crack detection trace divide the first reference voltage to obtain a voltage division signal. Finally, the resistance value detection circuit 4 accesses the second reference voltage and calculates the detection impedance value of the crack detection trace according to the voltage division signal.

[0095] Referring again to Figure 5 , as an embodiment of the resistor array, the resistor array circuit 2 includes a plurality of resistor sub-circuits. Each resistor sub-circuit is connected to the gear selection circuit 3 and accesses the first reference voltage. The resistors in each resistor sub-circuit are sequentially connected in series, and each resistor is respectively connected to the gear selection circuit 3 so that the gear selection circuit 3 sequentially selects each resistor.

[0096] As an example, four groups of resistor sub-circuits can be set, namely the first resistor sub-circuit 21, the second resistor sub-circuit 22, the third resistor sub-circuit 23, and the fourth resistor sub-circuit 24. The first resistor sub-circuit 21, the second resistor sub-circuit 22, the third resistor sub-circuit 23, and the fourth resistor sub-circuit 24 are all connected to the gear selection circuit 3 and access the first reference voltage. As an example, the first resistor sub-circuit 21 can include n first resistors R11 - R1n connected in series in sequence, where n is a positive integer. The first resistor R11 at the head accesses the first reference voltage, the first resistor R1n at the tail is connected to the gear selection circuit 3, and the series connection nodes between every two first resistors are also connected to the gear selection circuit 3. Similarly, the second resistor sub-circuit 22 can include n second resistors R21 - R2n connected in series in sequence, the third resistor sub-circuit 23 can include n third resistors R31 - R3n connected in series in sequence, and the fourth resistor sub-circuit 24 can include n fourth resistors R41 - R4n connected in series in sequence. Their connection relationships are the same as those of the first resistor and will not be elaborated here. And the resistance values of the first resistors R11 - R1n can be equal, the resistance values of the second resistors R21 - R2n can be equal, the resistance values of the third resistors R31 - R3n can be equal, and the resistance values of the fourth resistors R41 - R4n can be equal. However, the resistance values of the first resistor, the second resistor, the third resistor, and the fourth resistor are different from each other.

[0097] In the above embodiments, multiple resistors in the resistor sub-circuit are connected in series in sequence. The gear selection circuit 3 can sequentially select these resistors through a control signal. When each resistor is selected, it acts together with the crack detection trace and the first reference voltage to generate different voltage division signals, thereby providing a variety of different resistor combinations to adapt to different measurement ranges and precisions. Furthermore, by selecting different resistors, the measurement of the resistance detection result of the crack detection trace is achieved.

[0098] Referring to Figure 5 , as an embodiment of the gear selection circuit 3, the gear selection circuit 3 includes a gear adjustment sub-circuit 31 and a selection sub-circuit. The gear adjustment sub-circuit 31 includes gear adjustment switches corresponding one-to-one to the resistor sub-circuit. Each gear adjustment switch includes a control pole for accessing a range switching signal, a first end connected to the corresponding selection sub-circuit, and a second end connected to the resistance detection circuit 4. The selection sub-circuit includes selection switches corresponding one-to-one to the resistors in the resistor sub-circuit. Each selection switch includes a control pole for accessing a selection control signal, a first end connected to the resistor, and a second end connected to the corresponding gear adjustment switch.

[0099] As an example, taking the resistor sub-circuit as the first resistor sub-circuit 21, the second resistor sub-circuit 22, the third resistor sub-circuit 23, and the fourth resistor sub-circuit 24 respectively, the gear adjustment sub-circuit 31 may include a first adjustment switch S1, a second adjustment switch S2, a third adjustment switch S3, and a fourth adjustment switch S4. The range switching signals may include a first range switching signal, a second range switching signal, a third range switching signal, and a fourth range switching signal. Among them, the first adjustment switch S1 is connected to the first resistor sub-circuit 21 and the resistance detection circuit 4, and is used to control the on-off between the first resistor sub-circuit 21 and the resistance detection circuit 4 according to the first range switching signal. Similarly, the second adjustment switch S2 is connected to the second resistor sub-circuit 22 and the resistance detection circuit 4, and is used to control the on-off between the second resistor sub-circuit 22 and the resistance detection circuit 4 according to the second range switching signal. The third adjustment switch S3 is connected to the third resistor sub-circuit 23 and the resistance detection circuit 4, and is used to control the on-off between the third resistor sub-circuit 23 and the resistance detection circuit 4 according to the third range switching signal. The fourth adjustment switch S4 is connected to the fourth resistor sub-circuit 24 and the resistance detection circuit 4, and is used to control the on-off between the fourth resistor sub-circuit 24 and the resistance detection circuit 4 according to the fourth range switching signal.

[0100] As an example, the gating sub-circuit includes a first gating sub-circuit 321, a second gating sub-circuit 322, a third gating sub-circuit 323, and a fourth gating sub-circuit 324, and the gating control signals include a first gating control signal, a second gating control signal, a third gating control signal, and a fourth gating control signal. The first gating sub-circuit 321 is configured to sequentially gate each first resistor in the first resistor sub-circuit 21 according to the first gating control signal, the second gating sub-circuit 322 is configured to sequentially gate each second resistor in the second resistor sub-circuit 22 according to the second gating control signal, the third gating sub-circuit 323 is configured to sequentially gate each third resistor in the third resistor sub-circuit 23 according to the third gating control signal, and the fourth gating sub-circuit 324 is configured to sequentially gate each fourth resistor in the fourth resistor sub-circuit 24 according to the fourth gating control signal. Among them, the first gating sub-circuit 321 includes n gating switches corresponding to the first resistors one by one, which are S11 - S1n respectively. For example, the gating switch S11 is connected to the series point of the first resistors R11 and R12 and the first adjustment switch S1, and the gating switch S12 is connected to the series point of the first resistors R12 and R13 and the first adjustment switch S1, and so on. When the first adjustment switch S1 is turned on, the first gating control signal controls the gating switches S11 - S1n to be turned on in sequence. When the gating switch S11 is turned on, the first reference voltage is divided by the first resistor R11, the first adjustment switch S1, and then divided by the crack detection trace. Similarly, when the gating switch S12 is turned on, the first reference voltage is divided by the first resistors R11 and R12, the first adjustment switch S1, and then divided by the crack detection trace. In this way, the effect of traversing and gating combinations of different numbers of resistors is achieved.

[0101] Similarly, the second gating sub-circuit 322 includes n gating switches corresponding to the second resistors one by one, which are S21 - S2n respectively, the third gating sub-circuit 323 includes n gating switches corresponding to the third resistors one by one, which are S31 - S3n respectively, and the fourth gating sub-circuit 324 includes n gating switches corresponding to the fourth resistors one by one, which are S41 - S4n respectively. Their working principles are similar to those of the first gating sub-circuit 321 and will not be elaborated here.

[0102] In the above embodiment, the adjustment of the measurement range is achieved through the range adjustment sub-circuit 31, and the corresponding resistors are gated by the gating sub-circuit according to the gating control signal, so as to determine an appropriate voltage division signal for calculating the resistance detection result of the crack detection trace.

[0103] As an implementation of the resistance value detection circuit 4, the resistance value detection circuit 4 includes a comparator U1 and a controller 41. Among them, the comparator U1 includes a first input terminal connected to a second reference voltage, a second input terminal connected to the gear selection circuit 3, and an output terminal connected to the controller 41. The comparator U1 is configured to output a test completion signal according to the voltage division signal and the second reference voltage. The controller 41 is configured to obtain a resistance value measurement result according to the resistance value of the resistor selected in the resistor array circuit 2 corresponding to the test completion signal.

[0104] As an example, the first input terminal of the comparator U1 may be the non-inverting input terminal, and the second input terminal may be the inverting input terminal. When the input potential of the first input terminal of the comparator U1 is greater than the input potential of its second input terminal, the comparator U1 outputs a test completion signal in a high level state. When the input potential of the first input terminal of the comparator U1 is less than the input potential of its second input terminal, the comparator U1 outputs a signal in a low level state. By sequentially selecting each resistor in the resistor array circuit 2 until the comparator U1 outputs a test completion signal, and recording the resistance value of the resistor selected in the current resistor array circuit 2, the resistance value measurement result can be expressed as R_PCD = Vref / (Vref0 - Vref)*nRx; where, Vref0 represents the first reference voltage; Vref represents the second reference voltage, and nRx represents the resistance value of the selected resistor. In this way, the generation of the resistance value measurement result is realized.

[0105] In the embodiments, implementation manners and related technical features of the present application, they can be combined and replaced with each other without conflict.

[0106] The above are only the preferred embodiments of the present application, and do not impose any form of limitation on the present application. However, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present application without departing from the content of the technical solution of the present application still fall within the scope of the technical solution of the present application.

Claims

1. A method for detecting edge cracks of a display panel, characterized in that, Including: Obtain the initial impedance value of the crack detection trace of the display panel in the module manufacturing process stage; In the crack detection stage, perform a resistance value detection on the crack detection trace to obtain a detected impedance value; According to the initial impedance value and the detected impedance value, obtain the crack detection result of the display panel.

2. The method for detecting edge cracks of a display panel according to claim 1, wherein Before obtaining the initial impedance value of the crack detection trace of the display panel in the module manufacturing process stage, it further includes: In the module manufacturing process stage of the display panel, perform an impedance detection on the crack detection trace to obtain the initial impedance value, and store the initial impedance value in the display panel.

3. The method for detecting edge cracks of a display panel according to claim 1, wherein The performing a resistance value detection on the crack detection trace to obtain a detected impedance value includes: Use a preset initial range as the measurement range, and perform a resistance value detection on the crack detection trace according to the measurement range to obtain a resistance value measurement result; If the ratio between the resistance value measurement result and the measurement range is within a preset range, use the resistance value measurement result as the detected impedance value; If the ratio between the resistance value measurement result and the measurement range is not within the preset range, adjust the measurement range, and re-perform a resistance value detection on the crack detection trace until the ratio between the resistance value measurement result and the measurement range is within the preset range.

4. The display panel edge crack detection method according to claim 3, wherein The performing a resistance value detection on the crack detection trace according to the measurement range to obtain a resistance value measurement result includes: According to the measurement range, output a range switching signal to the detection device to cause the detection device to switch to the measurement gear; wherein, the detection device is used to measure the resistance value of the crack detection trace; Control each resistor corresponding to the measurement gear in the detection device to be sequentially selected until the detection device feeds back a test completion signal; According to the resistance value of the resistor selected when the test completion signal is fed back, obtain the resistance value measurement result.

5. The method for detecting edge cracks of a display panel according to claim 1, wherein According to the initial impedance value and the detected impedance value, obtaining the crack detection result of the display panel includes: If the difference between the initial impedance value and the detected impedance value exceeds a preset difference threshold, determine that the crack detection result of the display panel is that there is a crack; If the difference between the initial impedance value and the detected impedance value does not exceed the preset difference threshold, determine that the crack detection result of the display panel is that there is no crack.

6. The display panel edge crack detection method according to claim 5, wherein, The method further includes: If the difference between the initial impedance value and the detected impedance value does not exceed the preset difference threshold, determine whether the detected impedance value is greater than a preset resistance value threshold; If the detected impedance value is greater than or equal to the preset resistance value threshold, determine that the crack detection result of the display panel is that there is a crack; If the detected impedance value is less than the preset resistance value threshold, determine that the crack detection result of the display panel is that there is no crack.

7. A display panel edge crack detection device, characterized in that, Including: A connection end, connected to the crack detection trace in the display panel; A resistor array circuit, including a plurality of resistors; A gear selection circuit, connected to the resistor array circuit, for sequentially selecting the resistors in the resistor array circuit, so that the selected resistor and the crack detection trace divide the first reference voltage to obtain a divided voltage signal; A resistance detection circuit, connected to the gear selection circuit and connected to a second reference voltage, is configured to obtain a detection impedance value of the crack detection trace according to the voltage division signal and the second reference voltage; Wherein, the detection impedance value is used to obtain a crack detection result of the display panel.

8. The display panel edge crack detection device according to claim 7, wherein, The resistor array circuit includes a plurality of resistor sub-circuits; Each of the resistor sub-circuits is connected to the gear selection circuit and connected to the first reference voltage; the resistors in each of the resistor sub-circuits are connected in series in sequence, and each of the resistors is respectively connected to the gear selection circuit, so that the gear selection circuit sequentially selects each of the resistors.

9. The display panel edge crack detection device according to claim 8, wherein, The gear selection circuit includes a gear adjustment sub-circuit and a selection sub-circuit; The gear adjustment sub-circuit includes gear adjustment switches corresponding to the resistor sub-circuits one by one. Each of the gear adjustment switches includes a control pole for accessing a range switching signal, a first end connected to the corresponding selection sub-circuit, and a second end connected to the resistance detection circuit; The selection sub-circuit includes selection switches corresponding to the resistors in the resistor sub-circuits one by one. Each selection switch includes a control pole for accessing a selection control signal, a first end connected to the resistor, and a second end connected to the corresponding gear adjustment switch.

10. The display panel edge crack detection device according to claim 7, wherein, The resistance detection circuit includes a comparator and a controller; The comparator includes a first input terminal for accessing the second reference voltage, a second input terminal connected to the gear selection circuit, and an output terminal connected to the controller. The comparator is configured to output a test completion signal according to the voltage division signal and the second reference voltage; The controller is configured to obtain a resistance measurement result according to the resistance value of the resistor selected in the resistor array circuit corresponding to the test completion signal.

Images