Display panel pixel defect detection method, lighting detection device and display device

Abstract

The invention discloses a pixel defect detection method of a display panel, a lighting detection device and a display device, and belongs to the technical field of display. The display panel comprises at least one sub-pixel, a first power line and a reference signal line, the sub-pixel comprises a light-emitting device, a first pole of the light-emitting device is connected with the reference signal line, and a second pole of the light-emitting device is connected with the first power line. The method comprises: providing a detection voltage to the first power line; acquiring a feedback voltage on the reference signal line; and judging whether the first pole of the light-emitting device and the second pole of the light-emitting device are short-circuited or not according to the change condition of the feedback voltage. According to the embodiment of the invention, whether the first electrode and the second electrode of the light-emitting device in the display panel are short-circuited can be identified, and the yield of the display panel and the display effect can be improved.

Description

Technical Field

[0001] The present invention relates to the field of display technology, and in particular to a method for detecting defective pixels of a display panel, a lighting detection device and a display device. Background Art

[0002] With the development of display technology, people have higher and higher requirements on the display quality of display panels. However, the display effect of current display panels cannot meet the needs of users. Summary of the invention

[0003] The present invention provides a method for detecting defective pixels of a display panel, a lighting detection device and a display device, so as to identify whether a short circuit occurs between a first electrode and a second electrode of a light-emitting device in the display panel, which is beneficial to improving the yield of the display panel and improving the display effect.

[0004] In a first aspect, an embodiment of the present invention provides a method for detecting pixel defects of a display panel, wherein the display panel includes at least one sub-pixel, a first power line, and a reference signal line, wherein the sub-pixel includes a light-emitting device, wherein a first electrode of the light-emitting device is connected to the reference signal line, and a second electrode of the light-emitting device is connected to the first power line;

[0005] The method comprises:

[0006] providing a detection voltage to the first power line;

[0007] Acquiring a feedback voltage on the reference signal line;

[0008] Whether there is a short circuit between the first electrode of the light emitting device and the second electrode of the light emitting device is determined according to the change of the feedback voltage.

[0009] Optionally, the pixel defect detection method of the display panel comprises: at least one detection stage; in each detection stage, at least one sub-pixel is selected as a sub-pixel to be tested;

[0010] Preferably, all the sub-pixels to be tested selected in each of the testing stages include all the sub-pixels in the display panel;

[0011] Preferably, providing a detection voltage to the first power line comprises:

[0012] In each of the detection stages, providing a detection voltage to the first power line connected to each of the sub-pixels to be detected selected in the detection stage;

[0013] Preferably, obtaining the feedback voltage on the reference signal line includes:

[0014] In each of the detection stages, obtaining a feedback voltage on the reference signal line connected to each of the sub-pixels under test selected in the detection stage;

[0015] Preferably, judging whether there is a short circuit between the first electrode of the light emitting device and the second electrode of the light emitting device according to the change of the feedback voltage includes:

[0016] In each of the detection stages, it is determined according to the change of the feedback voltage whether there is a defective sub-pixel with a short circuit between the first electrode of the light-emitting device and the second electrode of the light-emitting device in each of the sub-pixels selected in the detection stage.

[0017] Optionally, the sub-pixel further comprises a pixel circuit, the pixel circuit comprises a first reset module, and the first reset module is connected between the reference signal line and the first electrode of the light-emitting device;

[0018] The method further comprises:

[0019] In each of the detection stages, controlling the first reset module of each of the sub-pixels under test in the detection stage to be turned on;

[0020] Preferably, the display panel further comprises a plurality of first scanning lines, which are respectively connected to the control ends of the first reset modules in the sub-pixels in different rows;

[0021] In each detection stage, the sub-pixels connected to the same first scanning line are selected as the sub-pixels to be detected in the detection stage;

[0022] Preferably, controlling the first reset module of each of the sub-pixels under test in the detection phase to be turned on comprises: transmitting a turn-on potential of the first reset module to the first scan line connected to each of the sub-pixels under test in the detection phase.

[0023] Optionally, the pixel circuit further includes: a driving module and at least one light emitting control module; the display panel further includes a second power line, and the driving module and the light emitting control module are connected in series between the second power line and the first pole of the light emitting device;

[0024] The method further comprises:

[0025] In each of the detection stages, controlling the light emitting control module of each of the sub-pixels under test in the detection stage to be turned off;

[0026] Preferably, the display panel further comprises a plurality of light emitting control signal lines, one of the light emitting control signal lines being connected to the control end of the light emitting control module in at least one row of the sub-pixels;

[0027] For any of the sub-pixels, controlling the light emitting control module of the sub-pixel to be turned off includes: transmitting a cutoff potential of the light emitting control module to the light emitting control signal line connected to the sub-pixel.

[0028] Optionally, it is characterized in that judging whether there is a short circuit between the first electrode of the light emitting device and the second electrode of the light emitting device according to the change of the feedback voltage comprises:

[0029] If the feedback voltage deviates from the normal voltage range after the detection voltage is provided to the first power line, it is determined that there is a short circuit between the first pole of the light-emitting device and the second pole of the light-emitting device; wherein the normal voltage range is the voltage fluctuation range on the reference signal line when the detection voltage is applied to the first power line without a short circuit between the first pole and the second pole of the light-emitting device.

[0030] Optionally, the method for detecting defective pixels of a display panel further includes:

[0031] Providing a reference voltage source, and controlling the reference voltage source to output a high impedance state during the period of obtaining the feedback voltage output by the reference signal line; wherein the reference voltage source is connected to the reference signal line;

[0032] Preferably, the method for detecting defective pixels of a display panel further comprises:

[0033] Providing a detection voltage source, and controlling the reference voltage source and the detection voltage source to share a common ground; wherein the detection voltage source is connected to the first power line;

[0034] Providing the detection voltage to the first power line includes: controlling the detection voltage source to output the detection voltage.

[0035] Optionally, the absolute value of the voltage within the normal voltage range is less than the first preset voltage value;

[0036] Preferably, the first preset voltage value is less than or equal to 0.3V;

[0037] Preferably, the first preset voltage value includes one of 0.15V, 0.2V and 0.25V.

[0038] Optionally, after determining that the feedback voltage deviates from the normal voltage range, the method further includes:

[0039] changing the detection voltage at least once, and acquiring a corresponding feedback voltage after each change of the detection voltage;

[0040] If the feedback voltage changes along the same direction as the detection voltage each time the detection voltage is changed, it is determined that there is a short circuit between the first electrode of the light emitting device and the second electrode of the light emitting device.

[0041] Optionally, judging whether there is a short circuit between the first electrode of the light emitting device and the second electrode of the light emitting device according to a change in the feedback voltage includes:

[0042] If the feedback voltage is within the normal voltage range after the detection voltage is provided to the first power line, it is determined that there is no short circuit between the first electrode of the light-emitting device and the second electrode of the light-emitting device; wherein the normal voltage range is the voltage fluctuation range on the reference signal line when the detection voltage is applied to the first power line when there is no short circuit between the first electrode and the second electrode of the light-emitting device;

[0043] Preferably, after determining that the feedback voltage is within the normal voltage range, the method further includes:

[0044] changing the detection voltage at least once, and acquiring a corresponding feedback voltage after each change of the detection voltage;

[0045] If the feedback voltage remains within the normal voltage range each time the detection voltage is changed, it is determined that there is no short circuit between the first electrode of the light emitting device and the second electrode of the light emitting device.

[0046] Optionally, the first pole of the light-emitting device is an anode, the second pole of the light-emitting device is a cathode, and the first power line transmits a cathode voltage when the display panel displays a picture; the cathode voltage and the detection voltage are both negative voltages;

[0047] Preferably, the absolute value of the detection voltage is greater than or equal to the absolute value of the cathode voltage.

[0048] Optionally, the display panel comprises a plurality of display sub-areas arranged along a row direction, and the reference signal lines of different display sub-areas are insulated from each other;

[0049] The obtaining of the feedback voltage on the reference signal line comprises: respectively obtaining the feedback voltage on the reference signal line in each of the display sub-areas;

[0050] Judging whether there is a short circuit between the first pole of the light-emitting device and the second pole of the light-emitting device according to the change of the feedback voltage, including: judging whether there is a bad sub-pixel in each display sub-area with a short circuit between the first pole of the light-emitting device and the second pole of the light-emitting device according to the change of each feedback voltage.

[0051] Optionally, the pixel circuit further includes a driving module, a first light-emitting control module, and a second light-emitting control module; the display panel further includes a second power line, the first light-emitting control module is connected between the second power line and the first end of the driving module, and the second light-emitting control module is connected between the second end of the driving module and the first pole of the light-emitting device;

[0052] The method further comprises: in each of the detection phases, controlling the first light emitting control module and the second light emitting control module of each of the sub-pixels under test in the detection phase to be turned off;

[0053] Preferably, the pixel circuit further includes a data writing module connected to the first end of the driving module; the method further includes: in each of the detection stages, controlling the data writing module of each of the sub-pixels under test in the detection stage to be turned off;

[0054] Preferably, the pixel circuit further includes a threshold compensation module connected between the control terminal and the second terminal of the driving module; the method further includes: in each of the detection stages, controlling the threshold compensation module of each of the sub-pixels under test in the detection stage to be turned off;

[0055] Preferably, the pixel circuit further includes a second reset module connected to the control end or the second end of the driving module; the method further includes: in each of the detection stages, controlling the second reset module of each of the sub-pixels under test in the detection stage to be turned off;

[0056] Preferably, the pixel circuit further includes a third reset module connected to the second end of the driving module; the method further includes: in each of the detection stages, controlling the third reset module of each of the sub-pixels under test in the detection stage to be turned on;

[0057] Preferably, the control end of the third reset module and the control end of the first reset module in the same pixel circuit are connected to the same scan line;

[0058] or,

[0059] The method further comprises: in each of the detection stages, controlling the third reset module of each of the sub-pixels under test in the detection stage to be turned off;

[0060] Preferably, a control end of the third reset module and a control end of the first reset module in the same pixel circuit are connected to different scan lines.

[0061] In a second aspect, an embodiment of the present invention further provides a lighting detection device connected to a first power line and a reference signal line in a display panel, and used to execute a pixel defect detection method for a display panel provided by any embodiment of the present invention.

[0062] Optionally, the display panel includes a lighting detection circuit; the lighting detection circuit includes: a first pad connected to the first power line, and a second pad connected to the reference signal line;

[0063] The lighting detection device comprises:

[0064] A signal output terminal connected to the first pad;

[0065] The signal input terminal is connected to the second pad.

[0066] Optionally, the lighting detection device further includes:

[0067] A detection voltage source connected to the signal output terminal;

[0068] A reference voltage source connected to the second pad;

[0069] The detection voltage source and the reference voltage source share a common ground.

[0070] In a third aspect, an embodiment of the present invention further provides a display device, comprising: a display panel and a detection module; the detection module is connected to a first power line and a reference signal line in the display panel, and the detection module is used to execute the pixel defect detection method of the display panel provided in any embodiment of the present invention.

[0071] Optionally, the display device further includes a display driver chip, and the detection module is integrated in the display driver chip.

[0072] Optionally, the display panel further comprises: a substrate and an isolation structure located on one side of the substrate; the isolation structure is arranged around each of the light-emitting devices;

[0073] Preferably, the isolation structure comprises a first isolation portion and a second isolation portion which are sequentially stacked in a direction away from the substrate;

[0074] The orthographic projection of the first isolation portion on the substrate is located within the orthographic projection of the second isolation portion on the substrate, and the area of ​​the orthographic projection of the first isolation portion on the substrate is smaller than the area of ​​the orthographic projection of the second isolation portion on the substrate;

[0075] Preferably, the isolation structure is reused as the first power line.

[0076] Optionally, the detection module includes:

[0077] Comparison unit;

[0078] A first switch connected between the reference signal line and a first input terminal of the comparison unit;

[0079] A detection voltage source, used for generating a detection voltage;

[0080] A second switch connected between the detection voltage source and the first power line;

[0081] a control unit, connected to the control end of the first switch, the control end of the second switch, the control end of the detection voltage source, and the second input end of the comparison unit, respectively; the control unit is used to control the first switch and the second switch to be turned on, control the detection voltage source to generate and output the detection voltage, and transmit a reference value of the feedback voltage to the second input end of the comparison unit when the detection module performs the pixel defect detection method of the display panel;

[0082] Among them, the detection voltage is transmitted to the first power line through the second switch, and the feedback voltage output by the reference signal line is transmitted to the comparison unit through the first switch; the comparison unit is used to output a comparison result based on the feedback voltage and the reference value of the feedback voltage, and the comparison result is used to characterize whether there are defective sub-pixels in the display panel.

[0083] Optionally, the display device further comprises: a reference voltage source connected to the reference signal line; the control unit is also connected to the reference voltage source, and the control unit is further used to control the reference voltage source to output a high impedance state when the detection module executes the pixel defect detection method of the display panel;

[0084] and / or,

[0085] The display device also includes: a first voltage source connected to the first power line; the control unit is also connected to the first voltage source, and the control unit is also used to control the first voltage source to stop output when the detection module executes the pixel defect detection method of the display panel.

[0086] The pixel defect detection method of the display panel provided by the embodiment of the present invention controls the detection voltage provided by the first power line and monitors the change of the feedback voltage on the reference signal line. This is equivalent to considering the voltage characteristics under the short-circuit state between the first pole and the second pole of the light-emitting device to identify such defective sub-pixels, which is conducive to timely troubleshooting the cause of the defect and avoiding subsequent damage, thereby improving the yield of the display panel and improving the display effect.

[0087] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0088] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0089] Figure 1 is a schematic diagram of a cross-sectional structure of a display panel provided by an embodiment of the present invention;

[0090] Figure 2 It is a schematic diagram of a flow chart of a method for detecting defective pixels of a display panel provided by an embodiment of the present invention;

[0091] Figure 3 is a schematic diagram of the structure of a sub-pixel provided by an embodiment of the present invention;

[0092] Figure 4 is a schematic diagram of a driving timing of a sub-pixel during a display process provided by an embodiment of the present invention;

[0093] Figure 5 This is a schematic diagram of a working state of a sub-pixel in a light-emitting stage provided by an embodiment of the present invention;

[0094] Figure 6 is a schematic structural diagram of a display panel provided by an embodiment of the present invention;

[0095] Figure 7 is a schematic diagram of a driving timing of a sub-pixel during a detection process provided by an embodiment of the present invention;

[0096] Figure 8 is a schematic diagram of a working state of a sub-pixel in a detection phase provided by an embodiment of the present invention;

[0097] Fig. 9 is a schematic structural diagram of another display panel provided by an embodiment of the present invention;

[0098] Fig.10 is a schematic diagram of the connection relationship between a lighting detection device and a display panel provided by an embodiment of the present invention;

[0099] Fig.11 is a structural schematic diagram of a display device provided by an embodiment of the present invention;

[0100] Fig.12 It is a structural schematic diagram of a detection module provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0101] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0102] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions.

[0103] The embodiment of the present invention provides a method for detecting pixel defects of a display panel, which can effectively identify pixel defects caused by short circuits between two electrodes of a light emitting device. To facilitate the explanation of the method, the causes of short circuits of light emitting devices and their effects are briefly described below.

[0104] Figure 1 is a schematic diagram of a cross-sectional structure of a display panel provided by an embodiment of the present invention. Figure 1 , exemplarily, the display panel may include: a substrate 10, a pixel definition layer PDL located on one side of the substrate 10, and an isolation structure 50 located on the side of the pixel definition layer PDL away from the substrate 10. The pixel definition layer PDL encloses a plurality of pixel openings, and the isolation structure 50 encloses a plurality of isolation openings, and each pixel opening corresponds to each isolation opening one by one. The display panel may include at least one sub-pixel, and the sub-pixel is composed of a pixel circuit and a light-emitting device OLED. The pixel circuit can be arranged in the substrate 10; the light-emitting device OLED is arranged in the pixel opening, and includes a first pole 41, a light-emitting layer 42, and a second pole 43 which are sequentially stacked in a direction away from the substrate 10. Exemplarily, the first pole 41 of the light-emitting device OLED is its anode, and the second pole 43 is its cathode.

[0105] Among them, based on the isolation effect of the isolation structure 50, a self-alignment pixelation technology without a fine metal mask (FMM) can be realized. Specifically, the isolation structure 50 may include a first isolation portion 51 and a second isolation portion 52 stacked in sequence in a direction away from the substrate 10. The orthographic projection of the first isolation portion 51 on the substrate 10 is located within the orthographic projection of the second isolation portion 52 on the substrate 10, and the area of ​​the orthographic projection of the first isolation portion 51 on the substrate 10 is smaller than the area of ​​the orthographic projection of the second isolation portion 52 on the substrate 10. Based on the setting of such an isolation structure 50, each light-emitting layer 42 and each second electrode 43 can be evaporated into the corresponding pixel opening without the need for a fine metal mask. And based on the isolation effect of the isolation structure 50, a pixel encapsulation structure 44 can be formed on the side of each second electrode 43 away from the substrate 10, so that each light-emitting device OLED is independently encapsulated. The above preparation method can avoid the risk of color mixing and color deficiency caused by the Shadow effect and the offset of evaporation, and at the same time, the independent RGB sub-pixel structure can cut off the lateral leakage and reduce the crosstalk phenomenon of the light-emitting device OLED. However, in the process of manufacturing independent sub-pixels, due to factors such as poor or excessive overlap of the second electrode, a single sub-pixel may not light up normally. When the overlap is excessive, the electrical distance between the second electrode 43 and the first electrode 41 is relatively close, forming a Figure 1 The leakage path Leak represented by the dotted line in the middle will cause strong coupling between the first electrode 41 and the second electrode 43 of the light-emitting device OLED. The short circuit or micro short circuit between the two electrodes of the light-emitting device OLED mentioned in the following description represents the abnormal state described above. In the above abnormal state, the voltage of the second electrode 43 of the light-emitting device OLED will affect the voltage of the first electrode 41, which is manifested as a dark pixel defect on a macro scale.

[0106] The display panel further includes: a first power line and a reference signal line. The first electrode 41 of the light emitting device OLED is connected to the reference signal line, and the second electrode 43 of the light emitting device OLED is connected to the first power line. Figure 2 FIG. 1 is a flow chart of a method for detecting pixel defects of a display panel provided by an embodiment of the present invention. Figure 2 , the pixel defect detection method of the display panel includes:

[0107] S110 , providing a detection voltage to the first power line.

[0108] Among them, the first power line can be connected as a mesh structure arranged on the entire surface of the display panel, connecting the second poles of the light-emitting devices in all sub-pixels; or, multiple insulated first power lines can be arranged in the display panel, and each power line connects the second poles of the light-emitting devices in some sub-pixels.

[0109] S120 , obtaining a feedback voltage on the reference signal line.

[0110] The reference signal line may also be a mesh structure arranged on the entire surface of the display panel, or a plurality of insulated reference signal lines may be arranged in the display panel.

[0111] Based on the above analysis, it can be known that when there is a micro short circuit between the two poles of the light-emitting device OLED, the second pole 43 of the light-emitting device OLED is equivalent to being short-circuited with the first pole 41. Then, the voltage of the second pole 43 of the light-emitting device OLED will be transmitted through the leakage path Leak, thereby affecting the feedback voltage on the reference signal line. On the contrary, if there is no micro short circuit between the two poles of the light-emitting device OLED, there is no leakage path on the light-emitting device OLED, and the voltage on the first power line will not affect the voltage on the reference signal line. Based on the above characteristics, by observing the change in the feedback voltage after applying the detection voltage, it can be determined whether there is a defective sub-pixel with a micro short circuit between the second pole 43 and the first pole 41 of the light-emitting device in each sub-pixel connected to the first power line and the reference signal line.

[0112] S130, judging whether there is a short circuit between the first electrode of the light-emitting device and the second electrode of the light-emitting device according to the change of the feedback voltage.

[0113] Among them, the normal voltage range of the feedback voltage on the reference signal line can be determined in advance through experiments when the light-emitting device is normal and there is no short circuit problem. During the detection process, by judging whether the feedback voltage deviates from the normal voltage range after applying the detection voltage, it can be determined whether there is a short circuit between the first electrode 41 of the light-emitting device OLED and the second electrode 43 of the light-emitting device OLED.

[0114] The pixel defect detection method of the display panel provided by the embodiment of the present invention controls the detection voltage provided by the first power line and monitors the change of the feedback voltage on the reference signal line. This is equivalent to considering the voltage characteristics under the short-circuit state between the first pole and the second pole of the light-emitting device to identify such defective sub-pixels, which is conducive to timely troubleshooting the cause of the defect and avoiding subsequent damage, thereby improving the yield of the display panel and improving the display effect.

[0115] On the basis of the above embodiments, optionally, in the process of the display panel displaying the picture normally (hereinafter referred to as the display process), the reference signal line is used to provide a first initialization voltage, and the first initialization voltage is used to realize the initialization of the first pole of the light-emitting device; in the pixel defect detection process of the display panel (hereinafter referred to as the detection process), the reference signal line is used to transmit the feedback voltage. And, in the display process, the first power line is used to provide the voltage required by the second pole of the light-emitting device, for example, if the second pole is a cathode, the first power line is used to provide a cathode voltage so that the light-emitting device can emit light normally; in the detection process, the first power line is used to provide a detection voltage.

[0116] Then, the embodiment of the present invention is equivalent to realizing time-division multiplexing of the reference signal line and the first power line during the display process and the detection process. In this way, pixel defect detection of the display panel can be realized without increasing the signal line for detection, reducing the wiring difficulty of the display panel and reducing the detection cost.

[0117] On the basis of the above-mentioned embodiments, optionally, the pixel defect detection method of the display panel includes: at least one detection stage; at least one sub-pixel is selected as the sub-pixel to be tested in each detection stage. All the sub-pixels to be tested selected in each detection stage cover all the sub-pixels in the display panel, so that the detection process traverses all the sub-pixels to ensure a comprehensive detection of the display panel. Among them, when there is a defective sub-pixel with a short circuit between the two poles of the light-emitting device in the sub-pixels to be tested in any detection stage, it can be determined that there is a defective sub-pixel in the display panel.

[0118] Accordingly, providing the detection voltage to the first power line includes: in each detection stage, providing the detection voltage to the first power line connected to each sub-pixel selected in the detection stage. That is, in each detection stage, the second electrode of the light-emitting device of the sub-pixel under test in the detection stage is controlled to receive the detection voltage.

[0119] Acquiring the feedback voltage on the reference signal line includes: in each detection stage, acquiring the feedback voltage on the reference signal line connected to each sub-pixel selected in the detection stage. That is, in each detection stage, the feedback voltage of the first electrode of the light-emitting device of the sub-pixel under test in the detection stage is collected.

[0120] Judging whether there is a short circuit between the first pole of the light-emitting device and the second pole of the light-emitting device according to the change of the feedback voltage, including: in each detection stage, judging whether there is a bad sub-pixel with a short circuit between the first pole of the light-emitting device and the second pole of the light-emitting device in each sub-pixel selected in the detection stage according to the change of the feedback voltage.

[0121] Among them, a detection stage can be set in the method to uniformly detect all sub-pixels. Alternatively, the method can be set to include multiple detection stages set in time division, and some sub-pixels are selected as sub-pixels to be tested in each detection stage. In each detection stage, the detection of each sub-pixel to be tested in the detection stage is realized, and after the previous detection stage is completed, the next detection stage begins. In this way, by detecting some sub-pixels in each detection stage, the positioning of the bad display area can be realized, which is beneficial to subsequent processing.

[0122] The method is described below in conjunction with the specific structure of the sub-pixel.

[0123] Figure 3 is a schematic diagram of a sub-pixel structure provided by an embodiment of the present invention. Figure 3The sub-pixel also includes a pixel circuit, and the pixel circuit includes a first reset module 27, and the first reset module 27 is connected between the reference signal line and the first electrode of the light-emitting device OLED. In the pixel circuit, a short circuit between the two electrodes of the light-emitting device OLED will make the working state of the pixel circuit unable to achieve the expected effect. Figure 3 The first reset module 27 is connected to the first electrode of the light emitting device OLED and is used to initialize the first electrode of the light emitting device OLED using the first initialization voltage Vrefn2. When a micro short circuit occurs between the two electrodes of the light emitting device OLED, the second electrode of the corresponding light emitting device OLED is short-circuited with the first reset module 27. The driving timing of the sub-pixel 20 during the display process can be seen in Figure 4 The working state of the sub-pixel 20 in the light-emitting stage T14 can be seen in Figure 5 . Combined Figure 4 and Figure 5 , when entering the light-emitting stage T14, the first-pole charge of the light-emitting device OLED leaks through the leakage path Leak, and the light-emitting device OLED is short-circuited, so that the sub-pixel 20 cannot be turned on, and the macroscopic performance is a dark spot. And because the driving force of the cathode voltage VSS in the plane is strong, after the first reset module 27 is turned on, the cathode voltage VSS reversely affects the first-pole voltage, and then affects the first initialization voltage Vrefn2 through the turned-on first reset module 27; this causes the first initialization voltage Vrefn2 to be a non-set value when the pixel circuits in other normally turned-on sub-pixels 20 are working, so that the first-pole reset effect of the light-emitting device OLED in other sub-pixels 20 is not good, thereby causing low-frequency flickering, and even generating a large current backflow, which will damage the reference voltage source (for example, set in the display driver chip) used to provide the first initialization voltage Vrefn2, causing the display module to display abnormally or fail.

[0124] On the basis of the above-mentioned embodiments, optionally, the method for detecting defective pixels of a display panel further includes: in each detection stage, controlling the first reset module 27 of each sub-pixel under test in the detection stage to be turned on.

[0125] A voltage detection path can be provided by controlling the first reset module 27 in the pixel circuit of the sub-pixel 20 to be turned on. When the detection process includes one detection stage, the first reset module 27 of each sub-pixel 20 can be controlled to be turned on at the same time; when the detection process is divided into multiple detection stages, the first reset module 27 of the sub-pixel to be tested is controlled to be turned on in each detection stage.

[0126] During the detection process, for any sub-pixel, see Figure 3, the sub-pixel 20 includes a light-emitting device OLED and a first reset module 27 connected in series between a first power line and a reference signal line. Based on the above analysis, it can be seen that when there is a micro short circuit between the two poles of the light-emitting device OLED, the second pole of the light-emitting device OLED is equivalent to being short-circuited with the first reset module 27. When the first reset module 27 is turned on, if there is a micro short circuit between the two poles of the light-emitting device OLED, the voltage of the second pole of the light-emitting device OLED will be transmitted through the leakage path, and further transmitted to the reference signal line by the first reset module 27, thereby affecting the feedback voltage on the reference signal line.

[0127] In this embodiment, the original first reset module 27 in the sub-pixel 20 is used as a voltage transmission path during the detection process, so that pixel defect detection of the display panel can be achieved without changing the original structure of the display panel, and will not affect the actual display effect of the product, making the detection method low-cost and highly versatile.

[0128] On the basis of the above-mentioned embodiments, optionally, the method for detecting defective pixels of a display panel further includes: providing a reference voltage source, and controlling the reference voltage source to output a high impedance state (Hiz) during the period of obtaining the feedback voltage output by the reference signal line.

[0129] The reference voltage source is connected to the reference signal line. The reference voltage source is used to provide a first initialization voltage to the reference signal line when the display panel displays a picture (i.e., during the display process). During the entire detection phase, the reference voltage source can be controlled to maintain a high impedance state, not output voltage, and not affect the voltage on the reference signal line, so that the voltage value of the feedback voltage extracted from the reference signal line is accurate.

[0130] On the basis of the above-mentioned embodiments, optionally, the pixel defect detection method of the display panel also includes: providing a detection voltage source, and controlling the reference voltage source and the detection voltage source to be grounded. This step is performed, for example, before the detection phase starts, for example, before the first reset module of each sub-pixel is turned on. The detection voltage source is connected to the first power line. The output voltage of the detection voltage source is adjustable. In practical applications, the voltage output by the detection voltage source can be adjusted according to demand. Accordingly, providing a detection voltage to the first power line includes: controlling the detection voltage source to output the detection voltage.

[0131] In an embodiment of the present invention, setting a reference voltage source and a detection voltage source to share a common ground is equivalent to connecting two voltage sources related to the detection process to the same system ground, which is beneficial to improving the detection accuracy and avoiding the influence of the measurement results due to the difference in the grounds of the two voltage sources. It is mainly to avoid the reference voltage source coupling a certain voltage to the floating reference signal line due to the deviation of the ground signal when the reference voltage source outputs a high-impedance state.

[0132] For example, during the display process, the detection voltage source may provide the voltage required by the second pole of the light-emitting device to the first power line, and other voltage sources may also provide the voltage required by the second pole of the light-emitting device. In the case where the voltage required by the second pole of the light-emitting device is provided by other voltage sources, during the period when the detection voltage source provides the detection voltage to the first power line, the other voltage sources may be controlled to stop outputting; during the period when the other voltage sources provide the voltage required by the second pole of the light-emitting device to the first power line, the detection voltage source may be controlled to stop outputting to avoid signal competition.

[0133] On the basis of the above embodiments, optionally, whether there is a short circuit between the first pole of the light-emitting device and the second pole of the light-emitting device is determined according to changes in the feedback voltage, including: if the feedback voltage deviates from the normal voltage range after providing a detection voltage to the first power line, then it is determined that there is a short circuit between the first pole of the light-emitting device and the second pole of the light-emitting device.

[0134] Wherein, the normal voltage range is the voltage fluctuation range on the reference signal line when the detection voltage is applied to the first power line when there is no short circuit between the second pole and the first pole of the light-emitting device in the sub-pixel, if a first reset module is provided, and the first reset module is turned on at the same time. Wherein, due to factors such as voltage coupling between signal lines, when the detection voltage changes, the feedback voltage also fluctuates to a certain extent under the condition that there are no bad pixels, but the fluctuation range is very small. Exemplarily, the normal voltage range can be obtained, for example, based on multiple experimental measurements. The normal voltage range can be determined based on the voltage fluctuation range on the reference signal line when the first reset module is turned on in one or more sub-pixels. Specifically, the detection process in the detection process can be considered, a normal display panel without bad pixels is selected, and the same control process as the detection process is used for experiments to obtain a more accurate normal voltage range.

[0135] On the basis of the above embodiments, optionally, the normal voltage range is a voltage range that fluctuates around 0V; the absolute value of the voltage within the normal voltage range is less than the first preset voltage value. The first preset voltage value may be equal to or slightly greater than the absolute value of the voltage with the largest absolute value obtained from the reference signal line when the normal display panel is tested multiple times. Exemplarily, the first preset voltage value is less than or equal to 0.3V. The first preset voltage value may specifically be 0.15V, 0.2V, or 0.25V, etc.

[0136] On the basis of the above embodiments, optionally, the first power line transmits the voltage required by the second pole of the light-emitting device during the display process when the display panel displays the picture (i.e., during the display process). For example, the first pole of the light-emitting device is an anode, and the second pole is a cathode, and the first power line transmits the cathode voltage during the actual process. Both the cathode voltage and the detection voltage are negative voltages. In other words, the detection voltage can be set to a voltage in the same direction as the cathode voltage received by the sub-pixel when it is displayed normally.

[0137] Furthermore, the absolute value of the detection voltage can be set to be greater than or equal to the absolute value of the cathode voltage. When the detection voltage is a relatively large negative voltage, the pulling effect on the voltage on the reference signal line is more obvious, which will make the feedback voltage also a relatively large negative voltage, causing the feedback voltage to deviate more from the normal voltage range, which is conducive to improving the accuracy of the detection result.

[0138] Based on the above implementations, optionally, after determining that the feedback voltage deviates from the normal voltage range, the method further includes:

[0139] The detection voltage is changed at least once, and a corresponding feedback voltage is obtained after each change of the detection voltage.

[0140] If the feedback voltage changes in the same direction as the detection voltage each time the detection voltage is changed, it is determined that there is a short circuit between the first electrode of the light-emitting device and the second electrode of the light-emitting device, that is, there is a defective sub-pixel in the display panel.

[0141] In the embodiment of the present invention, after detecting that the feedback voltage deviates from the normal voltage range, the detection voltage is adjusted again. If the feedback voltage follows the movement, it can be confirmed that the light-emitting device does have a micro-short circuit fault, thereby ensuring the accuracy of the judgment result and avoiding misidentification of bad pixels. For example, the absolute value of the detection voltage after each change can be set to be greater than the absolute value of the detection voltage before the change.

[0142] Based on the above embodiments, optionally, judging whether there is a short circuit between the first electrode of the light-emitting device and the second electrode of the light-emitting device according to the change of the feedback voltage may further include: if the feedback voltage is within the normal voltage range after the detection voltage is provided to the first power line, then judging that there is no short circuit between the first electrode of the light-emitting device and the second electrode of the light-emitting device. If the feedback voltage collected in each detection stage during the entire detection process is within the normal voltage range, it can be judged that there are no defective sub-pixels in the display panel.

[0143] Among them, for each sub-pixel being detected, after determining that the feedback voltage is within the normal voltage range, the detection voltage can be changed at least once, and the corresponding feedback voltage can be obtained after each change of the detection voltage; if the feedback voltage remains within the normal voltage range after each change of the detection voltage, which is equivalent to the feedback voltage being near 0V and does not change with the detection voltage, it can be determined that there is no short circuit between the first electrode of the light-emitting device and the second electrode of the light-emitting device, and there are no defective sub-pixels in the sub-pixels being detected.

[0144] On the basis of the above-mentioned embodiments, optionally, the detection phases may be divided and the sub-pixels to be detected may be selected in the detection phases according to the wiring of the display panel, which is exemplified below but is not intended to limit the present invention.

[0145] Figure 6 is a schematic diagram of the structure of a display panel provided by an embodiment of the present invention. Figure 6 In one embodiment, the display panel 100 may further include a plurality of first scan lines LSP2, which are respectively connected to the control terminals of the first reset modules in the sub-pixels 20 in different rows. The first scan line LSP2 is used to provide Figure 3 The first scanning signal SP2 in the detection stage is used to control the on and off of the first reset module 27. In each detection stage, each sub-pixel 20 connected to the same first scanning line can be selected as the sub-pixel to be tested in the detection stage. In this way, since all sub-pixels 20 in the same detection stage are controlled by the same first scanning line LSP2, it is beneficial to control the first reset modules of all sub-pixels to be tested in the detection stage to be turned on at the same time. Exemplarily, each first scanning line LSP2 can be set to connect the control end of the first reset module in a row of sub-pixels 20, then, the display panel is equivalent to performing pixel defect detection row by row, and the position of the defective sub-pixel can be located in the sub-pixel row.

[0146] Correspondingly, controlling the first reset module of each sub-pixel under test in the detection phase to be turned on includes: transmitting the turn-on potential of the first reset module to the first scan line connected to each sub-pixel under test in the detection phase.

[0147] Based on the above embodiments, optionally, see Figure 3, the pixel circuit also includes: a driving module 21 and at least one light-emitting control module; the display panel also includes a second power line for providing a positive voltage VDD. The driving module 21 and the light-emitting control module are connected in series between the second power line and the first pole of the light-emitting device OLED. The pixel defect detection method of the display panel also includes: in each detection stage, controlling the light-emitting control module of each sub-pixel under test in the detection stage to turn off. During the detection process, while the first reset module 27 in the same sub-pixel 20 is turned on, the light-emitting control module in the sub-pixel 20 is controlled to turn off. In this way, during the detection process, the connection between the driving module 21 and the light-emitting device OLED can be cut off to prevent the electrical signal output by the driving module 21 from affecting the voltage of the first pole of the light-emitting device OLED.

[0148] Figure 2 For example, the pixel circuit includes two light-emitting control modules, namely, a first light-emitting control module 25 and a second light-emitting control module 26. The first light-emitting control module 25 is connected between the second power line and the first end of the driving module 21, and the second light-emitting control module 26 is connected between the second end of the driving module 21 and the first electrode of the light-emitting device OLED. Then, in each detection stage, the first light-emitting control module and the second light-emitting control module of each sub-pixel under test in the detection stage are both turned off.

[0149] See also Figure 6 Exemplarily, the display panel further includes a plurality of light emitting control signal lines LEM, and one light emitting control signal line LEM is connected to the control end of the light emitting control module in at least one row of sub-pixels 20. Exemplarily, the control end of each light emitting control module in the same sub-pixel 20 is connected to the same light emitting control signal line LEM. The light emitting control signal line LEM is used to provide a light emitting control signal EM to control the on and off of each light emitting control module. For any sub-pixel 20, controlling the light emitting control module of the sub-pixel 20 to turn off includes: transmitting the cut-off potential of the light emitting control module to the light emitting control signal line LEM connected to the sub-pixel 20.

[0150] The following is an explanation of other module structures in the pixel circuit and their control methods during the detection process, but it is not intended to limit the present invention. It can be understood that since the light-emitting control module is turned off, the connection between other modules in the pixel circuit and the first electrode of the light-emitting device OLED is cut off. During the detection process, whether other functional modules are turned on or off does not affect the detection process. It is preferred to set other functional modules to be turned off to reduce circuit power consumption; or, for the functional modules associated with the first reset module 27 during the control process, the on-off requirements of the first reset module 27 can also be mainly considered.

[0151] Continue to see Figure 3On the basis of the above embodiments, optionally, the pixel circuit further includes a data writing module 22 connected to the first end of the driving module 21; the pixel defect detection method of the display panel further includes: in each detection stage, controlling the data writing module 22 of each sub-pixel under test in the detection stage to be turned off. Specifically, the display panel may also include a plurality of second scanning lines, which correspond to the control ends of the data writing modules 22 connected to the sub-pixels in different rows, respectively, and are used to provide the second scanning signal SP1. Controlling the data writing module 22 of each sub-pixel to be turned off includes: in each detection stage, controlling the second scanning line connected to each sub-pixel under test to maintain the cut-off potential of the data writing module.

[0152] Continue to see Figure 2 On the basis of the above embodiments, optionally, the pixel circuit further includes a threshold compensation module 23 connected between the control terminal and the second terminal of the driving module 21; the pixel defect detection method of the display panel further includes: in each detection stage, controlling the threshold compensation module 23 of each sub-pixel under test in the detection stage to be turned off. Specifically, the display panel further includes a plurality of third scanning lines, which correspond to the control terminals of the threshold compensation modules 23 in the sub-pixels 20 in different rows, respectively, and are used to provide the third scanning signal SN2. Controlling the threshold compensation module 23 of each sub-pixel to be turned off includes: in each detection stage, controlling the third scanning line connected to each sub-pixel under test to maintain the cut-off potential of the threshold compensation module 23.

[0153] Continue to see Figure 2 On the basis of the above-mentioned embodiments, optionally, the pixel circuit further includes a second reset module 24, which is connected to the control end or the second end of the driving module 21, and is exemplarily connected to the second end of the driving module 21 here. The second reset module 24 is used to initialize the control end of the driving module 21 using the second initialization voltage Vrefn1. The pixel defect detection method of the display panel also includes: in each detection stage, controlling the second reset module 24 of each sub-pixel under test in the detection stage to turn off. Specifically, the display panel also includes a plurality of fourth scanning lines, which correspond to the control ends of the second reset modules 24 in the sub-pixels 20 in different rows, respectively, and are used to provide a fourth scanning signal SN1. Controlling the second reset module 24 of each sub-pixel to turn off includes: in each detection stage, controlling the fourth scanning line connected to each sub-pixel under test to maintain the cut-off potential of the second reset module 24.

[0154] Continue to see Figure 2, based on the above embodiments, optionally, the pixel circuit further includes a third reset module 28 connected to the second end of the driving module 21. The third reset module 28 is used to initialize the second end of the driving module 21 using a third initialization voltage Vrefp. The pixel defect detection method of the display panel also includes: in each detection stage, controlling the third reset module 28 of each sub-pixel under test in the detection stage to be turned on. Exemplarily, the control end of the third reset module 28 in the same pixel circuit is connected to the same scan line as the control end of the first reset module 27, that is, the control end of the third reset module 28 is also connected to the first scan line, and the conduction potential of the third reset module 28 is the same as the conduction potential of the first reset module 27. Alternatively, the pixel defect detection method of the display panel also includes: in each detection stage, controlling the third reset module 28 of each sub-pixel under test in the detection stage to be turned off. Exemplarily, the control end of the third reset module 28 in the same pixel circuit is connected to different scan lines as the control end of the first reset module 27. Specifically, the display panel may further include a plurality of fifth scanning lines, which are respectively connected to the control ends of the third reset modules 28 in different rows of sub-pixels 20, and are used to provide a fifth scanning signal. Controlling the third reset modules 28 of each sub-pixel to be turned off includes: in each detection stage, controlling the fifth scanning lines connected to each sub-pixel under test to maintain the cut-off potential of the third reset module 28.

[0155] Specifically, the driving module 21 may include a driving transistor M1, the data writing module 22 may include a data writing transistor M2, the threshold compensation module 23 may include a threshold compensation transistor M3, the second reset module 24 may include a second reset transistor M4, the first light emission control module 25 may include a first light emission control transistor M5, the second light emission control module 26 may include a second light emission control transistor M6, the first reset module 27 may include a first reset transistor M7, and the third reset module 28 may include a third reset transistor M8. The control end of the driving module 21 may also be connected to a storage capacitor Cst to maintain the potential of the control end of the driving module 21. Among them, the threshold compensation transistor M3 and the second reset transistor M4 may be set as N-type transistors, whose on-potential is high potential and whose off-potential is low potential; the other transistors are P-type transistors, whose on-potential is low potential and whose off-potential is high potential.

[0156] Then, see Figure 7 In the detection stage T21, the light-emitting control signal EM and the second scanning signal SP1 connected to the sub-pixel under test can be set to high potentials, and the first scanning signal SP2, the third scanning signal SN2 and the fourth scanning signal SN1 connected to the sub-pixel under test can be set to low potentials to meet the on-off requirements of the above-mentioned functional modules.

[0157] Based on the above-mentioned methods, optionally, in the detection stage, only the timing waveforms of the first scanning line LSP2 and the light emitting control signal line LEM can be adjusted, and the timing waveforms on other scanning lines can be kept consistent with those in the display process, so as to realize the detection process with minimized adjustment. Figure 4 and Figure 7 Before the detection stage T21, the second scanning signal SP1, the third scanning signal SN2 and the fourth scanning signal SN1 can still refer to the waveforms of the first reset stage T11, the data writing stage T12 and the second reset stage T13, but the first scanning signal SP2 remains constant low and the light emitting control signal EM remains constant high. The working state of the sub-pixel in the detection stage T21 can be referred to Figure 8 ,and Figure 5 The difference between the working state of the middle light emitting stage T14 is that the two light emitting control transistors are turned off, but the first reset transistor M7 and the third reset transistor M8 are turned on.

[0158] In summary, the pixel defect detection method of the display panel provided by the embodiment of the present invention adopts the existing panel structure, and only adjusts the pixel circuit timing in the detection stage T21 through the special pixel circuit timing, provides the detection voltage through the first power line LV1, and monitors the feedback voltage transmitted by the reference signal line LREF, which can distinguish whether the dark spot is a regular defect or a defect caused by a micro short circuit between the two poles of the light-emitting device. The detection method is simple and easy to implement. Exemplarily, the detection module for executing the bad pixel detection method of the display panel can be integrated in the lighting detection device, and is used to detect bad pixels in the panel segment; or, the detection module can be integrated in the display driver chip, and is used to detect bad pixels in the module segment. Then, the detection can be achieved only by monitoring the voltage change in the display driver chip.

[0159] Continue to see Figure 6 In one embodiment, optionally, the first power line LV1 is connected to the second electrodes of the light-emitting devices in all sub-pixels 20 in the display panel 100, and in any detection stage, the detection voltage is provided to all sub-pixels 20 through the first power line LV1. Exemplarily, the isolation structure 50 is made of metal material, and the isolation structure 50 can be reused as the first power line LV1.

[0160] The reference signal line LREF is connected to the first pole of the light-emitting device in all sub-pixels 20 in the display panel 100, for example, connected to the first pole of the light-emitting device through the first reset module 27. In any detection stage, the feedback voltage is collected through the reference signal line LREF; since at least one sub-pixel 20 is selected as the sub-pixel to be tested in each detection stage, the feedback voltage on the reference signal line LREF substantially represents the voltage output by the first pole of the light-emitting device of all the sub-pixels to be tested. It can be understood that as long as the sub-pixels to be tested include a bad sub-pixel, the feedback voltage will be pulled out of the normal voltage range; the more bad sub-pixels there are in the sub-pixels to be tested, the higher the degree to which the feedback voltage is pulled, and the more it deviates from the normal voltage range.

[0161] The above embodiment exemplarily provides a solution for setting the reference signal line LREF on the entire surface, but it is not intended to limit the present invention. Fig. 9 Considering the driving capability of the first initialization voltage, the display panel 100 may include a plurality of display sub-areas arranged along the row direction X and extending along the column direction Y, and the reference signal lines of different display sub-areas are insulated from each other. The reference signal lines in different display sub-areas independently provide the first initialization voltage for the corresponding display sub-areas. Fig. 9 2 exemplarily shows a first display sub-area AA1 , in which each sub-pixel 20 is connected to a first reference signal line LREF1 , and a second display sub-area AA2 , in which each sub-pixel 20 is connected to a second reference signal line LREF2 .

[0162] Then, obtaining the feedback voltage on the reference signal line includes: respectively obtaining the feedback voltage on the reference signal line in each display sub-area.

[0163] Judging whether there is a short circuit between the first electrode of the light-emitting device and the second electrode of the light-emitting device according to the change of the feedback voltage includes: judging whether there is a bad sub-pixel with a short circuit between the first electrode of the light-emitting device and the second electrode of the light-emitting device in each display sub-area according to the change of each feedback voltage.

[0164] The structure of this embodiment can locate the defective sub-pixel at the position of each sub-pixel row corresponding to each display sub-area, thereby achieving more accurate identification.

[0165] In order to verify the feasibility of the pixel defect detection method of the display panel provided by the embodiment of the present invention, the inventors tested the abnormal products with micro short circuits and normal products respectively, and the test results are shown in Table 1 and Table 2. Among them, Table 1 is a comparison of the test results of the abnormal product with an isolation structure 50 and the normal product 1 prepared by FMM, and Table 2 is a comparison of the test results of the abnormal product with an isolation structure 50 and the normal product 2 with an isolation structure 50.

[0166] Table 1

[0167]

[0168] Table 2

[0169]

[0170]

[0171] According to the results in the above table, the feedback voltage of a normal product is around 0V, and the feedback voltage of an abnormal product is a relatively large negative voltage, and changes in the same direction as the detection voltage. This indicates that the detection method provided by the embodiment of the present invention can correctly identify defective sub-pixels with micro-short circuits between the anode and cathode of a light-emitting device.

[0172] An embodiment of the present invention further provides a lighting detection device, which is used to execute the pixel defect detection method of the display panel provided by any embodiment of the present invention, and has corresponding beneficial effects. Fig.10 Schematic diagram of the connection relationship between a lighting detection device and a display panel provided by an embodiment of the present invention. Fig.10 , exemplarily, a cell test (CT) device 300 is connected to a first power line LV1 and a reference signal line LREF in the display panel 100, and is used to perform a pixel defect detection method of the display panel, such as performing pixel defect detection in a screen segment.

[0173] Exemplarily, the display panel includes a lighting detection circuit. The lighting detection circuit includes: a first pad connected to the first power line LV1, and a second pad connected to the reference signal line LREF. The lighting detection device includes: a signal output terminal OUT and a signal input terminal IN; the signal output terminal OUT is connected to the first pad; the signal input terminal IN is connected to the second pad. The signal output terminal OUT is used to output a detection voltage, and the signal input terminal IN is used to receive a feedback voltage.

[0174] The embodiment of the present invention utilizes the relevant pads in the lighting detection circuit to realize the connection between the lighting detection device 300 and the display panel 100. It can be understood that the lighting detection circuit can also include pads required for controlling the display panel to perform display-related tests, connecting the corresponding components and wiring in the display panel; the controller in the lighting detection device can also connect these pads to control the performance of display-related tests.

[0175] On the basis of the above-mentioned embodiments, optionally, the lighting detection device 300 further includes: a detection voltage source 310 and a reference voltage source 320. The detection voltage source 310 is connected to the signal output terminal OUT, and the reference voltage source 320 is connected to the second pad. The detection voltage source 310 is used to provide a detection voltage, and the reference voltage source 320 is used to provide a first initialization voltage. The detection voltage source 310 and the reference voltage source 320 share a common ground. Among them, the relevant control process of the detection voltage source 310 and the reference voltage source 320 can be referred to the above-mentioned embodiments, and will not be repeated here. Exemplarily, the lighting detection device 300 also includes a controller, which is respectively connected to the signal input terminal IN, the detection voltage source 310 and the reference voltage source 320, and is used for data analysis and controlling the output state of each voltage source.

[0176] An embodiment of the present invention further provides a display device, including a display panel and a detection module, wherein the detection module is used to perform a pixel defect detection method for a display panel provided in any embodiment of the present invention, and has corresponding beneficial effects. The detection module is connected to a first power line and a reference signal line in the display panel, and the detection module is used to perform a pixel defect detection method for a display panel, for example, performing pixel defect detection in a module segment.

[0177] Fig.11 is a schematic diagram of a display device provided by an embodiment of the present invention, see Fig.11 The display device also includes a control component 200, and the control component 200 includes a display driver chip DDIC. The detection module can be integrated in the display driver chip DDIC. Exemplarily, the display driver chip provides the display panel 100 with voltages required for the display process, such as the power supply voltage VG required by the scan driver, the first initialization signal Vrefn2, the second initialization signal Vrefn1, and the third initialization signal Vrefp. The positive voltage VDD and the second pole voltage VSS required by the sub-pixel are usually provided by an external voltage source. When the detection function is turned on by the display driver chip DDIC, the feedback voltage can be compared inside the display driver chip DDIC and the detection result can be output.

[0178] See also Figure 1, based on the above embodiments, optionally, the display panel further includes: a substrate 10 and an isolation structure 50 located on one side of the substrate 10; the isolation structure 50 is arranged around each light-emitting device OLED. Exemplarily, the isolation structure 50 includes a first isolation portion 51 and a second isolation portion 52 stacked in sequence in a direction away from the substrate 10. The orthographic projection of the first isolation portion 51 on the substrate 10 is located within the orthographic projection of the second isolation portion 52 on the substrate 10, and the area of ​​the orthographic projection of the first isolation portion 51 on the substrate 10 is smaller than the area of ​​the orthographic projection of the second isolation portion 52 on the substrate 10. It should be noted that the relevant technical solutions of the isolation structure 50 are recorded in the patents with application numbers PCT / CN2023 / 134518, 202310759370.2, 202310740412.8, 202310707209.0 and 202311346196.5, and their contents are incorporated into this application by reference for reference, and will not be repeated in this embodiment.

[0179] The isolation structure 50 is connected to the second electrode 43 in each light-emitting device OLED, and each second electrode 43 is, for example, overlapped to the side wall of the first isolation portion 51. The isolation structure 50 can be made of a conductive material, such as a metal material, and the isolation structure 50 can be reused as a first power line for transmitting a detection voltage during the detection process and transmitting a cathode voltage during the display process.

[0180] Fig.12 is a schematic diagram of the structure of a detection module provided by an embodiment of the present invention. Fig.12 In one implementation, optionally, the detection module 60 includes: a comparison unit 62 , a first switch K1 , a detection voltage source 63 , a second switch K2 and a control unit 61 .

[0181] The first switch K1 is connected between the reference signal line LREF and the first input terminal of the comparison unit 62. The detection voltage source 63 is used to generate the detection voltage. The second switch K2 is connected between the detection voltage source 63 and the first power line LV1. The control unit 61 is respectively connected to the control end of the first switch K1, the control end of the second switch K2, the control end of the detection voltage source 63 and the second input terminal of the comparison unit 62. The control unit 61 is used to control the first switch K1 and the second switch K2 to be turned on when the detection module 60 performs the pixel defect detection method of the display panel, control the detection voltage source 63 to generate and output the detection voltage, and transmit the reference value REF of the feedback voltage to the second input terminal of the comparison unit 62.

[0182] Among them, the detection voltage is transmitted to the first power line LV1 through the second switch K2, and the feedback voltage on the reference signal line is transmitted to the first input terminal of the comparison unit 62 through the first switch K1; the comparison unit 62 is used to output a comparison result Error Flag according to the feedback voltage and the reference value REF of the feedback voltage, and the comparison result Error Flag is used to characterize whether there are defective sub-pixels in the display panel.

[0183] Exemplarily, the reference value REF of the feedback voltage is a reference value set by the control unit 61, which is a value outside the normal voltage range. For example, it can be a fault range that the feedback voltage may reach in the presence of a micro-short circuit determined by multiple experimental measurements. The absolute value of the reference value REF of the feedback voltage can be equal to or less than the minimum absolute value of the voltage within the fault range. Alternatively, under the condition that the detection result card control is relatively loose, the reference value REF of the feedback voltage can also be set according to the normal voltage range, for example, the absolute value of the reference value REF of the feedback voltage is set equal to or greater than the maximum absolute value of the voltage within the normal voltage range. Taking the detection voltage as a negative voltage as an example, the reference value REF of the feedback voltage can be a slightly negative value. Once the measured feedback voltage is more negative than the reference value REF of the feedback voltage, it can be considered that there is a bad sub-pixel.

[0184] Continue to see Fig.12 On the basis of the above embodiments, optionally, the display device further includes: a reference voltage source 72 connected to the reference signal line LREF; and the control unit 61 is also connected to the reference voltage source 72. The control unit 61 is also used to control the reference voltage source 72 to output a high impedance state when the detection module 60 performs the pixel defect detection method of the display panel. The reference voltage source 72 can be a charge pump, which can be integrated into the display driver chip DDIC or can be separately provided outside the display driver chip DDIC.

[0185] Continue to see Fig.12 On the basis of the above embodiments, optionally, the display device further includes: a first voltage source 71 connected to the first power line LV1; and the control unit 61 is also connected to the first voltage source 71. The control unit 61 is also used to control the first voltage source 71 to stop outputting when the detection module 60 performs the pixel defect detection method of the display panel. Exemplarily, the first voltage source 71 can be a power chip (power IC) separately provided outside the display driver chip DDIC.

[0186] Exemplarily, the first switch K1 and the second switch K2 are linked, and are turned on or off at the same time under the control of the control unit 61. After the display driver chip DDIC turns on the detection function, in addition to controlling the pixel circuit timing to change as described above, it also controls the actions of the relevant components of the detection module 60. Specifically, the two selection switches, the first switch K1 and the second switch K2, are controlled to be turned on, and the first voltage source 71 is controlled to stop outputting; the detection voltage source 63 inside the display driver chip DDIC is controlled to supply the detection voltage, and the feedback voltage actually collected is compared with the reference value REF of the feedback voltage, and the comparison result Error Flag is output through the external channel; and then the detection voltage is adjusted multiple times (such as -6V, -5V, etc.), and the comparison result Error Flag is output multiple times. When the Error Flag of multiple comparison results shows that the feedback voltage is abnormal and changes with the detection voltage, it is determined that the tested sub-pixel includes a defective sub-pixel with a micro-short circuit between the anode and cathode of the light-emitting device. Exemplarily, the control unit 61 can be integrated into the display driver chip DDIC, or it can be separately set outside the display driver chip DDIC, for example, in the main control board. The comparison result Error Flag can be transmitted to the control unit 61 or the main control board.

[0187] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and this document does not limit this.

[0188] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for detecting defective pixels of a display panel, characterized in that: The display panel comprises at least one sub-pixel, a first power line and a reference signal line, the sub-pixel comprises a light-emitting device, a first electrode of the light-emitting device is connected to the reference signal line, and a second electrode of the light-emitting device is connected to the first power line; The method comprises: providing a detection voltage to the first power line; Obtaining a feedback voltage on the reference signal line; Whether there is a short circuit between the first electrode of the light emitting device and the second electrode of the light emitting device is determined according to the change of the feedback voltage.

2. The method for detecting defective pixels of a display panel according to claim 1, wherein: include: At least one detection stage; in each detection stage, at least one sub-pixel is selected as a sub-pixel to be detected; Preferably, all the sub-pixels to be tested selected in each of the testing stages include all the sub-pixels in the display panel; Preferably, providing a detection voltage to the first power line comprises: In each of the detection stages, providing a detection voltage to the first power line connected to each of the sub-pixels to be detected selected in the detection stage; Preferably, obtaining the feedback voltage on the reference signal line includes: In each of the detection stages, obtaining a feedback voltage on the reference signal line connected to each of the sub-pixels selected in the detection stage; Preferably, judging whether there is a short circuit between the first electrode of the light emitting device and the second electrode of the light emitting device according to the change of the feedback voltage includes: In each of the detection stages, it is determined according to the change of the feedback voltage whether there is a defective sub-pixel with a short circuit between the first electrode of the light-emitting device and the second electrode of the light-emitting device in each of the sub-pixels selected in the detection stage.

3. The method for detecting defective pixels of a display panel according to claim 2, wherein: The sub-pixel further includes a pixel circuit, wherein the pixel circuit includes a first reset module, and the first reset module is connected between the reference signal line and the first electrode of the light-emitting device; The method further comprises: In each of the detection stages, controlling the first reset module of each of the sub-pixels under test in the detection stage to be turned on; Preferably, the display panel further comprises a plurality of first scanning lines, which are respectively connected to the control ends of the first reset modules in the sub-pixels in different rows; In each detection stage, the sub-pixels connected to the same first scanning line are selected as the sub-pixels to be detected in the detection stage; Preferably, controlling the first reset module of each of the sub-pixels under test in the detection phase to be turned on comprises: transmitting a turn-on potential of the first reset module to the first scan line connected to each of the sub-pixels under test in the detection phase.

4. The method for detecting defective pixels of a display panel according to claim 2, wherein: The pixel circuit further includes: a driving module and at least one light emitting control module; the display panel further includes a second power line, and the driving module and the light emitting control module are connected in series between the second power line and the first electrode of the light emitting device; The method further comprises: In each of the detection stages, controlling the light emitting control module of each of the sub-pixels under test in the detection stage to be turned off; Preferably, the display panel further comprises a plurality of light emitting control signal lines, one of the light emitting control signal lines being connected to the control end of the light emitting control module in at least one row of the sub-pixels; For any of the sub-pixels, controlling the light emitting control module of the sub-pixel to be turned off includes: transmitting a cutoff potential of the light emitting control module to the light emitting control signal line connected to the sub-pixel.

5. The method for detecting defective pixels of a display panel according to claim 1, wherein: Judging whether there is a short circuit between the first electrode of the light emitting device and the second electrode of the light emitting device according to a change in the feedback voltage includes: If the feedback voltage deviates from the normal voltage range after the detection voltage is provided to the first power line, it is determined that there is a short circuit between the first pole of the light-emitting device and the second pole of the light-emitting device; wherein the normal voltage range is the voltage fluctuation range on the reference signal line when the detection voltage is applied to the first power line without a short circuit between the first pole and the second pole of the light-emitting device.

6. The method for detecting defective pixels of a display panel according to claim 1, wherein: Also includes: Providing a reference voltage source, and controlling the reference voltage source to output a high impedance state during the period of obtaining the feedback voltage output by the reference signal line; wherein the reference voltage source is connected to the reference signal line; Preferably, the method for detecting defective pixels of a display panel further comprises: Providing a detection voltage source, and controlling the reference voltage source and the detection voltage source to share a common ground; wherein the detection voltage source is connected to the first power line; Providing the detection voltage to the first power line includes: controlling the detection voltage source to output the detection voltage.

7. The method for detecting defective pixels of a display panel according to claim 5, wherein: The absolute value of the voltage within the normal voltage range is less than the first preset voltage value; Preferably, the first preset voltage value is less than or equal to 0.3V; Preferably, the first preset voltage value includes one of 0.15V, 0.2V and 0.25V.

8. The method for detecting defective pixels of a display panel according to claim 5, wherein: After determining that the feedback voltage deviates from the normal voltage range, the method further includes: changing the detection voltage at least once, and acquiring a corresponding feedback voltage after each change of the detection voltage; If the feedback voltage changes along the same direction as the detection voltage each time the detection voltage is changed, it is determined that there is a short circuit between the first electrode of the light emitting device and the second electrode of the light emitting device.

9. The method for detecting defective pixels of a display panel according to claim 1, wherein: Judging whether there is a short circuit between the first electrode of the light emitting device and the second electrode of the light emitting device according to a change in the feedback voltage includes: If the feedback voltage is within the normal voltage range after the detection voltage is provided to the first power line, it is determined that there is no short circuit between the first electrode of the light-emitting device and the second electrode of the light-emitting device; wherein the normal voltage range is the voltage fluctuation range on the reference signal line when the detection voltage is applied to the first power line when there is no short circuit between the first electrode and the second electrode of the light-emitting device; Preferably, after determining that the feedback voltage is within the normal voltage range, the method further includes: changing the detection voltage at least once, and acquiring a corresponding feedback voltage after each change of the detection voltage; If the feedback voltage remains within the normal voltage range each time the detection voltage is changed, it is determined that there is no short circuit between the first electrode of the light emitting device and the second electrode of the light emitting device.

10. The method for detecting defective pixels of a display panel according to claim 1, wherein: The first pole of the light-emitting device is an anode, the second pole of the light-emitting device is a cathode, and the first power line transmits a cathode voltage when the display panel displays a picture; the cathode voltage and the detection voltage are both negative voltages; Preferably, the absolute value of the detection voltage is greater than or equal to the absolute value of the cathode voltage.

11. The method for detecting defective pixels of a display panel according to claim 2, wherein: The pixel circuit further includes a driving module, a first light-emitting control module and a second light-emitting control module; the display panel further includes a second power line, the first light-emitting control module is connected between the second power line and the first end of the driving module, and the second light-emitting control module is connected between the second end of the driving module and the first pole of the light-emitting device; The method further comprises: in each of the detection phases, controlling the first light emitting control module and the second light emitting control module of each of the sub-pixels under test in the detection phase to be turned off; Preferably, the pixel circuit further includes a data writing module connected to the first end of the driving module; the method further includes: in each of the detection stages, controlling the data writing module of each of the sub-pixels under test in the detection stage to be turned off; Preferably, the pixel circuit further includes a threshold compensation module connected between the control terminal and the second terminal of the driving module; the method further includes: in each of the detection stages, controlling the threshold compensation module of each of the sub-pixels under test in the detection stage to be turned off; Preferably, the pixel circuit further includes a second reset module connected to the control end or the second end of the driving module; the method further includes: in each of the detection stages, controlling the second reset module of each of the sub-pixels under test in the detection stage to be turned off; Preferably, the pixel circuit further includes a third reset module connected to the second end of the driving module; the method further includes: in each of the detection stages, controlling the third reset module of each of the sub-pixels under test in the detection stage to be turned on; Preferably, the control end of the third reset module and the control end of the first reset module in the same pixel circuit are connected to the same scan line; or, The method further comprises: in each of the detection stages, controlling the third reset module of each of the sub-pixels under test in the detection stage to be turned off; Preferably, a control end of the third reset module and a control end of the first reset module in the same pixel circuit are connected to different scan lines.

12. The method for detecting defective pixels of a display panel according to any one of claims 1 to 11, characterized in that: The display panel comprises a plurality of display sub-areas arranged along a row direction, and the reference signal lines of different display sub-areas are insulated from each other; The obtaining of the feedback voltage on the reference signal line comprises: respectively obtaining the feedback voltage on the reference signal line in each of the display sub-areas; Judging whether there is a short circuit between the first pole of the light-emitting device and the second pole of the light-emitting device according to the change of the feedback voltage, including: judging whether there is a bad sub-pixel in each display sub-area with a short circuit between the first pole of the light-emitting device and the second pole of the light-emitting device according to the change of each feedback voltage.

13. A lighting detection device, characterized in that: A first power line and a reference signal line in a display panel are connected to execute a pixel defect detection method for a display panel according to any one of claims 1 to 12.

14. The lighting detection device according to claim 13, characterized in that: The display panel includes a lighting detection circuit; the lighting detection circuit includes: a first pad connected to the first power line, and a second pad connected to the reference signal line; The lighting detection device comprises: A signal output terminal connected to the first pad; The signal input terminal is connected to the second pad.

15. The lighting detection device according to claim 14, characterized in that: Also includes: A detection voltage source connected to the signal output terminal; A reference voltage source connected to the second pad; The detection voltage source and the reference voltage source share a common ground.

16. A display device, characterized in that: include: Display panel and detection module; The detection module is connected to a first power line and a reference signal line in the display panel, and the detection module is used to execute the pixel defect detection method for the display panel according to any one of claims 1-12.

17. The display device according to claim 16, characterized in that: It also includes a display driver chip, in which the detection module is integrated.

18. The display device according to claim 16, characterized in that: The display panel further comprises: a substrate and an isolation structure located on one side of the substrate; the isolation structure is arranged around each of the light emitting devices; Preferably, the isolation structure comprises a first isolation portion and a second isolation portion which are sequentially stacked in a direction away from the substrate; The orthographic projection of the first isolation portion on the substrate is located within the orthographic projection of the second isolation portion on the substrate, and the area of ​​the orthographic projection of the first isolation portion on the substrate is smaller than the area of ​​the orthographic projection of the second isolation portion on the substrate; Preferably, the isolation structure is reused as the first power line.

19. The display device according to any one of claims 16 to 18, characterized in that: The detection module comprises: Comparison unit; A first switch connected between the reference signal line and a first input terminal of the comparison unit; A detection voltage source, used for generating a detection voltage; A second switch connected between the detection voltage source and the first power line; a control unit, connected to the control end of the first switch, the control end of the second switch, the detection voltage source and the second input end of the comparison unit respectively; the control unit is used to control the first switch and the second switch to be turned on, control the detection voltage source to generate and output the detection voltage, and transmit a reference value of the feedback voltage to the second input end of the comparison unit when the detection module performs the pixel defect detection method of the display panel; Among them, the detection voltage is transmitted to the first power line through the second switch, and the feedback voltage output by the reference signal line is transmitted to the comparison unit through the first switch; the comparison unit is used to output a comparison result based on the feedback voltage and the reference value of the feedback voltage, and the comparison result is used to characterize whether there are defective sub-pixels in the display panel.

20. The display device according to claim 19, characterized in that Also includes: A reference voltage source connected to the reference signal line; the control unit is also connected to the reference voltage source, and the control unit is also used to control the reference voltage source to output a high impedance state when the detection module executes the pixel defect detection method of the display panel; and / or, The display device further includes: a first voltage source connected to the first power line; The control unit is also connected to the first voltage source, and the control unit is further used to control the first voltage source to stop outputting when the detection module executes the pixel defect detection method of the display panel.

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