A method and device for detecting line defects of a display panel

Abstract

The application discloses a line defect detection method and device of a display panel, and the method comprises the following steps: dividing a first pixel driving circuit column with a line defect into N pixel driving circuit groups; cutting off the positions of a data line and a compensation signal line connected by the first pixel driving circuit column between two adjacent pixel driving circuit groups in the direction from the display area to the binding area; when the cutting-off position is between the i-th pixel driving circuit group and the i+1-th pixel driving circuit group, if the light-emitting element corresponding to the first pixel driving circuit column in the driving stage does not display a dark line, and / or the line defect detection signal in the badness detection stage is less than the detection threshold, then the defect position of the line defect is located in the i-th pixel driving circuit group; the line defect detection signal is the difference between the sensing signal before a set time period and the sensing signal after the set time period. The technical scheme provided by the application can accurately lock the short-circuit line defect position of the display panel.

Description

Technical Field

[0001] This invention relates to the field of display technology, and in particular to a method and apparatus for detecting line defects in display panels. Background Technology

[0002] OLED, or Organic Light-Emitting Diode, also known as organic electroluminescent device, refers to the phenomenon where light-emitting materials emit light through carrier injection and recombination under the influence of an electric field. Compared to liquid crystal displays (LCDs), OLED displays are thinner and lighter, and offer better viewing angles and contrast, thus attracting widespread attention.

[0003] In the OLED panel manufacturing process, numerous metal patterns such as data lines, power signal lines, and reference voltage signal lines are incorporated. Because the data lines and reference voltage signal lines are located close together, there is a possibility that foreign objects from the upper metal layer may fall onto the lower metal layer, easily causing short circuits and creating line defects. These defects can result in entire rows or columns of dark lines during display, affecting the normal operation of the display panel. Summary of the Invention

[0004] This invention provides a method for detecting line defects in a display panel, so as to accurately locate the position of a line defect where a short circuit has occurred in the display panel.

[0005] In a first aspect, embodiments of the present invention provide a method for detecting line defects in a display panel. The display panel includes a display area and a bonding area located on one side of the display area along a first direction. The display area includes multiple rows of pixel driving circuits extending along the first direction and arranged sequentially along a second direction. The first direction intersects the second direction. The display area also includes data lines and compensation signal lines extending along the first direction. The data lines are used to provide data signals to corresponding pixel driving circuits. The compensation signal lines are used to provide compensation signals to corresponding pixel driving circuits and output sensing signals corresponding to the pixel driving circuits.

[0006] The method for detecting line defects in the display panel includes:

[0007] The first pixel driving circuit column with line defects is divided into N pixel driving circuit groups along the first direction; each pixel driving circuit group includes multiple pixel driving circuits; N is an integer greater than 1;

[0008] Along the first direction from the display area to the binding area, the data lines and compensation signal lines connected by the first pixel driving circuit column are sequentially cut off at the positions between two adjacent pixel driving circuit groups;

[0009] When the data line and the compensation signal line are cut off at the position between the i-th pixel driving circuit group and the (i+1)-th pixel driving circuit group, if the light-emitting element corresponding to the first pixel driving circuit column in the driving stage does not display a dark line, and / or the inductive line type defect detection signal in the defect detection stage is less than the detection threshold, then the defect position of the locked line defect is located in the i-th pixel driving circuit group; the inductive line type defect detection signal is the difference between the inductive signal before and after a set time period; 1≤i≤N-1; i is an integer.

[0010] As a preferred embodiment of the line defect detection method for a display panel, when the data line and the compensation signal line are cut to the position between the (N-1)th pixel driving circuit group and the Nth pixel driving circuit group, if the light-emitting element corresponding to the first pixel driving circuit column displays a dark line, and / or the sensing line shape defect detection signal obtained according to the sensing signal is greater than or equal to the detection threshold, then the defect location of the line defect is locked at the Nth pixel driving circuit group.

[0011] As a preferred embodiment of the line defect detection method for display panels, the set time period is 50 seconds; the detection threshold is 450-500 mA.

[0012] As a preferred embodiment of a line defect detection method for a display panel, the pixel driving circuit includes: a switching transistor, a driving transistor, a sensing transistor, and a storage capacitor; the control terminal of the switching transistor is connected to a scanning signal; the first terminal of the switching transistor is electrically connected to a corresponding data line; the second terminal of the switching transistor is electrically connected to the control terminal of the driving transistor; the first terminal of the driving transistor is connected to a first power signal; the second terminal of the driving transistor is electrically connected to the first terminal of a corresponding light-emitting element; the second terminal of the light-emitting element is connected to a second power signal; the first terminal of the storage capacitor is electrically connected to the control terminal of the driving transistor; the second terminal of the storage capacitor is electrically connected to the first terminal of the driving transistor; and the second terminal of the storage capacitor is electrically connected to the second terminal of the driving transistor. The two terminals are electrically connected; the control terminal of the sensing transistor is connected to a control signal; the first terminal of the sensing transistor is electrically connected to the second terminal of the driving transistor; the second terminal of the sensing transistor is electrically connected to a corresponding compensation signal line; the pixel driving circuit is configured such that: in the driving phase, the switching transistor, the driving transistor, and the sensing transistor are turned on, and the data signal input by the data line and the compensation signal input by the compensation signal line control the light-emitting element to emit light; in the defect detection phase, the switching transistor, the driving transistor, and the sensing transistor are turned off; in the first phase, the compensation signal line inputs a charging signal to the second terminal of the sensing transistor; in the second phase, the compensation signal line outputs a sensing signal.

[0013] As a preferred embodiment of the line defect detection method for a display panel, before dividing the first pixel driving circuit column with line defects into N pixel driving circuit groups along the first direction, the method further includes: controlling the display panel to perform a driving phase, and acquiring the pixel driving circuit column in the display area whose corresponding light-emitting element is displayed as a dark line as the first pixel driving circuit column; the dark line is a display state in which the display brightness of the light-emitting element corresponding to the pixel driving circuit column is lower than the brightness threshold.

[0014] As a preferred embodiment of the line defect detection method for display panels, the brightness threshold is the average brightness of the light-emitting elements corresponding to the pixel driving circuit column that does not have line defects in the current driving stage.

[0015] As a preferred embodiment of a line defect detection method for a display panel, when the data line and the compensation signal line are cut to a position between the i-th pixel driving circuit group and the (i+1)-th pixel driving circuit group, if the light-emitting element corresponding to the first pixel driving circuit group in the driving phase does not display a dark line, and / or the sensing line type defect detection signal in the defect detection phase is less than the detection threshold, then the defect location of the line defect is locked to be located in the i-th pixel driving circuit group. This includes: when the data line and the compensation signal line are cut to a set position in the i-th pixel driving circuit group, controlling the display panel to execute the driving phase and determining whether the light-emitting element corresponding to the first pixel driving circuit group displays a dark line; and controlling the display panel to execute the sensing phase and determining whether the sensing line type defect detection signal is less than the detection threshold; if the light-emitting element corresponding to the first pixel driving circuit group does not display a dark line, and / or the sensing line type defect detection signal is less than the detection threshold, then the specific location of the line defect is locked to be located in the i-th pixel driving circuit group.

[0016] As a preferred embodiment of the line defect detection method for display panels, the method for locking the defect location of the line defect to be located after the i-th pixel driving circuit group further includes: locating the defect location in the i-th pixel driving circuit group to the short circuit location between the data line and the compensation signal line using a microscopic device; performing cross-sectional analysis on the short circuit location using a focused ion beam process and feeding it back to the controller.

[0017] As a preferred embodiment of a line defect detection method for a display panel, the display area includes an array of pixel units; the pixel unit includes a first pixel driving circuit, a second pixel driving circuit, a third pixel driving circuit, and a fourth pixel driving circuit arranged along a second direction;

[0018] The first pixel driving circuit is used to drive the corresponding first color light-emitting element; the second pixel driving circuit is used to drive the corresponding second color light-emitting element; the third pixel driving circuit is used to drive the corresponding third color light-emitting element; the fourth pixel driving circuit is used to drive the corresponding fourth color light-emitting element; the pixel units form a pixel unit column along the first direction; the same pixel unit column shares a data line; the same pixel unit column shares a compensation signal line; the line defect detection method of the display panel includes: dividing the first pixel unit column with line defects into N pixel unit groups along the first direction; along the first direction from the display area to the binding area, sequentially cutting the data line and compensation signal line connected to the first pixel unit column at positions between two adjacent pixel unit groups; when the data line and compensation signal line are cut to the position between the i-th pixel unit group and the (i+1)-th pixel unit group, if the light-emitting element corresponding to the first pixel unit column in the driving stage does not display a dark line, and / or, the sensing line defect detection signal in the defect detection stage is less than the detection threshold, then the defect position of the line defect is locked in the i-th pixel unit group.

[0019] Secondly, embodiments of the present invention also provide a line defect detection device for a display panel, applicable to the line defect detection method for a display panel provided in any embodiment of the present invention, comprising: a controller and a laser cutting device;

[0020] The controller is used to divide the first pixel driving circuit column with line defects into N pixel driving circuit groups along the first direction; each pixel driving circuit group includes multiple pixel driving circuits; N is an integer greater than 1;

[0021] The laser cutting device is electrically connected to the controller and is used to sequentially cut the data lines and compensation signal lines connected to the first pixel driving circuit group at the positions between two adjacent pixel driving circuit groups along the first direction from the display area to the binding area.

[0022] The controller is further configured to, when the laser cutting device cuts the data line and the compensation signal line at the position between the i-th pixel driving circuit group and the (i+1)-th pixel driving circuit group, obtain that the light-emitting element corresponding to the first pixel driving circuit group in the driving stage does not display a dark line, and / or, the inductive line type defect detection signal in the defect detection stage is less than the detection threshold, and thereby lock the defect position of the line defect to be located in the i-th pixel driving circuit group; the inductive line type defect detection signal is the difference between the inductive signal before and after a set time period; 1≤i≤N-1; i is an integer.

[0023] In this invention, the display panel includes a pixel driving circuit column extending along a first direction. A pixel driving circuit column with a line defect can be designated as the first pixel driving circuit column. During line defect detection, the first pixel driving circuit column with the line defect is divided into N pixel driving circuit groups along the first direction. Each pixel driving circuit group includes multiple pixel driving circuits arranged along the first direction. Then, data lines and compensation signal lines between adjacent pixel driving circuit groups in the first pixel driving circuit column are sequentially cut from the side furthest from the bonding area. After cutting one data line and compensation signal line, the display panel is sequentially controlled to enter the driving stage and the defect detection stage. During the driving stage, it is detected whether the light-emitting element connected to the first pixel driving circuit column displays a dark line. During the defect detection stage, a induced line defect detection signal is acquired. Finally, if the light-emitting element corresponding to the first pixel driving circuit column does not display a dark line during the driving stage, or if the induced line defect detection signal during the defect detection stage is less than the detection threshold, the defect location of the line defect is determined to be in the i-th pixel driving circuit group. This embodiment can accurately locate the pixel drive circuit group where the line defect occurs, making it easier for subsequent staff to directly locate the short circuit position of the data line and compensation signal line from the pixel drive circuit group. This eliminates the need for staff to check each pixel drive circuit individually, improving the efficiency of line defect investigation, enhancing the accuracy of line defect location, and facilitating the tracing and analysis of the cause of the line defect. Attached Figure Description

[0024] Figure 1 This is a flowchart illustrating the line defect detection method for a display panel provided in an embodiment of the present invention.

[0025] Figure 2 This is a schematic diagram of the structure of a display panel provided in an embodiment of the present invention;

[0026] Figure 3 This is a schematic diagram of a pixel driving circuit provided in an embodiment of the present invention;

[0027] Figure 4 This is a schematic diagram of another pixel driving circuit provided in an embodiment of the present invention;

[0028] Figure 5 A waveform diagram of the sensing signal provided in an embodiment of the present invention;

[0029] Figure 6 This is a layout diagram of the pixel driving circuit provided in an embodiment of the present invention;

[0030] Figure 7 for Figure 6 A magnified view of a portion of region C1 in the middle;

[0031] Figure 8 for Figure 7 Enlarged view of the local structure at the location of the medium-short circuit;

[0032] Figure 9 This is a schematic diagram of a line defect detection device for a display panel provided in an embodiment of the present invention. Detailed Implementation

[0033] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0034] This invention provides a method for detecting line defects in a display panel, such as... Figure 1 and Figure 2 As shown, Figure 1 This is a schematic flowchart of a line defect detection method for a display panel provided in an embodiment of the present invention. Figure 2 This is a schematic diagram of a display panel provided in an embodiment of the present invention. The display panel includes a display area AA and a binding area B1 located on one side of the display area AA along a first direction Y; the display area AA includes multiple pixel driving circuit columns 115 extending along the first direction Y and arranged sequentially along a second direction X; the first direction Y intersects the second direction X, and optionally, the first direction Y and the second direction X can be set perpendicularly; the display area AA also includes data lines extending along the first direction Y (… Figure 2 (not shown in the image) and compensation signal lines ( Figure 2 (Not shown in the image); the data line is used to provide data signals to the corresponding pixel driving circuit; the compensation signal line is used to provide compensation signals to the corresponding pixel driving circuit and output the sensing signal of the corresponding pixel driving circuit;

[0035] Specifically, the method for detecting line defects in display panels includes the following steps:

[0036] Step S101: Divide the first pixel driving circuit column with line defects into N pixel driving circuit groups along the first direction; each pixel driving circuit group includes multiple pixel driving circuits; N is an integer greater than 1.

[0037] Figure 3 This is a schematic diagram of a pixel driving circuit provided in an embodiment of the present invention, with reference to... Figure 2 and Figure 3In this embodiment, among the multiple pixel driving circuit columns 115, those with line defects may have significantly lower brightness of their driven light-emitting elements 114 compared to those of other pixel driving circuit columns during the normal driving process of the display panel, resulting in a dark line in the display effect. Therefore, in this embodiment, the pixel driving circuit column that produces a dark line in the display effect can be referred to as the first pixel driving circuit column 112. The first pixel driving circuit column 112 is divided into N pixel driving circuit groups 111 along the first direction Y. Each pixel driving circuit group 111 includes multiple pixel driving circuits 113 arranged sequentially along the first direction Y, and each pixel driving circuit 113 provides driving current to its corresponding light-emitting element 114.

[0038] Step S102: Along the first direction from the display area to the binding area, the data lines and compensation signal lines connected to the first pixel driving circuit column are sequentially cut off at the positions between two adjacent pixel driving circuit groups.

[0039] Figure 4 This is a schematic diagram of another pixel driving circuit provided in an embodiment of the present invention, with reference to... Figure 3 and Figure 4 The data line Vdata and the compensation signal line Vref extend along the first direction Y. When cutting the data line Vdata and the compensation signal line Vref, the cutting of the data line Vdata and the compensation signal line Vref needs to be performed in a direction perpendicular to the first direction Y. The cutting position is between two adjacent pixel driving circuit groups 111. Figure 4 As shown in the figure, the cutting position 21 marked with "×" is the position cut between two adjacent pixel driving circuit groups.

[0040] Step S103: When the data line and compensation signal line between the i-th pixel driving circuit group and the (i+1)-th pixel driving circuit group are cut off, if the light-emitting element corresponding to the first pixel driving circuit column in the driving stage does not display a dark line, and / or the inductive line type defect detection signal in the defect detection stage is less than the detection threshold, then the defect location of the locked line defect is located in the i-th pixel driving circuit group; the inductive line type defect detection signal is the difference between the inductive signal before and after the set time period; 1≤i≤N-1; i is an integer.

[0041] Continue to refer to Figure 3 and Figure 4Optionally, the pixel driving circuit includes: a switching transistor T1, a driving transistor T2, a sensing transistor T3, and a storage capacitor Cst; the control terminal of the switching transistor T1 is connected to the scan signal SCAN; the first terminal of the switching transistor T1 is electrically connected to the corresponding data line Vdata; the second terminal of the switching transistor T1 is electrically connected to the control terminal of the driving transistor T2; the first terminal of the driving transistor T2 is connected to the first power signal EVDD; the second terminal of the driving transistor T2 is electrically connected to the first terminal of the corresponding light-emitting element 114; the second terminal of the light-emitting element 114 is connected to the second power signal EVSS; the first terminal of the storage capacitor Cst is electrically connected to the control terminal of the driving transistor T2; the second terminal of the storage capacitor Cst is electrically connected to the second terminal of the driving transistor T2; the control terminal of the sensing transistor T3 is connected to the control signal SENSE; sensing... The first terminal of transistor T3 is electrically connected to the second terminal of driving transistor T2; the second terminal of sensing transistor T3 is electrically connected to the corresponding compensation signal line Vref; the pixel driving circuit is configured such that: during the driving phase, switching transistor T1, driving transistor T2 and sensing transistor T3 are turned on, and the data signal input by data line Vdata and the compensation signal input by compensation signal line Vref control the light-emitting element 114 to emit light; during the driving phase, all transistors are turned on, driving the light-emitting element 114, and the compensation signal line Vref can output the driving current of the light-emitting element 114 to the controller. When the controller detects that the driving current of the light-emitting element 114 is different from that of the surrounding light-emitting elements, it can calculate and generate the corresponding compensation current, and transmit the compensation current to the first terminal of the light-emitting element 114 through the compensation signal line Vref and sensing transistor T3. When the data line Vdata and the compensation signal line Vref are not short-circuited, the data signal of the data line Vdata and the compensation signal input of the compensation signal line Vref jointly apply voltage to drive the light-emitting element 114. However, when the data line Vdata and the compensation signal line Vref are short-circuited, the voltage value detected by the second terminal of the sensing transistor T3 will increase. As a result, the compensation current transmitted from the compensation signal line Vref to the second terminal of the sensing transistor T3 will decrease. Consequently, when the display panel is driven normally, the compensation value of the compensation signal line Vref for the first pixel driving circuit column is lower than the compensation value of the surrounding pixel driving circuit columns. The resulting display effect is that the first pixel driving circuit column forms a dark line with a lower brightness than the surrounding pixel driving circuit columns.

[0042] During the defect detection phase, switching transistor T1, driving transistor T2, and sensing transistor T3 are turned off. In the first phase, the compensation signal line Vref inputs a charging signal to the second terminal of sensing transistor T3 to charge the second terminal of sensing transistor T3. In the second phase, the compensation signal line Vref outputs a sensing signal to detect the discharge state of the second terminal of sensing transistor T3, specifically detecting the rate of decrease of the sensing current at the second terminal of sensing transistor T3. If the data line Vdata and the compensation signal line Vref are short-circuited at this time, the sensing current output at the second terminal will decrease rapidly.

[0043] When cutting the data line and compensation signal line between the i-th pixel driving circuit group and the (i+1)-th pixel driving circuit group, firstly, the display panel needs to be controlled to enter the driving stage, and it needs to be determined whether the light-emitting element corresponding to the first pixel driving circuit column displays a dark line. It should be noted that the display of a dark line means that there is a short circuit between the data line Vdata and the compensation signal line Vref, and the disappearance of the dark line (increased display brightness) means that there is no short circuit between the data line Vdata and the compensation signal line Vref. Therefore, if when cutting the data line and compensation signal line between the (i-1)-th pixel driving circuit group and the i-th pixel driving circuit group, a dark line is detected on the light-emitting element corresponding to the first pixel driving circuit column, and when cutting the data line and compensation signal line between the i-th pixel driving circuit group and the (i+1)-th pixel driving circuit group, the dark line is detected to disappear, then the short circuit location can be determined to be within the i-th pixel driving circuit group.

[0044] Similarly, it is also necessary to control the display panel to enter the defect detection stage. The defect detection stage includes a first stage and a second stage. Specifically, in the first stage, a charging signal is input, and after charging is completed, the second stage is entered directly. That is, the compensation signal line Vref outputs a sensing signal. When the difference between the sensing signal before and after a set time period is large, or when the sensing current decreases significantly within the set time period, that is, when the sensing line defect detection signal (Sensing LD Detection, SLDD) is too large (greater than or equal to the detection threshold), it indicates that a short circuit exists. When the sensing line defect detection signal is less than the detection threshold, there is no short circuit. In this embodiment, if the sensing line defect detection signal is greater than or equal to the detection threshold when the data line and compensation signal line are cut to the position between the (i-1)th pixel driving circuit group and the ith pixel driving circuit group, and the sensing line defect detection signal is less than the detection threshold when the data line and compensation signal line are cut to the position between the ith pixel driving circuit group and the (i+1)th pixel driving circuit group, then the short circuit location can be determined to be within the ith pixel driving circuit group. In this embodiment, one of the two judgment conditions mentioned above can be selected to determine the location of the line defect, or both judgment conditions can be selected at the same time to enhance the accuracy of the final short circuit location determination.

[0045] Figure 5 This is a waveform diagram of the sensing signal provided in an embodiment of the present invention. Optionally, the time period is set to 50 seconds; the detection threshold is 450-500 mA. When there is a short circuit between the compensation signal line Vref and the data line Vdata, the difference in discharge level is used to determine the short circuit condition. In the first stage, all transistors are in the off state, and the charging voltage input to the second terminal of the sensing transistor T3 can be 3V (low). After charging, the second stage begins, and the induced current is detected after a certain period of time (every 5 seconds). A discharge curve is plotted. Figure 5 The diagram shows the discharge curve without a short circuit: the normal line; and the discharge curve with a short circuit: the defective line. The current drop in the defective line is greater than the current drop in the normal line. For example, when the difference in the sensed current is greater than 450mA within a set time period of 50 seconds, the discharge curve is a defective line, which can be defined as NG state. At this time, the compensation signal line Vref is short-circuited.

[0046] In this embodiment of the invention, the display panel includes a pixel driving circuit column extending along a first direction. If a pixel driving circuit column with a line defect exists, it can be designated as the first pixel driving circuit column. During the line defect detection process, the first pixel driving circuit column with the line defect is divided into N pixel driving circuit groups along the first direction. Each pixel driving circuit group includes multiple pixel driving circuits arranged along the first direction. Then, data lines and compensation signal lines between adjacent pixel driving circuit groups in the first pixel driving circuit column are sequentially cut from the side furthest from the bonding area. After cutting one data line and compensation signal line, the display panel is sequentially controlled to enter the driving stage and the defect detection stage. During the driving stage, it is detected whether the light-emitting element connected to the first pixel driving circuit column displays a dark line. During the defect detection stage, a induced line defect detection signal is acquired. Finally, if the light-emitting element corresponding to the first pixel driving circuit column does not display a dark line during the driving stage, or if the induced line defect detection signal during the defect detection stage is less than the detection threshold, the defect location of the line defect is determined to be in the i-th pixel driving circuit group. This embodiment can accurately locate the pixel drive circuit group where the line defect occurs, making it easier for subsequent staff to directly locate the short circuit position of the data line and compensation signal line from the pixel drive circuit group. This eliminates the need for staff to check each pixel drive circuit individually, improving the efficiency of line defect investigation, enhancing the accuracy of line defect location, and facilitating the tracing and analysis of the cause of the line defect.

[0047] The above is the core idea of ​​this invention. The technical solutions in the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0048] Based on the above embodiments, when the data line and compensation signal line between the (N-1)th pixel driving circuit group and the Nth pixel driving circuit group are cut off, if the light-emitting element corresponding to the first pixel driving circuit column displays a dark line, and / or the detection signal of poor line shape obtained according to the sensing signal is greater than or equal to the detection threshold, then the defect location of the locking line defect is located in the Nth pixel driving circuit group.

[0049] When the data line and compensation signal line are cut to the position between the (N-1)th pixel driving circuit group and the Nth pixel driving circuit group, if the light-emitting element corresponding to the first pixel driving circuit column in the driving stage does not display a dark line, and / or the induction line type defect detection signal in the defect detection stage is less than the detection threshold, then the defect location of the line defect is locked in the (N-1)th pixel driving circuit group. It is worth noting that if, when the data line and compensation signal line are cut to the position between the (N-1)th pixel driving circuit group and the Nth pixel driving circuit group, the light-emitting element corresponding to the first pixel driving circuit column still displays a dark line, or the induction line type defect detection signal is greater than or equal to the detection threshold, then the short circuit location is not in the (N-1)th pixel driving circuit group, but in the Nth pixel driving circuit group. In this embodiment, when the data line and compensation signal line are cut to the position between the (N-1)th pixel driving circuit group and the Nth pixel driving circuit group, the final location of the line defect can be determined as being in the (N-1)th pixel driving circuit group or the Nth pixel driving circuit group. The line defect detection method in this embodiment can quickly lock onto the specific pixel driving circuit group, improving the reliability of line defect detection.

[0050] Optionally, each pixel driving circuit group includes M pixel driving circuits; M is an integer greater than 1. In this embodiment, the first pixel driving circuit column can be evenly divided into N first pixel driving circuit columns along the first direction, that is, each group includes M pixel driving circuits, which improves the clarity of the pixel driving circuit group range and further improves the accuracy of short circuit position detection.

[0051] Optionally, before dividing the first pixel driving circuit column with line defects into N pixel driving circuit groups along the first direction, the method further includes: controlling the display panel to execute a driving phase, and acquiring the pixel driving circuit column in the display area whose corresponding light-emitting element is displayed as a dark line as the first pixel driving circuit column; the dark line is a display state where the display brightness of the light-emitting element corresponding to the pixel driving circuit column is lower than a brightness threshold. Optionally, the brightness threshold is the average brightness of the light-emitting element corresponding to the pixel driving circuit column without line defects in the current driving phase. In this embodiment, the dark line is a display state where the display brightness of the light-emitting element corresponding to the pixel driving circuit column is lower than the brightness threshold. The brightness threshold can be based on the average brightness of the light-emitting elements corresponding to other pixel driving circuit columns besides the first pixel driving circuit column in the current frame, or it can be other values ​​set by the controller that meet the line defect determination. This embodiment does not specifically limit this. In addition, the brightness threshold may not be set to the average brightness of the light-emitting element corresponding to the pixel driving circuit column without line defects. Instead, the value is taken as the brightness range of the light-emitting element corresponding to the pixel driving circuit column without line defects. For example, if the lowest brightness of the light-emitting element in the pixel driving circuit column without line defects is the first brightness value and the highest brightness is the second brightness value, then the brightness threshold can be the brightness range between the first brightness value and the second brightness value. In this case, the display brightness of the light-emitting element corresponding to the first pixel driving circuit column is lower than the above brightness range.

[0052] Optionally, when the data line and compensation signal line are cut to the position between the i-th pixel driving circuit group and the (i+1)-th pixel driving circuit group, if the light-emitting element corresponding to the first pixel driving circuit column in the driving phase does not display a dark line, and / or the sensing line type defect detection signal in the defect detection phase is less than the detection threshold, then the defect location of the locked line defect is located in the i-th pixel driving circuit group. This includes: when the data line and compensation signal line are cut to the set position of the i-th pixel driving circuit group, controlling the display panel to execute the driving phase and determining whether the light-emitting element corresponding to the first pixel driving circuit column displays a dark line; and controlling the display panel to execute the sensing phase and determining whether the sensing line type defect detection signal is less than the detection threshold; if the light-emitting element corresponding to the first pixel driving circuit column does not display a dark line, and / or the sensing line type defect detection signal is less than the detection threshold, then the specific location of the locked line defect is located in the i-th pixel driving circuit group. As can be seen from the above, in this embodiment, a driving phase and a sensing phase need to be executed once each time the data line and compensation signal line are cut to the position between two adjacent pixel driving circuit groups. During the driving phase, the entire display panel is driven normally to make the first pixel driving circuit column present bright or dark lines. During the sensing phase, the display panel is not driven normally. Instead, a charging signal is applied to the second terminal of the sensing transistor T3 in the first stage of the sensing phase, and the sensing signal is detected at the second terminal of the sensing transistor T3 in the second stage to determine whether the sensing line defect detection signal is less than the detection threshold. By using different detection methods in the two stages, the accuracy of line defect detection of the display panel is further enhanced.

[0053] Optionally, the location of the locking line defect is located after the i-th pixel driving circuit group, and further includes: locating the defect location in the i-th pixel driving circuit group to the short circuit position between the data line and the compensation signal line using a microscope; performing cross-sectional analysis of the short circuit position using focused ion beam technology and feeding it back to the controller. After determining the pixel driving circuit group where the final line defect is located, the pixel driving circuit group can be magnified using a microscope to pinpoint the specific location of the short circuit to the exact pixel driving circuit. Finally, performing cross-sectional analysis of the short circuit position using focused ion beam technology and feeding it back to the controller facilitates analysis of the cause of the short circuit and the film layer containing the impurities causing the short circuit, thereby improving the process of the film layer containing the impurities and preventing line defects from occurring in the manufacturing process.

[0054] Figure 6 This is a layout diagram of the pixel driving circuit provided in an embodiment of the present invention. Figure 7 for Figure 6 A magnified view of a portion of region C1 in the middle. Figure 8 for Figure 7 A magnified view of the partial structure of the short-circuit location C2. Optionally, the display area includes an array of pixel units; Figure 6 for Figure 4 The layout diagram of the pixel unit shows that the pixel unit includes a first pixel driving circuit 1131, a second pixel driving circuit 1132, a third pixel driving circuit 1133, and a fourth pixel driving circuit 1134 arranged along the second direction X. The first pixel driving circuit 1131 is used to drive the corresponding first color light-emitting element B; the second pixel driving circuit 1132 is used to drive the corresponding second color light-emitting element W; the third pixel driving circuit 1133 is used to drive the corresponding third color light-emitting element R; and the fourth pixel driving circuit 1134 is used to drive the corresponding fourth color light-emitting element G. The pixel units form a pixel unit column along the first direction Y. The same pixel unit column shares a data line (data line Vdata(B), data line Vdata(W), data line Vdata(R), and data line Vdata(G) can be time-division multiplexed). A data line Vdata is used to reduce the number of terminals on the driver chip of the display panel; a compensation signal line Vref is shared by the same pixel unit column; the line defect detection method of the display panel includes: dividing the first pixel unit column with line defects into N pixel unit groups along a first direction; along the first direction Y from the display area to the bonding area, sequentially cutting the data line Vdata and the compensation signal line Vref connected to the first pixel unit column at the position between two adjacent pixel unit groups; when the data line and the compensation signal line are cut to the position between the i-th pixel unit group and the (i+1)-th pixel unit group, if the light-emitting element corresponding to the first pixel unit column in the driving stage does not display a dark line, and / or the inductive line type defect detection signal in the defect detection stage is less than the detection threshold, then the defect position of the line defect is locked in the i-th pixel unit group. It should be noted that after the pixel unit C1 where the short circuit is located is determined by the microscopic device, it is necessary to further determine the pixel driving circuit where the short circuit is located. For example, after identifying the specific pixel unit group, microscopic analysis is performed. Using image processing, the 200 pixel driving circuits between groups are distinguished. By taking pictures and identifying them, the microscope images of the normal pixel driving circuits are compared. The abnormal area C2 identified by the comparison is saved and the magnification is confirmed. The short circuit location on the panel is automatically located.

[0055] Based on the same concept, embodiments of the present invention also provide a line defect detection device for a display panel, applicable to the line defect detection method for display panels provided in any embodiment of the present invention. Figure 9 A schematic diagram of a line defect detection device for a display panel provided in an embodiment of the present invention includes: a controller 331 and a laser cutting device 332;

[0056] The controller 331 is used to divide the first pixel driving circuit column with line defects into N pixel driving circuit groups along a first direction; each pixel driving circuit group includes multiple pixel driving circuits; N is an integer greater than 1;

[0057] The laser cutting device 332 is electrically connected to the controller 331 and is used to sequentially cut the data lines and compensation signal lines connected to the first pixel driving circuit column at the positions between two adjacent pixel driving circuit groups along the first direction from the display area to the binding area.

[0058] The controller is also used to, when the laser cutting device cuts the data line and compensation signal line at the position between the i-th pixel driving circuit group and the (i+1)-th pixel driving circuit group, obtain that the light-emitting element corresponding to the first pixel driving circuit column in the driving stage does not display a dark line, and / or, the inductive line type defect detection signal in the defect detection stage is less than the detection threshold, and thereby lock the defect position of the line defect to be located in the i-th pixel driving circuit group; the inductive line type defect detection signal is the difference between the inductive signal before and after the set time period; 1≤i≤N-1; i is an integer.

[0059] In this embodiment, the display panel includes a pixel driving circuit column extending along a first direction. A pixel driving circuit column with a line defect can be designated as the first pixel driving circuit column. During line defect detection, the first pixel driving circuit column with the line defect is divided into N pixel driving circuit groups along the first direction. Each pixel driving circuit group includes multiple pixel driving circuits arranged along the first direction. Then, data lines and compensation signal lines between adjacent pixel driving circuit groups in the first pixel driving circuit column are sequentially cut from the side furthest from the bonding area. After cutting one data line and compensation signal line, the display panel is sequentially controlled to enter the driving stage and the defect detection stage. During the driving stage, it is detected whether the light-emitting element connected to the first pixel driving circuit column displays a dark line. During the defect detection stage, a induced line defect detection signal is acquired. Finally, if the light-emitting element corresponding to the first pixel driving circuit column does not display a dark line during the driving stage, or if the induced line defect detection signal during the defect detection stage is less than the detection threshold, the defect location of the line defect is determined to be in the i-th pixel driving circuit group. This embodiment can accurately locate the pixel drive circuit group where the line defect occurs, making it easier for subsequent staff to directly locate the short circuit position of the data line and compensation signal line from the pixel drive circuit group. This eliminates the need for staff to check each pixel drive circuit individually, improving the efficiency of line defect investigation, enhancing the accuracy of line defect location, and facilitating the tracing and analysis of the cause of the line defect.

[0060] The line defect detection device in this embodiment includes the technical features of the line defect detection method of any embodiment of the present invention, and has the beneficial effects of the technical features, which will not be repeated here.

[0061] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

Claims

1. A method for detecting line defects in a display panel, characterized in that, The display panel includes a display area and a bonding area located on one side of the display area along a first direction; the display area includes multiple rows of pixel driving circuits extending along the first direction and arranged sequentially along a second direction; the first direction and the second direction intersect; the display area also includes data lines and compensation signal lines extending along the first direction; the data lines are used to provide data signals to the corresponding pixel driving circuits; the compensation signal lines are used to provide compensation signals to the corresponding pixel driving circuits and output sensing signals corresponding to the pixel driving circuits; The method for detecting line defects in the display panel includes: The first pixel driving circuit column with line defects is divided into N pixel driving circuit groups along the first direction; each pixel driving circuit group includes multiple pixel driving circuits; N is an integer greater than 1; Along the first direction from the display area to the binding area, the data lines and compensation signal lines connected by the first pixel driving circuit column are sequentially cut off at the positions between two adjacent pixel driving circuit groups; When the data line and the compensation signal line are cut off at the position between the i-th pixel driving circuit group and the (i+1)-th pixel driving circuit group, if the light-emitting element corresponding to the first pixel driving circuit column in the driving stage does not display a dark line, and / or the inductive line type defect detection signal in the defect detection stage is less than the detection threshold, then the defect position of the locked line defect is located in the i-th pixel driving circuit group; the inductive line type defect detection signal is the difference between the inductive signal before and after a set time period; 1≤i≤N-1; i is an integer.

2. The method for detecting line defects in a display panel according to claim 1, characterized in that, When the data line and the compensation signal line are cut at the position between the (N-1)th pixel driving circuit group and the Nth pixel driving circuit group, if the light-emitting element corresponding to the first pixel driving circuit column displays a dark line, and / or the detection signal of poor line shape obtained according to the sensing signal is greater than or equal to the detection threshold, then the defect position of the locking line defect is located in the Nth pixel driving circuit group.

3. The method for detecting line defects in a display panel according to claim 1, characterized in that, The set time period is 50 seconds; the detection threshold is 450-500 mA.

4. The method for detecting line defects in a display panel according to claim 1, characterized in that, The pixel driving circuit includes: a switching transistor, a driving transistor, a sensing transistor, and a storage capacitor; The control terminal of the switching transistor is connected to a scan signal; the first terminal of the switching transistor is electrically connected to the corresponding data line; the second terminal of the switching transistor is electrically connected to the control terminal of the driving transistor; the first terminal of the driving transistor is connected to a first power signal; the second terminal of the driving transistor is electrically connected to the first terminal of the corresponding light-emitting element; the second terminal of the light-emitting element is connected to a second power signal; the first terminal of the storage capacitor is electrically connected to the control terminal of the driving transistor; the second terminal of the storage capacitor is electrically connected to the second terminal of the driving transistor. The control terminal of the sensing transistor is connected to a control signal; the first terminal of the sensing transistor is electrically connected to the second terminal of the driving transistor; the second terminal of the sensing transistor is electrically connected to the corresponding compensation signal line. The pixel driving circuit is configured as follows: During the driving phase, the switching transistor, driving transistor, and sensing transistor are turned on, and the data signal input by the data line and the compensation signal input by the compensation signal line control the light-emitting element to emit light. During the defect detection phase, the switching transistor, driving transistor, and sensing transistor are turned off; in the first phase, the compensation signal line inputs a charging signal to the second terminal of the sensing transistor; in the second phase, the compensation signal line outputs a sensing signal.

5. The method for detecting line defects in a display panel according to claim 1, characterized in that, Before dividing the first pixel driving circuit column with line defects into N pixel driving circuit groups along the first direction, the method further includes: The display panel is controlled to perform the driving phase, and the pixel driving circuit column in the display area whose corresponding light-emitting element is displayed as a dark line is obtained as the first pixel driving circuit column; the dark line is the display state in which the display brightness of the light-emitting element corresponding to the pixel driving circuit column is lower than the brightness threshold.

6. The method for detecting line defects in a display panel according to claim 5, characterized in that, The brightness threshold is the average brightness of the light-emitting elements corresponding to the pixel driving circuit column that does not have line defects in the current driving stage.

7. The method for detecting line defects in a display panel according to claim 1, characterized in that, When the data line and the compensation signal line are cut at the position between the i-th pixel driving circuit group and the (i+1)-th pixel driving circuit group, if the light-emitting element corresponding to the first pixel driving circuit column in the driving phase does not display a dark line, and / or the inductive line type defect detection signal in the defect detection phase is less than the detection threshold, then the defect location of the locked line defect is located in the i-th pixel driving circuit group, including: When the data line and the compensation signal line to the set position of the i-th pixel driving circuit group are cut off, the display panel is controlled to perform the driving phase, and it is determined whether the light-emitting element corresponding to the first pixel driving circuit column displays a dark line; and the display panel is controlled to perform the sensing phase, and it is determined whether the sensing line shape defect detection signal is less than the detection threshold. If the light-emitting element corresponding to the first pixel driving circuit column does not display a dark line, and / or the detection signal for poor line shape is less than the detection threshold, then the specific location of the locked line defect is located in the i-th pixel driving circuit group.

8. The method for detecting line defects in a display panel according to claim 1, characterized in that, The location of the locking line defect is after the i-th pixel driving circuit group, and also includes: The defect location in the i-th pixel driving circuit group was located to the short circuit location between the data line and the compensation signal line using a microscopic device. The short-circuit location is analyzed by cross-section analysis using focused ion beam technology and fed back to the controller.

9. The method for detecting line defects in a display panel according to claim 8, characterized in that, The display area includes pixel units arranged in an array; the pixel unit includes a first pixel driving circuit, a second pixel driving circuit, a third pixel driving circuit, and a fourth pixel driving circuit arranged along a second direction; The first pixel driving circuit is used to drive the corresponding first color light-emitting element; The second pixel driving circuit is used to drive the corresponding second color light-emitting element; The third pixel driving circuit is used to drive the corresponding third color light-emitting element; The fourth pixel driving circuit is used to drive the corresponding fourth color light-emitting element; The pixel units form a pixel unit column along the first direction; The same pixel unit column shares a common data line; A single compensation signal line is shared by the same column of pixel units; The method for detecting line defects in the display panel includes: The first pixel unit column with line defects is divided into N pixel unit groups along the first direction; Along the first direction from the display area to the binding area, the data lines and compensation signal lines connecting the first pixel unit column are sequentially cut at the positions between two adjacent pixel unit groups; When the data line and the compensation signal line are cut at the position between the i-th pixel unit group and the (i+1)-th pixel unit group, if the light-emitting element corresponding to the first pixel unit column in the driving stage does not display a dark line, and / or the inductive line defect detection signal in the defect detection stage is less than the detection threshold, then the defect position of the locked line defect is located in the i-th pixel unit group.

10. A line defect detection device for a display panel, characterized in that, A method for detecting line defects in a display panel according to any one of claims 1-9, comprising: a controller and a laser cutting device; The controller is used to divide the first pixel driving circuit column with line defects into N pixel driving circuit groups along the first direction; each pixel driving circuit group includes multiple pixel driving circuits; N is an integer greater than 1; The laser cutting device is electrically connected to the controller and is used to sequentially cut the data lines and compensation signal lines connected to the first pixel driving circuit group at the positions between two adjacent pixel driving circuit groups along the first direction from the display area to the binding area. The controller is further configured to, when the laser cutting device cuts the data line and the compensation signal line at the position between the i-th pixel driving circuit group and the (i+1)-th pixel driving circuit group, obtain that the light-emitting element corresponding to the first pixel driving circuit group in the driving stage does not display a dark line, and / or, the inductive line type defect detection signal in the defect detection stage is less than the detection threshold, and thereby lock the defect position of the line defect to be located in the i-th pixel driving circuit group; the inductive line type defect detection signal is the difference between the inductive signal before and after a set time period; 1≤i≤N-1; i is an integer.

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