Method and device for detecting display panel

Abstract

A method of detecting a display panel and an apparatus for detecting a display panel are provided. The method includes: obtaining luminance data by measuring, over time, luminance of a display area of a display panel to which an input signal including a plurality of pulses is applied; obtaining a pair of a first-order difference value with respect to time and a second-order difference value with respect to time from the luminance data or from a graph in which luminance corresponding to the luminance data varies over time; obtaining a pair-based response map by setting one of the x-axis and the y-axis as an axis of a first-order differential value with respect to time and setting the other as an axis of a second-order differential value with respect to time; and determining whether the display panel is normal according to the response diagram.

Description

[0001] Cross-reference with related applications

[0002] This application claims priority and benefit to Korean Patent Application No. 10-2024-0107087, filed with the Korean Intellectual Property Office on August 9, 2024, the entire disclosure of which is incorporated herein by reference. Technical Field

[0003] One or more embodiments relate to methods and apparatus for detecting a display panel and an electronic device including the display panel, and more specifically, to methods and apparatus for detecting a display panel that allow for rapid determination of whether the display panel is functioning properly. Background Technology

[0004] Typically, a display panel includes a display area for displaying images. Numerous pixels are arranged within this display area, and when the pixels include defective pixels, the quality of the image displayed by the display panel will inevitably deteriorate. Therefore, during the manufacturing process of a display panel, a process is required to determine whether the display area is functioning correctly. Summary of the Invention

[0005] However, existing methods and apparatus for testing display panels require a significant amount of time to acquire and analyze the data used for testing.

[0006] To address the various problems including those mentioned above, one or more embodiments of this disclosure provide a method and apparatus for detecting a display panel, wherein it can be quickly determined whether the display panel is functioning properly. However, such technical problems are exemplary, and this disclosure is not limited thereto.

[0007] Additional aspects will be set forth in part in the description which follows, and will be apparent in part from the description, or may be learned by practicing embodiments of the present disclosure.

[0008] According to one or more embodiments, a method for detecting a display panel includes: obtaining brightness data by measuring the brightness of a display area of ​​the display panel to which an input signal comprising multiple pulses is applied over time; obtaining a pair of first-order difference values ​​and second-order difference values ​​relative to time from the brightness data or from a graph of brightness changes over time corresponding to the brightness data; obtaining a response graph based on the pair by setting one of the x-axis and y-axis as the axis of the first-order difference value relative to time and the other as the axis of the second-order difference value relative to time; and determining whether the display panel is functioning properly based on the response graph.

[0009] This determination may include determining whether the display panel is functioning correctly based on the internal area of ​​the response map.

[0010] This determination can include identifying a display panel malfunction when the internal area of ​​the response graph is greater than a preset value.

[0011] This determination may include identifying a display panel malfunction when the maximum width of the response graph in the x-axis direction exceeds a preset value.

[0012] This determination may include identifying a display panel malfunction when the maximum width of the response graph in the y-axis direction exceeds a preset value.

[0013] This determination may include identifying a display panel malfunction when the maximum value of the response graph in the x-axis direction is greater than a preset maximum value or when the minimum value of the response graph in the x-axis direction is less than a preset minimum value.

[0014] This determination may include identifying a display panel malfunction when the maximum value of the response graph in the y-axis direction is greater than a preset maximum value or when the minimum value of the response graph in the y-axis direction is less than a preset minimum value.

[0015] Obtaining the pair may include inputting luminance data into a differential circuit unit.

[0016] According to one or more embodiments, an apparatus for detecting a display panel includes: an input signal application unit configured to apply an input signal comprising a plurality of pulses to the display panel; a brightness measurement unit configured to measure the brightness of a display area of ​​the display panel over time; and a differential circuit unit configured to differentially analyze the time-varying brightness data obtained by the brightness measurement unit relative to time, wherein whether the display panel is functioning correctly is determined by a pair of first-order differential values ​​relative to time and second-order differential values ​​relative to time of the time-varying brightness data obtained by the brightness measurement unit, the pair being obtained by the differential circuit unit.

[0017] The response graph can be obtained by setting one of the x-axis and y-axis to a first-order difference value relative to time and the other to a second-order difference value relative to time, where the functionality of the display panel can be determined based on the response graph.

[0018] Whether the display panel is functioning properly can be determined based on the internal area of ​​the response graph.

[0019] When the internal area of ​​the response graph is greater than a preset value, the display panel can be identified as abnormal.

[0020] When the maximum width of the response graph in the x-axis direction is greater than a preset value, the display panel can be identified as abnormal.

[0021] When the maximum width of the response graph in the y-axis direction is greater than a preset value, the display panel can be identified as abnormal.

[0022] The display panel can be identified as abnormal when the maximum value of the response graph in the x-axis direction is greater than the preset maximum value or when the minimum value of the response graph in the x-axis direction is less than the preset minimum value.

[0023] The display panel can be identified as abnormal when the maximum value of the response graph in the y-axis direction is greater than the preset maximum value or when the minimum value of the response graph in the y-axis direction is less than the preset minimum value. Attached Figure Description

[0024] The above and other aspects and features of specific embodiments of the present disclosure will become more apparent from the following description taken in conjunction with the accompanying drawings, in which:

[0025] Figure 1 This is a schematic block diagram of an electronic device according to an embodiment;

[0026] Figure 2 This is a schematic diagram of an electronic device according to an embodiment;

[0027] Figure 3 This is a schematic diagram illustrating an example of a wearable electronic device as an electronic device according to an embodiment;

[0028] Figure 4 This is a schematic diagram illustrating an example of a vehicle electronic device as an electronic device according to an embodiment;

[0029] Figure 5 This is a schematic plan view of the display panel to be tested;

[0030] Figure 6 Based on enabling Figure 5 A graph showing how the brightness of the red subpixels of the display panel changes over time, based on the data obtained from their illumination.

[0031] Figure 7 Is using Figure 6 The response graph obtained from the chart;

[0032] Figure 8 Based on enabling Figure 5 A graph showing how the brightness of the green subpixels of the display panel changes over time, based on the data obtained by the light emission of the pixels.

[0033] Figure 9 Is using Figure 8 The response graph obtained from the chart;

[0034] Figure 10 Based on enabling Figure 5 A graph showing how the brightness of the blue subpixels of the display panel changes over time, based on the data obtained by the light emission of these subpixels.

[0035] Figure 11 Is using Figure 10 The response graph obtained from the chart;

[0036] Figure 12 This is a schematic block diagram of an apparatus for detecting a display panel according to one or more embodiments; and

[0037] Figure 13 It shows that it can be included in Figure 12 The circuit diagram of the differential circuit unit in the device. Detailed Implementation

[0038] Reference will now be made in detail to embodiments, examples of which are illustrated in the accompanying drawings, wherein the same reference numerals always refer to the same elements. In this respect, embodiments may take different forms and should not be construed as limited to the description set forth herein. Therefore, embodiments are described below only by reference to the accompanying drawings to explain aspects of this disclosure. As used herein, the term “and / or” includes any and all combinations of one or more of the items listed. Throughout this disclosure, the expression “at least one of a, b, and c” indicates only a, only b, only c, both a and b, both a and c, both b and c, all of a, b, and c, or variations thereof.

[0039] Because this disclosure allows for various modifications and numerous embodiments, specific embodiments will be illustrated in the accompanying drawings and described in the written description. The effects and features of one or more embodiments, as well as methods of implementing them, will become apparent from the following detailed disclosure of one or more embodiments in conjunction with the accompanying drawings. However, embodiments of this disclosure may take different forms and should not be construed as limited to the description set forth herein.

[0040] One or more embodiments will now be described in more detail with reference to the accompanying drawings. Elements that are the same or corresponding to each other are given the same reference numerals, regardless of the drawing number, and redundant descriptions of elements that are the same or corresponding to each other are omitted.

[0041] It will be understood that when an element such as a layer, film, region, or plate is referred to as being "on" another element, the element may be "directly" on the other element, or an intermediate element may exist between the element and the other element. Furthermore, for ease of explanation, the dimensions of the elements in the figures may be exaggerated or reduced. For example, because the dimensions and thicknesses of the elements in the figures are arbitrarily illustrated for ease of description, the following embodiments are not limited thereto.

[0042] The x-axis, y-axis, and z-axis are not limited to the three axes of a Cartesian coordinate system, but can be interpreted in a broader sense. For example, the x-axis, y-axis, and z-axis can be perpendicular to each other, or they can represent different directions that are not perpendicular to each other.

[0043] While terms such as "first" and "second" can be used to describe various elements, such elements are not necessarily limited to these terms. These terms are only used to distinguish one element from another.

[0044] It will be further understood that the terms “comprising,” “including,” and “having” as used herein indicate the presence of the stated features or elements, but do not preclude the addition of one or more other features or elements.

[0045] As used herein, the expression "A and / or B" refers to A, B, or A and B. Furthermore, the expression "at least one of A and B" refers to A, B, or A and B.

[0046] It will be further understood that when layers, regions, or elements are referred to as being connected to each other, they can be directly connected to each other, or they can be indirectly connected to each other with intermediate layers, regions, or elements between them. For example, when layers, regions, or elements are referred to as being electrically connected to each other, they can be directly electrically connected to each other, or they can be indirectly electrically connected to each other with intermediate layers, regions, or elements between them.

[0047] In view of the entire contents of this disclosure, those skilled in the art will understand that each suitable feature of the various embodiments of this disclosure may be combined in part or in whole, or combined with each other, and may be technically interlocked and operated in a variety of suitable ways, and each embodiment may be implemented independently of each other or in combination with each other in any suitable way, unless otherwise stated or implied.

[0048] Figure 1 It includes a display panel 10 with the object to be tested (see...) Figure 5 This is a schematic block diagram of the electronic device 1, which includes the display module 10'. The electronic device 1 may be a display device, or it may further include modules with additional functions other than those of the display module 10'.

[0049] like Figure 1 As shown, the electronic device 1 may include a display module 10', a processor 51, a memory 52, a power module 54, an input module 55, an output module 56, and a communication module 57.

[0050] Display module 10' may include display panel 10 as described below. As an example, display module 10' may include display panel 10 and driver chip 20 mounted on display panel 10, etc. Display panel 10 is described below.

[0051] Processor 51 can control most of the components of electronic device 1. As an example, processor 51 can output digital video data to display module 10', causing display module 10' to display an image, and can receive input data from input module 55 to allow functions corresponding to the relevant data to be executed by electronic device 1. Processor 51 may include at least one of a central processing unit (CPU), application processor (AP), graphics processing unit (GPU), communication processor (CP), image signal processor (ISP), and controller.

[0052] When needed, processor 51 can be divided into two or more parts from a functional or structural perspective. As an example, processor 51 may include a main processor in the form of a first driver chip containing a central processing unit and an auxiliary processor in the form of a second driver chip that is part of display module 10'. The auxiliary processor in the form of the second driver chip may include a controller that receives image signals from the main processor and processes the image signals to match the interface specifications of the display panel 10 included in display module 10'.

[0053] The memory 52 may include at least one of non-volatile memory and volatile memory. The memory 52 may store data information required for the operation of the processor 51 or the display module 10'. When the processor 51 executes the application stored in the memory 52, image data signals and / or input control signals may be transmitted to the display module 10', and the display module 10' may process the provided signals and output image information.

[0054] The power module 54 may include a power module such as a power adapter or battery cell, and a power conversion module that converts the power supplied by the power module to generate the power required for the operation of the electronic device 1. The power conversion by the power conversion module may include DC-DC conversion, AC-DC conversion, or DC-AC conversion. However, this disclosure is not limited thereto.

[0055] Input module 55 can provide input information to processor 51 and / or display module 10'. Input module 55 may include not only physical buttons, keyboards, and microphones, but also various types of sensor modules. Examples of sensor modules may include touch sensors, pressure sensors, proximity sensors, position sensors, digitizers, motion recognition sensors, camera sensors, light receiving sensors, photoelectric conversion sensors, and / or temperature sensors. Furthermore, sensor modules may include biometric sensors such as blood pressure sensors, blood glucose sensors, electrocardiogram sensors, and / or heart rate sensors.

[0056] Output module 56 can receive information other than the image received from processor 51 and can provide that information to the user. Output module 56 may include, for example, a sound module, a tactile module, and / or a light-emitting module. Furthermore, output module 56 may include functional modules specific to electronic device 1, such as a cooling module for a refrigerator.

[0057] For reference, display module 10' can also be responsible for output functions. As an example, the display panel 10 included in display module 10' can display (output) information processed by electronic device 1. As an example, display panel 10 can display execution screen information, user interface (UI), or graphical user interface (GUI) information corresponding to the execution screen information of an application driven by electronic device 1. Display panel 10 may include a display layer and a touchscreen layer, wherein the display layer displays images and the touchscreen layer senses user touch input. Therefore, display panel 10 can serve as part of the input module 55 providing an input interface between electronic device 1 and the user, and simultaneously as part of the output module 56 providing an output interface between electronic device 1 and the user.

[0058] The communication module 57 is responsible for transmitting / receiving information between the electronic device 1 and external devices, and may include a receiver and a transmitter. The communication module 57 may include various types of wireless communication modules or various types of wired communication modules, such as mobile communication modules, broadcast receiving modules, wireless internet modules, short-range communication modules, Wi-Fi modules and / or Bluetooth modules.

[0059] Figure 1 The electronic device 1 shown is merely an example. As an example, a display device without communication functionality may not include the communication module 57. Furthermore, when electronic device 1 includes a display device, at least one of the elements of electronic device 1 may be included in the display device. Additionally, some modules that are functionally included in a single module may be included in the display device, while others may be included separately from the display device in electronic device 1. As an example, the display device may include a display module 10', and the processor 51, memory 52, and power module 54 may be elements of electronic device 1, rather than elements of the display device. Alternatively, the display device may include a display module 10' and a power module 54, and the power module 54 may supply power to elements such as the processor 51 and memory 52 of electronic device 1. However, various modifications are possible.

[0060] Figure 2 This is a schematic diagram of electronic device 1. Figure 2Examples of electronic devices 1 include a smartphone 1_1a, a tablet PC 1_1b, a laptop computer 1_1c, a TV 1_1d, and a desktop monitor 1_1e.

[0061] The smartphone 1_1a may include not only a processor 51, a memory 52, a power module 54, and a display module 10', but also an input module 55 such as a touch sensor and a communication module 57. The smartphone 1_1a can process information received through the communication module 57 or other input modules and display the information through the display module 10'.

[0062] Similar to the smartphone 1_1a, the tablet PC 1_1b, laptop computer 1_1c, TV 1_1d and / or desktop monitor 1_1e may include a display module 10' and an input module 55, and may include a communication module 57 as appropriate.

[0063] Figure 3 This is a schematic diagram showing the case where electronic device 1 is a wearable electronic device. Figure 3 Examples of electronic devices 1 include smart glasses 1_2a, head-mounted displays 1_2b, and smartwatches 1_2c.

[0064] The smart glasses 1_2a and the head-mounted display 1_2b may include a display module 10' for displaying images and a reflector for reflecting light from the display surface of the display module 10' and providing the image to the user's eyes. The user can use the electronic device 1 to experience virtual reality or augmented reality.

[0065] The smartwatch 1_2c may include a biometric sensor as an input module 55 and provide the user with the biometric information identified by the biometric sensor through the display module 10'.

[0066] Figure 4 This is a schematic diagram illustrating the case where electronic device 1 is vehicle electronic device 1_3. For example... Figure 4 As shown, the vehicle electronic device 1_3 may be included in the vehicle's dashboard or central instrument panel, or may be a central information display (CID) installed on the vehicle's dashboard or an in-vehicle rearview mirror display instead of a rearview mirror.

[0067] However, the electronic device 1 is not limited thereto. As an example, the electronic device 1 may include not only display-centric devices (such as billboards, electronic boards, and / or game consoles), but also various household appliances that display information via the display module 10', such as refrigerators, washing machines, dryers, air conditioners, and / or robotic vacuum cleaners. Furthermore, where the display module 10' has a light-transmitting function, the electronic device 1 may be a smart window or a transparent display device that displays a background and, together with, an image. However, the electronic device 1 according to this disclosure is not limited thereto. Any electronic device can fall within the scope of this disclosure as long as the electronic device 1 includes the display panel 10 described below.

[0068] Figure 5 This is a schematic plan view of the display panel 10 to be tested. The display panel 10 to be tested can be the final product of a display device, or it can be part of another display device. In the latter case, the display device can be any device that includes the display panel 10. For example, the display device can be any of a variety of products such as smartphones, tablet computers, laptop computers, televisions, billboards, vehicle dashboards, and vehicle display devices.

[0069] The display panel 10 may include a display area DA in which a plurality of pixels are arranged, and a peripheral area PA outside the display area DA along the edge or periphery of the display area DA. This can be understood to mean that the substrate 100 of the display panel 10 includes the display area DA and the peripheral area PA.

[0070] The peripheral area PA includes the pad area PADA to which electronic components such as driver chip 20 or printed circuit board (PCB) are electrically attached. Additionally, the scan driver SD, common voltage input line CPIL, common voltage supply line 11, drive voltage input line DPIL, and drive voltage supply line 13 can also be arranged in the peripheral area PA. Various wiring, including the clock signal line CKL to be input to the scan driver SD, can also pass through the peripheral area PA.

[0071] The driver chip 20 may include an integrated circuit (IC) configured to drive the display panel 10. The integrated circuit may be a data driver integrated circuit configured to generate data signals, but this disclosure is not limited thereto. The substrate 100 may include a first edge E1 and a second edge E2 extending generally in a first direction (y-axis direction) and facing each other, and may also include a third edge E3 and a fourth edge E4 extending generally in a second direction (x-axis direction) intersecting the first direction and connecting the first edge E1 and the second edge E2 to each other. The driver chip 20 may be mounted in the peripheral region PA adjacent to the fourth edge E4 of the substrate 100.

[0072] For reference only. Figure 5This can also be understood as a plan view of the substrate 100, etc., during the manufacturing process. In the final manufactured display device or electronic device including the display device (such as a smartphone), a portion of the substrate 100, etc., can be bent to reduce the area of ​​the peripheral area PA that is recognized by the user. For example, the peripheral area PA may include a bending area BA such that the bending area BA is located between the pad area PADA and the main display area. In this case, the substrate 100 can be bent in the bending area BA, and therefore, the first area A1 on one side of the bending area BA and the second area A2 on the other side of the bending area BA can overlap each other.

[0073] For example, the substrate 100 can be bent in the bending region BA, and therefore, at least a portion of the pad area PADA of the second region A2, in which the display area DA is placed, can overlap with the first region A1, in which the display area DA is placed. In this case, the bending direction is set so that the pad area PADA is placed behind the display area DA, etc. Therefore, the user perceives the display area DA as occupying most of the display device. Although the driver chip 20 described above is mounted on the same surface as the display surface of the display area DA, when the display panel 10 is bent in the bending region BA, the driver chip 20 can be placed in the rear direction of the display area DA.

[0074] The substrate 100 may comprise various materials having flexible or bendable properties, and for example, may comprise polymer resins such as polyethersulfone, polyacrylate, polyetherimide, polyethylene naphthalate, polyethylene terephthalate, polyphenylene sulfide, polyarylate, polyimide, polycarbonate, and / or cellulose acetate propionate. The substrate 100 may be modified in various ways, for example, to have a multilayer structure comprising two layers containing the aforementioned polymer resins and a barrier layer between the two layers containing an inorganic material (such as silicon oxide, silicon nitride, and / or silicon oxynitride). Furthermore, when the substrate 100 is not bendable, the substrate 100 may comprise glass.

[0075] The edge of the display area DA can have an overall shape similar to a rectangle or a square. Therefore, the substrate 100 can also have an overall shape similar to a rectangle or a square. If needed, the edge of the display area DA can have a shape such as a circle, an ellipse, or other polygons.

[0076] As described above, substrate 100 may include a first edge E1 and a second edge E2 extending generally in a first direction (y-axis direction) and facing each other, and may also include a third edge E3 and a fourth edge E4 extending generally in a second direction (x-axis direction) intersecting the first direction and connecting the first edge E1 and the second edge E2 to each other. The pad area PADA may be the area in the peripheral area PA of substrate 100 adjacent to the fourth edge E4. If desired, substrate 100 may have bent portions between the first edge E1 and the fourth edge E4 and between the second edge E2 and the fourth edge E4, and thus substrate 100, etc., can be easily bent in the bent area BA. Therefore, as Figure 5 As shown, the width of the substrate 100 in the second region A2 in the second direction (x-axis direction) may be smaller than the width of the substrate 100 in the first region A1 in the second direction (x-axis direction).

[0077] Although the following description, by way of example, illustrates a case where the display panel 10 to be detected includes an organic light-emitting device, the display panel 10 to which the method for detecting the display panel is objected according to this disclosure is not limited thereto. For example, the display panel 10 may include an inorganic light-emitting device, or may include display elements such as quantum dot light-emitting devices. For example, the emitting layer of the display element of the display panel 10 may include an organic or inorganic material. Alternatively, the display panel 10 may include an emitting layer and quantum dots placed in the path of light emitted from the emitting layer.

[0078] Multiple pixels are arranged in the display area DA. Each pixel refers to a subpixel and may include a display element such as an organic light-emitting diode (OLED) and pixel circuitry electrically connected to the display element. Pixels may emit, for example, red, green, blue, or white light. Pixels may be electrically connected to external circuitry arranged in the peripheral area PA. Scan driver SD, common voltage supply line 11, and drive voltage supply line 13 may be arranged in the peripheral area PA.

[0079] The scan driver SD can extend along the first edge E1 of the substrate 100. The scan driver SD can provide scan signals to the pixels via scan lines extending into the display area DA in a second direction (x-axis direction). The scan driver SD can also be placed along the second edge E2 of the substrate 100. In this case, some of the pixels arranged in the display area DA can be electrically connected to the scan driver SD near the first edge E1, while other pixels can be electrically connected to the scan driver SD near the second edge E2. Alternatively, instead of the scan driver SD, an emission control driver can be placed near the second edge E2 of the substrate 100 to provide emission control signals, etc., to the pixels via emission control lines that are substantially parallel to the scan lines.

[0080] Multiple pads can be arranged in the pad area PADA of the display panel 10. These pads may not be covered by an insulating layer, but rather exposed and electrically connected to the printed circuit board (PCB). In other words, the pads of the printed circuit board (PCB) can be electrically connected to multiple pads of the display panel 10.

[0081] The display panel 10 can be tested without the printed circuit board (PCB) being electrically connected to the multiple pads of the display panel 10. That is, after the display panel 10 is tested, the PCB can be electrically connected to the multiple pads of the display panel 10. If necessary, testing can be performed with the PCB attached to the display panel 10. The following describes the case where the display panel 10 is tested without the PCB being electrically connected to the multiple pads of the display panel 10.

[0082] To test the display panel 10, an input signal in the form of a repetitive pulse can be applied to the display area DA via the data line DL. Therefore, a control signal for the same purpose can be applied to the driver chip 20. This can be performed by allowing such a control signal to be input via multiple pads in the pad area PADA. Alternatively, when the display panel 10 is tested before the driver chip 20 is attached to the display panel 10, the input signal in the form of a repetitive pulse can be applied to the display area DA via the data line DL using test pads electrically connected to the data line DL. This can be performed by allowing the input signal in the form of a repetitive pulse to be transmitted to the data line DL via the test pads. For example, the test pads can be placed in the area where the driver chip 20 is attached.

[0083] For this type of detection, the relevant electrical signals can also be applied to the scan drive SD, etc. Figure 5 The clock signal line CKL is shown, configured to receive a clock signal via a pad and transmit the clock signal to the scan driver SD. In some cases, the clock signal line CKL can be configured to receive a clock signal from the driver chip 20 and transmit the clock signal to the scan driver SD.

[0084] Furthermore, a common voltage can be supplied to the common electrode of the organic light-emitting device in the display area DA via the common voltage input line CPIL to the common voltage supply line 11. Additionally, a driving voltage can be supplied to the driving voltage supply line 13 via the driving voltage input line DPIL, and therefore, the driving voltage can be supplied to the pixel circuitry in the display area DA via a driving voltage line extending from the driving voltage supply line 13 into the display area DA in the first direction (y-axis direction). For reference, the common voltage supply line 11 may have an annular shape with an open side in the direction of the fourth edge E4, and may have a shape extending along the first edge E1, the third edge E3, and the second edge E2.

[0085] Figure 6 Based on enabling Figure 5 The display panel 10 displays a graph showing the brightness of its red subpixels as they emit light, representing a change in brightness over time. Figure 6 In the diagram, the horizontal axis represents time, measured in microseconds (μs), and the vertical axis represents the relative brightness, which is the ratio of the current brightness to the preset brightness. The preset brightness, which is the reference brightness for the relative brightness, can be set in various ways as needed.

[0086] The display area DA can include red, green, and blue sub-pixels. To test whether the display panel 10 is functioning correctly, only sub-pixels emitting light of one of these colors can be allowed to emit light. Figure 6 This is a graph showing the change in brightness over time, obtained by emitting only red sub-pixels capable of emitting red light. As described above, an input signal in the form of repetitive pulses can be applied to the display area DA of the display panel 10. Therefore, as... Figure 6 The graph showing the change in red light brightness over time can also represent a roughly repeating pulse shape. Unlike input signals that are digital signals, the measured brightness may not appear in a perfect pulse shape. Specifically, when defects exist in the display panel 10 (such as defects in any of the sub-pixels that are allowed to emit light), the graph of the measured brightness may appear in a shape different from the pulse shape. For example, the slope of the portion of increased brightness may be lower, or the absolute value of the slope of the portion of decreased brightness may be lower.

[0087] Figure 7 Is using Figure 6 The response graph obtained from the chart. From such... Figure 6 The graph showing the change in brightness over time provides the first-order difference d(EL) / dt of the brightness EL relative to time and the second-order difference dt of the brightness EL relative to time. 2 (EL) / dt 2Yes. This can be performed by: measuring the brightness of the display area DA of the display panel 10, which is an input signal in the form of repetitive pulses, applied to it over time; identifying the closest graph using the measured data via iteration, etc.; and then differentially dividing the graph relative to time. Alternatively, while measuring the brightness of the display area DA of the display panel 10, which is an input signal in the form of repetitive pulses, applied to it over time, a first-order difference value relative to time can be obtained by inputting the measured data into a differential circuit unit as described below, and a second-order difference value relative to time can be obtained by inputting the first-order difference value relative to time into the differential circuit unit, and thus a pair of the first-order difference value and the second-order difference value relative to time can be obtained.

[0088] After obtaining the first-order difference value and the second-order difference value relative to time as described above, a response plot based on the pair can be obtained by setting one of the x-axis and y-axis as the axis of the first-order difference value relative to time and the other as the axis of the second-order difference value relative to time. Figure 7 The response graph is shown, in which the response graph is obtained by using Figure 6 The brightness data in the chart shown is plotted with the x-axis set to the first-order difference value relative to time and the y-axis set to the second-order difference value relative to time. For example... Figure 7 As shown, the response diagram can appear in the shape obtained by rotating the number "8" by approximately 90 degrees.

[0089] exist Figure 7 In the response graph, a relatively large number of points are located near the origin, because... Figure 6 The pulse shape of the brightness map, in which the brightness remains approximately constant, corresponds to the points located at... Figure 7 Near the origin in the response graph. Figure 7 Points farthest from the origin can be compared with Figure 6 The pulse shape corresponds to a portion of the brightness map in which the brightness increases or decreases. More specifically, Figure 7 Points in the first and fourth quadrants can be combined with Figure 6 The brightness pattern of the pulse shape corresponds to the portion in which the brightness increases, and Figure 7 Points in the second and third quadrants can be compared with Figure 6 The brightness diagram of the pulse shape corresponds to a portion of the brightness that decreases.

[0090] In this way, using Figure 7 The response diagram shown can determine whether the red sub-pixel in the display area DA of the display panel 10 is normal. For example, depending on... Figure 7 The internal area of ​​the response diagram shown can determine whether the display panel 10 is functioning correctly. More specifically, when... Figure 7 When the internal area of ​​the response diagram shown is greater than a preset value, the display panel 10 can be determined to be abnormal. That is, when... Figure 7 When the internal area of ​​the response map shown is greater than a preset value, it can be determined that there is an abnormal red sub-pixel in the red sub-pixel of the display panel 10.

[0091] exist Figure 6 In the brightness diagram of the pulse shape, as the slope of the brightness increase (or rise) portion decreases or the absolute value of the slope of the brightness decreases (or falls), the display element in the display area DA can be considered to be operating inaccurately according to the input signal in the form of repetitive pulses. As described above, Figure 7 Points farthest from the origin can be compared with Figure 6 The pulse shape corresponds to the portion of the brightness map where the brightness increases or decreases. Therefore, Figure 7 The increase in the internal area of ​​the response map shown can be interpreted as the presence of many pixels in the display area DA that do not operate accurately according to the input signal in the form of repetitive pulses. Therefore, depending on... Figure 7 The internal area of ​​the response map shown can be used to determine whether the display panel 10 is normal by identifying the presence or ratio of defective red subpixels in the red subpixels of the display area DA.

[0092] Alternatively, when such Figure 7 When the maximum width W1 in the x-axis direction of the response graph shown in the figure is greater than a preset value, the display panel 10 can be determined to be abnormal. Figure 7 In the process, the difference between the x-coordinate of the first point P1 and the x-coordinate of the second point P2 can be called the maximum width W1 of the response map in the x-axis direction, and when the maximum width W1 is greater than a preset value, the display panel 10 can be determined to be abnormal.

[0093] Alternatively, when such Figure 7 When the maximum width W2 of the response graph shown in the diagram is greater than a preset value in the y-axis direction, the display panel 10 can be determined to be abnormal. Figure 7 In the diagram, the difference between the y-coordinate of the third point P3 and the y-coordinate of the fourth point P4 can be called the maximum width W2 of the response diagram in the y-axis direction, and when the maximum width W2 is greater than the preset value, the display panel 10 can be determined to be abnormal.

[0094] Alternatively, when such Figure 7 The response graph shown in the figure has a maximum value in the x-axis direction (e.g., the x-coordinate of the first point P1) that is greater than a preset maximum value or as... Figure 7 When the minimum value of the response graph shown in the figure in the x-axis direction (e.g., the x-coordinate of the second point P2) is less than a preset minimum value, the display panel 10 can be determined to be abnormal.

[0095] Alternatively, when such Figure 7 The response graph shown in the figure has a maximum value in the y-axis direction (e.g., the y-coordinate of the third point P3) that is greater than a preset maximum value or as... Figure 7 When the minimum value of the response graph shown in the figure in the y-axis direction (e.g., the y-coordinate of the fourth point P4) is less than a preset minimum value, the display panel 10 can be determined to be abnormal.

[0096] So far, references have been made Figure 6 and Figure 7 This describes determining whether the display panel 10 is functioning correctly by measuring the brightness of the red sub-pixels of the display area DA of the display panel 10. The same applies to the green or blue sub-pixels of the display area DA of the display panel 10.

[0097] In other words, by activating only the green sub-pixels capable of emitting green light, it is possible to achieve... Figure 8 The graph shown shows how brightness changes over time. Figure 8 Based on enabling Figure 5 The display panel 10 displays a graph showing the brightness change over time, based on the data obtained by the green subpixels emitting light. Figure 8 In the diagram, the horizontal axis represents time, measured in microseconds (μs), and the vertical axis represents the relative brightness, which is the ratio of the current brightness to the preset brightness. The preset brightness, which is the reference brightness for the relative brightness, can be set in various ways as needed. Figure 8 The brightness data is obtained by applying an input signal in the form of repetitive pulses to the display area DA of the display panel 10 and causing only the green sub-pixels to emit light. A graph showing the change in green light brightness over time can also represent a roughly repetitive pulse shape. Unlike input signals that are digital signals, the measured brightness may not appear in a perfect pulse shape. The description of the measured brightness is the same as described above.

[0098] Figure 9 Is using Figure 8 The response graph obtained from the chart. See the reference above. Figure 6 and Figure 7 The description can be used Figure 8 The chart can be displayed as Figure 8 The brightness data from the chart is used to obtain the first-order difference value d(EL) / dt of the brightness EL relative to time and the second-order difference value dt of the brightness EL relative to time. 2 (EL) / dt 2 Furthermore, a response plot based on pairs can be obtained by setting one of the x-axis and y-axis as the first difference value relative to time and the other as the second difference value relative to time. Figure 9 The response graph is shown, in which the response graph is obtained by using Figure 8 The brightness data in the chart shown is plotted with the x-axis set to the first difference value relative to time and the y-axis set to the second difference value relative to time. Similarly, in... Figure 9 In, with Figure 7 Similarly, the response map can appear in the shape obtained by rotating the number "8" by approximately 90 degrees.

[0099] use Figure 9 The response diagram shown can be used to determine whether the green sub-pixels in the display area DA of the display panel 10 are normal.

[0100] For example, depending on such Figure 9 The internal area of ​​the response diagram shown can determine whether the display panel 10 is functioning correctly. More specifically, when... Figure 9 When the internal area of ​​the response diagram shown is greater than a preset value, the display panel 10 can be determined to be abnormal. That is, when... Figure 9 When the internal area of ​​the response map shown is greater than a preset value, it can be determined that there is an abnormal green sub-pixel among the green sub-pixels of the display panel 10. Thus, depending on... Figure 9 The internal area of ​​the response map shown can be used to determine whether the display panel 10 is normal by identifying the presence or ratio of defective green subpixels in the green subpixels of the display area DA.

[0101] Alternatively, when such Figure 9 When the maximum width of the response graph shown in the figure is greater than a preset value in the x-axis direction, the display panel 10 can be determined to be abnormal. Alternatively, when such... Figure 9 When the maximum width of the response graph shown in the diagram in the y-axis direction exceeds a preset value, the display panel 10 can be determined to be abnormal. Alternatively, when... Figure 9 The response graph shown in the figure has a maximum value in the x-axis direction that is greater than the preset maximum value or as... Figure 9 When the minimum value in the response graph shown is less than a preset minimum value in the x-axis direction, the display panel 10 can be determined to be abnormal. Alternatively, when such... Figure 9 The response graph shown in the figure has a maximum value in the y-axis direction that is greater than a preset maximum value or as... Figure 9 When the minimum value in the response graph shown in the figure is less than the preset minimum value in the y-axis direction, the display panel 10 can be identified as abnormal.

[0102] This also applies to blue subpixels. In other words, by activating only the blue subpixels capable of emitting blue light, one can achieve results such as... Figure 10 The graph shown shows how brightness changes over time. Figure 10 Based on enabling Figure 5The display panel 10 displays a graph showing the brightness change over time, based on the data obtained by the blue subpixels emitting light. Figure 10 In the diagram, the horizontal axis represents time, measured in microseconds (μs), and the vertical axis represents the relative brightness, which is the ratio of the current brightness to the preset brightness. The preset brightness, which is the reference brightness for the relative brightness, can be set in various ways as needed. Figure 10 The brightness data is obtained by applying an input signal in the form of repetitive pulses to the display area DA of the display panel 10 and causing only the blue sub-pixels to emit light. A graph showing the change in blue light brightness over time can also represent a roughly repetitive pulse shape. Unlike input signals that are digital signals, the measured brightness may not appear in a perfect pulse shape. The description of the measured brightness is the same as described above.

[0103] Figure 11 Is using Figure 10 The response graph obtained from the chart. See the reference above. Figure 6 and Figure 7 The description can be used Figure 10 The chart can be displayed as Figure 10 The brightness data from the chart is used to obtain the first-order difference value d(EL) / dt of the brightness EL relative to time and the second-order difference value dt of the brightness EL relative to time. 2 (EL) / dt 2 Furthermore, a response plot based on pairs can be obtained by setting one of the x-axis and y-axis as the first difference value relative to time and the other as the second difference value relative to time. Figure 11 The response graph is shown, in which the response graph is obtained by using Figure 10 The brightness data in the chart shown is plotted with the x-axis set to the first difference value relative to time and the y-axis set to the second difference value relative to time. Similarly, in... Figure 11 In, with Figure 7 Similarly, the response map can appear in the shape obtained by rotating the number "8" by approximately 90 degrees.

[0104] use Figure 11 The response diagram shown can be used to determine whether the blue sub-pixel in the display area DA of the display panel 10 is normal.

[0105] For example, depending on such Figure 11 The internal area of ​​the response diagram shown can determine whether the display panel 10 is functioning correctly. More specifically, when... Figure 11 When the internal area of ​​the response diagram shown is greater than a preset value, the display panel 10 can be determined to be abnormal. That is, when... Figure 11When the internal area of ​​the response map shown is greater than a preset value, it can be determined that there is an abnormal blue sub-pixel among the blue sub-pixels of the display panel 10. Thus, depending on... Figure 11 The internal area of ​​the response map shown can be used to determine whether the display panel 10 is normal by identifying the presence or ratio of defective blue subpixels in the blue subpixels of the display area DA.

[0106] Alternatively, when such Figure 11 When the maximum width of the response graph shown in the figure is greater than a preset value in the x-axis direction, the display panel 10 can be determined to be abnormal. Alternatively, when such... Figure 11 When the maximum width of the response graph shown in the diagram in the y-axis direction exceeds a preset value, the display panel 10 can be determined to be abnormal. Alternatively, when... Figure 11 The response graph shown in the figure has a maximum value in the x-axis direction that is greater than the preset maximum value or as... Figure 11 When the minimum value in the response graph shown is less than a preset minimum value in the x-axis direction, the display panel 10 can be determined to be abnormal. Alternatively, when such... Figure 11 The response graph shown in the figure has a maximum value in the y-axis direction that is greater than a preset maximum value or as... Figure 11 When the minimum value in the response graph shown in the figure is less than the preset minimum value in the y-axis direction, the display panel 10 can be identified as abnormal.

[0107] In this method for detecting the display panel 10 according to this embodiment, the brightness in the display area DA is measured by applying an input signal in the form of repetitive pulses to the display panel 10, and then, by obtaining, as Figure 7 , Figure 9 and / or Figure 11 The response diagram shown in the figure is used to determine whether the display panel 10 is functioning properly. Therefore, when using the method for detecting the display panel 10 according to this embodiment, the brightness is measured in a very short time, and the functioning of the display panel 10 is determined based on the brightness. Therefore, the functioning of the display panel 10 can be determined simply, quickly, and intuitively.

[0108] The above-described testing method can be used not only for the display panel 10 in the manufacturing process, but also for display devices including the display panel 10. Therefore, the above-described testing method can be used not only to detect whether defects occur during the manufacturing process of the display panel 10, but also to determine whether the display elements deteriorate during the use of the display device.

[0109] So far, a method for detecting whether the display panel 10 is functioning properly has been described, and therefore, the apparatus for detecting the display panel that can be used in this method also falls within the scope of this disclosure. Figure 12This is a schematic block diagram of an apparatus 31 for detecting a display panel according to one or more embodiments. Figure 12 The device 31 shown may include an input signal application unit 37, a brightness measurement unit 39, and a differential circuit unit 35. Furthermore, the device 31 may include a processor 32 and a memory 33.

[0110] Processor 32 can use various programs and / or data stored in memory 33 to perform operations that typically control the means 31 used for detecting the display panel. Processor 32 may include processing units such as microprocessors, central processing units (CPUs), processor cores, multiprocessors, application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), etc., but one or more embodiments are not limited thereto.

[0111] The memory 33 may temporarily or permanently store data processed by the device 31 for detecting the display panel. The memory 33 may include permanent mass storage devices such as random access memory (RAM), read-only memory (ROM), and disk drives, but one or more embodiments are not limited thereto.

[0112] The input signal application unit 37 can generate an input signal in the form of repetitive pulses and apply the input signal to the display panel 10 to be detected. For this purpose, the device 31 for detecting the display panel can include components that can interact with... Figure 5 The input pads of the pad area PADA of the display panel 10 shown are in contact with the pads. Alternatively, the device 31 for detecting the display panel may include input pads that can be connected to... Figure 5 The test pads of the display panel 10 shown in the figure are in contact with the input pads.

[0113] The brightness measurement unit 39 can measure the brightness of the display area DA of the display panel 10 over time. For example, when only the red sub-pixel among the sub-pixels included in the display area DA of the display panel 10 is allowed to emit light, the brightness data obtained by the brightness measurement unit 39 can be as follows: Figure 6 As shown in the diagram. Similarly, when only the green sub-pixels among the sub-pixels included in the display area DA of the display panel 10 are allowed to emit light, the brightness data obtained by the brightness measurement unit 39 can be as follows: Figure 8 As shown in the diagram. Furthermore, when only the blue sub-pixels among the sub-pixels included in the display area DA of the display panel 10 are allowed to emit light, the brightness data obtained by the brightness measurement unit 39 can be as follows: Figure 10 As shown in the diagram.

[0114] The differential circuit unit 35 can generate differential data, which is the result of differentiating the time-based brightness data obtained by the brightness measurement unit 39 relative to time. When the time-based brightness data obtained by the brightness measurement unit 39 is input to the differential circuit unit 35, a first-order time-based difference value of the time-based brightness data obtained by the brightness measurement unit 39 can be obtained. When the first-order time-based difference value is input to the differential circuit unit 35, a second-order time-based difference value of the time-based brightness data obtained by the brightness measurement unit 39 can be obtained. As described above, the pair of first-order time-based difference values ​​and second-order time-based difference values ​​of the time-based brightness data obtained by the brightness measurement unit 39 can be obtained using the differential circuit unit 35. Temporary data or final data during the process of obtaining information about these pairs can be stored in the memory 33.

[0115] The device 31 for testing the display panel can determine whether the display panel 10 is functioning properly by using the obtained pair, as described above. The specific method for determining whether the display panel 10 is functioning properly using the device 31 for testing the display panel is the same as described above. Figures 6 to 11 The methods used to describe them are the same.

[0116] Figure 13 It shows that it can be included in Figure 12 The circuit diagram of the differential circuit unit 35 in the device 31. Figure 13 The circuit diagram is an example circuit diagram of the differential circuit unit 35, and the differential circuit unit 35 included in the apparatus 31 for detecting the display panel according to this embodiment is not affected by... Figure 13 Limitations of the circuit diagram shown.

[0117] like Figure 13 As shown, the differential circuit unit 35 may include an operational amplifier (OP amp), a capacitor C1, and two resistors R1 and Rs. One end of resistor R1 may be electrically connected to the negative terminal of the OP amp, and the other end of resistor R1 may be electrically connected to the output terminal Vout of the OP amp. One end of capacitor C1 may be electrically connected to the negative terminal of the OP amp, and the other end of capacitor C1 may be electrically connected to one end of resistor Rs, and the other end of resistor Rs may be electrically connected to the input terminal Vin of the differential circuit unit 35. The positive terminal of the OP amp may be grounded.

[0118] By inputting the brightness data obtained by the brightness measurement unit 39 to the input terminal Vin of the differential circuit unit 35, the first-order difference value relative to time can be obtained from the output terminal Vout of the differential circuit unit 35. When the first-order difference value relative to time is input to the input terminal Vin of the differential circuit unit 35, the second-order difference value relative to time can be obtained from the output terminal Vout of the differential circuit unit 35. The first-order difference value relative to time and the second-order difference value relative to time can each be stored in the memory 33, and thus, a pair of brightness data relative to time, the first-order difference value relative to time, and the second-order difference value relative to time obtained by the brightness measurement unit 39 can be obtained. The specific operation and method for determining whether the display panel 10 is normal by using this pair are the same as those mentioned above. Figures 6 to 11 The specific operations and methods described are the same.

[0119] In this apparatus 31 for detecting a display panel according to this embodiment, the brightness in the display area DA is measured by applying an input signal in the form of repetitive pulses to the display panel 10, and then, by obtaining... Figure 7 , Figure 9 and / or Figure 11 The response diagram shown in the figure is used to determine whether the display panel 10 is functioning properly. Therefore, when using the apparatus for detecting the display panel according to this embodiment, the brightness is measured in a very short time, and the functioning of the display panel 10 is determined based on the brightness. Therefore, the functioning of the display panel 10 can be determined simply, quickly, and intuitively.

[0120] The apparatus 31 for inspecting the display panel according to this embodiment can be used not only for the display panel 10 in the manufacturing process, but also for a display device including the display panel 10. Therefore, the apparatus 31 can be used not only to detect whether defects occur during the manufacturing process of the display panel 10, but also to determine whether the display elements deteriorate during the use of the display device.

[0121] According to one or more of the above embodiments, a method and apparatus for detecting a display panel can be implemented, in which the functionality of the display panel can be quickly determined. However, one or more embodiments are not limited to this effect.

[0122] It should be understood that the embodiments described herein should be considered in a descriptive sense only and not for limiting purposes. The description of features or aspects within each embodiment should generally be considered applicable to similar features or aspects in other embodiments. Although one or more embodiments have been described with reference to the accompanying drawings, those skilled in the art will understand that various changes in form and detail may be made in one or more embodiments without departing from the spirit and scope defined by the claims and their equivalents.

Claims

1. A method for detecting a display panel, the method comprising: Brightness data is obtained by measuring the brightness of the display area of ​​the display panel, which is composed of multiple pulses, applied to it over time. Obtain a pair of first-order difference values ​​and second-order difference values ​​relative to time from the brightness data or from a graph of brightness changes over time corresponding to the brightness data; A response plot based on the pair is obtained by setting one of the x-axis and y-axis as the axis of the first difference relative to time and the other as the axis of the second difference relative to time; and Determine whether the display panel is functioning properly based on the response diagram.

2. The method according to claim 1, wherein, The determination includes: determining whether the display panel is functioning properly based on the internal area of ​​the response map.

3. The method according to claim 2, wherein, The determination includes: when the internal area of ​​the response map is greater than a preset value, determining that the display panel is abnormal.

4. The method according to claim 1, wherein, The determination includes: when the maximum width of the response map in the x-axis direction is greater than a preset value, determining that the display panel is abnormal.

5. The method according to claim 1, wherein, The determination includes: when the maximum width of the response map in the y-axis direction is greater than a preset value, determining that the display panel is abnormal.

6. The method according to claim 1, wherein, The determination includes: determining that the display panel is abnormal when the maximum value of the response graph in the x-axis direction is greater than a preset maximum value or when the minimum value of the response graph in the x-axis direction is less than a preset minimum value.

7. The method according to claim 1, wherein, The determination includes: determining that the display panel is abnormal when the maximum value of the response graph in the y-axis direction is greater than a preset maximum value or when the minimum value of the response graph in the y-axis direction is less than a preset minimum value.

8. The method according to any one of claims 1 to 7, wherein, The acquisition of the pair includes: obtaining the pair by inputting the brightness data into a differential circuit unit.

9. An apparatus for detecting a display panel, the apparatus comprising: An input signal application unit is configured to apply an input signal comprising multiple pulses to the display panel; A brightness measurement unit is configured to measure the brightness of the display area of ​​the display panel over time. and The differential circuit unit is configured to differentially analyze the time-varying brightness data obtained by the brightness measurement unit relative to time. The determination of whether the display panel is functioning correctly is based on a pair of first-order difference values ​​and second-order difference values ​​relative to time obtained by the brightness measurement unit, which are derived from the brightness data that varies with time over time. This pair is obtained by the differential circuit unit.

10. The apparatus according to claim 9, wherein, The response plot is obtained based on the pair obtained by setting one of the x-axis and y-axis as the first difference value relative to time and the other as the second difference value relative to time. Whether the display panel is functioning properly is determined based on the response graph.

11. The apparatus according to claim 10, wherein, Whether the display panel is functioning properly is determined based on the internal area of ​​the response graph.

12. The apparatus according to claim 11, wherein, When the internal area of ​​the response graph is greater than a preset value, the display panel is determined to be abnormal.

13. The apparatus according to claim 10, wherein, When the maximum width of the response graph in the x-axis direction is greater than a preset value, the display panel is determined to be abnormal.

14. The apparatus according to claim 10, wherein, When the maximum width of the response graph in the y-axis direction is greater than a preset value, the display panel is determined to be abnormal.

15. The apparatus according to claim 10, wherein, The display panel is determined to be abnormal when the maximum value of the response graph in the x-axis direction is greater than a preset maximum value or when the minimum value of the response graph in the x-axis direction is less than a preset minimum value.

16. The apparatus according to claim 10, wherein, The display panel is determined to be abnormal when the maximum value of the response graph in the y-axis direction is greater than a preset maximum value or when the minimum value of the response graph in the y-axis direction is less than a preset minimum value.

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