On-chip test architecture for display systems

Abstract

Embodiments disclosed herein provide systems and methods for testing and repairing various aspects of an electronic display. The electronic display includes a reference array and an active array. The electronic display also includes test circuitry for testing individual pixels or any combination of pixels of the electronic display. Switches can be disposed between the pixels and the test circuitry to repair various components of the electronic display.

Description

[0001] Cross-references to related applications

[0002] This application claims the benefit of U.S. Provisional Application No. 63 / 076,846, filed September 10, 2020, entitled “ON-CHIP TESTING ARCHITECTUREFOR DISPLAY SYSTEM,” the contents of which are incorporated herein by reference in their entirety for all purposes. Summary of the Invention

[0003] This disclosure relates in general to electronic displays, and more specifically to testing and correcting voltage degradation in electronic displays having voltage-driven pixels and / or current-driven pixels.

[0004] Flat panel displays, such as light-emitting diode (LED) displays or organic LED (OLED) displays, are commonly used in a variety of electronic devices, including consumer electronics such as televisions, computers, and handheld devices (e.g., cellular phones, audio and video players, gaming systems, etc.). These display panels are typically provided in thin packages suitable for a wide range of electronic products. Furthermore, such devices use less power than comparable display technologies, making them suitable for battery-powered devices or other environments where minimal power consumption is desired.

[0005] LED displays typically comprise image elements (e.g., pixels) arranged in a matrix to display an image that can be viewed by a user. When current is applied to each pixel, the individual pixels of an LED display generate light. Current can be applied to each pixel by programming a voltage into the pixel, which is then converted into current by pixel circuitry. The pixel circuitry that converts voltage into current can include, for example, thin-film transistors (TFTs). However, when a specific voltage is applied, certain operating conditions such as aging or temperature can affect the amount of current applied to the pixel.

[0006] Similarly, components that supply current to pixels, such as source drivers, can fail for various reasons. In this case, no current can be supplied to the corresponding pixel. Conventionally, test electrodes coupled to each source driver are connected to external test circuitry to identify the malfunctioning component. This method is time-consuming to connect and test each component. Furthermore, the additional test electrodes and corresponding data lines consume a significant amount of space on the display's integrated circuits, leaving little space for additional pixels that could be used to increase the display's resolution.

[0007] Display panel sensing allows for the identification of the operational properties of pixels in an electronic display to improve its performance. For example, variations in temperature and pixel aging (among other factors) on an electronic display cause pixels at different locations on the display to behave differently. In fact, the same image data programmed onto different pixels of a display may look different due to variations in temperature and pixel aging. For instance, a pixel emits a certain amount of light, gamma, or grayscale level based at least in part on the amount of current supplied to the diode (e.g., an LED) of the pixel. For voltage-driven pixels, a target voltage can be applied to the pixel so that a target current is applied to the diode (e.g., as represented by a current-voltage relationship or curve) to emit a target gamma value. Variations can affect the pixel, for example, by changing the resulting current applied to the diode when the target voltage is applied. Without proper compensation, these variations can produce undesirable visual artifacts.

[0008] Therefore, the techniques and systems described below can be used to test and compensate for the functionality of various components of a display. Test circuitry is coupled to each pixel of the display. Test circuitry can compensate for one or more components of the display that have malfunctioned (e.g., been damaged). Test circuitry can determine the current through the circuitry of each pixel of the display to confirm the operation of each pixel and its corresponding component.

[0009] Various modifications to the above-described features may exist with respect to various aspects of the invention. Other features may also be incorporated into these aspects. These modifications and additional features may exist individually or in any combination. For example, various features discussed below relating to one or more illustrated embodiments may be incorporated individually or in any combination into any of the above aspects of the invention. The brief summary presented above is intended only to familiarize the reader with specific aspects and context of the embodiments disclosed herein and does not limit the claimed subject matter. Attached Figure Description

[0010] A better understanding of the various aspects of this disclosure can be achieved by reading the following detailed description and referring to the accompanying drawings.

[0011] Figure 1 This is a block diagram of an electronic device according to an embodiment of the present disclosure.

[0012] Figure 2 It means Figure 1 A perspective view of a laptop computer as an implementation scheme for an electronic device.

[0013] Figure 3 It means Figure 1 A front view of a handheld device in another embodiment of an electronic device.

[0014] Figure 4 It means Figure 1A front view of another handheld device in another implementation of the electronic device.

[0015] Figure 5 It means Figure 1 A front view of a desktop computer in another implementation of an electronic device.

[0016] Figure 6 It means Figure 1 A perspective view of another implementation of a wearable electronic device.

[0017] Figure 7 This is a block diagram of a system for display sensing and testing according to an embodiment of the present disclosure.

[0018] Figure 8 This is a block diagram of an exemplary architecture for a source driver for screening a display according to an embodiment of this disclosure.

[0019] Figure 9 This is a block diagram of an exemplary architecture for repairing a source driver according to an embodiment of this disclosure.

[0020] Figure 10 It is a method for repair according to the implementation of this disclosure. Figure 9 A block diagram of an exemplary architecture for a source driver.

[0021] Figure 11 Use according to the implementation scheme of this disclosure Figure 9 and Figure 10 A block diagram illustrating an exemplary fix for the source driver architecture.

[0022] Figure 12 This is a block diagram of an exemplary architecture for repairing a data line using a repair bus, according to an embodiment of this disclosure.

[0023] Figure 13 This is a block diagram illustrating an exemplary repair using the data line of the repair bus according to an embodiment of this disclosure.

[0024] Figure 14 This is a block diagram of an exemplary architecture for repairing a data cable according to an embodiment of this disclosure.

[0025] Figure 15 This is a block diagram illustrating an exemplary repair using a copied data cable according to an embodiment of this disclosure.

[0026] Figure 16 This is a block diagram of an exemplary architecture for rapid detection of defective pixels according to an embodiment of the present disclosure.

[0027] Figure 17This is a block diagram of an exemplary architecture of an on-chip IV sensing system according to an embodiment of the present disclosure.

[0028] Figure 18 It is based on the implementation scheme of this disclosure for the purpose of... Figure 17 A block diagram of an exemplary architecture for the test bus under discussion.

[0029] Figure 19 This is a block diagram of an exemplary architecture for repairing gate drivers and / or gate driver line data lines according to embodiments of this disclosure. Detailed Implementation

[0030] One or more specific implementations will be described below. To provide a brief description of these implementations, not all characteristics of the actual implementations are described in this specification. It should be understood that in the development of any such actual implementation, as in any engineering or design project, decisions must be made specific to many implementations to achieve the developer's specific objectives, such as compliance with system-related and business-related constraints that may vary from one implementation to another. Furthermore, it should be understood that such development work can be complex and time-consuming, but will still be routine work of design, fabrication, and manufacturing for those skilled in the art who benefit from this disclosure.

[0031] When describing elements of various embodiments of this disclosure, the articles “a” and “the” are intended to mean the presence of one or more of the elements. The terms “comprising,” “including,” and “having” are intended to be included and to mean that additional elements may exist in addition to the listed elements. Additionally, it should be understood that reference to “an embodiment” or “an embodiment” in this disclosure is not intended to be construed as excluding the existence of additional embodiments also incorporating the cited features. Furthermore, the phrase A “based on” B is intended to mean that A is at least partially based on B. Moreover, the term “or” is intended to be included (e.g., logical OR) and is not exclusive (e.g., logical XOR). In other words, the phrase A “or” B is intended to mean A, B, or both A and B.

[0032] Electronic displays are widely used in modern electronic devices. As electronic displays achieve increasingly higher resolution and dynamic range capabilities, image quality improves significantly. Generally speaking, an electronic display contains many image elements, or "pixels," programmed with image data. Each pixel emits a specific amount of light, at least in part, based on the image data. By programming different pixels with different image data, graphical content, including images, videos, and text, can be displayed.

[0033] Display panel sensing allows for the identification of the operational properties of pixels in an electronic display to improve its performance. For example, variations in temperature and pixel aging (among other factors) on an electronic display cause pixels at different locations on the display to behave differently. In fact, the same image data programmed onto different pixels of a display may look different due to variations in temperature and pixel aging. For instance, a pixel emits a certain amount of light, gamma, or grayscale level based at least in part on the amount of current supplied to the diode (e.g., an LED) of the pixel. For voltage-driven pixels, a target voltage can be applied to the pixel so that a target current is applied to the diode (e.g., as represented by a current-voltage relationship or curve) to emit a target gamma value. Variations can affect the pixel, for example, by changing the resulting current applied to the diode when the target voltage is applied. Without proper compensation, these variations can produce undesirable visual artifacts.

[0034] Therefore, the techniques and systems described below can be used to test and compensate for the functionality of various components of a display. Test circuitry is coupled to each pixel of the display. Test circuitry can compensate for one or more components of the display that have malfunctioned (e.g., been damaged). Test circuitry can determine the current through the circuitry of each pixel of the display to confirm the operation of each pixel and its corresponding component.

[0035] With this in mind, Figure 1 A block diagram of electronic device 10 is shown. As will be described in more detail below, electronic device 10 may represent any suitable electronic device, such as a computer, mobile phone, portable media device, tablet computer, television, virtual reality headset, vehicle dashboard, etc. Electronic device 10 may represent, for example, Figure 2 The laptop computer 10A shown is as follows: Figure 3 The handheld device 10B shown is as follows: Figure 4 The handheld device 10C shown is as follows: Figure 5 The desktop computer 10D shown is as follows: Figure 6 The wearable electronic device 10E or similar device shown.

[0036] Figure 1 The electronic device 10 shown may include, for example, a processor core complex 12, local memory 14, main memory storage device 16, electronic display 18, input structure 22, input / output (I / O) interface 24, network interface 26, and power supply 29. Figure 1 The various functional blocks shown may include hardware elements (including circuitry), software elements (including machine-executable instructions stored on tangible, non-transitory media, such as local memory 14 or main memory storage device 16), or combinations of hardware and software elements. It should be noted that... Figure 1This is merely one example of a specific implementation and is intended to illustrate the types of components that may exist in electronic device 10. In reality, various depicted components may be combined into fewer components or separated into additional components. For example, local memory 14 and main memory storage device 16 may be included in a single component.

[0037] The processor core complex 12 can perform various operations of the electronic device 10, such as causing the electronic display 18 to perform display panel sensing and use feedback to repair detected defects in the circuitry of the electronic display 18 and / or adjust image data for display on the electronic display 18. The processor core complex 12 may include any suitable data processing circuitry for performing these operations, such as one or more microprocessors, one or more application-specific integrated circuits (ASICs), or one or more programmable logic devices (PLDs). In some cases, the processor core complex 12 can execute programs or instructions (e.g., operating systems or applications) stored on suitable artifacts, such as local memory 14 and / or main memory storage device 16. In addition to instructions for the processor core complex 12, local memory 14 and / or main memory storage device 16 may also store data to be processed by the processor core complex 12. For example, local memory 14 may include random access memory (RAM), and main memory storage device 16 may include read-only memory (ROM), rewritable non-volatile memory (such as flash memory, hard disk drive, optical disk, etc.).

[0038] Electronic display 18 may display image frames, such as a graphical user interface (GUI) or application interface for an operating system, still images, or video content. Processor core complex 12 may provide at least some image frames. Electronic display 18 may be a self-emissive display, such as an organic light-emitting diode (OLED) display, a micro-LED display, a micro-OLED type display, or a backlit liquid crystal display (LCD). In some embodiments, electronic display 18 may include a touchscreen that allows the user to interact with the user interface of electronic device 10. Electronic display 18 may employ display panel sensing to identify changes in operation of electronic display 18. This may allow processor core complex 12 to adjust the image data sent to electronic display 18 to compensate for these changes, thereby improving the quality of the image frames appearing on electronic display 18.

[0039] The input structure 22 of electronic device 10 allows a user to interact with electronic device 10 (e.g., press a button to increase or decrease the volume level). Like network interface 26, I / O interface 24 enables electronic device 10 to interact with various other electronic devices. Network interface 26 may include interfaces for, for example, networks such as Bluetooth networks for personal area networks (PANs), 802.11x Wi-Fi networks for local area networks (LANs) or wireless local area networks (WLANs), and / or cellular networks for wide area networks (WANs). Network interface 26 may also include interfaces for, for example, broadband fixed wireless access networks (WiMAX), mobile broadband wireless networks (mobile WiMAX), asynchronous digital subscriber lines (e.g., ADSL, VDSL), digital video terrestrial broadcasting (DVB-T) and its extension DVB handheld devices (DVB-H), ultra-wideband (UWB), AC power lines, etc. Power supply 29 may include any suitable power source, such as a rechargeable lithium polymer (Li-poly) battery and / or an AC power converter.

[0040] In some embodiments, electronic device 10 may take the form of a computer, portable electronic device, wearable electronic device, or other types of electronic device. Such computers may include typically portable computers (e.g., laptops, notebooks, and tablets) and computers typically used in one location (e.g., conventional desktop computers, workstations, and / or servers). In some embodiments, electronic device 10 in the form of a computer may be a MacBook purchased from Apple Inc. in Cupertino, California. ® MacBook ® Pro, MacBook Air ® iMac ® Mac ® mini or Mac Pro ® Model. By way of example, according to one embodiment of this disclosure, in... Figure 2 An electronic device 10 in the form of a laptop computer 10A is shown. The illustrated computer 10A may include a casing or housing 36, an electronic display 18, input structures 22, and ports for I / O interfaces 24. In one embodiment, the input structures 22 (such as a keyboard and / or touchpad) can be used to interact with the computer 10A, such as to launch, control, or operate a GUI or applications running on the computer 10A. For example, the keyboard and / or touchpad can allow a user to navigate on a user interface or application interface displayed on the electronic display 18.

[0041] Figure 3A front view of a handheld device 10B is depicted, representing one embodiment of an electronic device 10. The handheld device 10B can represent, for example, a portable telephone, media player, personal data manager, handheld gaming platform, or any combination of such devices. By way of example, the handheld device 10B could be an iPod purchased from Apple Inc. ® Or iPhone ® Model. The handheld device 10B may include a housing 36 to protect internal components from physical damage and electromagnetic interference. The housing 36 may enclose the electronic display 18. The I / O interface 24 can be opened through the housing 36 and may include, for example, I / O ports for rigid wired connections for charging and / or content manipulation using standard connectors and protocols such as the Lightning connector provided by Apple Inc., Universal Serial Bus (USB), or other similar connectors and protocols.

[0042] The user input structure 22, combined with the electronic display 18, allows the user to control the handheld device 10B. For example, the input structure 22 can activate or deactivate the handheld device 10B, navigate the user interface to a home screen, a user-configurable application screen, and / or activate the voice recognition features of the handheld device 10B. Other input structures 22 may provide volume control or switch between vibration and ringtone modes. The input structure 22 may also include a microphone for receiving user voice for various voice-related features, and a speaker for enabling audio playback and / or certain telephone functions. The input structure 22 may also include a headphone input for connecting to external speakers and / or headphones.

[0043] Figure 4 A front view of another handheld device 10C is depicted, representing another embodiment of electronic device 10. Handheld device 10C may represent, for example, a tablet computer, or one of various portable computing devices. By way of example, handheld device 10C may be a tablet-sized embodiment of electronic device 10, specifically, for example, an iPad purchased from Apple Inc. ® model.

[0044] See Figure 5 Computer 10D can represent Figure 1 Another embodiment of the electronic device 10. The computer 10D can be any computer, such as a desktop computer, server, or laptop, but can also be a standalone media player or video game console. For example, the computer 10D could be Apple Inc.'s iMac. ® MacBook ®Other similar devices. It should be noted that computer 10D may also refer to a personal computer (PC) from another manufacturer. A similar housing 36 may be provided to protect and enclose the internal components of computer 10D, such as electronic display 18. In some embodiments, the user of computer 10D may interact with computer 10D using various peripheral input devices that can be connected to computer 10D, such as input structures 22A or 22B (e.g., keyboard and mouse).

[0045] Similarly, Figure 6 Depicting the representation Figure 1 Another embodiment of the electronic device 10, a wearable electronic device 10E, can be operated using the techniques described herein. For example, the wearable electronic device 10E may include a wristband 43, which could be an Apple Watch from Apple Inc. ® However, in other embodiments, the wearable electronic device 10E may include any wearable electronic device, such as, for example, a wearable motion monitoring device (e.g., a pedometer, accelerometer, heart rate monitor) or other devices from another manufacturer. The electronic display 18 of the wearable electronic device 10E may include a touchscreen display 18 (e.g., an LCD, OLED display, active-matrix organic light-emitting diode (AMOLED) display, etc.) and an input structure 22 that allows a user to interact with the user interface of the wearable electronic device 10E.

[0046] Figure 7 This is a block diagram of a system 50 for display sensing and testing according to an embodiment of this disclosure. System 50 may be included in relation to... Figure 1 In the display 18 of the electronic device 10 discussed, system 50 includes an active array 52 and a reference array 54. The reference array 54 includes a plurality of reference pixels 55. The reference array 54 can be used to test and track the operation of the reference pixels 55, each of which may correspond to one or more pixels 67 of the active array 52. ​​As shown, the pixels 67 of the active array 52 may include pixel circuitry 64 and light-emitting diodes such as microLEDs, microOLEDs, or organic light-emitting diodes (OLEDs) 66. Based on the operation of the reference pixels 55, one or more parameters (e.g., current, output brightness, etc.) of the corresponding pixel 67 of the active array 52 can be adjusted. The pixel circuitry 64 of the pixel 67 can be tested with or without the OLED 66 installed in the active array 52. ​​This allows the circuitry of the active array 52 to be tested before the OLED 66 is installed to ensure correct operation.

[0047] The active array 52 includes a plurality of pixels 67 arranged in a matrix. About Figure 1The processor core complex 12 discussed may provide image data to pixel 67 via driver circuitry (such as one or more source drivers 58A, 58B and one or more gate drivers 84). One or more source drivers 58A, 58B and one or more gate drivers 84 may be coupled to the respective pixel 67 via pixel circuitry 64 to activate or illuminate the OLED 66 based on the image data. In some embodiments, one or more gate drivers 84 may also provide a reset, conduction bias stress, and / or pixel activation signal to pixel 67 to prepare pixel 67 to receive data via source drivers 58A, 58B. Source latches 56A, 56B are coupled to each of the source drivers 58A, 58B. Source latches 56A, 56B may provide image data to each of the source drivers 58A, 58B to activate / illuminate each pixel 67.

[0048] Each source driver 58A, 58B can be coupled to test buses 60, 62 via corresponding test switches 92A, 92B to provide signals to test circuits 68, 76. Test circuits 68, 76 may include an analog front end (AFE) and / or an analog-to-digital converter (ADC). That is, analog signals can be received by test circuits 68, 76 via the test buses and converted by the ADC for testing. During normal operation of system 50, test switches 92A, 92B are open, decoupling source drivers 58A, 58B from test buses 60, 62. During testing of source drivers 58A, 58B, test switches 92A, 92B can be closed, coupling source drivers 58A, 58B to test buses 60, 62. Test switches 92A, 92B enable simultaneous testing of one, all, or a combination of source drivers 58A, 58B.

[0049] Therefore, test switches 92A and 92B enable the isolation of one or more source drivers 58A and 58B under test. In some embodiments, data switches 90A and 90B may be positioned between and coupled to the source drivers 58A and 58B and the pixel circuitry 64. During normal operation, data switches 90A and 90B may be closed, such that the source drivers 58A and 58B are coupled to the pixel circuitry 64 of the pixel 67. During test operation, data switches 90A and 90B may be open.

[0050] Test buses 60 and 62 are coupled to test circuits 68 and 76. Signals provided to test circuits 68 and 76 by source drivers 58A and 58B can be voltages or currents originally provided to the corresponding pixel circuits 64. Test circuits 68 and 76 may include various components such as multiplexers and / or switches to receive one or more signals from source drivers 58A and 58B, gate driver 84, pixel circuit 64, data lines 70 between source drivers 58A and 58B, and pixel circuit 64. For each pixel 67, test circuits 68 and 76 can determine, at least in part, the presence of a defect in the data lines between the corresponding source drivers 58A and 58B, the corresponding gate driver 84, the corresponding pixel circuit 64, and the corresponding pixel circuit 64, based on one or more signals. The following section discusses... Figures 8 to 19 The various components of test circuits 68 and 76 will be discussed in more detail.

[0051] Figure 8 This is a block diagram of an exemplary architecture 100 for a source driver for screening a display according to an embodiment of the present disclosure. Architecture 100 includes a plurality of source drivers 106A, 106B coupled to a plurality of multiplexers 104A, 104B, 108A, 108B. In some embodiments, source drivers 106A, 106B may respectively correspond to... Figure 7 The source drivers discussed are 58A and 58B.

[0052] Input signals (e.g., gamma) are provided to source drivers 106A and 106B via multiplexers 104A and 104B. Based on corresponding code lines 102A and 102B, multiplexer 104A provides the input signal to a first source driver 106A, and multiplexer 104B provides the input signal to a second source driver 106B. In some embodiments, the first multiplexer 108A and the second multiplexer 108B are switches that route the outputs of at least some of the source drivers 106A and 106B to corresponding switches of the opposite source driver 106B or 106A.

[0053] To test multiple first source drivers 106A and corresponding data lines 112, a corresponding number of second source drivers 106B can be used as voltage comparators. A corresponding first multiplexer 108A is switched such that the output from the corresponding second source driver 106B is provided to the controller 122. For example, a second source driver 106B can be coupled to receive an input signal and coupled to the corresponding data line 112 of the first source driver 106A. In this case, the first multiplexer 108A can provide feedback from the data line 112 to the first source driver 106A. The second source driver 106B can receive an input signal from multiplexer 104B and compare that input signal with the signal from the first source driver 106A via data line 112. The second source driver 106B provides the comparison result to the controller 122. The comparison performed by the second multiplexer 108B can be performed for each of the first source drivers 106A, regardless of whether an input signal is received. In other words, a comparison can be performed to ensure that the input signal is provided to the data line 112 and / or to ensure that the data line 112 is not short-circuited.

[0054] A similar configuration can be used to test the second source driver 106B and the corresponding data line 110. In this case, the second multiplexer 108B can provide feedback to the second source driver 106B. The first multiplexer 108A can receive and compare the input signal from the multiplexer 104A and the signal from the second source driver 106B via the data line 110. The first source driver 106A provides the comparison result to the controller 122.

[0055] Although not shown, data lines 110, 112 may be coupled to one or more pixels of display 18, such as regarding Figure 7 The pixel 67 in question. That is, architecture 100 can be used to test source drivers 106A, 106B with or without pixels mounted in the display. In this way, architecture 100 can be tested during manufacturing, which reduces downtime for correcting problems with source drivers 106A, 106B and data lines 110, 112. Testing the pixel before mounting it in the display 18 also reduces voltage degradation of pixel 67 during testing.

[0056] Testing the source driver (and corresponding data lines) simultaneously with the source driver being tested reduces the testing time. Furthermore, multiple first multiplexers 108A and multiple second multiplexers 108B enable testing of the source driver with a minimal number of components added to the display architecture 100. That is, for example, an existing circuitry of the display panel is used for testing without significantly increasing the size of the existing architecture.

[0057] Figure 9 This is a block diagram of an exemplary architecture 130 for repairing a source driver 132 according to an embodiment of this disclosure. Architecture 130 includes a source driver 132 coupled to an active array 52. ​​In some embodiments, the source driver 132 corresponds to... Figure 8 The first source driver 106A or the second source driver 106B are discussed. In some embodiments, each source driver 132 corresponds to a column of pixels 67 in the active array 52. ​​That is, the number (X) of source drivers 132 corresponds to the number of columns of pixels 67 in the active array 52.

[0058] Each source driver 132 may include a gamma multiplexer 136 and an amplifier 138. The gamma multiplexer 136 converts a digital data signal into a voltage to drive a corresponding column pixel 67 of the active array 52. ​​A source latch 134 is coupled to each source driver 132 and provides an input signal to each source driver. A switch 140 is disposed between each source driver 132 and the active array 52. ​​In some embodiments, each switch 140 is a multiplexer. The switch 140 is coupled to adjacent and alternating source drivers 132. That is, a first switch 140 may be coupled to a first source driver 132 (1) and a second source driver 132 (2) adjacent to the first source driver 132 (1). The second switch 140 may be coupled to the third source driver 132 (3) and the fourth source driver 132 (4) adjacent to the third source driver 132 (3), wherein the third source driver 132 (3) is also adjacent to the second source driver 132 (2).

[0059] In some implementations, architecture 130 includes one or more spare source drivers 144, such that the number of source drivers 132 is greater than the number of columns of pixels 67 in the active array 52. ​​If a defective source driver 144 is identified, one or more spare source drivers 132 can be used, as discussed below. Test architectures such as those described above can be used. Figure 8 The architecture 100 discussed is used to test the source driver 132.

[0060] Upon detection of a defective source driver 132 (e.g., through testing or calibration during manufacturing or once detected in operation), a backup source latch 146 may be coupled to a backup source driver 144. One or more repair registers 142 may also change the state of switch 140 depending on the location of the defective source driver 132. Although a single backup source driver 144 is shown to the right of source driver 132, it should be understood that more than one backup source driver 144 may be present and / or may be positioned between and / or to the right of source drivers 132. Furthermore, although a backup source driver 144 is shown, it should be understood that one or more backup gate drivers may be included in relation to... Figure 7 In the gate driver 84 discussed, one or more alternative gate drivers may function in a similar manner to the alternative source driver 144, as discussed below.

[0061] Figure 10 This is a block diagram of another architecture 141 for repairing a source driver according to an embodiment of this disclosure. As used herein, repairing a defective source driver may involve using a backup source driver to compensate for the defective source driver. Figure 10 The exemplary architecture 141 shows a source driver 132 coupled to a source latch 134 via one or more switches 152. One or more switches 152 are disposed between the source latch 150 and the source driver 132. In some embodiments, the one or more switches 152 may be multiplexers, similar to switch 140 between the source driver 132 and the active array 52.

[0062] exist Figure 10 In the exemplary state shown, the output of each repair register 142 is high (e.g., 1), causing switch 140 to pass the output of source driver 132 to the corresponding pixel 67 in active array 52. ​​When a defective source driver 132 is detected, the state of one or more repair registers in repair register 142 can be changed along with the corresponding switch 140, as shown in the diagram. Figure 11 The discussion.

[0063] Figure 11 It is for use according to the embodiments of this disclosure. Figure 10 A block diagram of architecture 141 to repair an exemplary state of source driver 132. As shown, in the fourth source driver 154 (i.e., Figure 10A defect is detected in source driver 132 (shown as source driver 4). Upon detection of a defect, the state of the repair register 142 corresponding to the first four source drivers 132 can be changed from high to low (e.g., from 1 to 0), causing a change in the state of the corresponding switch 140. Switch 140 can change the connection of one or more source drivers 132 such that the one or more source drivers 132 are coupled to adjacent columns (or rows) of pixels 67 in the active array 52. ​​For example, if a defect is detected in the fourth source driver 154, the state of one or more switches 156 to the left of the fourth source driver 154 can be changed. The state of the corresponding switch 152 coupled to the source latch 134 can also be changed.

[0064] Changing the states of switches 140 and 152 couples the backup source driver 144 to the first column (or row) of pixels 67 in the active array 52. ​​Therefore, the backup source driver 144 can become... Figure 10 The first source driver is shown in the diagram. Similarly, the first source driver can become a second source driver and can be coupled to a second column (or row) of pixels 67 in the active array 52. ​​The second source driver can become a third source driver and can be coupled to a third column (or row) of pixels 67 in the active array 52. ​​The third source driver can become a fourth source driver and can be coupled to a fourth column (or row) of pixels 67 in the active array 52.

[0065] Although the connection of the source driver 132 to the left of the defective source driver 154 is shown as coupled to the adjacent column (or row) of pixel 67, it should be understood that a similar change can occur to the source driver to the right of the defective source driver 154. Replacing the defective source driver 154 with the adjacent source driver 132 after detecting the defective source driver slightly increases the routing distance between the source latch and the active array 52. ​​Therefore, the performance impact on source driver 132 and the spare source driver 144 can be mitigated.

[0066] In some cases, more than one defective driver may be identified during testing. In such cases, the first defective source driver may be replaced with a first alternative source driver as described above. If a second alternative source driver (not shown) exists in architecture 130, the second defective source driver may be replaced similarly with an adjacent source driver. If no second alternative source driver exists, the source driver adjacent to the second defective source driver may be coupled to the column (or row) of pixel 67 corresponding to the second defective source driver. That is, two columns (or two rows) of pixel 67 may be driven using the source driver adjacent to the second defective source driver, namely (1) the pixel corresponding to the adjacent source driver after replacing the first defective source driver and (2) the pixel corresponding to the second defective source driver.

[0067] Therefore, regarding Figures 9 to 11 The proposed implementation reduces the time required to detect and replace defective source drivers, while mitigating the impact on the performance of remaining source drivers and on multiple components added to the display architecture to perform the test.

[0068] Figure 12 This is a block diagram of an exemplary architecture 160 for repairing a data line using a repair bus, according to an embodiment of this disclosure. Architecture 160 can be related to... Figure 8 The test architecture 100 discussed is used together to test multiple source drivers 132A, 132B. In some implementations, the multiple source drivers 132A, 132B may each correspond to approximately... Figure 7 The source drivers 58A and 58B are discussed. Each column of source drivers 132A and 132B includes backup source drivers 144A and 144B, respectively. Architecture 160 includes one or more first switches 172A and one or more second switches 172B opposite to the one or more first switches 172A. Architecture 160 also includes test multiplexers 107A and 170B, respectively coupled to the first switches 172A and the second switches 172B. Test multiplexers 107A and 170B are coupled to test circuits 68 and 76.

[0069] A first switch 172A is located between the source driver 132A and the first repair bus 188A. A second switch 172B is located between the source driver 132B and the second repair bus 188B. The first switch 172A controls whether the source driver 132A is coupled to the corresponding data line 178 and / or the test multiplexer 170A and the test circuit 68. Similarly, the second switch 172B controls whether the source driver 132B is coupled to the corresponding data line 176 and / or the test multiplexer 170B and the test circuit 76.

[0070] Test circuits 68 and 76 can be used to identify defective data lines 176 and 178 coupled to the corresponding source drivers 132A and 132B. For example, if a defect is identified in architecture 160 via the test circuits, but each of the source drivers 132A and 132B is operating normally, the defect may exist in data lines 176 and 178 (or switches 172A and 172B). In this case, the states of switches 172A and 172B are changed such that backup source drivers 144A and 144B are coupled to the first portion of the defective data lines 176 and 178. Similarly, the states of the switches are changed such that the source drivers 132A and 132B initially coupled to the defective data lines 176 and 178 are copied and provided to the backup source drivers 144A and 144B now connected to the defective data lines 176 and 178.

[0071] Figure 13 The use of the implementation scheme of this disclosure is based on Figure 12 A block diagram illustrating an exemplary repair of the data lines of the architecture 160 under discussion. Upon detecting a defect in the fourth data line 186 coupled to source driver 132A, the state of the corresponding switch 184 is changed to couple a first portion of the defective data line 186 to repair bus 188A. Similarly, the state of the corresponding switch 182 is changed to couple a second portion of the defective data line 186 to repair bus 188B. The first portion of the defective data line 186 is driven via a backup source driver 144A, and the second source driver is driven via a corresponding source driver 180. Depending on the position of pixel 67 coupled to the defective data line 186, the first portion of the defective data line 186 may be driven via a corresponding source driver 164, and the second portion of the defective data line may be driven via a backup source driver 144B. Test circuits 68 and 76 can be used to identify which source drivers 132A, 132B, 144A, and 144B are used to drive a specific portion of the defective data line 186.

[0072] In some implementations, architecture 160 can be used to repair defective source drivers 132A and 132B. For example, if a fourth source driver 164 is identified as defective, a spare source driver 144A can be coupled to the corresponding data line 186 via a corresponding switch 184. In this way, the remaining source drivers 132A and 132B remain coupled to the corresponding data lines 176 and 178, and the defective source driver 164 is replaced only via the spare source driver 144A.

[0073] Using repair buses 188A and 188B to repair defective data lines 176 and 178 and / or defective source drivers 132A and 132B reduces the time interval between detection and correction. Furthermore, repair buses 188A and 188B and switches 172A and 172B have a relatively small impact on the power consumption used to perform the repair and a relatively small impact on the size of the architecture 160 within system 50.

[0074] Figure 14 This is a block diagram 190 of an exemplary architecture for repairing data lines according to an embodiment of this disclosure. Architecture 190 includes a plurality of switches 196A, 196B disposed between adjacent source drivers 132A and coupled to the outputs of these source drivers. That is, switch 196 is coupled to at least one data line 200 and may be coupled to an adjacent data line 200 when in a closed state. In some embodiments, switch 196 may be implemented using a plurality of multiplexers disposed between adjacent source drivers 132A and coupled to the outputs of these source drivers. Although switch 196 is shown as disposed between source drivers 132A and active array 52, it should be understood that additional switches (not shown) may be disposed between active array 52 and about Figure 12 and Figure 13 The source driver 132B under discussion.

[0075] During normal operation, such as Figure 14 As shown, switch 196 is in the open state, preventing the output of the adjacent source driver 132A from being connected. After detecting a defective data line 200, as per... Figure 10 and Figure 11 The discussed method can change the state of switches 196A and 196B between the defective data line 200 and the adjacent data line 200, so that the defective data line 200 is coupled to the adjacent data line 200.

[0076] Figure 15 The use of the implementation scheme of this disclosure is based on Figure 14 A block diagram illustrating an exemplary fix for the data line of the architecture 190 discussed. As shown, it can be used as described regarding... Figures 7 to 12 The test circuits 68 and 76 discussed are used to detect defective data lines 212. Once a defective data line 212 is detected, the states of the corresponding switches 214A and 214B can be changed so that the defective data line 212 is coupled to the adjacent data line 216. As shown in the figure, each end of the defective data line 212 is coupled to the adjacent data line 216 so that the position of the corresponding pixel 67 of the active array 52 on the defective data line 212 does not affect its operation.

[0077] Architecture 190 can also be used to repair defective source driver 132A. For example, if defective source driver 132A is identified via test circuits 68 and 76, the data line 200 corresponding to defective source driver 132A is coupled to an adjacent source driver 132A via switches 196A and 196B, and the adjacent source driver 132A replaces the defective source driver 132A.

[0078] Testing and repairing defective data lines (and / or defective source drivers) in this manner replicates signals or data on adjacent data lines. Therefore, switches 196A and 196B add a relatively small number of components to the architecture of display 18, while reducing the time required to test the architecture of display 18 and minimizing the impact on the performance of source driver 132A and system 50.

[0079] Figure 16 This is a block diagram of an exemplary architecture 300 for rapid detection of defective pixel drivers according to an embodiment of this disclosure. Architecture 300 includes a plurality of comparators 306. The comparators 306 are coupled to one or more pixel circuits of the active array 52, such as those relating to… Figure 7 The pixel circuit 64 under discussion. Comparator 306 receives voltages supplied to one or more corresponding pixel circuits 64 (or pixels 67) via source drivers (such as source drivers 58A, 58B, 106A, 106B, 132A, 132B discussed above) and compares these voltages with one or more reference voltages 302, 304. The voltage supplied to the pixel circuit 64 (or pixel 67) can be determined by sensing and converting the current through the pixel circuit 64 (or pixel 67).

[0080] Reference voltages 302 and 304 are programmable and can be set as threshold voltages to identify defective pixel circuits 64 (or pixels 67) by determining whether the voltage from pixel circuit 64 meets the reference voltages 302 and 304. A comparator uses the reference voltages 302 and 304 to determine whether the current of the source drivers (such as source drivers 58A, 58B, 106A, 106B, 132A, 132B discussed above) is relatively small or relatively large compared to the reference voltages 302 and 304. The current from the source drivers can be converted into a voltage by accumulating it across parasitic capacitances, and this voltage can be compared with the reference voltages 302 and 304. If the voltage of a particular source driver is greater than the threshold voltage, that source driver can be interpreted as a defective bright source driver. Similarly, if the voltage of a particular source driver is less than the threshold voltage, that source driver can be interpreted as a defective dark source driver. Reference voltages 302 and 304 can be programmed differently to detect defective bright source drivers and defective dark source drivers. For example, to detect defective bright source drivers, the threshold voltage can be programmed to be relatively small. To detect defective dark source drivers, the threshold voltage can be programmed to be relatively high. Once the defective source driver is identified, any suitable search (e.g., binary search) of the corresponding pixel column can be used to identify the row of the active array 52 in which the defective pixel exists.

[0081] In some implementations, comparator 306 is coupled to more than one column of pixels 67 and the corresponding pixel circuitry 64 of the active array 52. ​​Coupling more than one column of pixels to comparator 306 reduces the number of comparators 306 required to test all columns of the active array 52, and significantly reduces the time required to test each column of pixels 67 in the active array 52. ​​For example, each comparator 306 may be coupled to six columns of pixels 67. In this case, one-sixth (1 / 6) of the columns in the active array 52 can be tested simultaneously. Therefore, comparators 306 coupled to multiple columns of the active array 52 significantly reduce the time and cost of testing each column of the active array 52.

[0082] Figure 17 This is a block diagram of an exemplary architecture 350 of an on-chip IV sensing system according to an embodiment of the present disclosure. Pixel degradation of each pixel circuit 64 or OLED 66 can occur during aging of each pixel circuit 64 or OLED 66 in the active array 52. ​​Near real-time sensing and performance tracking of each pixel circuit 64 or OLED 66 are achieved via on-chip IV sensing through a current sensor 358. The current sensor 358 can be coupled to the output of each OLED 66 via a test bus 362.

[0083] In some implementations, the current sensor 358 can be used to test the aggregate current of all OLEDs 66 in the active array 52. ​​Additionally or alternatively, the current sensor 358 can be used to sense the current through any combination of each individual OLED 66 and / or pixel 67 in the active array. For this purpose, the anode of each pixel 67 is coupled to a test bus 362. The voltage of the cathode of each OLED 66 is provided to the active array 52 as an input voltage 354. The difference between the voltage at the cathode of each OLED 66 and the voltage at the anode of each OLED 66 can be used to generate a current-voltage (IV) profile for any combination of OLEDs 66 or pixels 67 in the active array 52. ​​The IV profile for each OLED 66 can be used to determine and correct for voltage and / or current degradation in each OLED 66.

[0084] The current sensor 358 enables rapid current and / or voltage sensing for each pixel 67 individually and for any combination of pixels 67. Furthermore, the current sensor 358 is capable of testing all pixels 67 in the active array 52. ​​Pixel degradation can be compensated for using the IV curve generated based on the sensing performed by the current sensor 358, which improves the quality of the active array 52 and extends its lifetime.

[0085] Figure 18 It is based on the implementation scheme of this disclosure for the purpose of relating to Figure 17 A block diagram of an exemplary architecture 400 of the test bus 362 under discussion. Figure 18 The test bus 362 shown can correspond to the following: Figure 17 The test bus under discussion. As shown in the figure, test bus 362 is coupled to multiplexer 404 for each column 356 of the active array 52. ​​Input 352 is also coupled to multiplexer 404. In some implementations, the input voltage may be coupled to the cathode of each OLED 66, such as regarding Figure 17 The input voltage under discussion is 354.

[0086] In some implementations, multiplexer 404 may be implemented as a switch. Multiplexer 404 is coupled to each pixel 67 via data line 402. In architecture 400, data line 402 may serve a dual purpose. For example, during test operation, data line 402 may be used to test the voltage and / or current of each pixel 67. In this case, data line 402 may be coupled to test bus 362 via multiplexer 404. During normal operation, data line 402 may provide voltage, such as VRST via input 352, to pixel 67. In this case, data line 402 may be coupled to input 352 via multiplexer 404.

[0087] The dual use of data line 402 eliminates the need for separate test lines from test bus 362 to each pixel 67. In other words, the combination of data line 402 and the dual use of multiplexer 404 and test bus 362 allows for testing of each pixel 67 without utilizing a large portion of the display area. Therefore, more area in architecture 400 is available for use with additional pixels of higher resolution that can be used to increase the active array 52.

[0088] Figure 19 This is a block diagram of an exemplary architecture 420 for repairing gate drivers 422, 434, 436 and / or gate driver data line 432 according to embodiments of this disclosure. Architecture 420 can serve as a reference for... Figures 8 to 18 The architectures 100, 130, 160, 190, 300, 350, and 400 discussed may be used as additional or alternatives. Architecture 420 includes one or more switches 430A, 430B between adjacent data lines 432. Data lines 432 are coupled to gate driver 422 and shift register 424. Shift register 424 may be coupled to test circuitry 426. Shift register 424 may collect data in parallel and continuously shift data from shift register 424 to test circuitry 426.

[0089] Architecture 420 may also include a switch 428 between the gate driver 422 and the active array 52. ​​During normal operation, switches 430A and 430B are in the open state and switch 428 is in the closed state. Therefore, signals from each gate driver 422 are provided along the corresponding data line 432 to the corresponding pixel row 67 of the active array 52 and to the corresponding shift register 424.

[0090] Test circuit 426 receives signals from each shift register 424 and can identify one or more defective gate drivers 422 and / or defective data lines 432 based on the received signals. For example, if no signal is received from a particular gate driver 422 and / or corresponding data line 432, the particular gate driver 422 and / or corresponding data line 432 can be identified as defective. Regardless of whether the particular gate driver 422 or corresponding data line 432 is actually defective, the state of switch 428, which couples the gate driver 422 to the active array, is changed to open. Therefore, the gate driver 422 identified as defective or coupled to the defective data line 432 is decoupled from the active array 52. ​​The states of switches 430A and 430B are also changed such that the data line 432 corresponding to the decoupled gate driver 422 is coupled to the adjacent gate driver 422 and corresponding data line 432. Therefore, the data line 432 corresponding to the defective gate driver 422 (or defective data line 432) is coupled to the adjacent gate driver 422 and corresponding data line 432.

[0091] For example, test circuit 426 can determine that data line 450 is defective. In this case, the state of switch 456, which is located between the gate driver 436 corresponding to the defective data line 450 and the active array 52, is changed to open. Therefore, gate driver 436 is decoupled from active array 52. ​​The states of switches 454 and 456 are changed to closed, causing the defective data line 450 to be coupled to the adjacent data line 452. If gate driver 436 is defective, the same procedure can be used.

[0092] Architecture 420 enables the repair of gate drivers and / or data lines using adjacent gate drivers and data lines. Therefore, the data signal provided to the adjacent data line is a copy of the data signal on the defective data line. This method allows for relatively rapid repair of defective gate drivers and / or data lines while reducing the size impact of architecture 420. In other words, relatively few components are added to the architecture to achieve adjacent line replication. For example, to achieve adjacent line replication, as few as four switches can be added for every two data lines.

[0093] While some of the implementation schemes discussed above relate to the testing, inspection, and repair of source drivers and corresponding data lines, it should be understood that the same circuitry and techniques can be used to test, inspect, and repair gate drivers and corresponding data lines. That is, the implementation schemes described herein can be used to test, inspect, and repair vertical and / or horizontal drivers and data lines of electronic displays. Furthermore, it should be noted that the testing, inspection, and repair of the drivers and corresponding data lines described herein can be performed with or without light-emitting diodes (e.g., LEDs and / or OLEDs 66) in the active array 52.

[0094] The techniques described herein and protected by the claims are referenced and applied to specific examples of physical and practical nature that significantly improve the technical field and are therefore not abstract, intangible, or purely theoretical. Furthermore, if any claim appended to the end of this specification contains one or more elements designated as "means for [performing] [function]..." or "steps for [performing] [function]...", those elements shall be interpreted in accordance with 35 USC 112(f). However, for any claim containing elements designated in any other manner, those elements shall not be interpreted in accordance with 35 U.SC 112(f).

Claims

1. An electronic display having a test circuit for identifying defective circuits in the electronic display, the electronic display comprising: An active array, the active array comprising multiple pixel circuits; A first plurality of source drivers, the first plurality of source drivers being configured to be coupled to a first subset of the plurality of pixel circuits via a first data line; A test bus, configured to be coupled to the first plurality of source drivers via a plurality of switches; and A test circuit coupled to the test bus and configured to identify defective source drivers among the first plurality of source drivers, defective pixel circuits among the plurality of pixel circuits, or defective first data lines among the first plurality of data lines via an additional source driver included in the electronic display and configured to sense voltages from the first plurality of source drivers to the plurality of pixel circuits.

2. The electronic display according to claim 1, comprising: A plurality of gate drivers are coupled to a plurality of pixel circuits via a third data line, wherein the test circuit is configured to detect defective gate drivers or defective third data lines.

3. The electronic display of claim 1, wherein the additional source driver is a corresponding source driver in a second plurality of source drivers, the second plurality of source drivers being configured to be coupled to a second subset of the plurality of pixel circuits via a second data line, wherein the test bus is coupled to the second plurality of source drivers.

4. The electronic display according to claim 3, wherein the test circuit comprises: A plurality of first switches, the plurality of first switches being configured to be coupled to the outputs of the plurality of source drivers via the first data line; A plurality of second switches are configured in a feedback loop to the first plurality of source drivers; An input line coupled to a first plurality of source drivers and a second plurality of source drivers, the second plurality of source drivers being configured to compare an input signal via the input line with the output of the first plurality of source drivers; and A controller configured to be coupled to the output of the second plurality of source drivers.

5. The electronic display according to claim 3, wherein the active array, the first plurality of source drivers, the second plurality of source drivers, the test bus, and the test circuit are disposed in a single integrated circuit.

6. The electronic display of claim 1, wherein the active array does not include light-emitting diodes (LEDs) during the testing procedure.

7. An electronic device having a display capable of identifying defective circuits, the electronic device comprising: The display includes: An active array, the active array comprising multiple pixel circuits; Multiple source drivers are coupled to the multiple pixel circuits via data lines; A test bus, configured to be coupled to the plurality of source drivers via a first plurality of switches; and A test circuit coupled to the test bus and configured to identify defective source drivers, defective pixel circuits, or defective data lines via an additional source driver included in the display and configured to sense voltages from the plurality of source drivers to the plurality of pixel circuits.

8. The electronic device of claim 7, wherein the active array does not include light-emitting diodes (LEDs) during the test procedure.

9. The electronic device according to claim 7, comprising: A plurality of gate drivers coupled to a plurality of pixel circuits, wherein the test circuit is configured to detect defective gate drivers or defective source drivers.

10. The electronic device of claim 7, wherein the active array, the plurality of source drivers, the test bus, and the test circuit are disposed in a single integrated circuit.

11. The electronic device according to claim 7, comprising: A second plurality of switches are configured to couple the plurality of source drivers to a data line, wherein the data line is coupled to the pixel circuit, wherein the second plurality of switches are closed during test operation of the plurality of source drivers.

12. An electronic display having a test circuit for identifying defective circuits in the electronic display, the electronic display comprising: An active array, the active array comprising multiple pixel circuits; A first plurality of source drivers, the first plurality of source drivers being configured to be coupled to a first subset of the plurality of pixel circuits; The second plurality of source drivers are configured to be coupled to a second subset of the plurality of pixel circuits and serve as voltage comparators for comparing the voltage of a respective source driver among the first plurality of source drivers with an input voltage. A test bus, configured to be coupled to the first plurality of source drivers and the second plurality of source drivers via a plurality of switches; A plurality of switches, the plurality of switches being configured to couple the plurality of source drivers to the test bus; A second plurality of switches are configured to couple the first plurality of source drivers to the pixel circuit via a first data line; A third plurality of switches, the third plurality of switches being configured to couple the second plurality of source drivers to the test bus; A fourth plurality of switches are configured to couple the second plurality of source drivers to the pixel circuit via a second data line; and A test circuit coupled to the test bus and configured to identify a defective source driver among the first plurality of source drivers, a defective pixel circuit among the plurality of pixel circuits, or a defective first data line among the first data lines via a respective source driver among the second plurality of source drivers.

13. The electronic display of claim 12, wherein during a test operation testing the first plurality of source drivers, the first plurality of switches are open and the third plurality of switches are closed.

14. The electronic display of claim 13, wherein the second plurality of switches are closed and the fourth plurality of switches are open.

15. The electronic display of claim 12, wherein the test circuit is further configured to identify a defective source driver in the second plurality of source drivers, a defective pixel circuit in the plurality of pixel circuits, or a defective second data line in the second data line via a respective source driver in the first plurality of source drivers.

16. The electronic display of claim 12, wherein during a test operation testing the second plurality of source drivers, the first plurality of switches are closed and the third plurality of switches are open.

17. The electronic display of claim 12, wherein the active array, the first plurality of source drivers, the second plurality of source drivers, the test bus, the first plurality of switches, the second plurality of switches, the third plurality of switches, the fourth plurality of switches, and the test circuit are disposed in a single integrated circuit.

18. The electronic display according to claim 12, wherein: The test circuit includes: Input lines, coupled to a first plurality of source drivers and a second plurality of source drivers, wherein the second plurality of source drivers are configured to compare an input signal via the input lines with the outputs of the first plurality of source drivers; and A controller configured to be coupled to the output of the second plurality of source drivers.

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