Patent Publication Number: US-11645957-B1

Title: Defective display source driver screening and repair

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 63/076,848, filed Sep. 10, 2020, and entitled “DEFECTIVE DISPLAY SOURCE DRIVER SCREENING AND REPAIR,” which is incorporated herein by reference in its entirety for all purposes. 
    
    
     SUMMARY 
     The present disclosure generally relates to electronic displays and, more particularly, to testing and correcting voltage degradation in an electronic display with voltage-driven and/or current-driven pixels. 
     Flat panel displays, such as light-emitting diode (LED) displays or organic-LED (OLED) displays, are commonly used in a wide variety of electronic devices, including such consumer electronics such as televisions, computers, and handheld devices (e.g., cellular telephones, audio and video players, gaming systems, and so forth). Such display panels typically provide a flat display in a relatively thin package that is suitable for use in a variety of electronic goods. In addition, such devices may use less power than comparable display technologies, making them suitable for use in battery-powered devices or in other contexts where it is desirable to minimize power usage. 
     LED displays typically include picture elements (e.g., pixels) arranged in a matrix to display an image that may be viewed by a user. Individual pixels of an LED display may generate light as current is applied to each pixel. Current may be applied to each pixel by programming a voltage to the pixel that is converted by circuitry of the pixel into the current. The circuitry of the pixel that converts the voltage into the current may include, for example, thin film transistors (TFTs). However, certain operating conditions, such as aging or temperature, may affect the amount of current applied to a pixel when applying a certain voltage. 
     Similarly, components providing the current to the pixel, such as a source driver, may fail for various reasons. In that case, no current may be provided to a corresponding pixel. Conventionally, a test electrode coupled to each source driver is connected to an external test circuit to identify the failed component. This approach takes a significant amount of time to connect to and test each component. Further, the additional test electrodes and corresponding data lines use a significant amount of space on the integrated circuit of the display leaving a small amount of space for additional pixels that can be used to increase a resolution of the display. 
     Display panel sensing allows for operational properties of pixels of an electronic display to be identified to improve the performance of the electronic display. For example, variations in temperature and pixel aging (among other things) across the electronic display cause pixels in different locations on the display to behave differently. Indeed, the same image data programmed on different pixels of the display could appear to be different due to the variations in temperature and pixel aging. For example, a pixel emits an amount of light, gamma, or gray level based at least in part on an amount of current supplied to a diode (e.g., an LED) of the pixel. For voltage-driven pixels, a target voltage may be applied to the pixel to cause a target current to be applied to the diode (e.g., as expressed by a current-voltage relationship or curve) to emit a target gamma value. Variations may affect a pixel by, for example, changing the resulting current that is applied to the diode when applying the target voltage. Without appropriate compensation, these variations could produce undesirable visual artifacts. 
     Accordingly, the techniques and systems described below may be used to test and compensate for functionality of various components of the display. Testing circuitry is coupled to each pixel of the display. The testing circuitry may compensate for one or more components of the display that malfunction (e.g., are broken). The testing circuitry may determine a current through circuitry of each pixel of the display to confirm operation of each pixel and corresponding components. 
     Various refinements of the features noted above may exist in relation to various aspects of the present disclosure. Further features may also be incorporated in these various aspects as well. These refinements and additional features may exist individually or in any combination. For instance, various features discussed below in relation to one or more of the illustrated embodiments may be incorporated into any of the above-described aspects of the present disclosure alone or in any combination. The brief summary presented above is intended only to familiarize the reader with certain aspects and contexts of embodiments of the present disclosure without limitation to the claimed subject matter. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Various aspects of this disclosure may be better understood upon reading the following detailed description and upon reference to the drawings described below. 
         FIG.  1    is a block diagram of an electronic device, according to an embodiment of the present disclosure. 
         FIG.  2    is a perspective view of a notebook computer representing an embodiment of the electronic device of  FIG.  1   . 
         FIG.  3    is a front view of a handheld device representing another embodiment of the electronic device of  FIG.  1   . 
         FIG.  4    is a front view of another handheld device representing another embodiment of the electronic device of  FIG.  1   . 
         FIG.  5    is a front view of a desktop computer representing another embodiment of the electronic device of  FIG.  1   . 
         FIG.  6    is a perspective view of a wearable electronic device representing another embodiment of the electronic device of  FIG.  1   . 
         FIG.  7    is a block diagram of a system for display sensing and testing, according to an embodiment of the present disclosure. 
         FIG.  8    is a block diagram of an example architecture for screening source drivers of a display, according to an embodiment of the present disclosure. 
         FIG.  9    is a block diagram of an example architecture for repairing a source driver, according to an embodiment of the present disclosure. 
         FIG.  10    is a block diagram of the example architecture for repairing a source driver of  FIG.  9   , according to an embodiment of the present disclosure. 
         FIG.  11    is a block diagram of an example repair of a source driver using the architecture of  FIGS.  9  and  10   , according to an embodiment of the present disclosure. 
         FIG.  12    is a block diagram of an example architecture for repairing a data line using a repair bus, according to an embodiment of the present disclosure. 
         FIG.  13    is a block diagram of an example repair of a data line using a repair bus, according to an embodiment of the present disclosure. 
         FIG.  14    is a block diagram of an example architecture for repairing a data line, according to an embodiment of the present disclosure. 
         FIG.  15    is a block diagram of an example repair of a data line using replication, according to an embodiment of the present disclosure. 
         FIG.  16    is a block diagram of an example architecture for fast detection of a defective pixel, according to an embodiment of the present disclosure. 
         FIG.  17    is a block diagram of an example architecture of an on-chip IV sensing system, according to an embodiment of the present disclosure. 
         FIG.  18    is a block diagram of an example architecture for a test bus discussed with respect to  FIG.  17   , according to an embodiment of the present disclosure. 
         FIG.  19    is a block diagram of an example architecture for repairing a gate driver and/or gate driver line data line, according to an embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS 
     One or more specific embodiments will be described below. In an effort to provide a concise description of these embodiments, not all features of an actual implementation are described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers&#39; specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure. 
     When introducing elements of various embodiments of the present disclosure, the articles “a,” “an,” and “the” are intended to mean that there are one or more of the elements. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. Additionally, it should be understood that references to “one embodiment” or “an embodiment” of the present disclosure are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited 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 inclusive (e.g., logical OR) and 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. 
     Electronic displays are ubiquitous in modern electronic devices. As electronic displays gain ever-higher resolutions and dynamic range capabilities, image quality has increasingly grown in value. In general, electronic displays contain numerous picture elements, or “pixels,” that are programmed with image data. Each pixel emits a particular amount of light based at least in part on the image data. By programming different pixels with different image data, graphical content including images, videos, and text can be displayed. 
     Display panel sensing allows for operational properties of pixels of an electronic display to be identified to improve the performance of the electronic display. For example, variations in temperature and pixel aging (among other things) across the electronic display cause pixels in different locations on the display to behave differently. Indeed, the same image data programmed on different pixels of the display could appear to be different due to the variations in temperature and pixel aging. For example, a pixel emits an amount of light, gamma, or gray level based at least in part on an amount of current supplied to a diode (e.g., an LED) of the pixel. For voltage-driven pixels, a target voltage may be applied to the pixel to cause a target current to be applied to the diode (e.g., as expressed by a current-voltage relationship or curve) to emit a target gamma value. Variations may affect a pixel by, for example, changing the resulting current that is applied to the diode when applying the target voltage. Without appropriate compensation, these variations could produce undesirable visual artifacts. 
     Accordingly, the techniques and systems described below may be used to test and compensate for functionality of various components of the display. Testing circuitry is coupled to each pixel of the display. The testing circuitry may compensate for one or more components of the display that malfunction (e.g., are broken). The testing circuitry may determine a current through circuitry of each pixel of the display to confirm operation of each pixel and corresponding components. 
     With this in mind, a block diagram of an electronic device  10  is shown in  FIG.  1   . As will be described in more detail below, the electronic device  10  may represent any suitable electronic device, such as a computer, a mobile phone, a portable media device, a tablet, a television, a virtual-reality headset, a vehicle dashboard, or the like. The electronic device  10  may represent, for example, a notebook computer  10 A as depicted in  FIG.  2   , a handheld device  10 B as depicted in  FIG.  3   , a handheld device  10 C as depicted in  FIG.  4   , a desktop computer  10 D as depicted in  FIG.  5   , a wearable electronic device  10 E as depicted in  FIG.  6   , or a similar device. 
     The electronic device  10  shown in  FIG.  1    may include, for example, a processor core complex  12 , a local memory  14 , a main memory storage device  16 , an electronic display  18 , input structures  22 , an input/output (I/O) interface  24 , network interfaces  26 , and a power source  29 . The various functional blocks shown in  FIG.  1    may include hardware elements (including circuitry), software elements (including machine-executable instructions stored on a tangible, non-transitory medium, such as the local memory  14  or the main memory storage device  16 ) or a combination of both hardware and software elements. It should be noted that  FIG.  1    is merely one example of a particular implementation and is intended to illustrate the types of components that may be present in electronic device  10 . Indeed, the various depicted components may be combined into fewer components or separated into additional components. For example, the local memory  14  and the main memory storage device  16  may be included in a single component. 
     The processor core complex  12  may carry out a variety of operations of the electronic device  10 , such as causing the electronic display  18  to perform display panel sensing and using the feedback to repair a detected defect in the circuitry of the electronic display  18  and/or adjust image data to be displayed on the electronic display  18 . The processor core complex  12  may include any suitable data processing circuitry to perform these operations, such as one or more microprocessors, one or more application specific processors (ASICs), or one or more programmable logic devices (PLDs). In some cases, the processor core complex  12  may execute programs or instructions (e.g., an operating system or application program) stored on a suitable article of manufacture, such as the local memory  14  and/or the main memory storage device  16 . In addition to instructions for the processor core complex  12 , the local memory  14  and/or the main memory storage device  16  may also store data to be processed by the processor core complex  12 . By way of example, the local memory  14  may include random access memory (RAM) and the main memory storage device  16  may include read only memory (ROM), rewritable non-volatile memory such as flash memory, hard drives, optical discs, or the like. 
     The electronic display  18  may display image frames, such as a graphical user interface (GUI) for an operating system or an application interface, still images, or video content. The processor core complex  12  may supply at least some of the image frames. The electronic display  18  may be a self-emissive display, such as an organic light emitting diodes (OLED) display, a micro-LED display, a micro-OLED type display, or a liquid crystal display (LCD) illuminated by a backlight. In some embodiments, the electronic display  18  may include a touch screen, which may allow users to interact with a user interface of the electronic device  10 . The electronic display  18  may employ display panel sensing to identify operational variations of the electronic display  18 . This may allow the processor core complex  12  to adjust image data that is sent to the electronic display  18  to compensate for these variations, thereby improving the quality of the image frames appearing on the electronic display  18 . 
     The input structures  22  of the electronic device  10  may enable a user to interact with the electronic device  10  (e.g., pressing a button to increase or decrease a volume level). The I/O interface  24  may enable electronic device  10  to interface with various other electronic devices, as may the network interface  26 . The network interface  26  may include, for example, interfaces for a personal area network (PAN), such as a Bluetooth network, for a local area network (LAN) or wireless local area network (WLAN), such as an 802.11x Wi-Fi network, and/or for a wide area network (WAN), such as a cellular network. The 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 broadcasting-terrestrial (DVB-T) and its extension DVB Handheld (DVB-H), ultra wideband (UWB), alternating current (AC) power lines, and so forth. The power source  29  may include any suitable source of power, such as a rechargeable lithium polymer (Li-poly) battery and/or an alternating current (AC) power converter. 
     In certain embodiments, the electronic device  10  may take the form of a computer, a portable electronic device, a wearable electronic device, or other type of electronic device. Such computers may include computers that are generally portable (such as laptop, notebook, and tablet computers) as well as computers that are generally used in one place (such as conventional desktop computers, workstations and/or servers). In certain embodiments, the electronic device  10  in the form of a computer may be a model of a MacBook®, MacBook® Pro, MacBook Air®, iMac®, Mac® mini, or Mac Pro® available from Apple Inc. of Cupertino, Calif. By way of example, the electronic device  10 , taking the form of a notebook computer  10 A, is illustrated in  FIG.  2    in accordance with one embodiment of the present disclosure. The depicted computer  10 A may include a housing or enclosure  36 , an electronic display  18 , input structures  22 , and ports of an I/O interface  24 . In one embodiment, the input structures  22  (such as a keyboard and/or touchpad) may be used to interact with the computer  10 A, such as to start, control, or operate a GUI or applications running on computer  10 A. For example, a keyboard and/or touchpad may allow a user to navigate a user interface or application interface displayed on the electronic display  18 . 
       FIG.  3    depicts a front view of a handheld device  10 B, which represents one embodiment of the electronic device  10 . The handheld device  10 B may represent, for example, a portable phone, a media player, a personal data organizer, a handheld game platform, or any combination of such devices. By way of example, the handheld device  10 B may be a model of an iPod® or iPhone® available from Apple Inc. The handheld device  10 B may include an enclosure  36  to protect interior components from physical damage and to shield them from electromagnetic interference. The enclosure  36  may surround the electronic display  18 . The I/O interfaces  24  may open through the enclosure  36  and may include, for example, an I/O port for a hard wired connection for charging and/or content manipulation using a standard connector and protocol, such as the Lightning connector provided by Apple Inc., a universal service bus (USB), or other similar connector and protocol. 
     User input structures  22 , in combination with the electronic display  18 , may allow a user to control the handheld device  10 B. For example, the input structures  22  may activate or deactivate the handheld device  10 B, navigate user interface to a home screen, a user-configurable application screen, and/or activate a voice-recognition feature of the handheld device  10 B. Other input structures  22  may provide volume control, or may toggle between vibrate and ring modes. The input structures  22  may also include a microphone may obtain a user&#39;s voice for various voice-related features, and a speaker may enable audio playback and/or certain phone capabilities. The input structures  22  may also include a headphone input may provide a connection to external speakers and/or headphones. 
       FIG.  4    depicts a front view of another handheld device  10 C, which represents another embodiment of the electronic device  10 . The handheld device  10 C may represent, for example, a tablet computer or portable computing device. By way of example, the handheld device  10 C may be a tablet-sized embodiment of the electronic device  10 , which may be, for example, a model of an iPad® available from Apple Inc. 
     Turning to  FIG.  5   , a computer  10 D may represent another embodiment of the electronic device  10  of  FIG.  1   . The computer  10 D may be any computer, such as a desktop computer, a server, or a notebook computer, but may also be a standalone media player or video gaming machine. By way of example, the computer  10 D may be an iMac®, a MacBook®, or other similar device by Apple Inc. It should be noted that the computer  10 D may also represent a personal computer (PC) by another manufacturer. A similar enclosure  36  may be provided to protect and enclose internal components of the computer  10 D such as the electronic display  18 . In certain embodiments, a user of the computer  10 D may interact with the computer  10 D using various peripheral input devices, such as input structures  22 A or  22 B (e.g., keyboard and mouse), which may connect to the computer  10 D. 
     Similarly,  FIG.  6    depicts a wearable electronic device  10 E representing another embodiment of the electronic device  10  of  FIG.  1    that may be operated using the techniques described herein. By way of example, the wearable electronic device  10 E, which may include a wristband  43 , may be an Apple Watch® by Apple, Inc. However, in other embodiments, the wearable electronic device  10 E may include any wearable electronic device such as, for example, a wearable exercise monitoring device (e.g., pedometer, accelerometer, heart rate monitor), or other device by another manufacturer. The electronic display  18  of the wearable electronic device  10 E may include a touch screen display  18  (e.g., LCD, OLED display, active-matrix organic light emitting diode (AMOLED) display, and so forth), as well as input structures  22 , which may allow users to interact with a user interface of the wearable electronic device  10 E. 
       FIG.  7    is a block diagram of a system  50  for display sensing and testing, according to an embodiment of the present disclosure. The system  50  may be included in the display  18  of the electronic device  10  discussed with respect to  FIG.  1   . The system  50  includes an active array  52  and a reference array  54 . The reference array  54  includes a number of reference pixels  55 . The reference array  54  may be used to test and track an operation of the reference pixels  55 , each of which may correspond to one or more pixels  67  of the active array  52 . As illustrated, the pixels  67  of the active array  52  may include pixel circuitry  64  and a light emitting diode such as a micro-LED, a micro-OLED, or an organic light-emitting diode (OLED)  66 . Based on the operation of the reference pixels  55 , one or more parameters (e.g., a current, an output luminance, etc.) of the corresponding pixels  67  of the active array  52  may be adjusted. The pixel circuitry  64  of the pixel  67  may be tested with or without the OLEDs  66  installed in the active array  52 . This may allow the circuitry of the active array  52  to be tested to ensure proper operation before the OLEDs  66  are installed. 
     The active array  52  includes a number of pixels  67  arranged in a matrix. The processor core complex  12 , discussed with respect to  FIG.  1   , may provide image data to the pixels  67  via driver circuitry such as one or more source drivers  58 A,  58 B and one or more gate drivers  84 . The one or more source drivers  58 A,  58 B and the one or more gate drivers  84  may be coupled to a respective pixel  67  via pixel circuitry  64  to activate or illuminate an OLED  66  based on image data. In some embodiments, the one or more gate drivers  84  may also provide reset, on-bias stress, and/or pixel activation signals to the pixels  67 , to prepare the pixels  67  to receive data via the source drivers  58 A,  58 B. A source latch  56 A,  56 B is coupled to each of the source drivers  58 A,  58 B. The source latch  56 A,  56 B may provide image data to each of the source drivers  58 A,  58 B to activate/illuminate each pixel  67 . 
     Each source driver  58 A,  58 B may couple to a test bus  60 ,  62  via a respective test switch  92 A,  92 B to provide a signal to test circuitry  68 ,  76 . The test circuitry  68 ,  76  may include an analog front end (AFE) and/or an analog to digital converter (ADC). That is, an analog signal may be received by the test circuitry  68 ,  76  via the test bus and converted by the ADC for testing. During normal operation of the system  50 , a state of the test switches  92 A,  92 B are open such that the source drivers  58 A,  58 B are decoupled from the test bus  60 ,  62 . During testing of the source drivers  58 A,  58 B, a state of the test switches  92 A,  92 B may be changed to closed such that the source drivers  58 A,  58 B are coupled to the test bus  60 ,  62 . The test switches  92 A,  92 B enable testing of one, all, or some combination of the source drivers  58 A,  58 B simultaneously. 
     Thus, the test switches  92 A,  92 B enable isolation of one or more source drivers  58 A,  58 B to be tested. In some embodiments, a data switch  90 A,  90 B may be disposed between and coupled to the source drivers  58 A,  58 B and the pixel circuitries  64 . During normal operation, the data switches  90 A,  90 B may be in a closed state such that the source drivers  58 A,  58 B are coupled to the pixel circuitry  64  of the pixels  67 . During a testing operation, the data switches  90 A,  90 B may be in an opened state. 
     The test buses  60 ,  62  are coupled to the test circuitry  68 ,  76 . The signal provided to the test circuitry  68 ,  76  by the source drivers  58 A,  58 B may be a voltage or current that would otherwise be provided to respective pixel circuitry  64 . The test circuitry  68 ,  76  may include various components, such as, for example, multiplexers and/or switches, to receive one or more signals from the source drivers  58 A,  58 B, the gate drivers  84 , the pixel circuitry  64 , data lines  70  between the source drivers  58 A,  58 B and the pixel circuitry  64 , and the like. For each pixel  67 , the test circuitry  68 ,  76  may determine whether a defect exists in a respective source driver  58 A,  58 B, a respective gate driver  84 , a respective pixel circuitry  64 , a data line between the respective source driver  58 A,  58 B and the respective pixel circuitry  64 , and the like based at least in part on the one or more signals. The various components of the test circuitry  68 ,  76  are discussed in more detail with respect to  FIGS.  8 - 19    below. 
       FIG.  8    is a block diagram of an example architecture  100  for screening source drivers of a display, according to an embodiment of the present disclosure. The architecture  100  includes a number of source drivers  106 A,  106 B coupled to a number of multiplexers  104 A,  104 B,  108 A,  108 B. In some embodiments, the source driver  106 A,  106 B may correspond to the source drivers  58 A,  58 B, respectively, discussed with respect to  FIG.  7   . 
     An input signal (e.g., gamma) is provided to the source drivers  106 A,  106 B via the multiplexers  104 A,  104 B. The multiplexers  104 A provide the input signal to the first source drivers  106 A and the multiplexers  104 B provide the input signal to the second source drivers  106 B, based on respective code lines  102 A,  102 B. In some embodiments, first multiplexers  108 A and second multiplexers  108 B are switches that route an output of at least some of the pluralities of source drivers  106 A,  106 B to a corresponding opposite source driver  106 B or  106 A. 
     To test a number of first source drivers  106 A and corresponding data lines  112 , a corresponding number of second source drivers  106 B may function as voltage comparators. Respective first multiplexers  108 A are switched such that outputs from respective second source drivers  106 B are provided to a controller  122 . For example, the second source drivers  106 B may be coupled to receive the input signal and coupled to respective data lines  112  of the first source drivers  106 A. In that case, the first multiplexers  108 A may provide feedback to the first source drivers  106 A from the data line  112 . The second source drivers  106 B may receive and compare the input signal from the multiplexers  104 B and a signal from the first source drivers  106 A via the data line  112 . The second source drivers  106 B provide a comparison result to the controller  122 . The comparison by the second multiplexers  108 B may be performed for each of the first source drivers  106 A regardless of whether the input signal is received. That is, the comparison may be performed to ensure the input signal is provided to the data line  112  and/or to ensure the data line  112  is not shorted. 
     A similar configuration may be used to test the second source drivers  106 B and corresponding data lines  110 . In that case, the second multiplexers  108 B may provide feedback to the second source drivers  106 B. The first multiplexers  108 A may receive and compare the input signal from the multiplexers  104 A and a signal from the second source drivers  106 B via the data line  110 . The first source drivers  106 A provide the comparison result to the controller  122 . 
     Although not shown, the data lines  110 ,  112  may be coupled to one or more pixels of the display  18 , such as the pixels  67  discussed with respect to  FIG.  7   . That is, the architecture  100  may be used to test the source drivers  106 A,  106 B with or without the pixels installed in the display. In this way, the architecture  100  can be tested during manufacturing which reduces downtime to correct an issue with the source drivers  106 A,  106 B and the data lines  110 ,  112 . Testing before the pixels are installed in the display  18  can also reduce voltage degradation of the pixels  67  during testing. 
     Testing via source drivers opposite the source drivers being tested reduces a time to test the source drivers (and respective data lines) by testing the source drivers simultaneously. Further, the pluralities of first and second multiplexers  108 A,  108 B enable testing of the source drivers with minimal components added to the architecture  100  of the display. That is, for example, some existing circuitry of a display panel is utilized for the testing without significantly increasing a size of the existing architecture. 
       FIG.  9    is a block diagram of an example architecture  130  for repairing a source driver  132 , according to an embodiment of the present disclosure. The architecture  130  includes source drivers  132  coupled to the active array  52 . In some embodiments, the source drivers  132  corresponds to the first source drivers  106 A or the second source drivers  106 B discussed with respect to  FIG.  8   . 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 in the active array  52 . 
     Each source driver  132  may include a gamma multiplexer  136  and an amplifier  138 . The gamma multiplexer  136  may convert a digital data signal to a voltage to drive a respective column of pixels  67  of the active array  52 . A source latch  134  is coupled to and provides an input signal to each source driver  132 . 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 switches  140  are coupled to adjacent and alternating source drivers  132 . That is, a first switch  140  may couple a first source driver  132  ( 1 ) and a second source driver  132  ( 2 ) adjacent to the first source driver  132  ( 1 ). A second switch  140  may couple a third source driver  132  ( 3 ) and a fourth source driver  132  ( 4 ) adjacent to the third source driver  132  ( 3 ), where the third source driver  132  ( 3 ) is also adjacent to the second source driver  132  ( 2 ). 
     In some embodiments, the 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 . The one or more spare source drivers  144  may be used if a defective source driver  132  is identified, as discussed below. The source drivers  132  may be tested using a testing architecture such as the architecture  100  discussed with respect to  FIG.  8   . 
     Upon detection of a defective source driver  132  (e.g., through a test or calibration during manufacture or once in operation), a spare source latch  146  may be coupled to the spare source driver  144 . One or more repair registers  142  may also change the state of the switches  140  depending on a location of the defective source driver  132 . Although a single spare source  144  driver is illustrated to the right of the source drivers  132 , it should be understood that more than one spare source driver  144  may be present and/or may be positioned between and/or to the right of the source drivers  132 . Further, although a spare source driver  144  is illustrated, it should be understood that one or more spare gate drivers may be included in the gate drivers  84  discussed with respect to  FIG.  7   . The one or more spare gate drivers may function in a similar way to the spare source drivers  144 , as discussed below. 
       FIG.  10    is a block diagram of another architecture  141  for repairing a source driver, according to an embodiment of the present disclosure. As used herein, repairing a defective source driver may involve using a spare source driver to make up for the defective source driver. The example architecture  141  in  FIG.  10    illustrates the source drivers  132  coupled to the source latch  134  via one or more switches  152 . The one or more switches  152  are disposed between the source latch  150  and the source drivers  132 . In some embodiments, the one or more switches  152  may be multiplexers, similar to the switches  140  between the source drivers  132  and the active array  52 . 
     In the example state illustrated in  FIG.  10   , an output of each repair register  142  is high (e.g.,  1 ) such that the switches  140  pass an output of the source drivers  132  to corresponding pixels  67  in the active array  52 . When a defective source driver  132  is detected, a state of one or more of the repair registers  142  may be changed along with the corresponding switches  140 , as discussed with respect to  FIG.  11   . 
       FIG.  11    is a block diagram of an example state for repair of a source driver  132  using the architecture  141  of  FIG.  10   , according to an embodiment of the present disclosure. As illustrated, a defect is detected in a fourth source driver  154  (i.e., source driver number  4  illustrated in  FIG.  10   ). Upon detecting the defect, a state of repair registers  142  corresponding to a first four source drivers  132  may be changed from high to low (e.g., 1 to 0), which causes a state of corresponding switches  140  to change. The switches  140  may change a connection of one or more of the source drivers  132  such that the one or more source drivers  132  are coupled to an adjacent column (or row) of pixels  67  in the active array  52 . For example, if a defect is detected in the fourth source driver  154 , a state of one or more switches  156  to the left of the fourth source driver  154  may be changed. A state of the respective switches  152  coupled to the source latch  134  may also be changed. 
     Changing the state of the switches  140 ,  152  may couple the spare source driver  144  to the first column (or row) of pixels  67  in the active array  52 . Thus, the spare source driver  144  may become the first source driver illustrated in  FIG.  10   . Similarly, the first source driver may become the second source driver and may be coupled to the second column (or row) of pixels  67  in the active array  52 . The second source driver may become the third source driver and may be coupled to the third column (or row) of pixels  67  in the active array  52 . The third source driver may become the fourth source driver and may be coupled to the fourth column (or row) of pixels  67  in the active array  52 . 
     Although a connection of the source drivers  132  to the left of the defective source driver  154  are illustrated as being coupled to an adjacent column (or row) of pixels  67 , it should be understood that a similar change could occur to source drivers to the right of the defective source driver  154 . Upon detection of a defective source driver, replacement of the defective source driver  154  with an adjacent source driver  132  slightly increased the routing distance between the source latch and the active array  52 . Thus, a performance impact on the source drivers  132  and the spare source driver  144  may be mitigated. 
     In some cases, more than one defective driver may be identified during testing. In that case, a first defective source driver may be replaced as discussed above using a first spare source driver. A second defective source driver may be similarly replaced with an adjacent source driver if a second spare source driver (not shown) is present in the architecture  130 . If a second spare source driver is not present, a source driver adjacent to the second defective source driver may be coupled to the column (or row) of pixels  67  corresponding to the second defective source driver. That is, the source driver adjacent to the second defective source driver may be used to drive two columns (or rows) of pixels  67 , namely (1) the pixels corresponding to the adjacent source driver after the first defective source driver is replaced and (2) the pixels corresponding to the second defective source driver. 
     Accordingly, the embodiments discussed with respect to  FIGS.  9 - 11    reduce a time to detect and replace a defective source driver while mitigating an impact on a performance of the remaining source drivers and mitigating an impact on a number of components added to the display architecture to perform the testing. 
       FIG.  12    is a block diagram of an example architecture  160  for repairing a data line using a repair bus, according to an embodiment of the present disclosure. The architecture  160  may be used in concert with the testing architecture  100  discussed with respect to  FIG.  8    to test pluralities of source drivers  132 A,  132 B. In some embodiments, pluralities of source drivers  132 A,  132 B may correspond to the source drivers  58 A,  58 B, discussed with respect to  FIG.  7   , respectively. Each of the pluralities of source drivers  132 A,  132 B include a spare source driver  144 A,  144 B, respectively. The architecture  160  includes one or more first switches  172 A and one or more second switches  172 B opposite the one or more first switches  172 A. The architecture  160  also includes testing multiplexers  170 A,  170 B coupled to the first switches  172 A and the second switches  172 B, respectively. The testing multiplexers  170 A,  170 B are coupled to the test circuitry  68 ,  76 . 
     The first switches  172 A are disposed between the source drivers  132 A and a first repair bus  188 A. The second switches  172 B are disposed between the source drivers  132 B and a second repair bus  188 B. The first switches  172 A control whether the source drivers  132 A are coupled to respective data lines  178  and/or a testing multiplexer  170 A and test circuitry  68 . Similarly, the second switches  172 B control whether the source drivers  132 B are coupled to respective data lines  176  and/or the testing multiplexer  170 B and the test circuitry  76 . 
     The test circuitry  68 ,  76  may be used to identify a defective data lines  176 ,  178  coupled to the respective source drivers  132 A,  132 B. For example, if a defect in the architecture  160  is identified via the test circuitry, but each of the source drivers  132 A,  132 B is operating properly, a defect is likely present in a data line  176 ,  178  (or a switch  172 A,  172 B). In that case, a state of the switches  172 A,  172 B is changed such that a spare source driver  144 A,  144 B is coupled to a first portion of the defective data line  176 ,  178 . Similarly, a state of the switches is changed such that the source driver coupled to the defective data line  176 ,  178  from the source driver  132 A,  132 B originally coupled to the defective data line  176 ,  178  is replicated and provided to the spare source driver  144 A,  144 B now connected to the defective data line  176 ,  178 . 
       FIG.  13    is a block diagram of an example repair of a data line using the architecture  160  discussed with respect to  FIG.  12   , according to an embodiment of the present disclosure. Upon detecting a defect in a fourth data line  186  coupled to a source driver  132 A, a state of a respective switch  184  is changed to couple a first portion of the defective data line  186  to the repair bus  188 A. Similarly, a state of a respective switch  182  is changed to couple a second portion of the defective data line  186  to the repair bus  188 B. The first portion of the defective data line  186  is driven via the spare source driver  144 A and the second source driver is driven via the respective source driver  180 . Depending on a location of the pixel  67  coupled to the defective data line  186 , the first portion of the defective data line  186  may be driven via the respective source driver  164  and the second portion of the defective data line may be driven via the spare source driver  144 B. The test circuitry  68 ,  76  may be used to identify which source driver  132 A,  132 B,  144 A,  144 B is used to drive a particular portion of the defective data line  186 . 
     In some embodiments, the architecture  160  may be used to repair a defective source driver  132 A,  132 B. For example, if the fourth source driver  164  is identified as defective, the spare source driver  144 A may be coupled to the respective data line  186  via the respective switch  184 . In this way, the remaining source drivers  132 A,  132 B remain coupled to the respective data lines  176 ,  178  and only the defective source driver  164  is replaced via the spare source driver  144 A. 
     Using the repair buses  188 A,  188 B to repair a defective data line  176 ,  178  and/or a defective source driver  132 A,  132 B reduces a time period between detection and correction. Further, the repair buses  188 A,  188 B and the switches  172 A,  172 B have a relatively small impact on power consumption for performing the repair and a relatively small impact on the size of the architecture  160  within the system  50 . 
       FIG.  14    is a block diagram of an example architecture  190  for repairing a data line, according to an embodiment of the present disclosure. The architecture  190  includes a number of switches  196 A,  196 B disposed between and coupled to an output of adjacent source drivers  132 A. That is, the switches  196  are coupled to at least one data line  200  and may couple to an adjacent data line  200  when in a closed state. In some embodiments, the switches  196  may be implemented using a number of multiplexers disposed between and coupled to outputs of the adjacent source drivers  132 A. While the switches  196  are illustrated as disposed between the source drivers  132 A and the active array  52 , it should be understood that additional switches (not shown) could be disposed between the active array  52  and the source drivers  132 B discussed with respect to  FIGS.  12  and  13   . 
     During normal operation, as illustrated in  FIG.  14   , the switches  196  are in an open state such that the outputs of adjacent source drivers  132 A are not connected. Upon detection of a defective data line  200 , as discussed with respect to  FIGS.  10  and  11   , a state of the switches  196 A,  196 B between the defective data line  200  and an adjacent data line  200  may be changed such that the defective data line  200  and the adjacent data line  200  are coupled together. 
       FIG.  15    is a block diagram of an example repair of a data line using the architecture  190  discussed with respect to  FIG.  14   , according to an embodiment of the present disclosure. As illustrated, a defective data line  212  may be detected using the test circuitry  68 ,  76  as discussed with respect to  FIGS.  7 - 12   . Once the defective data line  212  is detected, a state of respective switches  214 A and  214 B may be changed so that the defective data line  212  is coupled to an adjacent data line  216 . As illustrated, each end of the defective data line  212  is coupled to the adjacent data line  216  so that a location of the corresponding pixel  67  of the active array  52  on the defective data line  212  does not affect an operation thereof. 
     The architecture  190  may also be used to repair a defective source driver  132 A. For example, if a defective source driver  132 A is identified via the test circuitry  68 ,  76 , the defective source driver  132 A is replaced by an adjacent source driver  132 A by coupling the data line  200  corresponding to the defective source driver  132 A to the adjacent source driver  132 A via the switches  196 A,  196 B. 
     Testing and repairing a defective data line (and/or a defective source driver) in this way duplicates a signal or data on an adjacent data line. Accordingly, the switches  196 A,  196 B add a relatively small number of components to the architecture of the display  18  while reducing a time to test the architecture of the display  18  and reducing an impact on performance of the source drivers  132 A and the system  50 . 
       FIG.  16    is a block diagram of an example architecture  300  for fast detection of a defective pixel driver, according to an embodiment of the present disclosure. The architecture  300  includes a number of comparators  306 . The comparators  306  are coupled to one or more pixel circuitries of the active array  52 , such as the pixel circuitries  64  discussed with respect to  FIG.  7   . The comparators  306  receive and compare a voltage provided to the corresponding one or more pixel circuitries  64  (or pixels  67 ) via source drivers, such as the source drivers  58 A,  58 B,  106 A,  106 B,  132 A,  132 B discussed above, and one or more reference voltages  302 ,  304 . The voltage provided to the pixel circuitries  64  (or pixels  67 ) may be determined by sensing and converting a current through the pixel circuitries  64  (or pixels  67 ). 
     The reference voltages  302 ,  304  are programmable and may be set to a threshold voltage to identify a defective pixel circuitry  64  (or pixel  67 ) by determining whether the voltage from the pixel circuitry  64  satisfies the reference voltages  302 ,  304 . The reference voltages  302 ,  304  are used by the comparators to determine if a current of a source driver, such as the source drivers  58 A,  58 B,  106 A,  106 B,  132 A,  132 B discussed above, is relatively small or large compared to the reference voltages  302 ,  304 . The current from the source drivers may be converted to a voltage by integrating the current onto a parasitic capacitance and comparing the voltage to the reference voltages  302 ,  304 . If the voltage of a particular source driver is larger than the threshold voltage, that source driver may be understood to be a defective bright source driver. Similarly, if the voltage of the particular source driver is smaller than the threshold voltage, that source driver may be understood to be a defective dark source driver. The reference voltages  302 ,  304  may 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 may be programmed to be relatively small. To detect defective dark source drivers, the threshold voltage may be programmed to be relatively high. Once a defective source driver is identified, any suitable search (e.g., a binary search) of a corresponding column of pixels may be used to identify a row of the active array  52  in which a defective pixel resides. 
     In some embodiments, the comparators  306  are coupled to more than one column of pixels  67  and corresponding pixel circuitry  64  of the active array  52 . Coupling more than one column to the comparators  306  reduces a number of comparators  306  to test all columns of the active array  52  and significantly reduces a time 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 that case, one sixth (⅙) of the columns in the active array  52  can be tested simultaneously. Accordingly, the comparators  306  coupled to a number of columns of the active array  52  significantly reduces a time and cost to test each column of the active array  52 . 
       FIG.  17    is a block diagram of an example architecture  350  of an on-chip IV sensing system, according to an embodiment of the present disclosure. Pixel degradation of each pixel circuitry  64  or OLED  66  may occur as each pixel circuitry  64  or OLED  66  in the active array  52  ages. On-chip IV sensing via a current sensor  358  enables near real-time sensing and performance tracking of each pixel circuitry  64  or OLED  66 . The current sensor  358  may be coupled to the output of each OLED  66  via a test bus  362 . 
     In some embodiments, the current sensor  358  may be used to test an aggregate current of all OLEDs  66  in the active array  52 . In addition or in the alternative, the current sensor  358  may be used to sense a current through each individual OLED  66  and/or any combination of pixels  67  in the active array. To do so, an anode of each pixel  67  is coupled to the test bus  362 . A voltage of a cathode of each OLED  66  is provided as an input voltage  354  to the active array  52 . A difference between the voltage at the cathode of each OLED  66  and the voltage at the anode of each OLED  66  may be used to generate a current-voltage (IV) curve for each OLED  66  or any combination of pixels  67  in the active array  52 . The IV curve for each OLED  66  may be used to determine and correct voltage and/or current degradation of each OLED  66 . 
     The current sensor  358  enables fast current and/or voltage sensing of each pixel  67  individually and any combination of pixels  67 . Further, the current sensor  358  enables testing of all pixels  67  in the active array  52 . Using the IV curve generated based on sensing by the current sensor  358  enables compensation for pixel degradation which improves a quality of the active array  52  and extends a life of the active array  52 . 
       FIG.  18    is a block diagram of an example architecture  400  for the test bus  362  discussed with respect to  FIG.  17   , according to an embodiment of the present disclosure. The test bus  362  illustrated in  FIG.  18    may correspond to the test bus discussed with respect to  FIG.  17   . As illustrated, the test bus  362  is coupled to a multiplexer  404  for each column  356  of the active array  52 . An input  352  is also coupled to the multiplexers  404 . In some embodiments, an input voltage may be coupled to a cathode of each OLED  66 , such as the input voltage  354  discussed with respect to  FIG.  17   . 
     In some embodiments, the multiplexers  404  may be implemented as switches. The multiplexers  404  are coupled to each pixel  67  via a data line  402 . In the architecture  400 , the data lines  402  may serve a dual purpose. For example, during a test operation, the data lines  402  may be used to test a voltage and/or current of each pixel  67 . In that case, the data lines  402  may be coupled to the test bus  362  via the multiplexers  404 . During normal operation, the data lines  402  may provide a voltage to the pixels  67 , such as VRST via the input  352 . In that case, the data lines  402  may be coupled to the input  352  via the multiplexers  404 . 
     The dual usage of the data lines  402  eliminates an addition of a separate testing line from the test bus  362  to each pixel  67 . That is, the dual usage of the data lines  402  in combination with the multiplexers  404  and the test bus  362  enables testing of each pixel  67  without using a large amount of the display area. Thus, more area is available in the architecture  400  for additional pixels that can be used to increase a higher resolution of the active array  52 . 
       FIG.  19    is a block diagram of an example architecture  420  for repairing a gate driver  422 ,  434 ,  436  and/or gate driver data line  432 , according to an embodiment of the present disclosure. The architecture  420  may be used in addition to or alternative to the architectures  100 ,  130 ,  160 ,  190 ,  300 ,  350 , and  400  discussed with respect to  FIGS.  8 - 18   . The architecture  420  includes one or more switches  430 A,  430 B between adjacent data lines  432 . The data lines  432  are coupled to a gate driver  422  and a shift register  424 . The shift registers  424  may be coupled to a test circuitry  426 . The shift registers  424  may collect data in parallel and shift the data serially from shift register  424  to shift register  424  into the test circuitry  426 . 
     The architecture  420  may also include a switch  428  between the gate drivers  422  and the active array  52 . During normal operation, the switches  430 A,  430 B are in an open state and the switches  428  are in a closed state. Thus, a signal from each gate driver  422  is provided along a respective data line  432  to respective rows of pixels  67  of the active array  52  and to a respective shift register  424 . 
     The test circuitry  426  receives the signals from each shift register  424  and may identify one or more defective gate drivers  422  and/or data lines  432  based on the received signals. For example, a particular gate driver  422  and/or corresponding data line  432  may be identified as defective if a signal is not received from the particular gate driver  422  and/or corresponding data line  432 . Whether the particular gate driver  422  or corresponding data line  432  are actually defective, a state of the switch  428  coupling that gate driver  422  to the active array is changed to open. Thus, the gate driver  422  identified as defective or coupled to a defective data line  432  is de-coupled from the active array  52 . The states of the switches  430 A,  430 B are also changed such that the data line  432  corresponding to the decoupled gate driver  422  is coupled to an adjacent gate driver  422  and corresponding data line  432 . Thus, the data line  432  corresponding to the defective gate driver  422  (or the defective data line  432 ) is coupled to the adjacent gate driver  422  and corresponding data line  432 . 
     As an example, the test circuitry  426  may determine that the data line  450  is defective. In that case, a state of a switch  456  disposed between the gate driver  436  corresponding to the defective data line  450  and the active array  52  is changed to open. Thus, the gate driver  436  is decoupled from the active array  52 . A state of switches  454  and  456  is changed to closed, such that the defective data line  450  is coupled to the adjacent data line  452 . The same procedure may be used if the gate driver  436  were defective. 
     The architecture  420  enables repair of a gate driver and/or data line using an adjacent gate driver and data line. A data signal provided to the adjacent data line is thus replication on the defective data line. This approach enables a relatively fast repair of a defective gate driver and/or data line while reducing a size impact of the architecture  420 . That is, relatively few components are added to the architecture to enable adjacent line replication. For example, to enable adjacent line replication, as few as four switches may be added for every two data lines. 
     While some embodiments discussed above relate to testing, detection, and repair of source drivers and corresponding data lines, it should be understood that the same circuitry and techniques can be used to test, detect, and repair gate drivers and corresponding data lines. That is, the embodiments described herein may be used to test, detect, and repair vertical and/or horizontal drivers and data lines of an electronic display. Further, it should be noted that the testing, detection, and repair of drivers and corresponding data lines described herein can be performed with or without the light-emitting diodes (e.g., LEDs and/or OLEDs  66 ) installed in the active array  52 . 
     The techniques presented and claimed herein are referenced and applied to material objects and concrete examples of a practical nature that demonstrably improve the present technical field and, as such, are not abstract, intangible or purely theoretical. Further, if any claims appended to the end of this specification contain one or more elements designated as “means for [perform]ing [a function] . . . ” or “step for [perform]ing [a function] . . . ,” it is intended that such elements are to be interpreted under 35 U.S.C. 112(f). However, for any claims containing elements designated in any other manner, it is intended that such elements are not to be interpreted under 35 U.S.C. 112(f).