PATENT DOCUMENT

Publication Number: US-11164515-B2
Application Number: US-201816603188-A
Country: US
Kind Code: B2

Title: Sensing considering image

Abstract:
An electronic device comprises an electronic display having an active area having a pixel. The electronic device also comprises processing circuitry configured to receive image data to send to the pixel and adjust the image data to generate corrected image data based at least in part on a stored correction value for the pixel. The processing circuitry also is configured to generate a test data to send to the pixel subsequent to sending corrected image data to the pixel, wherein the test data is selected based upon a comparison of at least one aspect of the corrected image data with a threshold value.

Claims:
What is claimed is: 
     
       1. An electronic device comprising:
 an electronic display comprising an active area comprising a pixel; and 
 processing circuitry configured to: 
 receive image data to send to the pixel; 
 adjust the image data to generate corrected image data based at least in part on a stored correction value for the pixel; 
 generate test data to send to the pixel subsequent to sending corrected image data to the pixel, wherein the test data is selected based upon a comparison of a gray level of the corrected image data with a threshold value to account for hysteresis caused by the corrected image data; and 
 update the stored correction value based on a sensed condition affecting the pixel in response to the test data being sent to the pixel. 
 
     
     
       2. The electronic device of  claim 1 , wherein the processing circuitry is configured to transmit the corrected image data to the electronic display. 
     
     
       3. The electronic device of  claim 2 , wherein the electronic display is configured to utilize the corrected image data to drive the pixel. 
     
     
       4. The electronic device of  claim 1 , wherein the electronic display is configured to sense the condition affecting the pixel in response to the test data being sent to the pixel. 
     
     
       5. The electronic device of  claim 1 , wherein the processing circuitry is configured to transmit a first value as the test data when the least one aspect of the corrected image data is at or above the threshold value. 
     
     
       6. The electronic device of  claim 5 , wherein the processing circuitry is configured to transmit a second value as the test data when the least one aspect of the corrected image data is below the threshold value. 
     
     
       7. The electronic device of  claim 1 , wherein processing circuitry is configured to generate the stored correction value based upon a sensed condition affecting both the pixel and at least one additional pixel adjacent to the pixel. 
     
     
       8. The electronic device of  claim 1 , wherein the stored correction value is stored in a correction map configured to store multiple stored correction values. 
     
     
       9. The electronic device of  claim 8 , wherein the processing circuitry is configured to update the correction map. 
     
     
       10. An electronic device comprising:
 processing circuitry configured to: 
 generate test data to send to a pixel of the electronic device, wherein the test data is selected based upon a comparison of a gray level of corrected image data to be transmitted to the pixel with a threshold value to account for hysteresis caused by the corrected image data. 
 
     
     
       11. The electronic device of  claim 10 , wherein the processing circuitry is configured to set the threshold value to an initial predetermined value. 
     
     
       12. The electronic device of  claim 11 , wherein the processing circuitry is configured to receive or generate the initial predetermined value during an initial configuration of the electronic device. 
     
     
       13. The electronic device of  claim 11 , wherein the processing circuitry is configured to receive or generate the initial predetermined value during a startup of the electronic device. 
     
     
       14. The electronic device of  claim 11 , wherein the processing circuitry is configured to generate the initial predetermined value to correspond to a lowest gray level or desired gray level available for the pixel that meets or exceeds a sensing reliability level. 
     
     
       15. The electronic device of  claim 11 , wherein the processing circuitry is configured to generate the initial predetermined value to correspond to value above a lowest gray level or desired gray level available for the pixel that meets or exceeds a sensing reliability level. 
     
     
       16. The electronic device of  claim 10 , wherein the processing circuitry is configured to transmit a first value as the test data when the gray level of the corrected image data is at or above the threshold value, wherein the processing circuitry is configured to transmit a second value as the test data when the gray level of the corrected image data is below the threshold value. 
     
     
       17. The electronic device of  claim 10 , wherein the processing circuitry is configured to generate the corrected image data based upon a stored correction value calculated for the pixel. 
     
     
       18. The electronic device of  claim 17 , wherein the processing circuitry is configured to alter the stored correction value based on a sensed response of the pixel to the test data. 
     
     
       19. An electronic device comprising:
 an electronic display comprising an active area comprising a first pixel and a second pixel directly adjacent to the first pixel; and 
 processing circuitry configured to: 
 receive first image data to send to the first pixel; 
 receive second image data to send to the second pixel; 
 adjust the first image data to generate first corrected image data based at least in part on a first stored correction value for the first pixel; 
 adjust the second image data to generate second corrected image data based at least in part on a second stored correction value for the second pixel; 
 generate first test data to send to the first pixel subsequent to sending the first corrected image data to the pixel, wherein the first test data is selected based upon a comparison of a gray level of the first corrected image data with a threshold value to account for hysteresis caused by the corrected image data; 
 generate second test data to send to the second pixel subsequent to sending the second corrected image data to the pixel, wherein the second test data is selected based upon a comparison of the gray level of the second corrected image data with the threshold value; 
 update the first stored correction value based on a sensed condition affecting the first pixel in response to the test data being sent to the first pixel; and 
 update the second stored correction value based on a sensed condition affecting the second pixel in response to the test data being sent to the second pixel. 
 
     
     
       20. The electronic device of  claim 19 , wherein the processing circuitry is configured transmit identical data as the first test data and the second test data when the gray level of the first corrected image data is less than the threshold value and the gray level of the second corrected image data is less than the threshold value, wherein the processing circuitry is configured transmit differing data as the first test data and the second test data when the gray level of the first corrected image data is greater than the threshold value and the gray level of the second corrected image data is greater than the threshold value.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a national stage filing of PCT Application No. PCT/US2018/024580, filed Mar. 27, 2018, and entitled “Sensing Considering Image,” which is a continuation of and claims priority to U.S. Non-Provisional application Ser. No. 15/697,221, filed Sep. 6, 2017, and entitled “Sensing Considering Image,” which claims priority to and the benefit of U.S. Provisional Application No. 62/483,237, filed on Apr. 7, 2017, and entitled “Sensing Considering Image,” the disclosures of which are hereby incorporated by reference in their entireties. 
    
    
     BACKGROUND 
     The present disclosure relates generally to electronic displays and, more particularly, to devices and methods for achieving improvements in sensing attributes of a light emitting diode (LED) electronic display or attributes affecting an LED electronic display. 
     This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present disclosure, which are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present disclosure. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art. 
     Flat panel displays, such as active matrix organic light emitting diode (AMOLED) displays, micro-LED (μLED) displays, and the like, are commonly used in a wide variety of electronic devices, including such consumer electronics 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 a voltage is applied to each pixel. The voltage applied to a pixel of an LED display may be regulated by, for example, thin film transistors (TFTs). For example, a circuit switching TFT may be used to regulate current flowing into a storage capacitor, and a driver TFT may be used to regulate the voltage being provided to the LED of an individual pixel. Finally, the growing reliance on electronic devices having LED displays has generated interest in improvement of the operation of the displays. 
     SUMMARY 
     A summary of certain embodiments disclosed herein is set forth below. It should be understood that these aspects are presented merely to provide the reader with a brief summary of these certain embodiments and that these aspects are not intended to limit the scope of this disclosure. Indeed, this disclosure may encompass a variety of aspects that may not be set forth below. 
     The present disclosure relate to devices and methods for increased determination of the performance of certain electronic display devices including, for example, light emitting diode (LED) displays, such as organic light emitting diode (OLED) displays, active matrix organic light emitting diode (AMOLED) displays, or micro LED (μLED) displays. Under certain conditions, non-uniformity of a display induced by process non-uniformity temperature gradients, or other factors across the display should be compensated for to increase performance of a display (e.g., reduce visible anomalies). The non-uniformity of pixels in a display may vary between devices of the same type (e.g., two similar phones, tablets, wearable devices, or the like), it can vary over time and usage (e.g., due to aging and/or degradation of the pixels or other components of the display), and/or it can vary with respect to temperatures, as well as in response to additional factors. 
     To improve display panel uniformity, compensation techniques related to adaptive correction of the display may be employed. For example, as pixel response (e.g., luminance and/or color) can vary due to component processing, temperature, usage, aging, and the like, in one embodiment, to compensate for non-uniform pixel response, a property of the pixel (e.g., a current or a voltage) may be measured (e.g., sensed via a sensing operation) and compared to a target value, for example, stored in a lookup table or the like, to generate a correction value to be applied to correct pixel illuminations to match a desired gray level. In this manner, modified data values may be transmitted to the display to generate compensated image data (e.g., image data that accurately reflects the intended image to be displayed by adjusting for non-uniform pixel responses). 
     However, in some embodiments, the sensed data itself may be faulty, for example, due to hysteresis of driver TFTs of the display (e.g., a lag between a present input and a past input affecting the operation of the driver TFTs). To overcome this difficulty, active selection of reference currents or voltages may be performed. For example, the current passing through the driver TFT as an image is being displayed prior to the sensing operation may be utilized as a reference current when that current is above (or at or above) a threshold level (e.g., a predetermined reference current). Additionally, for example, use of the predetermined reference current for the sensing operation may be made when a current passing through the driver TFT is below (or at or below) a threshold level (e.g., a predetermined reference current). Additional selections of reference currents applied may be based on groups of adjacent pixels taken together to determine an average current value passing therethrough or select pixels of the group of pixels may be chosen as the basis to make the threshold determination described above. The predetermined threshold value may, in some embodiments, be dynamically selected based on one or more operational characteristics of the device or it may be set to a static level. 
     Various refinements of the features noted above may be made 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 in which: 
         FIG. 1  is a schematic block diagram of an electronic device that performs display sensing and compensation, in accordance with an embodiment; 
         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 hand-held device representing another embodiment of the electronic device of  FIG. 1 ; 
         FIG. 4  is a front view of another hand-held 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 front view and side view of a wearable electronic device representing another embodiment of the electronic device of  FIG. 1 ; 
         FIG. 7  is a block diagram of an electronic display of  FIG. 1  that performs display panel sensing, in accordance with an embodiment; 
         FIG. 8  is a block diagram of a pixel of the electronic display of  FIG. 7 , in accordance with an embodiment; 
         FIG. 9  is a graphical example of updating a correction map of the electronic display of  FIG. 7 , in accordance with an embodiment; 
         FIG. 10  is a second graphical example of updating a correction map of the electronic display of  FIG. 7 , in accordance with an embodiment; 
         FIG. 11  is a third graphical example of updating a correction map of the electronic display of  FIG. 7 , in accordance with an embodiment; and 
         FIG. 12  is a diagram illustrating a portion of the electronic display of  FIG. 7 , in accordance with an embodiment. 
     
    
    
     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 on the image data. By programming different pixels with different image data, graphical content including images, videos, and text can be displayed. 
     As noted above, 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. Without appropriate compensation, these variations could produce undesirable visual artifacts. However, compensation of these variations may hinge on proper sensing of differences in the images displayed on the pixels of the display. Accordingly, the techniques and systems described below may be utilized to enhance the compensation of operational variations across the display through improvements to the generation of reference images to be sensed to determine the operational variations. 
     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  28 . 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 adjust image data for display 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, or may be 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  28  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. 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 di splayed on the electronic di splay  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. of Cupertino, Calif. 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. of Cupertino, Calif. 
     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 configured to operate 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. 
     As shown in  FIG. 7 , in the various embodiments of the electronic device  10 , the processor core complex  12  may perform image data generation and processing circuitry  50  to generate image data  52  for display by the electronic display  18 . The image data generation and processing circuitry  50  of the processor core complex  12  is meant to represent the various circuitry and processing that may be employed by the core processor  12  to generate the image data  52  and control the electronic display  18 . As illustrated, the image data generation and processing circuitry  50  may externally coupled to the electronic display  18 . However, in other embodiments, the image data generation and processing circuitry  50  may be part of the display  12 . In some embodiments, the image data generation and processing circuitry  50  may represent a graphics processing unit, a display pipeline, or the like and to facilitate control of operation of the electronic display  18 . The image data generation and processing circuitry  50  may include a processor and memory such that the processor of the image data generation and processing circuitry  50  may execute instructions and/or process data stored in memory of the image data generation and processing circuitry  50  to control operation in the electronic display  12 . 
     As previously discussed, since it may be desirable to compensate for image data  52 , for example, based on manufacturing and/or operational variations of the electronic display  18 , the processor core complex  12  may provide sense control signals  54  to cause the electronic display  18  to perform display panel sensing to generate display sense feedback  56 . The display sense feedback  56  represents digital information relating to the operational variations of the electronic display  18 . The display sense feedback  56  may take any suitable form, and may be converted by the image data generation and processing circuitry  50  into a compensation value that, when applied to the image data  52 , appropriately compensates the image data  52  for the conditions of the electronic display  18 . This results in greater fidelity of the image data  52 , reducing or eliminating visual artifacts that would otherwise occur due to the operational variations of the electronic display  18 . 
     The electronic display  18  includes an active area  64  with an array of pixels  66 . The pixels  66  are schematically shown distributed substantially equally apart and of the same size, but in an actual implementation, pixels of different colors may have different spatial relationships to one another and may have different sizes. In one example, the pixels  66  may take a red-green-blue (RGB) format with red, green, and blue pixels, and in another example, the pixels  66  may take a red-green-blue-green (RGBG) format in a diamond pattern. The pixels  66  are controlled by a driver integrated circuit  68 , which may be a single module or may be made up of separate modules, such as a column driver integrated circuit  68 A and a row driver integrated circuit  68 B. The driver integrated circuit  68  (e.g.,  68 B) may send signals across gate lines  70  to cause a row of pixels  66  to become activated and programmable, at which point the driver integrated circuit  68  (e.g.,  68 A) may transmit image data signals across data lines  72  to program the pixels  66  to display a particular gray level (e.g., individual pixel brightness). By supplying different pixels  66  of different colors with image data to display different gray levels, full-color images may be programmed into the pixels  66 . The image data may be driven to an active row of pixel  66  via source drivers  74 , which are also sometimes referred to as column drivers. 
     As described above, display  18  may display image frames through control of its luminance of its pixels  66  based at least in part on received image data. When a pixel  66  is activated (e.g., via a gate activation signal across a gate line  70  activating a row of pixels  66 ), luminance of a display pixel  66  may be adjusted by image data received via a data line  72  coupled to the pixel  66 . Thus, as depicted, each pixel  66  may be located at an intersection of a gate line  70  (e.g., a scan line) and a data line  72  (e.g., a source line). Based on received image data, the display pixel  40  may adjust its luminance using electrical power supplied from a power supply  38 , for example, via power a supply lines coupled to the pixel  66 . 
     As illustrated in  FIG. 8 , each pixel  66  may include a circuit switching thin-film transistor (TFT)  76 , a storage capacitor  78 , an LED  80 , and a driver TFT  82  (whereby each of the storage capacitor  78  and the LED  80  may be coupled to a common voltage, Vcom or ground). However, variations may be utilized in place of illustrated pixel  66  of  FIG. 8 . To facilitate adjusting luminance, the driver TFT  82  and the circuit switching TFT  76  may each serve as a switching device that is controllably turned on and off by voltage applied to its respective gate. In the depicted embodiment, the gate of the circuit switching TFT  76  is electrically coupled to a gate line  70 . Accordingly, when a gate activation signal received from its gate line  70  is above its threshold voltage, the circuit switching TFT  76  may turn on, thereby activating the pixel  66  and charging the storage capacitor  78  with image data received at its data line  72 . 
     Additionally, in the depicted embodiment, the gate of the driver TFT  82  is electrically coupled to the storage capacitor  78 . As such, voltage of the storage capacitor  78  may control operation of the driver TFT  82 . More specifically, in some embodiments, the driver TFT  82  may be operated in an active region to control magnitude of supply current flowing through the LED  80  (e.g., from a power supply or the like providing Vdd). In other words, as gate voltage (e.g., storage capacitor  78  voltage) increases above its threshold voltage, the driver TFT  82  may increase the amount of its channel available to conduct electrical power, thereby increasing supply current flowing to the LED  80 . On the other hand, as the gate voltage decreases while still being above its threshold voltage, the driver TFT  82  may decrease amount of its channel available to conduct electrical power, thereby decreasing supply current flowing to the LED  80 . In this manner, the luminance of the pixel  66  may be controlled and, when similar techniques are applied across the display  18  (e.g., to the pixels  66  of the display  18 ), an image may be displayed. 
     As mentioned above, the pixels  66  may be arranged in any suitable layout with the pixels  66  having various colors and/or shapes. For example, the pixels  66  may appear in alternating red, green, and blue in some embodiments, but also may take other arrangements. The other arrangements may include, for example, a red-green-blue-white (RGBW) layout or a diamond pattern layout in which one column of pixels alternates between red and blue and an adjacent column of pixels are green. Regardless of the particular arrangement and layout of the pixels  66 , each pixel  66  may be sensitive to changes on the active area of  64  of the electronic display  18 , such as variations and temperature of the active area  64 , as well as the overall age of the pixel  66 . Indeed, when each pixel  66  is a light emitting diode (LED), it may gradually emit less light over time. This effect is referred to as aging, and takes place over a slower time period than the effect of temperature on the pixel  66  of the electronic display  18 . 
     Returning to  FIG. 7 , display panel sensing may be used to obtain the display sense feedback  56 , which may enable the processor core complex  12  to generate compensated image data  52  to negate the effects of temperature, aging, and other variations of the active area  64 . The driver integrated circuit  68  (e.g.,  68 A) may include a sensing analog front end (AFE)  84  to perform analog sensing of the response of pixels  66  to test data. The analog signal may be digitized by sensing analog-to-digital conversion circuitry (ADC)  86 . 
     For example, to perform display panel sensing, the electronic display  18  may program one of the pixels  66  with test data (e.g., having a particular reference voltage or reference current). The sensing analog front end  84  then senses (e.g., measures, receives, etc.) at least one value (e.g., voltage, current, etc.) alone sense line  88  of connected to the pixel  66  that is being tested. Here, the data lines  72  are shown to act as extensions of the sense lines  88  of the electronic display  18 . In other embodiments, however, the display active area  64  may include other dedicated sense lines  88  or other lines of the display  18  may be used as sense lines  88  instead of the data lines  72 . In some embodiments, other pixels  66  that have not been programmed with test data may be also sensed at the same time a pixel  66  that has been programmed with test data is sensed. Indeed, by sensing a reference signal on a sense line  88  when a pixel  66  on that sense line  88  has not been programmed with test data, a common-mode noise reference value may be obtained. This reference signal can be removed from the signal from the test pixel  66  that has been programmed with test data to reduce or eliminate common mode noise. 
     The analog signal may be digitized by the sensing analog-to-digital conversion circuitry  86 . The sensing analog front end  84  and the sensing analog-to-digital conversion circuitry  86  may operate, in effect, as a single unit. The driver integrated circuit  68  (e.g.,  68 A) may also perform additional digital operations to generate the display feedback  56 , such as digital filtering, adding, or subtracting, to generate the display feedback  56 , or such processing may be performed by the processor core complex  12 . 
     In some embodiments, a correction map (e.g., stored as a look-up table or the like) that may include correction values that correspond to or represent offsets or other values applied to generated compensated image data  52  being transmitted to the pixels  66  to correct, for example, for temperature differences at the display  18  or other characteristics affecting the uniformity of the display  18 . This correction map may be part of the image data generation and processing circuit (e.g., stored in memory therein) or it may be stored in, for example, memory  14  or storage  16 . Through the use of the correction map (i.e., the correction information stored therein), effects of the variation and non-uniformity in the display  18  may be corrected using the image data generation and processing circuitry  50  of the processor core complex  12 . The correction map, in some embodiments, correspond to the entire active area  64  of the display  18  or a sub-segment of the active area  64 . For example, to reduce the size of the memory required to store the correction map (or the data therein), the correction map may include correction values that correspond to only to predetermined groups or regions of the active area  64 , whereby one or more correction values may be applied to the group of pixels  66 . Additionally, in some embodiments, the correction map be a reduced resolution correction map that enables low power and fast response operations such that, for example, the image data generation and processing circuitry  50  may reduce the resolution of the correction values prior to their storage in memory so that less memory may be required, responses may be accelerated, and the like. Additionally, adjustment of the resolution of the correction map may be dynamic and/or resolution of the correction map may be locally adjusted (e.g., adjusted at particular locations corresponding to one or more regions or groups of pixels  66 ). 
     The correction map (or a portion thereof, for example, data corresponding to a particular region or group of pixels  66 ), may be read from the memory of the image data generation and processing circuitry  50 . The correction map (e.g., one or more correction values) may then (optionally) be scaled, whereby the scaling corresponds to (e.g., offsets or is the inverse of) a resolution reduction that was applied to the correction map. In some embodiments, whether this scaling is performed (and the level of scaling) may be based on one or more input signals received as display settings and/or system information by the image data generation and processing circuitry  50 . 
     Conversion of the correction map may be undertaken via interpolation (e.g., Gaussian, linear, cubic, or the like), extrapolation (e.g., linear, polynomial, or the like), or other conversion techniques being applied to the data of the correction map. This may allow for accounting of, for example, boundary conditions of the correction map and may yield compensation driving data that may be applied to raw display content (e.g., image data) so as to generate compensated image data  52  that is transmitted to the pixels  66 . 
     In some embodiments, the correction map may be updated, for example, based on input values generated from the display sense feedback  56  by the image data generation and processing circuitry  50 . This updating of the correction map may be performed globally (e.g., affecting the entirety of the correction map) and/or locally (e.g., affecting less than the entirety of the correction map). The update may be based on real time measurements of the active area  64  of the electronic display  18 , transmitted as display sense feedback  56 . Additionally and/or alternatively, a variable update rate of correction can be chosen, e.g., by the image data generation and processing system  50 , based on conditions affecting the display  18  (e.g., display  18  usage, power level of the device, environmental conditions, or the like). 
       FIG. 9  illustrates a graphical example of a technique for updating of the correction map. As shown in graph  90 , during frame  92  (e.g., represented by n-1), a current  94  passing through the driver TFT  82  may correspond to a brightness level (e.g., a gray level) above a threshold current value  96  (e.g., current  94  may correspond to a gray level or desired gray level for a pixel  66  above a reference gray level value that corresponds to threshold current value  96 ). For example, the current  94  may represent the current applied through the driver TFT  82  and transmitted to the LED  80  to generate a relatively bright portion of an image during frame  92 . Also illustrated in graph  90  is a current  98  passing through the driver TFT  82 , which illustrates an example of a different current than current  94  previously discussed, where only one of current  94  or current  98  is applied during frame  92 . The current  98  may correspond to a brightness level (e.g., a gray level) below a threshold current value  96  (e.g., current  98  may correspond to a gray level or desired gray level for a pixel  66  below a reference gray level value that corresponds to threshold current value  96 ). Current  98  may represent the current applied through the driver TFT  82  and transmitted to the LED  80  to generate a relatively dark portion of an image during frame  92 . 
     As illustrated at time  100 , the first frame  92  is completed and a second frame  102  (which may be referred to as frame n and may, for example, correspond to a frame refresh) begins. However, in other embodiments, frame  102  may begin at time  108  (discussed below) and, accordingly, the time between frame  92  and  102  may be considered a sensing frame (e.g., separate from frame  102  instead of part of frame  102 ). At time  100 , a display panel sensing operation may begin whereby, for example, the processor core complex  12  (or a portion thereof, such as image data generation and processing circuitry  50 ) may provide sense control signals  54  to cause the electronic display  18  to perform display panel sensing to generate display sense feedback  56 . These sense control signals  54  may be used to program one of the pixels  66  with test data (e.g., having a particular reference voltage or reference current). For the purposes of discussion, test currents will be sensed as part of the display panel sensing operation, however, it is understood that the display panel sensing operation may instead operate to sense voltage levels from one of more components of the pixels  66 , current levels from one or more components of the pixels  66 , brightness of the LED  80 , or any combination thereof based on test data supplied to the pixels  66 . 
     As illustrated, when the test data is applied to a pixel  66 , hysteresis (e.g., a lag between a present input and a past input affecting operation) of, for example, the driver TFT  82  of the pixel  66  or one or more transient conditions affecting the pixel  66  or one or more component therein can cause a transient state wherein the current to be sensed has not reached a steady state (e.g., such that measurements of the currents at this time would affect their reliability). For example, at time  100  as the pixel is programed with test data, when the pixel  66  previously had a driver TFT current  94  corresponding to a relatively high gray level, this current  94  swings below the threshold current value  96  corresponding to the test data gray level value. The driver TFT current  94  may continue to move towards a steady state. In some embodiments, the amount of time that the current  94  of the driver TFT  82  has to settle (e.g., the relaxation time) is illustrated as time period  104  which represents the time between time  100  and time  106  corresponding to a sensing of the current (e.g., the driver TFT  82  current). Time period  104  may be, for example, less than approximately 10 microseconds (μs), 20 μs, 30 μs, 40 μs, 50 μs, 75 μs, 100 μs, 200 μs, 300 μs, 400 μs, 500 μs, or a similar value. At time  108 , the pixel  66  may be programmed again with a data value, returning the current  94  to its original level (assuming the data signal has not changed between frame  92  and frame  102 ). 
     Likewise, at time  100  as the pixel is programed with test data, when the pixel  66  previously had a driver TFT current  98  corresponding to a relatively low gray level, this current  98  swings above the threshold current value  96  corresponding to the test data gray level value. The driver TFT current  94  may continue to move towards a steady state. In some embodiments, the amount of time that the current  98  of the driver TFT  82  has to settle (e.g., the relaxation time) is illustrated as time period  104 . At time  108 , the pixel  66  may be programmed again with a data value, returning the current  98  to its original level (assuming the data signal has not changed between frame  92  and frame  102 ). 
     As illustrated, the a technique for updating of the correction map illustrated in graph  90  in conjunction with a display panel sensing operation includes a double sided error (e.g., current  94  swinging below the threshold current value  96  corresponding to the test data gray level value and current  98  swinging above the threshold current value  96  corresponding to the test data gray level value) during time period  104 . However, techniques may be applied to reduce the double sided error present in  FIG. 9 . 
     For example,  FIG. 10  illustrates a graphical representation (e.g., graph  110 ) of a technique for updating of the correction map having only a single sided error present. As shown in graph  110 , during frame  92 , a current  94  passing through the driver TFT  82  may correspond to a brightness level (e.g., a gray level) above a threshold current value  96  (e.g., current  94  may correspond to a gray level or desired gray level for a pixel  66  above a reference gray level value that corresponds to threshold current value  96 ). For example, the current  94  may represent the current applied through the driver TFT  82  and transmitted to the LED  80  to generate a relatively bright portion of an image during frame  92 . Also illustrated in graph  90  is a current  98  passing through the driver TFT  82 , which illustrates an example of a different current than current  94  previously discussed, where only one of current  94  or current  98  is applied during frame  92 . The current  98  may correspond to a brightness level (e.g., a gray level) below a threshold current value  96  (e.g., current  98  may correspond to a gray level or desired gray level for a pixel  66  below a reference gray level value that corresponds to threshold current value  96 ). Current  98  may represent the current applied through the driver TFT  82  and transmitted to the LED  80  to generate a relatively dark portion of an image during frame  92 . 
     As illustrated at time  100 , the first frame  92  is completed and a second frame  102  (which, for example, may correspond to a frame refresh) begins. At time  100 , a display panel sensing operation may begin whereby, for example, the processor core complex  12  (or a portion thereof, such as image data generation and processing circuitry  50 ) may provide sense control signals  54  to cause the electronic display  18  to perform display panel sensing to generate display sense feedback  56 . These sense control signals  54  may be used to program one of the pixels  66  with test data (e.g., having a particular reference voltage or reference current). For the purposes of discussion, test currents will be sensed as part of the display panel sensing operation, however, it is understood that the display panel sensing operation may instead operate to sense voltage levels from one of more components of the pixels  66 , current levels from one or more components of the pixels  66 , brightness of the LED  80 , or any combination thereof based on test data supplied to the pixels  66 . 
     As illustrated, the processor core complex  12  (or a portion thereof, such as image data generation and processing circuitry  50 ) may dynamically provide sense control signals  54  to cause the electronic display  18  to perform display panel sensing to generate display sense feedback  56 . For example, the processor core complex  12  (or a portion thereof, such as image data generation and processing circuitry  50 ) may determine whether, in frame  92 , the current  94  corresponds to a gray level or desired gray level for a pixel  66  above (or at or above) a reference gray level value that corresponds to threshold current value  96 . Alternatively, the processor core complex  12  (or a portion thereof, such as image data generation and processing circuitry  50 ) may determine whether, in frame  92 , the gray level or desired gray level for a pixel  66  is above (or at or above) a reference gray level value that corresponds to threshold current value  96 . If the current  94  in frame  92  corresponds to a gray level or desired gray level for a pixel  66  above (or at or above) a reference gray level value corresponding to threshold current value  96 , or if the gray level or desired gray level for a pixel  66  in frame  92  is above (or at or above) a reference gray level value corresponding to threshold current value  96 , the processor core complex  12  (or a portion thereof, such as image data generation and processing circuitry  50 ) may produce and provide sense control signals  54  (e.g., test data) corresponding to the gray level or desired gray level of the pixel in frame  92  such that the current level to be sensed at time  106  is equivalent to the current level of the TFT driver  82  during frame  92 . This allows for a time period  112  that the current  94  of the driver TFT  82  has to settle (e.g., the relaxation time) which represents the time between the start of frame  92  and time  106  corresponding to a sensing of the current (e.g., the driver TFT  82  current). Time period  112  may be, for example, less than approximately 20 milliseconds (ms), 15 ms, 10 ms, 9 ms, 8 ms, 7, ms, 6 ms, 5 ms, or a similar value. 
     As additionally illustrated in  FIG. 10 , at time  100  (as the pixel is programed with test data), when the pixel  66  previously had a driver TFT current  98  corresponding to a relatively low gray level, this current  98  swings above the threshold current value  96  corresponding to the test data gray level value. The driver TFT current  94  may continue to move towards a steady state. In some embodiments, the amount of time that the current  98  of the driver TFT has to settle (e.g., the relaxation time) is illustrated as time period  104 . At time  108 , the pixel  66  may be programmed again with a data value, returning the current  98  to its original level (assuming the data signal has not changed between frame  92  and frame  102 ). However, as illustrated in  FIG. 10  and described above, through dynamic selection of test data sent to the pixel  66  (e.g., differential sensing using separate test data based on the operation of a pixel  66  in a frame  92 ), double sided errors illustrated in  FIG. 9  may be reduced to single sided errors in  FIG. 10 , thus allowing for more accurate readings (sensed data) to be retrieved as display sense feedback  56 , which allows for increased accuracy in the correction values calculated, stored (e.g., in a correction map), and/or applied as compensated image data  52 . The single sided errors of  FIG. 10  may be illustrative of, for example, hysteresis caused by a change of the gate-source voltage of the driver TFT  82  when sensing programming of a pixel  66  at time  100  alters the gray level corresponding to current  98  to a gray level corresponding to the threshold current value  96 , whereby the hysteresis may be proportional to a change in the gate-source voltage of the driver TFT  82 . 
     In some embodiments, further reduction of sensing errors (e.g., errors due to the sensed current not being able to reach or not being able to nearly reach a steady state) may also be reduced for example, through selection of test data having a gray level corresponding to a threshold current value differing from threshold current value  96 .  FIG. 11  illustrates a second graphical representation (e.g., graph  114 ) of a technique for updating of the correction map having only a single sided error present. As shown in graph  110 , during frame  92 , a current  94  passing through the driver TFT  82  may correspond to a brightness level (e.g., a gray level) above a threshold current value  116  (e.g., current  94  may correspond to a gray level or desired gray level for a pixel  66  above a reference gray level value that corresponds to threshold current value  116 ). 
     Current value  116  may be, for example, initially set at a predetermined level based upon, for example, an initial configuration of the device  10  (e.g., at the factory and/or during initial device  10  or display  18  testing) or may be dynamically performed and set (e.g., at predetermined intervals or in response to a condition, such as startup of the device). The current value  116  may be selected to correspond to the lowest gray level or desired gray level for a pixel  66  having a predetermined or desired reliability, a predetermined or desired signal to noise ratio (SNR), or the like. Alternatively, the current value  116  may be selected to correspond to a gray level within 2%, 5%, 10%, or another value the lowest gray level or desired gray level for a pixel  66  having a predetermined or desired reliability, a predetermined or desired SNR, or the like. For example, selection of a current value  116  corresponding to a gray level 0 may introduce too much noise into any sensed current value. However, each device  10  may have a gray level (e.g., gray level 10, 15, 20, 20, 30, or another level) at which a predetermined or desired reliability, a predetermined or desired SNR, or the like may be achieved and this gray value (or a gray value within a percentage value above the minimum gray level if, for example, a buffer regarding the reliability, SNR, or the like is desirable) may be selected for test data, which corresponds to threshold current value  116 . In some embodiments, the test data, which corresponds to threshold current value  116 , can also be altered based on results from the sensing operation (e.g., altered in a manner similar to the alteration of the compensated image data  52 ). 
     Thus, as illustrated in  FIG. 11 , the current  94  may represent the current applied through the driver TFT  82  and transmitted to the LED  80  to generate a relatively bright portion of an image during frame  92 . Also illustrated in graph  114  is a current  98  passing through the driver TFT  82 , which illustrates an example of a different current than current  94  previously discussed, where only one of current  94  or current  98  is applied during frame  92 . The current  98  may correspond to a brightness level (e.g., a gray level) below the threshold current value  116  (e.g., current  98  may correspond to a gray level or desired gray level for a pixel  66  below a reference gray level value that corresponds to threshold current value  116 ). Current  98  may represent the current applied through the driver TFT  82  and transmitted to the LED  80  to generate a relatively dark portion of an image during frame  92 . 
     As illustrated at time  100 , the first frame  92  is completed and a second frame  102  (which, for example, may correspond to a frame refresh) begins. At time  100 , a display panel sensing operation may begin whereby, for example, the processor core complex  12  (or a portion thereof, such as image data generation and processing circuitry  50 ) may provide sense control signals  54  to cause the electronic display  18  to perform display panel sensing to generate display sense feedback  56 . These sense control signals  54  may be used to program one of the pixels  66  with test data (e.g., having a particular reference voltage or reference current). For the purposes of discussion, test currents will be sensed as part of the display panel sensing operation, however, it is understood that the display panel sensing operation may instead operate to sense voltage levels from one of more components of the pixels  66 , current levels from one or more components of the pixels  66 , brightness of the LED  80 , or any combination thereof based on test data supplied to the pixels  66 . 
     As illustrated, the processor core complex  12  (or a portion thereof, such as image data generation and processing circuitry  50 ) may dynamically provide sense control signals  54  to cause the electronic display  18  to perform display panel sensing to generate display sense feedback  56 . For example, the processor core complex  12  (or a portion thereof, such as image data generation and processing circuitry  50 ) may determine whether, in frame  92 , the current  94  corresponds to a gray level or desired gray level for a pixel  66  above (or at or above) a reference gray level value that corresponds to threshold current value  116 . Alternatively, the processor core complex  12  (or a portion thereof, such as image data generation and processing circuitry  50 ) may determine whether, in frame  92 , the gray level or desired gray level for a pixel  66  is above (or at or above) a reference gray level value that corresponds to threshold current value  116 . If the current  94  in frame  92  corresponds to a gray level or desired gray level for a pixel  66  above (or at or above) a reference gray level value corresponding to threshold current value  116 , or if the gray level or desired gray level for a pixel  66  in frame  92  is above (or at or above) a reference gray level value corresponding to threshold current value  116 , the processor core complex  12  (or a portion thereof, such as image data generation and processing circuitry  50 ) may produce and provide sense control signals  54  (e.g., test data) corresponding to the gray level or desired gray level of the pixel in frame  92  such that the current level to be sensed at time  106  is equivalent to the current level of the TFT driver  82  during frame  92 . This allows for a time period  118  (e.g., less than time period  112 ) that the current  94  of the driver TFT  82  has to settle (e.g., the relaxation time) which represents the time between the start of frame  92  and time  106  corresponding to a sensing of the current (e.g., the driver TFT  82  current). Time period  118  may be, for example, less than approximately 20 ms, 15 ms, 10 ms, 9 ms, 8 ms, 7, ms, 6 ms, 5 ms, or a similar value. 
     As additionally illustrated in  FIG. 11 , at time  100  (as the pixel is programed with test data), when the pixel  66  previously had a driver TFT current  98  corresponding to a relatively low gray level, this current  98  swings above the threshold current value  116  corresponding to the test data gray level value. The driver TFT current  94  may continue to move towards a steady state. In some embodiments, the amount of time that the current  98  of the driver TFT has to settle (e.g., the relaxation time) is illustrated as time period  120  (e.g., less than time period  104 ). At time  108 , the pixel  66  may be programmed again with a data value, returning the current  98  to its original level (assuming the data signal has not changed between frame  92  and frame  102 ). However, as illustrated in  FIG. 11  and described above, through dynamic selection of test data sent to the pixel  66  (e.g., selection of a set or dynamic test data value corresponding to a desired gray value that generates threshold reference current  116 ), the single sided error of  FIG. 11  may be reduced in size, thus allowing for more accurate readings (sensed data) to be retrieved as display sense feedback  56 , which allows for increased accuracy in the correction values calculated, stored (e.g., in a correction map), and/or applied as compensated image data  52 . 
     Additionally and/or alternatively, sensing errors from hysteresis effects may appear as high frequency artifacts. Accordingly, suppression of a high frequency component of a sensing error may be obtained by having the sensing data run through a low pass filter, which may decrease the amount of visible artifacts. The low pass filter may be a two-dimensional spatial filter, such as a Gaussian filter, a triangle filter, a box filter, or any other two-dimensional spatial filter. The filtered data may then be used by the image data generation and processing circuitry  50  to determine correction factors and/or a correction map. Likewise, by grouping pixels  66  and filtering sensed data of the grouped pixels  66 , sensing errors may further be reduced. 
       FIG. 12  illustrates another technique for updating of the correction map, for example, using groupings of pixels  66  and utilizing the grouped pixels to make determinations relative to a gray level of test data corresponding to one of either threshold reference current  96  or threshold reference current  116 . For example,  FIG. 12  illustrates a schematic diagram  122  of a portion  124  of display  18  as well as a representation  126  of test data applied to the portion  112 . As illustrated in portion  112 , a group  128  of pixels  66  may include two rows of adjacent pixels  66  across all columns of the display  18 . Schematic diagram  122  may illustrate an image being displayed at frame  92  having various brightness levels (e.g., gray levels) for each of regions  130 ,  132 ,  134 ,  136 , and  138  (collectively regions  130 - 138 ). 
     In some embodiments, instead of performing a display panel sensing operation (e.g., performing display panel sensing) on each pixel  66  of the display  18 , the display panel sensing can be performed on subsets of the group  128  of pixels  66  (e.g., a pixel  66  in an upper row and a lower row of a common column of the group  128 ). It should be noted that each of the group  128  size and/or dimensions and/or the subsets of the group  128  chosen can be dynamically and/or statically selected and the present example is provided for reference and is not intended to be exclusive of other group  128  sizes and/or dimensions and/or alterations to the subsets of the group  128  (e.g., the number of pixels  66  in the subset of the group  128 . 
     In one embodiment, a current passing through the driver TFT  82  of a pixel  66  at location x,y in a given subset of the group  128  of pixels  66  in frame  92  may correspond to a brightness level (e.g., a gray level) represented by Gx,y. Likewise, a current passing through the driver TFT  82  of a pixel  66  at location x,y−1 in the subset of the group  128  of pixels  66  (e.g., a location in the same column but a row below the pixel  66  of the subset of the group  128  corresponding to the brightness level represented by Gx,y) in frame  92  may correspond to a brightness level (e.g., a gray level) represented by Gx,y−1. Instead of the processor core complex  12  (or a portion thereof, such as image data generation and processing circuitry  50 ) dynamically providing sense control signals  54  to cause the electronic display  18  to perform display panel sensing to generate display sense feedback  56  for each pixel  66  based on a grey level threshold comparison (as detailed above in conjunction with  FIGS. 9-11 ), the processor core complex  12  (or a portion thereof, such as image data generation and processing circuitry  50 ) may dynamically provide sense control signals  54  (e.g., a single or common test data value) to both pixels  66  of the subsets of the group  128  of pixels  66  based on a subset threshold comparison. 
     An embodiment of a threshold comparison is described below. If the processor core complex  12  (or a portion thereof, such as image data generation and processing circuitry  50 ) determines that Gx,y&lt;Gthreshold and Gx,y−1&lt;Gthreshold, whereby Gthreshold is equal to a reference gray level value that corresponds to threshold current value  116  (or the threshold current value  96 ), then Gtest(x,y)=Gthreshold and Gtest(x,y−1)=Gthreshold, whereby Gtest(x,y) is the test data gray level value (e.g., a reference gray level value that corresponds to threshold current value  116  or the threshold current value  96 , depending on the operation of the processor core complex  12  or a portion thereof, such as image data generation and processing circuitry  50 ) at time  100 . Thus, if each of the gray levels of the pixels  66  of a subset of the group of pixels  66  corresponds to a current level (e.g., current  98 ) below the threshold current value (e.g., threshold current value  116  or the threshold current value  96 ), the test data gray level that corresponds to threshold current value  116  or the threshold current value  96  is used in the sensing operation. These determinations are illustrated, for example, in regions  134  and  138  of  FIG. 12 . 
     Likewise, if the processor core complex  12  (or a portion thereof, such as image data generation and processing circuitry  50 ) determines that either Gx,y≥Gthreshold and/or Gx,y−1≥Gthreshold, then the processor core complex  12  (or a portion thereof, such as image data generation and processing circuitry  50 ) may choose one of Gx,y or Gx,y−1 to be applied as Gtest(x,y) at time  100 , such that Gtest(x,y)=Gx,y and Gtest(x,y−1)=Gx,y or Gtest(x,y)=Gx,y−1 and Gtest(x,y−1)=Gx,y−1. Alternatively, if the processor core complex  12  (or a portion thereof, such as image data generation and processing circuitry  50 ) determines that either Gx,y&gt;Gthreshold and/or Gx,y−1≥Gthreshold, then the processor core complex  12  (or a portion thereof, such as image data generation and processing circuitry  50 ) may choose one of Gx,y or Gx,y−1 to be applied at time  100  to one of the pixels  66  of the subset of the group  128  of pixels  66  and choose a lowest gray level value G0 to be applied to the other one of the pixels  66  of the subset of the group  128  of pixels  66 , such that Gtest(x,y)=Gx,y and Gtest(x,y−1)=G0 or Gtest(x,y)=G0 and Gtest(x,y−1)=G0. For example, it may be advantageous to apply separate test data values (one of which is the lowest available gray level or another gray level below Gthreshold) so that when the sensed values of the subset of the group  128  of pixels  66  are taken together and applied as correction values, the correction values can be averaged to a desired correction level when taken across the subset of the group  128  of pixels  66  (e.g., to generate a correction map average for the subset of the group  128  of pixels  66 ) to be applied as corrected feedback  56 , which allows for increased accuracy in the correction values calculated, stored (e.g., in a correction map), and/or applied as compensated image data  52 . 
     In some embodiments, a weighting operation may be performed and applied by the processor core complex  12  or a portion thereof, such as image data generation and processing circuitry  50 , to select which of Gx,y and Gx,y−1 is supplied with test data G0. For example, test data gray level selection may be based on the weighting of each gray level of the pixels  66  of the subset of the group  128  of pixels  66  in frame  92 , by weighting determined based on characteristics of the individual pixels  66  of the subset of the group  128  of pixels  66  (e.g., I-V characteristics, current degradation level of the pixels  66  of the subset, etc.), by weighting determined by the SNR of the respective sensing lines  88 , and/or a combination or one or more of these determinations. For example, if the processor core complex  12  or a portion thereof, such as image data generation and processing circuitry  50 , determines that, for example, Wx,y≥Wx,y−1, whereby Wx,y is the weight value of the pixel  66  at location x,y and Wx,y−1 is the weight value of the pixel  66  at location x,y−1 (e.g., a weighting factor determined and given to each pixel  66 ), then Gtest(x,y)=Gx,y and Gtest(x,y−1)=G0. These determinations are illustrated, for example, in regions  132  and  136  of  FIG. 12 . Likewise, if the processor core complex  12  or a portion thereof, such as image data generation and processing circuitry  50 , determines that, for example, Wx,y−1&gt; Wx,y−1, then Gtest(x,y)=G0 and Gtest(x,y−1)=G0. This determinations is illustrated, for example, in regions  130  of  FIG. 12 . 
     It may be appreciated that alternate weighing processes or selection of test data processes may additionally and/or alternatively be chosen. Additionally, in at least one embodiment, sensing circuitry (e.g., one or more sensors) may be present in, for example, AFE  84  to perform analog sensing of the response of more than one pixel  66  at a time (e.g., to sense each of the pixels  66  of a subset of the group  128  of pixels  66  in parallel) when, for example, the techniques described above in conjunction with  FIG. 12  are performed. Similarly, alteration to the column driver integrated circuit  68 A and/or the row driver integrated circuit  68 B may be performed (either via hardware or via the sense control signals  54  sent thereto) to allow for the column driver integrated circuit  68 A and the row driver integrated circuit  68 B to simultaneously drive each of the pixels  66  of a subset of the group  128  of pixels  66  in parallel 
     The specific embodiments described above have been shown by way of example, and it should be understood that these embodiments may be susceptible to various modifications and alternative forms. It should be further understood that the claims are not intended to be limited to the particular forms disclosed, but rather to cover all modifications, equivalents, and alternatives falling within the spirit and scope of this disclosure. 
     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).

Metadata:
Filing Date: 20180327
Publication Date: 20211102
Grant Date: 20211102
Priority Date: 20170407
Inventors: LIN, HUNG SHENG
NHO, HYUNWOO
CHANG, SUN-IL
TAN, JUNHUA
RYU, JIE WON
GAO, SHENGKUI
ZHANG, RUI
HWANG, INJAE
BRAHMA, KINGSUK
RICHMOND, JESSE AARON
SHEN, Shiping
KIM, HYUNSOO
Assignee: APPLE INC
CPC Classifications: [{"code": "G09G2320/043", "inventive": false, "first": false, "tree": "[]"}, {"code": "G09G2320/0295", "inventive": false, "first": false, "tree": "[]"}, {"code": "G09G2320/029", "inventive": false, "first": false, "tree": "[]"}, {"code": "G09G3/3233", "inventive": true, "first": false, "tree": "[]"}, {"code": "G09G2320/0233", "inventive": false, "first": false, "tree": "[]"}, {"code": "G09G2320/0295", "inventive": false, "first": false, "tree": "[]"}, {"code": "G09G3/3225", "inventive": true, "first": true, "tree": "[]"}, {"code": "G09G3/3216", "inventive": true, "first": false, "tree": "[]"}, {"code": "G09G2320/0233", "inventive": false, "first": false, "tree": "[]"}, {"code": "G09G2320/0285", "inventive": false, "first": false, "tree": "[]"}, {"code": "G09G3/3225", "inventive": true, "first": true, "tree": "[]"}, {"code": "G09G2320/0233", "inventive": false, "first": false, "tree": "[]"}, {"code": "G09G2320/0285", "inventive": false, "first": false, "tree": "[]"}, {"code": "G09G2320/029", "inventive": false, "first": false, "tree": "[]"}, {"code": "G09G2320/043", "inventive": false, "first": false, "tree": "[]"}, {"code": "G09G3/3216", "inventive": true, "first": false, "tree": "[]"}, {"code": "G09G2320/0295", "inventive": false, "first": false, "tree": "[]"}, {"code": "G09G3/3225", "inventive": true, "first": true, "tree": "[]"}]
Family ID: 70159431