PATENT DOCUMENT

Publication Number: US-10388201-B2
Application Number: US-201715697132-A
Country: US
Kind Code: B2

Title: Power cycle display sensing

Abstract:
Electronic devices and methods pertain to reducing artifacts resulting from a thermal profile preexisting a boot up of an electronic device are disclosed. Scanning driving circuitry of the electronic device scans at least a portion of one or more pixels of an active area of a display using a boot up scan before a boot up sequence of at least a portion of an electronic device completes. The results of the boot up scan are stored in local buffers and transferred to one or more processors upon connection to the one or more processors. The results of the boot up scan cause the one or more processors to modify image data to reduce or eliminate artifacts that may result during boot up due to thermal profiles or other parameters that may cause artifacts.

Claims:
What is claimed is: 
     
       1. An electronic device comprising:
 a display comprising:
 one or more pixels, wherein the one or more pixels of the display are configured to:
 in a display mode, display images based on image data; and 
 in a pixel sense mode, provide operational information about operation of the one or more pixels; and 
 
 sensing driving circuitry that drives sensing of the one or more pixels of the display during the pixel sense mode; and 
 
 at least one processor configured to modify image data before displaying on the display based at least in part on results of a boot up scan by the sensing driving circuitry that drives sensing of the operational information about the operation of the one or more pixels; 
 wherein the sensing driving circuitry is configured to:
 during a period before a boot up sequence of at least a portion of the electronic device completes, scan at least a portion of the one or more pixels using the boot up scan; 
 store the results of the boot up scan as a thermal profile used to modify image data based on the boot up scan to reduce likelihood of image artifacts after boot up; and 
 send the results of the boot up scan to the at least one processor upon connection to the at least one processor to cause the processor to modify initial image data after the boot up using the thermal profile. 
 
 
     
     
       2. The electronic device of  claim 1 , wherein the portion comprises only a portion of the electronic device comprising the display. 
     
     
       3. The electronic device of  claim 1 , wherein the period before the boot up sequence completes comprises a period before the boot up sequence has initiated. 
     
     
       4. The electronic device of  claim 3 , wherein the display is off during the period before the boot up sequence has initiated while one or more other parts of the electronic device are on. 
     
     
       5. The electronic device of  claim 1 , wherein the electronic device is in an off state prior to the boot up sequence and is configured to be booted up by the boot up sequence. 
     
     
       6. The electronic device of  claim 1 , wherein the period before the boot up sequence completes prior to established connection between the sensing driving circuitry and the at least one processor. 
     
     
       7. The electronic device of  claim 1 , wherein the period before the boot up sequence completes prior to the display receiving image data from the at least one processor. 
     
     
       8. The electronic device of  claim 1 , wherein the boot up sequence comprises:
 a power rail settling period in which power rails settle; and 
 a boot-up sensing period during which the scan is completed, wherein the boot-up sensing period follows the power rail settling period and occurs before normal operation of the display begins. 
 
     
     
       9. The electronic device of  claim 8 , wherein the power rail settling period comprises a period of four frames or fewer. 
     
     
       10. The electronic device of  claim 8 , wherein the boot-up sensing period spans a number of frames corresponding to a period of time used to scan the at least a portion of the one or more pixels. 
     
     
       11. The electronic device of  claim 10 , wherein a number of the at least a portion of the one or more pixels is based at least in part on a size of storage space for storing the results of the boot up scan. 
     
     
       12. The electronic device of  claim 10 , wherein the at least a portion of the one or more pixels comprises all of the pixels. 
     
     
       13. The electronic device of  claim 10 , wherein the at least a portion of the one or more pixels comprises pixels in certain distinct locations around the display. 
     
     
       14. The electronic device of  claim 13 , wherein the certain distinct locations comprise:
 locations configured to undergo more heating than other locations; 
 locations configured to be representative of the entire display; or 
 a combination thereof. 
 
     
     
       15. The electronic device of  claim 8 , wherein the boot up sequence comprises a clock transition phase wherein the display first establishes connection with the at least one processor during the boot up sequence after the power rail settling period and a boot-up sensing period. 
     
     
       16. A method for reducing artifacts during a boot up of at least a portion of an electronic device comprising:
 booting up the at least a portion of an electronic device; 
 before or during the boot up, scanning at least a portion of one or more pixels using a boot up scan using scanning driving circuitry; 
 storing results of the boot up scan as a thermal profile used to modify image data based on the boot up scan to reduce likelihood of image artifacts after boot up; 
 sending the results of the boot up scan to at least one processor upon first connection to the processor; and 
 compensating for potential artifacts using the at least one processor by modifying initial image data after the boot up based on the results of the boot up scan. 
 
     
     
       17. The method of  claim 16 , wherein the results of the boot up scan establish sensed values of the thermal profile that is present at boot up, wherein the thermal profile causes the potential artifacts if not compensated for while displaying images using the display. 
     
     
       18. The method of  claim 17 , wherein the thermal profile comprises:
 the thermal profile established while display or electronic device is off; 
 the thermal profile established during a previous ON mode that persists through a power cycle; or 
 a combination thereof. 
 
     
     
       19. Scanning driving circuitry comprising:
 control circuitry configured to scan at least a portion of one or more pixels of an active area of a display using a boot up scan before a boot up sequence of at least a portion of an electronic device completes, wherein the control circuitry is configured to scan the at least a portion using the boot up scan without interaction with any of one or more processors of the electronic device; 
 local buffers configured to store results of the boot up scan as a thermal profile used to modify image data based on the boot up scan to reduce likelihood of image artifacts after boot up; and 
 a transmitter configured to send the results of the boot up scan to the one or more processors after connection to the one or more processors to cause the processor to modify initial image data after the boot up using the thermal profile. 
 
     
     
       20. The scanning driving circuitry of  claim 19 , wherein the transmitter is configured transfer the results of the boot up scan to the one or more processors during a boot up sequence as soon as communication between the one or more processors and the scanning driving circuitry are established.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 62/396,547, filed on Sep. 19, 2016, the contents of which are herein expressly incorporated by reference for all purposes. 
    
    
     BACKGROUND 
     The present disclosure relates generally to techniques for correcting for thermal variation of a display after or during a power cycle. 
     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. 
     Image artifacts may appear on an electronic display due to thermal variations of the electronic display. Thermal variations may arise due to other electronic components near the electronic display, such as a processor or wireless network transceiver, but may also arise due to external sources such as sunlight on different areas on the display. Since individual pixels of the electronic display may operate differently depending on the temperature, these thermal variations could result in image artifacts. For example, if one area of the electronic display is hotter than another part of the electronic display, pixels from the different areas that receive image data of the same color might appear to be different when the pixels should be uniform. Pixel behavior sensing may be used to identify and correct these artifacts, but sensing takes some time, possibly causing display of the artifacts for some time. 
     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. 
     Electronic devices and methods pertain to reducing image artifacts on an electronic display that are caused by thermal variations on the electronic display. A stored thermal profile representing a map of the temperature of the electronic display may be used to adjust image data before it is sent to the electronic display, and therefore avoid image artifacts caused by the thermal variations. Yet an inaccurate thermal profile could result in improper corrections that do not fully correct the image artifacts. If the thermal profile is inaccurate upon boot-up of an electronic device, the image data may not be fully corrected until the thermal profile is updated through pixel behavior sensing, during which time any displayed images could have noticeable image artifacts. 
     Scanning driving circuitry of the electronic device may reduce image artifacts due to an inaccurate thermal profile on boot-up by scanning at least a portion of one or more pixels of an active area of a display using a boot-up scan before a boot-up sequence of at least a portion (e.g., display) of an electronic device completes. The results of the boot up scan are stored in local buffers and transferred to one or more processors upon connection to the one or more processors. The results of the boot up scan cause the one or more processors to modify image data to reduce or eliminate artifacts that may result during boot up due to inaccurate thermal profiles or other parameters that may cause artifacts. 
    
    
     
       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 including a display, 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 , in accordance with an embodiment; 
         FIG. 3  is a front view of a hand-held device representing another embodiment of the electronic device of  FIG. 1 , in accordance with an embodiment; 
         FIG. 4  is a front view of another hand-held device representing another embodiment of the electronic device of  FIG. 1 , in accordance with an embodiment; 
         FIG. 5  is a front view of a desktop computer representing another embodiment of the electronic device of  FIG. 1 , in accordance with an embodiment; 
         FIG. 6  is a front view of a wearable electronic device representing another embodiment of the electronic device of  FIG. 1 , in accordance with an embodiment; 
         FIG. 7  is a schematic view of a display system that includes an active area and driving circuitry for display and sensing modes, in accordance with an embodiment; 
         FIG. 8  is a schematic view of pixel circuitry of the active area of  FIG. 7 , in accordance with an embodiment; 
         FIG. 9  is a graph of a thermal profile by location of the active area of  FIG. 7  at boot up that may cause a display image artifact, in accordance with an embodiment; 
         FIG. 10  is a diagram of a screen that may be displayed when the thermal profile of  FIG. 9  exists at start up of a portion of the electronic device, in accordance with an embodiment; 
         FIG. 11  is a flow diagram of a process for sensing during boot up, in accordance with an embodiment; and 
         FIG. 12  is a timing diagram of the boot-up sensing of  FIG. 11 , in accordance with an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     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. 
     As previously discussed, image artifacts due to thermal variations on an electronic display (e.g., an organic light emitting diode, or OLED) display panel can be corrected using external compensation (e.g., using processors) by adjusting image data based on a correction profile using a sensed thermal profile of the electronic display. The thermal profile is actual distribution of heat inside the electronic display, and the correction profile is the sensed heating and a resulting image data correction for each heat level. For instance, higher thermal levels may cause pixels to display brighter in response to image data. Once these levels are sensed, the processor may create a correction profile based on the sensed data that inverts expected changes based on the thermal profile and applies them to image data so that the correction and the thermal variation cancel each other out causing the image data to appear as it was stored. 
     After power cycling, a residual (or pre-existing) thermal profile from previous usage can cause significant artifacts until an external compensation loop corrects the artifact using processors external to the display. The processors may use the external compensation loop to generate the correction profile In addition, any thermal variation built during off-display, such as LTE usage, light, and ambient temperature, can also cause artifacts. In this warm boot-up condition, sensing of variation due to temperature and correction of image data may be performed quickly to minimize initial artifacts. Every power cycle, sensing and correction of the whole screen can be performed during power-on sequence. This may take place even before panel starts to display images or even establishes communication with processors used to externally compensate for the thermal profile. Sensing and correction of the entire screen may involve programming driving circuitry to conduct sensing after a boot up before establishing communication with the processors that may cause sensing during scanning phases of normal operation. Furthermore, since the scanning may be performed before establishment of communication with the processors for external compensation, sensing results may be stored in a local buffer (e.g., group of line buffers) until communication with the processors  12  is established. 
     With the foregoing in mind and referring first to  FIG. 1 , an electronic device  10  according to an embodiment of the present disclosure may include, among other things, one or more processor(s)  12 , memory  14 , nonvolatile storage  16 , a display  18 , input structures  20 , an input/output (I/O) interface  22 , a power source  24 , and an interface(s)  26 . The various functional blocks shown in  FIG. 1  may include hardware elements (e.g., including circuitry), software elements (e.g., including computer code stored on a computer-readable medium) 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 . 
     In the electronic device  10  of  FIG. 1 , the processor(s)  12  and/or other data processing circuitry may be operably coupled with the memory  14  and the nonvolatile storage  16  to perform various algorithms. Such programs or instructions, including those for executing the techniques described herein, executed by the processor(s)  12  may be stored in any suitable article of manufacture that includes one or more tangible, computer-readable media at least collectively storing the instructions or routines, such as the memory  14  and the nonvolatile storage  16 . The memory  14  and the nonvolatile storage  16  may include any suitable articles of manufacture for storing data and executable instructions, such as random-access memory, read-only memory, rewritable flash memory, hard drives, and/or optical discs. Also, programs (e.g., e.g., an operating system) encoded on such a computer program product may also include instructions that may be executed by the processor(s)  12  to enable the electronic device  10  to provide various functionalities. 
     In certain embodiments, the display  18  may be any suitable electronic display to allow users to view images generated on the electronic device  10 . In some embodiments, the display  18  may include a touch screen, which may allow users to interact with a user interface of the electronic device  10 . The display  18  may be a self-emissive display that uses pixels formed from light emitting diodes (e.g., LED) or may be a backlit liquid crystal display (LCD). 
     The input structures  20  of the electronic device  10  may enable a user to interact with the electronic device  10  (e.g., e.g., pressing a button to increase or decrease a volume level, a camera to record video or capture images). The I/O interface  22  may enable electronic device  10  to interface with various other electronic devices. The I/O interface  22  may include various types of ports that may be connected to cabling. These ports may include standardized and/or proprietary ports, such as USB, RS232, Apple&#39;s Lightning® connector, as well as one or more ports for a conducted RF link. 
     As further illustrated, the electronic device  10  may include a power source  24 . The power source  24  may include any suitable source of power, such as a rechargeable lithium polymer (e.g., Li-poly) battery and/or an alternating current (e.g., AC) power converter. The power source  24  may be removable, such as a replaceable battery cell. 
     The interface(s)  26  enable the electronic device  10  to connect to one or more network types. The interface(s)  26  may also include, for example, interfaces for a personal area network (e.g., PAN), such as a Bluetooth network, for a local area network (e.g., LAN) or wireless local area network (e.g., WLAN), such as an 802.11x Wi-Fi network or an 802.15.4 network, and/or for a wide area network (e.g., WAN), such as a 3rd generation (e.g., 3G) cellular network, 4th generation (e.g., 4G) cellular network, or long term evolution (e.g., LTE) cellular network. The interface(s)  26  may also include interfaces for, for example, broadband fixed wireless access networks (e.g., WiMAX), mobile broadband Wireless networks (e.g., mobile WiMAX), and so forth. 
     By way of example, the electronic device  10  may represent a block diagram of the notebook computer depicted in  FIG. 2 , the handheld device depicted in either of  FIG. 3  or  FIG. 4 , the desktop computer depicted in  FIG. 5 , the wearable electronic device depicted in  FIG. 6 , or similar devices. It should be noted that the processor(s)  12  and/or other data processing circuitry may be generally referred to herein as “data processing circuitry.” Such data processing circuitry may be embodied wholly or in part as software, firmware, hardware, or any combination thereof. Furthermore, the data processing circuitry may be a single contained processing module or may be incorporated wholly or partially within any of the other elements within the electronic device  10 . 
     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 (e.g., such as laptop, notebook, and tablet computers) as well as computers that are generally used in one place (e.g., 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  30 A, is illustrated in  FIG. 2  in accordance with one embodiment of the present disclosure. The depicted computer  30 A may include a housing or enclosure  32 , a display  18 , input structures  20 , and ports of the I/O interface  22 . In one embodiment, the input structures  20  (e.g., such as a keyboard and/or touchpad) may be used to interact with the computer  30 A, such as to start, control, or operate a GUI or applications running on computer  30 A. For example, a keyboard and/or touchpad may allow a user to navigate a user interface or application interface displayed on display  18 . 
       FIG. 3  depicts a front view of a handheld device  30 B, which represents one embodiment of the electronic device  10 . The handheld device  30 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  30 B may be a model of an iPod® or iPhone® available from Apple Inc. of Cupertino, Calif. 
     The handheld device  30 B may include an enclosure  32  to protect interior components from physical damage and to shield them from electromagnetic interference. The enclosure  32  may surround the display  18 , which may display indicator icons  39 . The indicator icons  39  may indicate, among other things, a cellular signal strength, Bluetooth connection, and/or battery life. The I/O interfaces  22  may open through the enclosure  32  and may include, for example, an I/O port for a hard wired connection for charging and/or content manipulation using a connector and protocol, such as the Lightning connector provided by Apple Inc., a universal serial bus (e.g., USB), one or more conducted RF connectors, or other connectors and protocols. 
     The illustrated embodiments of the input structures  20 , in combination with the display  18 , may allow a user to control the handheld device  30 B. For example, a first input structure  20  may activate or deactivate the handheld device  30 B, one of the input structures  20  may navigate user interface to a home screen, a user-configurable application screen, and/or activate a voice-recognition feature of the handheld device  30 B, while other of the input structures  20  may provide volume control, or may toggle between vibrate and ring modes. Additional input structures  20  may also include a microphone that may obtain a user&#39;s voice for various voice-related features, and a speaker to allow for audio playback and/or certain phone capabilities. The input structures  20  may also include a headphone input (not illustrated) to provide a connection to external speakers and/or headphones and/or other output structures. 
       FIG. 4  depicts a front view of another handheld device  30 C, which represents another embodiment of the electronic device  10 . The handheld device  30 C may represent, for example, a tablet computer, or one of various portable computing devices. By way of example, the handheld device  30 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  30 D may represent another embodiment of the electronic device  10  of  FIG. 1 . The computer  30 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  30 D may be an iMac®, a MacBook®, or other similar device by Apple Inc. It should be noted that the computer  30 D may also represent a personal computer (e.g., PC) by another manufacturer. A similar enclosure  32  may be provided to protect and enclose internal components of the computer  30 D such as the display  18 . In certain embodiments, a user of the computer  30 D may interact with the computer  30 D using various peripheral input devices, such as a keyboard  37  or mouse  38 , which may connect to the computer  30 D via an I/O interface  22 . 
     Similarly,  FIG. 6  depicts a wearable electronic device  30 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  30 E, which may include a wristband  43 , may be an Apple Watch® by Apple, Inc. However, in other embodiments, the wearable electronic device  30 E may include any wearable electronic device such as, for example, a wearable exercise monitoring device (e.g., e.g., pedometer, accelerometer, heart rate monitor), or other device by another manufacturer. The display  18  of the wearable electronic device  30 E may include a touch screen (e.g., e.g., LCD, an organic light emitting diode display, an active-matrix organic light emitting diode (e.g., AMOLED) display, and so forth), which may allow users to interact with a user interface of the wearable electronic device  30 E. 
       FIG. 7  illustrates a display system  50  that may be included in the display  18  be used to display and scan an active area  52  of the display  18 . The display system  50  includes video driving circuitry  54  that drives circuitry in the active area  52  to display images. The display system  50  also includes scanning (or sensing) driving circuitry  56  that drives circuitry in the active area  52 . In some embodiments, at least some of the components of the video driving circuitry  54  may be common to the scanning driving circuitry  56 . Furthermore, some circuitry of the active area may be used both for displaying images and scanning. For example, pixel circuitry  70  of  FIG. 8  may be driven, alternatingly, by the video driving circuitry  54  and the scanning driving circuitry  56 . When a pixel current  72  is submitted to an organic light emitting diode (OLED)  74  from the video driving circuitry  54  and the scanning driving circuitry  56 , the OLED  74  turns on. However, emission of the OLED  74  during a scanning phase may be relatively low, such that the scan is not visible while the OLED  74  is being sensed. In some embodiments, the display  18  may include LEDs or other emissive elements rather than the OLED  74 . To control of scans during the scanning mode, a scanning controller  58  of  FIG. 7  may control scanning mode parameters used to drive the scanning mode via the scanning driving circuitry  56 . The scanning controller  58  may be embodied using software, hardware, or a combination thereof. For example, the scanning controller  58  may at least be partially embodied as the processors  12  using instructions stored in memory  14  or in communication with the processors  12 . 
     External or internal heat sources may heat at least a portion of the active area  52 . Operation of the electronic device  10  with the active area heated unevenly may result in display artifacts if these heat variations are not compensated for. For example, heat may change a threshold voltage of the an access transistor of a respective pixel, causing power applied to the pixel to appear differently than an appearance the same power would cause in adjacent pixels undergoing a different amount of heat. During operation of the electronic device  10 , compensation using the processors  12  may account for such artifacts due to ongoing sensing. However, during startup of the device  10 , this external compensation may generally begin after communication is established between the display  18  (e.g., scanning driving circuitry  56  and/or scanning controller  58 . During this startup time, if a preexisting thermal profile preexists the power cycle, the correction speed (e.g., τ=0.3 s) may be too slow to prevent a waving artifact issue. 
       FIG. 9  illustrates an embodiment of a possible thermal profile  100  illustrated on a graph  102  showing where actual heat exists in the electronic device  10 . As illustrated, the graph  102  includes an x-axis  104  that corresponds to an x-axis of the active area  52 . The graph  102  also includes a y-axis  106  that corresponds to a y-axis of the active area  52 . Furthermore, the graph  102  includes a z-axis  108  that corresponds to temperature at a corresponding location on the x-y plane formed by the x-axis  104  and the y-axis  106 . The thermal profile  100  includes multiple regions  110 ,  112 ,  114 ,  116 ,  118 , and  120  (collectively referred to as “regions  110 - 120 ”). The temperature level of each of the regions  110 - 120  may be at least partially due to heat sources internal to the electronic device  10 , such as wireless (e.g., LTE or WiFi) chips, processing circuitry, camera circuitry, batteries, and/or other heat sources within the electronic device  10 . The temperature level of each of the regions may also be at least partially due to heat sources external to the electronic device  10 . 
     Due to internal or external heat sources, heat in the regions  110 - 120  may vary throughout the active area  52  due to light (e.g., sunlight), ambient air temperatures, and/or other outside heat sources. As illustrated, the region  110  corresponds to a relatively high temperature. This temperature may correspond to a processing chip (e.g., camera chip, video processing chip) or other circuitry located underneath the active area  52 . When the electronic device  10  boots up while having the thermal profile  100 , the relatively high temperature of the region  110  may result in an artifact, such as the artifact  130  illustrated in  FIG. 10 . Specifically, the artifact  130  may be a brighter area of a screen  152  displayed by the display  18 . The screen  152  is intended to display a consistent grayscale level throughout the screen  152 . However, due to the temperature fluctuation throughout the screen  152  during boot up of the device, the screen  152  contains image artifacts due to temperature dependence of the active area  52 . Specifically, the elevated temperature may result in an area corresponding to the region  110  that is brighter than remaining portions of the screen  152 . 
     Furthermore, the thermal profile  100  may be built prior to or during the power cycle. For example, heat may remain through the power cycle due to operation of the electronic device  10  during a previous ON state for the electronic device  10 . Additionally or alternatively, the power cycle may correspond to only some portions of the electronic device  10  (e.g., the display  18 ) while other portions (e.g., interfaces  26  and/or power source  24 ) remain active and possibly generating heat. The thermal profile  100  may be stored in memory  14  upon shutdown of the previous ON state. However, this thermal profile  100  is likely to change over time, and external compensation using the processors  12  is unlikely to be correct since the processors  12  may correct video data using a thermal profile  100  that is no longer current. Thus, such embodiments may result in artifacts corresponding to an incorrect thermal profile. Instead, the thermal profile  100  may be reset and to be correctly mapped during a sense phase of the display  18 . However, since the sensing phase is generally sent to the processors  12  after communication is established with the processors  12  by the display  18 . In other words, the processors  12  traditionally send image data to the display  18  at substantially the same time that the first image data is sent to the display  18  after start up or image data is sent after the first image data is sent to the display  18 . 
     As illustrated in  FIG. 11 , the electronic device  10  may utilize a process  200  for accounting for potential artifacts due to boot up thermal profiles. The process  200  includes booting up at least a portion of the electronic device  10  (block  202 ). Booting up may include booting up the whole electronic device  10  or may include booting up only a portion (e.g., the display  18 ). During boot up, the scanning driving circuitry  56  may start sensing pixels of the active area  52  (block  204 ). The scanning driving circuitry  56  and/or the scanning controller  58  may be programmed to cause sensing of at least some of the pixels of the active area  52  before initiating communication with the processors  12  and/or prior to receiving any image data from the processors  12 . 
     Furthermore, sensing of the pixels of the active area  52  may include sensing only a portion of the pixels. For example, pixels in key locations, such as those near known heat sources, may be scanned. Additionally or alternatively, a sampling representative of the active area  52  may be made. It is noted that an amount of pixels scanned may be a function of available buffer space since the sensing data is stored in a local buffer (block  206 ). The local buffer may be located in or near the scanning driving circuitry  56  and/or the scanning controller  58 . The local buffer is used for boot up scanning since communication with the processors  12  has not been established in the boot up process before the sensing of pixels begin. As previously noted, the buffer size may be related to how many pixels are sensed during the sensing scan. For example, if only strategic locations are stored, the local buffer may include twenty line buffers, over a thousand line buffers may be used if all pixels are sensed during the boot up scan. 
     Once communication is established between the display  18  and the processors  12 , the sensing data is transferred to the processors  12  (block  208 ). The processors  12  then modify image data to compensate for the potential artifacts (block  210 ). For example, the image data may be modified to reduce luminance levels of pixels corresponding to locations indicating a relatively high temperature. 
       FIG. 12  illustrates a timing diagram  220  that may be used to sense pixels during a power-on sequence. As illustrated, the timing diagram  220  includes a power on sequence  222  that occurs before a normal operation mode  224  after a boot up event  226 . As previously discussed, the boot up event may be a boot up of the entire electronic device  10  or may only be a portion of the electronic device  10  (e.g., display  18 ). The power on sequence  222  includes a power rail settling period  228  that includes a period of time adequate to allow power rails of the display  18  to sufficiently settle. In the illustrated embodiment, the power rail settling period  228  includes a duration equivalent to four frames (e.g., 33.2 ms). However, the power rail settling period  228  may be set to any duration sufficient to adequately settle the power rails. After the power rails have settled, the scanning driving circuitry  56  and/or the scanning controller  58  begin boot-up sensing  230 . In the illustrated embodiment, the boot-up sensing  230  lasts through frames  232 ,  234 , and  236 . However, this duration may be programmable to any period and may at least partially depend on how many pixels are scanned during the boot-up sensing  230 . For example, the illustrated embodiment includes sensing lines  238 ,  240 ,  242 ,  244 ,  246 ,  248 , and  250 . If additional lines/pixels are to be scanned, additional frames may be programmed into the boot-up sensing  230 . During a clock transition period  252  after the boot-up sensing  230 , communication between the display  18  (e.g., the sensing driving circuitry  56  and/or the sensing controller  58 ) may be established and normal operation  224  uses a clock signal that is also used by the processors  12 . 
     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.

Metadata:
Filing Date: 20170906
Publication Date: 20190820
Grant Date: 20190820
Priority Date: 20160919
Inventors: CHANG, SUN-IL
NHO, HYUNWOO
LIN, HUNG SHENG
TAN, JUNHUA
RYU, JIE WON
BRAHMA, KINGSUK
RICHMOND, Jesse A.
VAHID FAR, MOHAMMAD B.
BI, YAFEI
Assignee: APPLE INC
CPC Classifications: [{"code": "G09G2320/0693", "inventive": false, "first": false, "tree": "[]"}, {"code": "G09G3/2092", "inventive": true, "first": false, "tree": "[]"}, {"code": "G09G5/00", "inventive": true, "first": false, "tree": "[]"}, {"code": "G09G2320/041", "inventive": false, "first": false, "tree": "[]"}, {"code": "G09G3/006", "inventive": true, "first": true, "tree": "[]"}, {"code": "G09G2330/026", "inventive": false, "first": false, "tree": "[]"}, {"code": "G09G2320/0693", "inventive": false, "first": false, "tree": "[]"}, {"code": "G09G2330/026", "inventive": false, "first": false, "tree": "[]"}, {"code": "G09G2320/041", "inventive": false, "first": false, "tree": "[]"}, {"code": "G09G5/00", "inventive": true, "first": false, "tree": "[]"}, {"code": "G09G2320/0693", "inventive": false, "first": false, "tree": "[]"}, {"code": "G09G2320/041", "inventive": false, "first": false, "tree": "[]"}, {"code": "G09G5/00", "inventive": true, "first": false, "tree": "[]"}, {"code": "G09G3/2092", "inventive": true, "first": false, "tree": "[]"}, {"code": "G09G3/006", "inventive": true, "first": true, "tree": "[]"}, {"code": "G09G2330/026", "inventive": false, "first": false, "tree": "[]"}, {"code": "G09G3/2092", "inventive": true, "first": true, "tree": "[]"}]
Family ID: 59895435