PATENT DOCUMENT

Publication Number: US-11740736-B2
Application Number: US-201916436756-A
Country: US
Kind Code: B2

Title: Electronic display adaptive touch interference scheme systems and methods

Abstract:
Techniques for implementing and/or operating an electronic device including a display pixel layer, which writes a display image during an active period and continues displaying the display image during a blanking period, and a touch sense layer, which generates a first touch image during the active period and a second touch image during the blanking period. The electronic device further includes a controller that determines a first noise metric indicative of display-to-touch noise resulting during the active period based on the first touch image, determines a second noise metric indicative of display-to-touch noise resulting during the blanking period based on the second touch image, and instructs the touch sense layer to not generate a third touch image during a subsequent active period in response to the first noise metric being greater than a noise threshold and the second noise metric not being greater than the noise threshold.

Claims:
What is claimed is: 
     
       1. An electronic device comprising:
 a display pixel layer comprising a plurality of display pixels, wherein the display pixel layer is configured to:
 write a first display image during a first active period by controlling electrical energy stored in each of the plurality of display pixels based at least in part on first display image data corresponding with the first display image; and 
 continue presenting the first display image during a first blanking period directly after the first active period; 
 
 a touch sense layer comprising a plurality of touch sense pixels, wherein the touch sense layer is configured to:
 generate a first touch image based at least in part on electromagnetic interaction with the plurality of touch sense pixels during a first touch scan period that overlaps with the first active period; and 
 generate a second touch image based at least in part on electromagnetic interaction with the plurality of touch sense pixels during a second touch scan period that overlaps with the first blanking period; and 
 
 a controller communicatively coupled to the display pixel layer and the touch sense layer, wherein the controller is programmed to:
 determine a first noise metric indicative of display-to-touch noise resulting during active periods of the display pixel layer based at least in part on the first touch image determined during the first active period; 
 determine a second noise metric indicative of display-to-touch noise resulting during blanking periods of the display pixel layer based at least in part on the second touch image determined during the first blanking period; and 
 instruct the touch sense layer to not generate a third touch image during a second active period used to write a second display image after the first display image in response to the first noise metric being greater than a noise threshold and the second noise metric not being greater than the noise threshold. 
 
 
     
     
       2. The electronic device of  claim 1 , wherein the controller is programmed to instruct the touch sense layer to generate the third touch image during the second active period based at least in part on electromagnetic interaction with the plurality of touch sense pixels during a third touch scan period that overlaps with the second active period only in response to the first noise metric being greater than the noise threshold and the second noise metric not being greater than the noise threshold. 
     
     
       3. The electronic device of  claim 1 , wherein;
 the display pixel layer is configured to:
 write the second display image during the second active period by controlling electrical energy stored in each of the plurality of display pixels based at least in part on second display image data corresponding with the second display image; and 
 continue presenting the second display image during a second blanking period directly after the second active period; and 
 
 the touch sense layer is configured to:
 generate the third touch image based at least in part on electromagnetic interaction with the plurality of touch sense pixels during a third touch scan period that overlaps with the second active period; and 
 generate a fourth touch image based at least in part on electromagnetic interaction with the plurality of touch sense pixels during a fourth touch scan period that overlaps with the second blanking period. 
 
 
     
     
       4. The electronic device of  claim 3 , wherein the controller is programmed to:
 update the first noise metric indicative of display-to-touch noise resulting during active periods of the display pixel layer based at least in part on the third touch image in response to the third touch image being determined during the second active period; 
 update the second noise metric indicative of display-to-touch noise resulting during blanking periods of the display pixel layer based at least in part on the fourth touch image determined during the second blanking period; and 
 instruct the touch sense layer to not generate a fifth touch image during a third active period used to write a third display image after the second display image in response to the first noise metric being greater than the noise threshold and the second noise metric not being greater than the noise threshold. 
 
     
     
       5. The electronic device of  claim 1 , wherein the controller is programmed to instruct the touch sense layer to generate the third touch image during the second active period used to write the second display image in response to the first noise metric being greater than the noise threshold. 
     
     
       6. The electronic device of  claim 1 , wherein the display pixel layer is configured to produce parasitic capacitance that affects accuracy, precision, or both of touch sensing provided by the touch sense layer. 
     
     
       7. The electronic device of  claim 1 , wherein:
 to determine the first noise metric, the controller is programmed to determine a standard deviation of a first plurality of touch images each determined during an active period of the display pixel layer; and 
 to determine the second noise metric, the controller is programmed to determine a standard deviation of a second plurality of touch images each determined during a blanking period of the display pixel layer. 
 
     
     
       8. The electronic device of  claim 7 , wherein:
 the first plurality of touch images comprises touch images determined during active periods of a plurality of display images; and 
 the second plurality of touch images comprises touch images determined during blanking periods of the plurality of display images. 
 
     
     
       9. The electronic device of  claim 1 , comprising an electronic display, wherein the electronic display comprises the display pixel layer and the touch sense layer disposed over the display pixel layer. 
     
     
       10. The electronic device of  claim 1 , wherein the controller comprises a timing controller implemented in an electronic display. 
     
     
       11. The electronic device of  claim 1 , wherein the electronic device comprises a portable phone, a media player, a personal data organizer, a handheld game platform, a tablet device, a computer, or any combination thereof. 
     
     
       12. A method for controlling operation of an electronic device implemented with a display pixel layer and a touch sense layer, comprising:
 determining, using a controller, a first noise metric indicative of display-to-touch noise resulting during active periods of the display pixel layer based at least in part on a first touch image determined during a first active period by the touch sense layer; 
 determining, using the controller, a second noise metric indicative of display-to-touch noise resulting during blanking periods of the display pixel layer based at least in part on a second touch image determined during a first blanking period by the touch sense layer; and 
 instructing, using the controller, the touch sense layer to not generate a third touch image during a second active period used to write a display image in response to the first noise metric being greater than a noise threshold and the second noise metric not being greater than the noise threshold. 
 
     
     
       13. The method of  claim 12 , comprising:
 updating, using the controller, the first noise metric based at least in part on the third touch image in response to the third touch image being determined during the second active period; 
 updating, using the controller, the second noise metric based at least in part on a fourth touch image determined during a second blanking period; and 
 instructing, using the controller, the touch sense layer to generate a fifth touch image during a third active period used to write a second display image after the display image in response to the first noise metric being greater than the noise threshold and the second noise metric not being greater than the noise threshold. 
 
     
     
       14. The method of  claim 12 , wherein:
 determining the first noise metric comprises determining, via the controller, a standard deviation of a first plurality of touch images determined by the touch sense layer during the active periods of the display pixel layer; and 
 determining the second noise metric comprises determining, via the controller, a standard deviation of a second plurality of touch images determined by the touch sense layer during the blanking periods of the display pixel layer. 
 
     
     
       15. The method of  claim 14 , wherein:
 the first plurality of touch images comprises touch images determined during active periods of a plurality of display images; and 
 the second plurality of touch images comprises touch images determined during blanking periods of the plurality of display images. 
 
     
     
       16. The method of  claim 12 , wherein a frequency of the display pixel layer is the same as a frequency of the touch sense layer. 
     
     
       17. A tangible, non-transitory, computer-readable medium that stores instructions executable by one or more processors of an electronic device, wherein the instructions comprise instructions to:
 instruct, using the one or more processors, the electronic device to determine a first noise metric indicative of display-to-touch noise resulting during active periods of a display pixel layer based at least in part on a first touch image determined during a first active period by a touch sense layer; 
 instruct, using the one or more processors, the electronic device to determine a second noise metric indicative of display-to-touch noise resulting during blanking periods of the display pixel layer based at least in part on a second touch image determined during a first blanking period by the touch sense layer; and 
 instruct, using the one or more processors, the touch sense layer to not generate a third touch image during a second active period used to write a display image in response to the first noise metric being greater than a noise threshold and the second noise metric not being greater than the noise threshold. 
 
     
     
       18. The tangible, non-transitory, computer-readable medium of  claim 17 , wherein:
 the first touch image is determined based at least in part on electromagnetic interaction with a plurality of touch sense pixels of the touch sense layer during a first touch scan period that overlaps with the first active period; 
 the second touch image is determined based at least in part on electromagnetic interaction with the plurality of touch sense pixels of the touch sense layer during a second touch scan period that overlaps with the first blanking period. 
 
     
     
       19. The tangible, non-transitory, computer-readable medium of  claim 17 , wherein the instructions executable by the one or more processors of the electronic device comprise instructions to:
 instruct, using the one or more processors, the electronic device to update the first noise metric based at least in part on the third touch image in response to the third touch image being determined during the second active period; 
 instruct, using the one or more processors, the electronic device to update the second noise metric based at least in part on a fourth touch image determined during a second blanking period; and 
 instruct, using the one or more processors, the electronic device to update the touch sense layer to generate a fifth touch image during a third active period used to write a second display image after the display image in response to the first noise metric being greater than the noise threshold and the second noise metric not being greater than the noise threshold. 
 
     
     
       20. The tangible, non-transitory, computer-readable medium of  claim 17 , wherein:
 instructions to determine the first noise metric comprise determining, using the one or more processors, a standard deviation of a first plurality of touch images determined by the touch sense layer during the first active period of the display pixel layer; and 
 instructions to determine the second noise metric comprise determining, using the one or more processors, a standard deviation of a second plurality of touch images determined by the touch sense layer during the first blanking period of the display pixel layer.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 62/690,634, entitled “Electronic Display Adaptive Touch Interference Scheme Systems and Methods,” filed Jun. 27, 2018, which is incorporated herein by reference in its entirety for all purposes. 
    
    
     BACKGROUND 
     The present disclosure relates generally to interactions between an electronic display and touch sensing components of an electronic device. More particularly, the present disclosure relates generally to reducing the display-to-touch interference that may arise due to electrical interactions between display pixels of the electronic display and a touch sense layer. 
     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. 
     Electronic devices often use one or more electronic displays to present visual representations of information (e.g., text, still images, video) based on corresponding image content. For example, such electronic devices may include computers, mobile phones, portable media devices, virtual-reality headsets, and smart watches, among many others. In any case, to display an image, the electronic display may control light emission (e.g., luminance) of its display pixels based at least in part on corresponding image data. Additionally, in some instances, luminance of the display pixel may vary based at least in part on electrical energy stored in the display pixel. Thus, to control light emission from the display pixel, the electronic display may supply a data (e.g., analog electrical) signal to the display pixel based at least in part on corresponding image data and instruct the display pixel to store electrical energy based at least in part on the data signal, thereby writing (e.g., refreshing) the display pixel. 
     Electronic devices may also often include touch sensing components that detect touch of an object (e.g., finger or stylus) on the screen of the electronic display. For example, when the touch sensing components detect a touch at or near an icon for an application, the electronic device may open the application and instruct its electronic display to present a visual representation of the application. The touch sensing components may rely on electrical variations to detect the touch indication. For example, the touch sensing components may employ capacitive touch sensors that use capacitive coupling to detect an object at or near the screen of the electronic display. However, as electronic devices become more compact, the touch sensing component may be located in closer proximity to the display pixels, which, at least in some instances, may result in display-to-touch noise that affects accuracy and/or precision of the touch indications detected by the touch sensing components. 
     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 generally relates to reducing display-to-touch interference arising from interactions between display pixels of an electronic display and touch sensing components (e.g., a touch sense layer) of an electronic device and/or the electronic display by dynamically controlling touch scanning frequency based on calculated display-to-touch noise. In one example, the touch sense layer implemented in an electronic device may be used by the electronic device to detect touch indications that may control the operation of the device. However, in some embodiments, the touch sense layer may significantly overlap (e.g., positioned above, below, within, around) with the display pixels. In some instances, the close proximity between the touch sense layer and the display pixel layer may increase interaction between the two layers, for example, due to parasitic capacitance coupling that results in display-to-touch noise (e.g., false touch, jittery touch, and mis-touch) that perceivably affects accuracy and/or precision of touch indications detected by the touch sense layer. 
     To facilitate improved quality of touch detection, in some embodiments, timing of the touch scanning period may be adjusted to reduce likelihood of display-to-touch noise affecting touch detection by the touch sense layer. For example, the touch scanning period may occur partially in a display active period and partially in a display blanking period when the electronic display actively determines that the display-to-touch noise is below a noise threshold during both the active period and the blanking period. Additionally or alternatively, the touch scanning period may occur only in the display blanking period when the electronic device determines that the display-to-touch noise during the active period is greater than the noise threshold, for example, on a rolling basis. 
    
    
     
       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 block diagram of an electronic device, in accordance with an embodiment of the present disclosure; 
         FIG.  2    is an example of the electronic device of  FIG.  1    in the form of a handheld device, in accordance with an embodiment of the present disclosure; 
         FIG.  3    is another example of the electronic device of  FIG.  1    in the form of a tablet device, in accordance with an embodiment of the present disclosure; 
         FIG.  4    is another example of the electronic device of  FIG.  1    in the form of a notebook computer, in accordance with an embodiment of the present disclosure; 
         FIG.  5    is another example of the electronic device of  FIG.  1    in the form of a smart watch, in accordance with an embodiment of the present disclosure; 
         FIG.  6    is a block diagram of an organic light emitting diode (OLED) electronic display, in accordance with an embodiment of the present disclosure; 
         FIG.  7    is a schematic diagram of an electronic display including a touch sense layer and a display pixel layer, in accordance with an embodiment of the present disclosure; 
         FIG.  8 A  is a diagrammatic representation of a touch image generated by the touch sense layer of  FIG.  7    when display-to-touch noise is less than a noise threshold, in accordance with an embodiment of the present disclosure; 
         FIG.  8 B  is a diagrammatic representation of a touch image generated by the touch sense layer of  FIG.  7    when the display-to-touch noise is greater than the noise threshold, in accordance with an embodiment of the present disclosure; 
         FIG.  9    is a flow diagram of a process for controlling operation of the touch sense layer of  FIG.  7   , in accordance with an embodiment of the present disclosure; 
         FIG.  10    is a timing diagram that describes operation of the touch sense layer and the display pixel layer of  FIG.  7   , in accordance with an embodiment of the present disclosure; 
         FIG.  11    is another timing diagram that describes operation of the touch sense layer and the display pixel layer of  FIG.  7   , in accordance with an embodiment of the present disclosure; 
         FIG.  12    is a flow diagram of a process for determining timing of the touch sense operations when the display-to-touch noise is above the noise threshold, in accordance with an embodiment of the present disclosure; and 
         FIG.  13    is another timing diagram that describes operation of the touch sense layer and the display pixel layer of  FIG.  7   , in accordance with an embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS 
     One or more specific embodiments will be described below. In an effort to provide a concise description of these embodiments, not all features of an actual implementation are described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers&#39; specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure. 
     When introducing elements of various embodiments of the present disclosure, the articles “a,” “an,” and “the” are intended to mean that there are one or more of the elements. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. Additionally, it should be understood that references to “one embodiment” or “an embodiment” of the present disclosure are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features. 
     The present disclosure generally relates to a touch sensing components (e.g., a touch sense layer), which may be used to detect presence of a touch indication that may control operations of an electronic device, and to electronic displays, which may be implemented to present visual representations of information, for example, in one or more image frames. Generally, an electronic display may display an image by controlling light emission and, thus, perceived (e.g., actual) luminance of its display pixel based at least in part on corresponding image data. In some electronic displays, light emission from the display pixel may vary based at least in part on electrical energy stored in the display pixel. For example, in a liquid crystal display (LCD), electrical energy may be stored in the pixel electrode of a display pixel to produce an electric field between the pixel electrode and a common electrode (display VCOM), which controls orientation of liquid crystals and, thus, light emission from the display pixel. Additionally, in an organic light-emitting diode (OLED) display, electrical energy may be stored in a storage capacitor of a display pixel to control electrical power (e.g., current) supplied to a self-emissive component (e.g., OLED) and, thus, light emission from the display pixel. 
     In some instances, image data may digitally indicate target luminance of display pixels for displaying an image on the electronic display. Since the image displayed is based on the stored electrical energy, the electronic display may write a display pixel by supplying an analog electrical (e.g., data) signal based at least in part on corresponding image data to the display pixel and instructing the display pixel to adjust electrical energy stored in its storage component (e.g., pixel electrode or storage capacitor) based at least in part the analog electrical signal. For example, to write an LCD display pixel, a data driver may output a data (e.g., source) signal and a scan driver may output a scan (e.g., gate) signal, which instructs the display pixel to supply the data signal to its pixel electrode to display the image frame. Additionally, to write an OLED display pixel, a data driver may output a data signal and a scan driver may output a scan control signal, which instructs the display pixel to supply the data signal to its storage capacitor. 
     The data driver may output the analog electrical (e.g., image data) signal corresponding to the image data to the electronic display during active periods (e.g., refresh periods). The display period of the image frame (e.g., frame period) may include the active period and a blanking period (e.g., vertical blanking period and/or horizontal blanking period) that occurs between successive active periods. Generally, during an active period, the display pixels of an electronic display may receive image data signals and store the corresponding amounts of electrical energy in the pixel electrodes, the display pixel storage capacitors, and/or the like. Additionally, the data drive may not send the image data signals during the blanking period and the display pixels may remain idle. The target refresh rate and other display pipeline parameters may determine the duration of the frame period, the active periods, and the blanking periods. 
     Additionally, the touch sense layer may be implemented in the electronic device to enable the electronic device to detect a touch indication on the electronic display. Examples include detecting touch from a finger, a stylus, and the like. The electronic device may use the touch indication to control operations of the device, such as opening an application when the touch indications occurs near the application icon on the electronic display. Generally, the touch sense layer may be integrated within, around, below, or above the electronic display, for example, for example depend on dimensions of the electronic device. 
     Further, the touch sense layer may include touch sensors (e.g., capacitive touch sensors and/or resistive touch sensors) that rely on changes in impedance (e.g., capacitance and/or resistance) to determine occurrence of a touch and, thus, a touch indication. For example, a voltage may be applied to the capacitive touch sensors to generate a relatively uniform electric field and, in response to an object coming near or touching the electronic display, the electric field local to the object may vary from the uniform value resulting in a change of capacitance sensed by touch sensors near that area of the display. In some instances, the electronic device may determine that a touch indication has occurred by periodically measuring the variations of the target electrical parameters during a touch scanning period. For example, a touch scan may occur using time-multiplexing with the electronic display. That is, the touch scan may occur during the blanking period (e.g., inter-frame pause) and/or during a pause inserted in the middle of the active period (e.g., intra-frame pause). 
     However, at least in some instances, display-to-touch noise may affect the value of target electrical parameter variations measured by the touch sense layer and, thus, the accuracy and precision of the detected touch indication. For example, when the display pixel is written to (e.g., refreshed) during the active period, the electric field generated as the display pixel stores the image data may non-uniformly contribute to the electric field across the touch sense layer, for example, causing one or more local fluctuations of the target electrical parameter (e.g., capacitance) that is detected as one or more touch indications by the electronic device. The effect on the values of the target electrical parameter may vary based at least in part on the strength of parasitic capacitance coupling between the touch sense layer and the display pixel layer, which encourages electric field interactions between the layers. 
     Since there is greater demand for thinner, higher display resolution, higher refresh rates, and faster touch response time electronic devices, the close proximity of the touch sense layer and the display pixel layer may increase the strength of the parasitic capacitance coupling and/or may increase the difficulty of time multiplexing the display operations and the touch sense layer operations. Thus, when the electronic device is implemented with both the display pixel layer and the touch sense layer, the electrical interactions between the layers of a compact electronic device may be high, thereby increasing likelihood of display-to-touch interferences (e.g., noise) affecting accuracy and/or precision of the detected touch indication, for example, perceivable as a false touch, a jittery touch, or a mis-touch. 
     As such, the present disclosure provides techniques to facilitate improving the accuracy and/or precision of touch indications determined by the electronic device implemented with a touch sense layer and an electronic display. For example, by dynamically controlling (e.g., adjusting) the touch scanning frequency based on display-to-touch noise calculated during the active periods and the blanking periods, the display-to-touch interferences may be reduced. In fact, the present techniques may mitigate or even eliminate random changes to the target electrical parameter values by the electric field generated when refreshing the display pixels, for example, without using additional hardware or shielding layers. Further, the present techniques may enable dynamically and seamlessly switching between a high precision, high frequency touch sense mode and a low frequency, low noise touch sense mode based at least in part on the display-to-touch noise. 
     To facilitate improving quality of touch detection, in some embodiments, a processor core complex (e.g., controller) may determine whether there is a greater likelihood that the measured variations of the target electrical parameter are due to noise. For example, the controller may actively calculate the display-to-touch noise of a touch image obtained during each touch scanning period. Additionally or alternatively, the controller may, on a rolling basis, determine a first noise metric (e.g., standard deviation) of the display-to-touch noise over multiple (e.g., 30) touch images obtained during the display active period and a second noise metric of multiple touch images obtained during the display blanking period to facilitate distinguishing between the image signal and the display-to-touch noise. 
     Moreover, in some embodiments, parameters (e.g., frequency and/or duration) of the touch scanning period may be adjusted by the controller when the calculated display-to-touch noise for the touch images detected during the active period and the blanking period are below a noise threshold. For example, the touch scanning period may be split such that touch images are obtained during the active period and the blanking period of each frame period. Splitting the touch scanning period may increase the amount of touch image frames obtained by the electronic device and, therefore, may enable the electronic device to respond to a touch indication at a faster rate. As such, in some embodiments, the controller may control the frequency (e.g., 120 Hz) and/or duration of the touch scanning period during each frame period such that each touch scanning period occurs partially in the active period and partially in the blanking period to facilitate improving response time to a touch indication. 
     Furthermore, in some embodiments, the parameters (e.g., frequency and/or duration) of the touch scanning period may be adjusted when the calculated display-to-touch noise for the touch images detected during the active period is above a noise threshold and the display-to-touch noise for the touch images detected during the blanking period is below the noise threshold. The touch scanning period, for example, may occur entirely during the display blanking period of each frame period. In some embodiments, the touch scanning period may occur entirely in the display blanking period. Additionally or alternatively, the touch scanning period may be split such that a touch scanning period of a smaller duration occurs during the blanking period. That is, the touch scanning period that may occur during the active period is dropped while the touch scanning period that occurs during the blanking period remains. As such, in some embodiments, the controller may control the frequency (e.g., 60 Hz) and/or duration of the touch scanning period of each frame period such that the accuracy and precision of touch indications measured by the touch sense layer is not affected by the display-to-touch noise. 
     Additionally or alternatively, the touch scanning frequency may be adjusted based at least in part on the display-to-touch noise and the refresh rate of a variable display refresh rate system. For example, when the display-to-touch noise is higher than the noise threshold in a variable display refresh rate system running in low power mode, the display blanking period may have a long enough duration such that the touch scanning period may occur during the display blanking period (e.g., as one or more periods). In other words, in some embodiments, the controller may determine the duration of the active period and the blanking period and change the frequency and/or duration of the touch scanning period based on the duration of the blanking period. 
     With the foregoing in mind, an electronic device  10 , which may utilize an electronic display  12  to display images and to detect touch indications, is shown in  FIG.  1   . As will be described in more detail below, the electronic device  10  may be any suitable computing device, such as a handheld computing device, a tablet computing device, a notebook computer, and/or the like. Thus, 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 the electronic device  10 . 
     In the depicted embodiment, the electronic device  10  includes the electronic display  12 , one or more input devices  14 , one or more input/output (I/O) ports  16 , a processor core complex  18  having one or more processor(s) or processor cores, memory  20  that may be local to the device  10 , a main memory storage device  22 , a network interface  24 , power source  26 , and image processing circuitry  27 . The various components described in  FIG.  1    may include hardware elements (e.g., circuitry), software elements (e.g., a tangible, non-transitory computer-readable medium storing instructions), or a combination of both hardware and software elements. It should be noted that the various depicted components may be combined into fewer components or separated into additional components. For example, the memory  20  and the main memory storage device  22  may be included in a single component. Additionally, the image processing circuitry  27  (e.g., a graphics processing unit (GPU)) may be included in the processor core complex  18 . 
     As depicted, the processor core complex  18  is operably coupled with memory  20  and the main memory storage device  22 . In some embodiments, the memory  20  and/or the main memory storage device  22  may be tangible, non-transitory, computer-readable media that stores instructions executable by the processor core complex  18  and/or data to be processed by the processor core complex  18 . For example, the memory  20  may include random access memory (RAM) and the main memory storage device  22  may include read only memory (ROM), rewritable non-volatile memory such as flash memory, hard drives, optical discs, and/or the like. 
     In some embodiments, the processor core complex  18  may execute instructions stored in memory  20  and/or the main memory storage device  22  to perform operations, such as signaling (e.g., instructing) the touch sense layer of the display  12  to generate a touch image. As such, the processor core complex  18  may include one or more general purpose microprocessors, one or more application specific processors (ASICs), one or more field programmable logic arrays (FPGAs), or any combination thereof. Additionally or alternatively, the processor core complex  18  include a controller (e.g., timing controller (TCON)) dedicated to the display  12  and/or additional controllers dedicated to other operations to the electronic device  10 . For example, the TCON may calculate the noise metric of each touch scan period and may instruct the touch sense layer to periodically scan for a touch indication. 
     Further, as depicted, the processor core complex  18  is operably coupled with I/O ports  16 , which may enable the electronic device  10  to interface with various other electronic devices. For example, a portable storage device may be connected to an I/O port  16 , thereby enabling the processor core complex  18  to communicate data with a portable storage device. In this manner, the I/O ports  16  may enable the electronic device  10  to output image content to the portable storage device and/or receive image content from the portable storage device. 
     Furthermore, the processor core complex  18  is also operably coupled to the power source  26 , which may provide power to the various components in the electronic device  10 . The power source  26  may include any suitable source of energy, such as a rechargeable lithium polymer (Li-poly) battery and/or an alternating current (AC) power converter. As depicted, the processor core complex  18  is operably coupled with input devices  14 , which may enable a user to interact with the electronic device  10 . In some embodiments, the inputs devices  14  may include buttons, keyboards, mice, trackpads, and the like. 
     Additionally, as depicted, the processor core complex  18  is operably coupled with the network interface  24 . Using the network interface  24 , the electronic device  10  may communicatively couple to a communication network and/or other electronic devices. For example, the network interface  24  may connect the electronic device  10  to a personal area network (PAN), such as a Bluetooth network, a local area network (LAN), such as an 802.11x Wi-Fi network, and/or a wide area network (WAN), such as a 4G or LTE cellular network. In this manner, the network interface  24  may enable the electronic device  10  to transmit image content to a network and/or receive image content from the network for display on the electronic display  12 . 
     The electronic display  12  may use, for example, organic light-emitting diode (OLED) or liquid-crystal display (LCD) technology to present visual representations of information by displaying images, such as a graphical user interface (GUI) of an operating system, an application interface, a still image, or video content. As described above, the electronic display  12  may display an images based on image data received from memory  20 , a storage device (e.g., main memory storage device  22  and/or an external storage device), and/or another electronic device  10 , for example, via the network interface  24  and/or the I/O ports  16 . The electronic display  12  may display the images once the image content has been fetched from memory  20  and processed by the image processing circuitry  27 . The electronic display  12  may also include touch sensing components (e.g., capacitive touch sensors) in the form of a touch sense layer that enables user input to the electronic device  10  by detecting touch indications and/or position of an object touching the screen (e.g., surface of the electronic display  12 ). The touch sense layer may be integrated with the display pixels and/or above, below, or encasing the screen. 
     As described above, the electronic device  10  may be any suitable electronic device. To help illustrate, one example of a suitable electronic device  10 , specifically a handheld device  10 A, is shown in  FIG.  2   . In some embodiments, the handheld device  10 A may be a portable phone, a media player, a personal data organizer, a handheld game platform, and/or the like. For illustrative purposes, the handheld device  10 A may be a smart phone, such as any iPhone® model available from Apple Inc. 
     As depicted, the handheld device  10 A includes an enclosure  28  (e.g., housing). In some embodiments, the enclosure  28  may protect interior components from physical damage and/or shield them from electric interference. Additionally, as depicted, the enclosure  28  surrounds the electronic display  12 . In the depicted embodiment, the electronic display  12  is displaying a graphical user interface (GUI)  30  having an array of icons  32 . By way of example, when an icon is selected either by an input device  14  or a touch sensing component of the electronic display  12 , an application program may launch. 
     Furthermore, as depicted, input devices  14  open through the enclosure  28 . As described above, the input devices  14  may enable a user to interact with the handheld device  10 A. For example, the input devices  14  may enable the user to activate or deactivate the handheld device  10 A, navigate a user interface to a home screen, navigate a user interface to a user-configurable application screen, activate a voice-recognition feature, provide volume control, and/or toggle between vibrate and ring modes. As depicted, the I/O ports  16  also open through the enclosure  28 . In some embodiments, the I/O ports  16  may include, for example, an audio jack to connect to external devices. 
     To further illustrate, another example of a suitable electronic device  10 , specifically a tablet device  10 B, is shown in  FIG.  3   . For illustrative purposes, the tablet device  10 B may be any iPad® model available from Apple Inc. A further example of a suitable electronic device  10 , specifically a computer  10 C, is shown in  FIG.  4   . For illustrative purposes, the computer  10 C may be any Macbook® or iMac® model available from Apple Inc. Another example of a suitable electronic device  10 , specifically a watch  10 D, is shown in  FIG.  5   . For illustrative purposes, the watch  10 D may be any Apple Watch® model available from Apple Inc. As depicted, the tablet device  10 B, the computer  10 C, and the watch  10 D each also includes an electronic display  12 , input devices  14 , I/O ports  16 , and an enclosure  28 . 
     As described above, an electronic display  12  that may display images based at least in part on the image data, for example, that indicates target luminance of its display pixels. Additionally, as described above, the electronic display  12  may detect a touch indication in response to an object coming near or contacting the electronic display  12 . In some embodiments, the timing of touch sensing may be coordinated (e.g., controlled) based on the timing of the electronic display  12  and/or the display-to-touch noise, for example, to reduce (e.g., minimize) likelihood that the display-to-touch noise perceivably affects touch sensing accuracy and/or responsiveness. 
     To help illustrate, an example of a display panel  64 , which may be implemented in an electronic display  12 , is shown in  FIG.  6   . As depicted, the display panel  64 A includes a pixel array  100 , a source driver  102 , a gate driver  104 , and a power supply  106 . In particular, the pixel array  100  may include multiple display pixels  108  arranged as an array or matrix defining multiple rows and columns. For example, the depicted embodiment includes six display pixels  108 . It should be appreciated that although only six display pixels  108  are depicted, in an actual implementation the pixel array  100  may include hundreds or even thousands of display pixels  108 . 
     As described above, an electronic display  12  may display image frames by controlling luminance of its display pixels  108  based at least in part on processed image data received via the display panel  64 . To facilitate displaying an image frame, a timing controller may determine and transmit timing data  110  to the gate driver  104  based at least in part on the processed image data. For example, in the depicted embodiment, the timing controller may be included in the source driver  102 . Accordingly, in such embodiments, the source driver  102  may receive the processed image data that indicates desired luminance of one or more display pixels  108  for displaying the image frame, analyze the processed image data to determine the timing data  110 , and transmit the timing data  110  to the gate driver  104 . Based at least in part on the timing data  110 , the gate driver  104  may then transmit gate activation signals to activate a row of display pixels  108  via a gate line  112 . 
     When activated, luminance of a display pixel  108  may be adjusted by processed image data received via data lines  114 . In some embodiments, the source driver  102  may generate the image by receiving a voltage corresponding to a processed image data. The source driver  102  may then supply the processed image data to the activated display pixels  108 . Thus, as depicted, each display pixel  108  may be located at an intersection of a gate line  112  (e.g., scan line) and a data line  114  (e.g., source line). Based on received image data, the display pixel  108  may adjust its luminance using electrical power supplied from the power supply  106  via power supply lines  116 . 
     Each display pixel  108  may include a circuit switching thin-film transistor (TFT)  118 , a storage capacitor  120 , an OLED  122 , and a driving TFT  124  whereby each of the storage capacitors  120  and the OLED  122  are coupled to a common voltage, VCOM. To facilitate adjusting luminance, the driving TFT  124  and the circuit switching TFT  118  may each serve as a switching device that is controllably turned on and off by voltage applied to the respective gate. In the depicted embodiment, the gate of the circuit switching TFT  118  is electrically coupled to a gate line  112 . Accordingly, when a gate activation signal received from its gate line  112  is above its threshold voltage, the circuit switching TFT  118  may turn on, thereby activating the display pixel  108  and charging the storage capacitor  120  with the processed image data received at its data line  114 . 
     Additionally, in the depicted embodiment, the gate of the driving TFT  124  is electrically coupled to the storage capacitor  120 . As such, voltage of the storage capacitor  120  may control operation of the driving TFT  124 . More specifically, in some embodiments, the driving TFT  124  may be operated in an active region to control magnitude of supply current flowing from the power supply line  116  through the OLED  122 . In other words, as gate voltage (e.g., storage capacitor  120  voltage) increases above its threshold voltage, the driving TFT  124  may increase the amount of its channel available to conduct electrical power, thereby increasing supply current flowing to the OLED  122 . On the other hand, as the gate voltage decreases while still being above its threshold voltage, the driving TFT  124  may decrease amount of its channel available to conduct electrical power, thereby decreasing supply current flowing to the OLED  122 . In this manner, the display panel  64 A may control luminance of the display pixel  108 . 
     Because of how OLED display technology drives the display pixels  108  (e.g., push the circuit switching TFT  118  into the active region, charge the storage capacitor  120 , and drive the driving TFT  124 ), OLED displays  64 A may generate relatively large amounts of display-to-touch noise when electrical signal is sent along the data line  114  to the display pixel  108  when the gate line  112  is activated. That is, the OLED displays  64 A may generate display-to-touch noise during the active period that interferes with the accuracy and precision of touch indication detection. Although OLED technology was described in detail above, any display technology (e.g., LCDs) that may encounter display-to-touch interference. 
     To help further illustrate, an example of an electronic display  12 A, which include a touch sense layer  606  and a display pixel layer  624 , is shown in  FIG.  7   . In some embodiments, the display  12 A may include a glass cover  602  that protects the internal components of the display  12 A and is the interface point for user inputs via touch indications from an object  604 . As in the depicted example, the touch sense layer  606  may include touch sensors  608 A- 608 D that detect the presence of the touch indication. In some embodiments, the touch sensors  608 A- 608 D (e.g., capacitive touch sensors, resistive touch sensors) may rely on changes in target electrical parameters (e.g., capacitance or resistance) to detect the presence of the touch indication. 
     For example, the electronic device  10  may apply a voltage to the touch sensors  608 A- 608 D to generate a relatively uniform, fringing electric field  610 A across the touch sense layer  606  and a capacitance of the touch sense layer  606 . When the object  604  approaches or touches the electronic display  12 A, a portion of the electric field  610 B is “stolen” by the object  604 . That is, a portion of the electric field  610 B extends to the object  604  instead of an accompanying touch sensors (e.g.,  608 B). Thus, the value of the electric field  610 C may locally vary from the uniform value, causing a change in the capacitance between one or more touch sensors (e.g.,  608 B) near the object  604  and a reference touch layer. 
     In some embodiments, the display pixel layer  624  of the electronic display  12 A may include the display pixels  620 . As mentioned above, the display pixels  620  may each have an image content storage component  626  (e.g., storage capacitor, pixel electrode) that stores electrical energy corresponding to the image data. Depending on the display technology (e.g., liquid crystal displays (LCDs), organic light-emitting diodes (OLEDs)), the electrical energy may cause a luminance corresponding to the image data for each display pixel  618  to display on the electronic display  12 . It should be understood that any number of touch sensors  608 A- 608 D, display pixels  620 , and display layers may be used during implementation of the electronic display  12 A, greater or less than the number shown in  FIG.  7   . Additionally, while discussion of the display  12 A refers to capacitive touch sensors  608 A- 608 D, it should be appreciated that any type of touch sensors may be implemented in by the electronic device  10 . 
     The demand for compact devices  10  and displays  12  with high resolution (e.g., high refresh rates) and/or high touch response, however, may make it difficult to preserve the accuracy and precision of detected touch indications. For example, compact device designs may remove the shielding layer (e.g., air gap and/or dielectric material) typically placed between the touch sense layer  606  and the display pixel layer  624  to block unwanted coupling between the layers. Because the design may place the touch sense layer  606  and the display pixel layer  624  is closer proximity, parasitic capacitance coupling  628  may occur between the touch sensors  608 A- 608 D and the display pixel layer  624 , resulting in greater display-to-touch noise that affects the accuracy and precision of detected touch indications. For example, false touch, jittery touch, and/or mis-touch may be perceivable to the user. 
     The display-to-touch noise may be greater during the active periods since the display pixels  620  may store electrical energy and generate an electric field during that time. The electric field generated by the display pixels  620  may interact with the electric field  610  of the touch sense layer  606 , causing unexpected variations in the electric field  610  and thus, false and/or inaccurate detections of touch. Since the display-to-touch noise may be somewhat dependent on the image data and may be greater during the active period, in some embodiments, it may advantageous to avoid the active period. That is, the processor core complex  18  may avoid overlapping the touch scanning period with the active period. However, high refresh rates, high touch scanning frequencies, and longer touch scanning duration times may be used to satisfy demands for high display resolution and/or faster touch response time, which, at least in some instances, make it difficult is not impossible to time multiplex the touch sense operations and the display active operations. 
       FIG.  8 A  and  FIG.  8 B  demonstrate the effect that display-to-touch noise may have on the precision and/or accuracy of touch indications sensed by a touch sense layer  606 . Each touch sensors  608 A- 608 D may sense a variation in the electric field  610  that is reported as variations in the sensed capacitance  612  between the touch sensors  608 A- 608 D and the touch drive electrodes  614 .  FIG.  8 A  illustrates an example touch image  700  of the touch indication values  706  sensed by multiple touch sensors  608 A- 608 D of the touch sense layer  606  when the display-to-touch noise is below a noise threshold. Each sector  702  represents area of the display  12  sensed by a touch sensor (e.g.,  608 A) and the value of each sector  702  represents the touch indication value  706  detected by the touch sensors (e.g.,  608 A) in that area. 
     The object  604  may approach or touch the display  12  at a specific location  704 . Because the object  604  may divert a portion of the electric field  610  local to the location  704  from the touch sensors (e.g.,  608 A), the capacitance value (e.g., touch indication value  706 ) at the location  704  may have a greater change and the touch sense layer  606  may determine that the touch indication occurred at the location  704 . That is, the shown gradient represents where the touch sensors  608 A- 608 H detected that a touch indication occurred on the display  12 , the darker sector  702  showing the exact location  704  that the touch was determined to occur, the lighter sectors  702  indicating that the touch occurred nearby, and the non-colored sectors  702  indicating that the touch did not occur near those areas of the display  12 . 
       FIG.  8 B  illustrates an example touch image  750  of the touch indication values sensed by multiple touch sensors  608 A- 608 D of the touch sense layer  606  when the display-to-touch noise is above a noise threshold. As in  FIG.  8 A , the object  604  may approach or touch the display  12  at a specific location  754 . The object  604  may divert a portion of the electric field  610  local to the location  754  from the touch sensors (e.g.,  608 A). 
     However, the display-to-touch noise (e.g., display electric field interacting with touch electric field  610  via parasitic capacitance coupling) may generate additional variations in the electric field  610 , causing the touch indication value  756  of a touch sensor (e.g.,  608 D) in an area of the display  12  different from the location  754  of the touch to have the highest touch indication value  756 . The touch sense layer  606  may determine that the touch indication occurred at the touch sensors (e.g.,  608 D) that sensed the highest touch indication value  756  instead of the actual location  754  of touch by the object  604 . That is, the shown gradient, representing where the touch sensors  608 A- 608 D detected that a touch indication occurred (e.g., darker sector) on the electronic display  12 , does not align with the actual location  754  of the touch indication due to the interference of display-to-touch noise. 
     In some embodiments, the electronic device  10  may determine that a touch indication has occurred by periodically measuring the variations of the target electrical parameters (e.g., capacitance) during a touch scanning period. For example, the touch scan operations may be time multiplexed with the display operations, such that the touch scanning period does not overlap with the active period. However, as discussed above, design demands of the electronic device  10  and the electronic display  12  make time multiplexing the display operations and touch sense operations difficult. 
     An example of a process  800  for controlling operation of an electronic display  12  is described in  FIG.  9   . Generally, the process  800  includes determining an active period and a blanking period of an electronic display (process block  802 ), performing one or more touch sense operations during the blanking period (process block  804 ), and performing one or more touch sense operations during the active period (process block  806 ). 
     While process  800  is described using steps in a specific sequence, it should be understood that the present disclosure contemplates that the described steps may be performed in different sequences than the sequence illustrated, and certain described steps may be skipped or not performed altogether. In some embodiments, the process  800  may be implemented at least in part executing instructions stored in a tangible, non-transitory, computer-readable medium, such as the memory  20 , using processing circuitry, such as the processor core complex  18  or a separate controller. Additionally or alternatively, the process  800  may be implemented at least in part by circuit connections and/or control logic implemented in an electronic device  10 . 
     Thus, in some embodiments, a controller (e.g., a timing controller (TCON)) separate from or included in the processor core complex  18  may determine the active period and the blanking period of the electronic display  12 . For example, the electronic display  12  may generate a tearing effect (TE) signal that indicates (e.g., signals) when the electronic display  12  is entering the active period. The processor core complex  18  may use the tearing effect signal to coordinate the timing of the touch scanning period with the display  12 . Based on the tearing effect signal, the target refresh rate, and the minimum duration and/or frequency of the touch scanning period, the processor core complex  18  may perform one or more touch sense operations during the display blanking period (process block  804 ) and during the display active period (process block  806 ). Examples of touch sense operations include scanning the area of the display  12  by driving the conductive lines of the touch drive electrodes  614  with the touch sensing circuitry and generating the touch image for each touch scanning period representative of the changes in capacitance values  612 . 
     Additionally, in some embodiments, the processor core complex  18  may control the duration and/or frequency of the touch sense operations based on the target refresh rate, target touch response time, and the target touch response period duration. For example, when the target refresh rate is high and, thus the display blanking period duration low, the processor core complex  18  may split the touch scanning period into two such that a first touch scanning period occurs during the active period and a second touch scanning period occurs during the blanking period for each frame period. In some embodiments, the split touch scanning periods may each have a shorter duration than the original touch scanning period; however the total duration of the split scanning periods may be equivalent to the original touch scanning period, for example, to meet that the minimum time for performing touch sense operations per image frame. Further, the touch response time and touch detection accuracy may be preserved since the touch scanning periods and, thus, the touch sensing operations may occur more frequently, for example, compared to if the touch scanning periods were limited only to the blanking period. By placing the touch sense operations partially in the active period and partially in the blanking period, the display-to-touch noise may be significantly reduced (e.g., by 30%) as compared to if the touch sense operation were to occur entirely during the active period. 
     In some embodiments, the target refresh rate may vary based upon the operation mode of the electronic display  12 . For example, the target refresh rate may decrease from 120 Hz to 1 Hz in power saving mode and/or when the image content to be displayed is a still image. In such cases, the controller (e.g., processor core complex  18 ) may place the touch scanning operation for each frame period entirely within the blanking period, for example, without compromising on the touch response time, touch detection precision, and the display-to-touch noise interference. For example, when the target refresh rate is 1 Hz, the blanking period may include most of the frame period and the controller may place the touch scanning period in the blanking period. The touch scanning period may be kept intact or the processor core complex  18  may split the touch scanning period such that touch sense operations occur more frequently per frame period. 
       FIG.  10    is a timing diagram  900  illustrating an example timing of touch sense operations and the display operations when an electronic display  12  implements split touch sensing periods. As described above, in some embodiments, the controller (e.g., processor core complex  18 ) may split the touch scanning period such that it is partially located in the active period and partially in the blanking period. For example, when the frame period is 16.67 ms (e.g., 1/60 Hz), the touch scanning period may also have a duration of 16.67 ms, thereby making it impossible to time multiplex the touch sense operations and the active period. The touch scanning period may be split such that the duration of each touch scanning period is 8.33 ms (e.g., 1/120 Hz) and the scanning frequency is 120 Hz. By timing the touch sense operations and the display operations, the display-to-touch noise may be significantly reduced (e.g., by 30%) assuming that the display-to-touch noise follows a Gaussian distribution and the touch response time as compared to when the touch scanning period is entirely or only in one of the blanking period and the active period. 
       FIG.  11    is a timing diagram  1000  illustrating another example timing of touch sense operations and display operations when an electronic display  12  implemented to utilize a variable display refresh rate. As discussed above, in some embodiments, the controller (e.g., processor core complex  18 ) may use the tearing effect signal to coordinate the active periods and the blanking periods with the touch scanning period. For example, when the refresh rate decreases from 60 Hz to 1 Hz (e.g., frame period  1002  to frame period  1004 ), the display blanking period may have a longer duration. Thus, the controller may change the timing and/or duration of the touch scanning period such that it occurs during the blanking period when the duration of the blanking period is greater than that of the touch scanning period. Additionally, the controller may split the touch scanning period such that the duration of each split touch scanning period is shorter than the original period and the frequency of the touch scanning period is greater than that of the original, thereby reducing the display-to-touch noise and improving the touch response time. 
     In some embodiments, the display-to-touch noise may be too high, such that the accuracy and precision of the detected touch indications is affected despite timing the touch sense operations and the display operations using process  800 .  FIG.  12    illustrates a process  1100  for determining the timing of touch sense operations when the display-to-touch noise is above a specified noise threshold. Generally, process  1100  includes determining noise metrics resulting from touch sense operations during the active period (process block  1102 ), determining noise metrics resulting from touch sense operations during the blanking periods (process block  1104 ), determining whether the accuracy and precision of the touch indication is affected (decision block  1106 ), using touch sense operations occurring during the active and blanking periods when the accuracy and precision of the touch indication is not affected (process block  1108 ), and using the touch sense operations occurring only during the blanking periods when the accuracy and precision of the touch indication is affected (process block  1110 ). 
     While process  1100  is described using steps in a specific sequence, it should be understood that the present disclosure contemplates that the described steps may be performed in different sequences than the sequence illustrated, and certain described steps may be skipped or not performed altogether. In some embodiments, the process  1100  may be implemented at least in part by executing instructions stored in a tangible, non-transitory, computer-readable medium, such as the memory  20 , using processing circuitry, such as the processor core complex  18  or a separate controller. Additionally or alternatively, the process  1100  may be implemented at least in part by circuit connections and/or control logic implemented in an electronic device  10 . 
     Thus, in some embodiments, a controller (e.g., processor core complex  18 ) may determine a noise metric resulting from touch sense operations that occurred during active periods (process block  1102 ). For example, the controller may calculate the display-to-touch noise for each touch pixel (e.g., each touch sensors) to determine the overall display-to-touch noise present in each touch image obtained during the touch scanning periods, which occur during the active periods. Further, the controller may determine a standard deviation of multiple (e.g., 30) touch images that were obtained during the active period, for example, to normalize the touch images. In some embodiments, the controller may determine the standard deviation of touch images obtained during the active period on a rolling basis. 
     Further, in some embodiments, the controller may determine the noise metric from touch sense operations that occurred during the blanking periods (process block  1104 ). For example, the processor core complex  18  may calculate the display-to-touch noise for each touch image obtained via the touch scanning periods, which occur during the blanking periods. Furthermore, the processor core complex  18  may determine the standard deviation of multiple (e.g., 30) touch images that were obtained during the blanking period, for example, to normalize the touch images. Because the display pixels  620  are idle during the blanking period, the touch images obtained during the display blanking period may be clean or nearly clean of the display-to-touch noise. In some embodiments, the controller may determine the standard deviation of touch images obtained during the blanking period on a rolling basis. 
     Additionally, in some embodiments, the controller may determine whether the accuracy and precision of the touch indication is affected by the display-to-touch noise (decision block  1106 ). For example, the controller, on a rolling basis, may determine whether the noise metrics of the active period touch images and of the blanking period touch images are below a specified noise threshold. In some embodiments, the controller may subtract the noise metric associated with the blanking period touch images from the noise metric associated with the active period touch images to remove the image data signal from the display-to-touch noise since the blanking period touch images may include only the image data signal while the active period touch images may include the image data signal and the display-to-touch noise. 
     When the result is below the noise threshold, the display-to-touch noise may be within an acceptable range such that the accuracy and precision of the touch indication is not affected. As such, the controller may use the touch images from the touch sense operations occurring during the active periods and the blanking periods (process block  1108 ). That is, the controller may instruct the touch sense layer  606  to keep the touch scanning period frequency as high as possible (e.g., 120 Hz), as shown in timing diagram  900 , to maintain accuracy and touch response time. 
     When the result obtained from comparing (e.g., subtracting) the noise metrics associated with the blanking period touch images and with the active period touch images is above the noise threshold and the noise metric associated with the active period touch images is above a touch scan noise threshold while the noise metric associated with the blanking period touch images is below a touch scan noise threshold, the display-to-touch noise may affect the accuracy and precision of the touch indication. Thus, the controller may instruct the touch sense layer  606  to reduce the touch scanning period frequency (e.g., from 120 Hz to 60 Hz) automatically in noisy environments, essentially removing the touch scanning periods occurring during the active period from consideration. That is, the touch scanning periods that occur during the display active period may be dropped such that only touch images obtained by touch operations occurring during the blanking period are used in determining the presence of the touch indication (process block  1100 ). In such cases, the touch response time may be affected to facilitate improving accuracy of touch indication detection. 
       FIG.  13    is a timing diagram  1200  illustrating an example timing of touch sense operations and display operations of an electronic display  12  when a display-to-touch noise is greater than a noise threshold. As described above, in some embodiments, the controller may instruct the touch sense layer  606  to drop the touch scanning periods that occur during the active period by reducing the touch scanning period frequency. For example, the touch scanning period frequency may drop 120 Hz to 60 Hz such that the touch scanning period occurs during the blanking periods. As shown in timing diagram  1200 , the controller may maintain a touch scanning period duration similar to that when the touch scanning period is split, as shown in timing diagram  900 . This may ensure that the touch scanning period remains within the blanking period so that the display-to-touch noise may not affect the accuracy and precision of the touch indication detection. 
     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: 20190610
Publication Date: 20230829
Grant Date: 20230829
Priority Date: 20180627
Inventors: LIANG, Anshi
YI, HE
XU, YANG
SACCHETTO, PAOLO
LI, JUN
HUANG, JINGYU
DEVINCENTIS, Marc Joseph
CHU, YUE JACK
Assignee: APPLE INC
CPC Classifications: [{"code": "G06F3/0418", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F3/044", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/046", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/04184", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F3/0418", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F3/0412", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/0443", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/046", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/044", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 69008165