PATENT DOCUMENT

Publication Number: US-11527582-B1
Application Number: US-202017006708-A
Country: US
Kind Code: B1

Title: Display stack with integrated photodetectors

Abstract:
An electronic device includes a frame and a display stack. The frame defines a first part of an interior volume. The display stack includes a cover attached to the frame. The cover may define a second part of the interior volume. The display stack also includes an array of organic light-emitting diodes (OLEDs) including an array of emissive electroluminescent (EL) regions, and at least one organic photodetector (OPD) disposed between the cover and at least one emissive EL region in the array of emissive electroluminescent regions. The at least one emissive EL region emits light through the at least one OPD. In alternative embodiments, the OLEDs may be stacked on the OPDs, or the OLEDs and OPDs may be interspersed with each other instead of stacked.

Claims:
What is claimed is: 
     
       1. An electronic device, comprising:
 a frame defining a first part of an interior volume; and 
 a display stack including,
 a cover attached to the frame and defining a second part of the interior volume; 
 an array of organic light-emitting diodes (OLEDs) comprising an array of emissive electroluminescent (EL) regions; 
 at least one organic photodetector (OPD) disposed between the cover and at least one emissive EL region in the array of emissive electroluminescent regions; 
 a touch sensor positioned between the array of OLEDs and at least one layer including the at least one OPD; and 
 an electrode positioned between the at least one OPD and the touch sensor and electrically connected to,
 a surface of the at least one OPD; and 
 the touch sensor; 
 
 
 wherein the at least one emissive EL region emits electromagnetic radiation through the at least one OPD. 
 
     
     
       2. The electronic device of  claim 1 , wherein:
 the display stack further comprises an OLED encapsulation layer positioned between the array of OLEDs and at least one layer including the at least one OPD. 
 
     
     
       3. The electronic device of  claim 1 , wherein:
 the electrode positioned between the at least one OPD and the touch sensor is a first electrode; and 
 the at least one OPD comprises an OPD; and 
 the display stack further comprises,
 a second electrode electrically connected to a second surface of the OPD; and 
 a thin-film transistor (TFT) backplane; 
 
 wherein at least one of the first electrode or the second electrode is electrically connected to the TFT backplane. 
 
     
     
       4. The electronic device of  claim 1 , wherein the at least one OPD comprises an OPD that overlaps an emissive EL region in the array of emissive EL regions in a one-to-one relationship. 
     
     
       5. The electronic device of  claim 1 , wherein the at least one OPD comprises an array of OPDs. 
     
     
       6. A display stack, comprising:
 an array of organic light-emitting diodes (OLEDs) comprising an array of emissive electroluminescent (EL) regions; 
 at least one organic photodetector (OPD); 
 an OLED encapsulation layer positioned between the array of OLEDs and at least one layer including the at least one OPD; 
 a touch sensor positioned between the array of OLEDs and at least one layer including the at least one OPD; and 
 an electrode positioned between the at least one OPD and the touch sensor and electrically connected to,
 a surface of the at least one OPD; and 
 the touch sensor; 
 
 wherein at least one emissive EL region emits electromagnetic radiation through the at least one OPD. 
 
     
     
       7. The display stack of  claim 6 , wherein the at least on OPD is disposed above at least one emissive EL region in the array of EL regions. 
     
     
       8. The display stack of  claim 7 , wherein the at least one OPD disposed above the at least one emissive EL region is partially or fully overlaps the at least one emissive EL region. 
     
     
       9. The display stack of  claim 6 , wherein the at least one OPD comprises an array of OPDs. 
     
     
       10. The display stack of  claim 6 , wherein the array of OLEDs is disposed below an exterior structural component through which an electronic image is displayed to a user. 
     
     
       11. The display stack of  claim 6 , wherein the at least one OPD corresponds to at least one OLED of the array of OLEDs. 
     
     
       12. The display stack of  claim 6 , wherein the at least OPD is disposed uniformly or non-uniformly over the array of OLEDs. 
     
     
       13. A display stack disposed in a frame of an electronic device, the display stack comprising:
 an array of organic light-emitting diodes (OLEDs) comprising an array of emissive electroluminescent (EL) regions; 
 at least one organic photodetector (OPD); 
 a touch sensor positioned between the array of OLEDs and at least one layer including the at least one OPD; 
 a backplane; and 
 a first electrode positioned between the at least one OPD and the touch sensor and electrically connected to,
 a surface of the at least one OPD; and 
 the touch sensor; 
 
 a second electrode electrically connected to a second surface of the at least one OPD and the backplane. 
 
     
     
       14. The display stack of  claim 13 , wherein at least one emissive EL region of the array of EL regions emits electromagnetic radiation through the at least one OPD. 
     
     
       15. The display stack of  claim 13 , wherein the first electrode is electrically connected to the backplane. 
     
     
       16. The display stack of  claim 13 , wherein the at least one OPD is disposed above at least one emissive EL region in the array of EL regions. 
     
     
       17. The display stack of  claim 13 , wherein the backplane comprises a thin-film transistor (TFT) backplane. 
     
     
       18. The display stack of  claim 13 , wherein the display stack further comprising:
 a third electrode electrically connected to,
 a first surface of an OLED of the array of OLEDs; and 
 the backplane. 
 
 
     
     
       19. The display stack of  claim 18 , wherein the display stack further comprising:
 a fourth electrode electrically connected to,
 a second surface of the OLED of the array of OLEDs; and 
 the backplane. 
 
 
     
     
       20. The display stack of  claim 19 , wherein:
 the first surface is closer to the at least one OPD; and 
 the second surface is closer to the backplane.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a nonprovisional of and claims the benefit under 35 U.S.C. 119(e) of U.S. Provisional Patent Application No. 62/905,301, filed Sep. 24, 2019, the contents of which are incorporated herein by reference as if fully disclosed herein. 
    
    
     FIELD 
     The described embodiments generally relate to devices that include an electronic display and one or more photodetectors, such as phones, computers, watches, and so on having ambient light sensors, biometric sensors, cameras, depth sensors, and so on. More particularly, the described embodiments relate to the integration of photodetectors into a display stack. 
     BACKGROUND 
     Sensors are included in many of today&#39;s electronic devices, including electronic devices such as smartphones, computers (e.g., tablet computers or laptop computers), wearable electronic devices (e.g., electronic watches, smart watches, or health monitors), game controllers, navigation systems (e.g., vehicle navigation systems or robot navigation systems), and so on. Sensors may variously sense the presence of objects, distances to objects, proximities of objects, movements of objects (e.g., whether objects are moving, or the speed, acceleration, or direction of movement of objects), and so on. Some sensors may include a photodetector, or an array of photodetectors. A photodetector or array of photodetectors may be used, for example, to determine a proximity of an object. An array of photodetectors may be variously configured as an ambient light sensor, a light-emitting element (e.g., organic light-emitting element (OLED)) health sensor (e.g., age sensor), a touch sensor, a proximity sensor, a health sensor, a biometric sensor (e.g., a fingerprint sensor or facial recognition sensor), a camera, a depth sensor, and so on. 
     Given the wide range of sensor applications, any new development in the configuration or operation of a system including a sensor can be useful. New developments that may be particularly useful are developments that reduce the cost, size, complexity, part count, or manufacture time of the sensor or sensor system, or developments that improve the sensitivity or speed of sensor or sensor system operation. 
     SUMMARY 
     Embodiments of the systems, devices, methods, and apparatus described in the present disclosure are directed to the integration of a photodetector, or an array of photodetectors, into a display stack. 
     In a first aspect, the present disclosure describes an electronic device. The electronic device may include a frame and a display stack. The frame may define a first part of an interior volume. The display stack may include a cover attached to the frame. The cover may define a second part of the interior volume. The display stack may further include an array of organic light-emitting diodes (OLEDs) including an array of emissive electroluminescent (EL) regions, and at least one organic photodetector (OPD) disposed between the cover and at least one emissive EL region in the array of emissive electroluminescent regions. The at least one emissive EL region may emit light through the at least one OPD. 
     In a second aspect, the present disclosure describes another electronic device. The electronic device may include a display stack. The display stack may include an exterior structural component through which electronic images are viewed by a user, an array of OLEDs disposed below the exterior structural component, and an array of OPDs disposed below the array of OLEDs. 
     In a third aspect, the present disclosure describes yet another electronic device. The electronic device may include a cover, an array of OLEDs disposed under the cover and including an array of emissive EL regions, and an array of OPDs disposed under the cover. The emissive EL regions in the array of emissive EL regions may have a first set of axes perpendicular to the cover, and the OPDs in the array of OPDs may have a second set of axes perpendicular to the cover. The axes of the OPDs may be interspersed with axes of the emissive EL regions. 
     In addition to the exemplary aspects and embodiments described above, further aspects and embodiments will become apparent by reference to the drawings and by study of the following description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The disclosure will be readily understood by the following detailed description in conjunction with the accompanying drawings, wherein like reference numerals designate like structural elements, and in which: 
         FIGS.  1 A and  1 B  show an example of a device that may include an array of photodetectors; 
         FIGS.  2 A and  2 B  show another example of a device that may include an array of photodetectors; 
         FIG.  3    shows an example plan view of arrays of light-emitting elements and photodetectors that may be included in a stack positioned under the cover of the device described with reference to  FIG.  1 A- 1 B or  2 A- 2 B ; 
         FIG.  4    shows an example elevation of a stack (e.g., a display stack or device stack); 
         FIGS.  5 ,  6 A- 6 C,  7 ,  8 A- 8 B,  9 , and  10 A- 10 C  show elevations of portions of example stacks including an OLED (or array of OLEDs) and an OPD (or array of OPDs); 
         FIG.  11    shows an example plan view of the stack described with reference to  FIG.  9 ,  10 A,  10 B , or  10 C; and 
         FIG.  12    shows a sample electrical block diagram of an electronic device, which electronic device may in some cases be implemented as the device described with reference to  FIG.  1 A- 1 B or  2 A- 2 B . 
     
    
    
     The use of cross-hatching or shading in the accompanying figures is generally provided to clarify the boundaries between adjacent elements and also to facilitate legibility of the figures. Accordingly, neither the presence nor the absence of cross-hatching or shading conveys or indicates any preference or requirement for particular materials, material properties, element proportions, element dimensions, commonalities of similarly illustrated elements, or any other characteristic, attribute, or property for any element illustrated in the accompanying figures. 
     Additionally, it should be understood that the proportions and dimensions (either relative or absolute) of the various features and elements (and collections and groupings thereof) and the boundaries, separations, and positional relationships presented therebetween, are provided in the accompanying figures merely to facilitate an understanding of the various embodiments described herein and, accordingly, may not necessarily be presented or illustrated to scale, and are not intended to indicate any preference or requirement for an illustrated embodiment to the exclusion of embodiments described with reference thereto. 
     DETAILED DESCRIPTION 
     Reference will now be made in detail to representative embodiments illustrated in the accompanying drawings. It should be understood that the following description is not intended to limit the embodiments to one preferred embodiment. To the contrary, it is intended to cover alternatives, modifications, and equivalents as can be included within the spirit and scope of the described embodiments as defined by the appended claims. 
     Electronic devices are being designed with increasingly large displays, which in some cases may cover the entire front surface of a device. This reduces the real estate that was once available for various optical sensors. The following description therefore describes how to integrate a photodetector, or an array of photodetectors, into a display stack. In some cases, a photodetector and a light-emitting element (e.g., an OLED) may be stacked to achieve lateral space efficiency and/or a high fill of light-emitting elements. 
     A photodetector or array of photodetectors, integrated into a display stack, may be variously configured as an ambient light sensor, a light-emitting element (e.g., OLED) health sensor (e.g., age sensor), a touch sensor, a proximity sensor, a health sensor, a biometric sensor (e.g., a fingerprint sensor or facial recognition sensor), a camera, a depth sensor, and so on. 
     An array of photodetectors may be used, for example, for security, health monitoring, or entertainment purposes. For example, when used for security purposes, an array of photodetectors may be used to obtain biometric information, such as fingerprints, palm-prints, 3D face scans, or retina scans. The biometric information may then be used to identify or authenticate a user. When used for health monitoring purposes, an array of photodetectors may be used, for example, to acquire an electrocardiogram (ECG), pulse, or ophthalmic scan from a user. When used for entertainment purposes, an array of photodetectors may be used, for example, for palm reading, social networking, or social matching. 
     These and other techniques are described with reference to  FIGS.  1 A- 12   . However, those skilled in the art will readily appreciate that the detailed description given herein with respect to these figures is for explanatory purposes only and should not be construed as limiting. 
     Directional terminology, such as “top”, “bottom”, “upper”, “lower”, “front”, “back”, “over”, “under”, “beneath”, “left”, “right”, etc. may be used with reference to the orientation of some of the components in some of the figures described below. Because components in various embodiments can be positioned in a number of different orientations, directional terminology is used for purposes of illustration only and is in no way limiting. The directional terminology is intended to be construed broadly, and therefore should not be interpreted to preclude components being oriented in different ways. The use of alternative terminology, such as “or”, is intended to indicate different combinations of the alternative elements. For example, A or B is intended to include, A, or B, or A and B. 
       FIGS.  1 A and  1 B  show an example of a device  100  that may include an array of photodetectors. The device  100  may include a housing  102  that defines an interior volume  104 .  FIG.  1 A  shows an isometric view of the device  100 , and  FIG.  1 B  shows a cross-section of the device  100  along line IB-IB. 
     The housing  102  may include, for example, a frame  102 - 1  and a cover  102 - 2 . Each component of the housing (e.g., each of the frame  102 - 1  and the cover  102 - 2 ) may define a part of the interior volume  104 . The frame  102 - 1  may further define an opening to the interior volume  104 . In some cases, the frame  102 - 1  may be a multi-part frame, such as a frame formed by a support plate and one or more edge members extending from the support plate to support the cover  102 - 2 . In some cases, the edge members may define a sidewall of the device  100 . In some cases, the frame  102 - 1  may include metal and/or plastic components. In some cases, the cover  102 - 2  may be a transparent cover, such as a glass, sapphire, or plastic cover. The components of the housing  102  may be semi-permanently or detachably joined to one another by a set of fasteners, adhesives, seals, or other components. In some cases, the housing  102  may include different or additional components. 
     In some embodiments, the interior volume  104  may be sealed to prevent gases (e.g., air) or fluids (e.g., water) from entering or leaving the interior volume  104 . In other embodiments, the interior volume  104  may not be sealed, thereby allowing gases and possibly fluids to enter or leave the interior volume  104 . In some embodiments, the interior volume  104  may be vented. For example, an optional port  106  may be defined in frame  102 - 1  or another portion of the housing  102 , and the port  106  may allow gases (e.g., air) but not fluids (e.g., water) to flow between the interior volume  104  and an ambient environment of the device  100 . 
     As shown in  FIG.  1 B , a display  108  (i.e., an electronic display) may be disposed within the interior volume  104  and configured to emit or project light (e.g., light that defines an image) through the cover  102 - 2 . The display  108  may be partially or completely surrounded by the frame  102 - 1  and/or covered by the cover  102 - 2 , and in some cases may be mounted to the frame  102 - 1  and/or suspended from the cover  102 - 2 . The display  108  may include one or more light-emitting elements or pixels, and in some cases may be a light-emitting diode (LED) display, an OLED display, a liquid crystal display (LCD), an electroluminescent (EL) display, a laser projector, or another type of electronic display. 
     In some embodiments, a stack  110  (or display stack, or device stack) including the display  108  (and in some cases the cover  102 - 2 ) may include, or be associated with, one or more touch and/or force sensors that are configured to detect a touch and/or force applied to an exterior surface of the cover  102 - 2 . For example, the stack  110  may include a touch sensor  112  (or touch sensing system), and the touch sensor  112  may include, for example, a set of capacitive touch sensing elements, a set of resistive touch sensing elements, or a set of ultrasonic touch sensing elements. When a user of the device  100  touches the cover  102 - 2 , the touch sensor  112  (or touch sensing system) may detect one or more touches on the cover  102 - 2  and indicate the locations of the touches on the cover  102 - 2 . The touches may include, for example, touches by a user&#39;s finger or stylus. 
     The stack  110  may also include a force sensor  114  (or force sensing system), and the force sensor  114  may include, for example, a set of capacitive force sensing elements, a set of resistive force sensing elements, or one or more pressure transducers. When a user of the device  100  presses on the cover  102 - 2  (i.e., applies a force to the cover  102 - 2 ), the force sensor  114  may determine an amount of force applied to the cover  102 - 2  (or in some cases, the amount of force applied to a side or sides of the frame  102 - 1 , a surface of the frame  102 - 1  opposite the cover  102 - 2 , and so on). In some embodiments, the force sensor  114  may be used alone or in combination with the touch sensor  112  to determine a location of an applied force, or an amount of force associated with each touch in a set of multiple contemporaneous touches, or a location of a touch. In some embodiments, the force sensor  114  may additionally or alternatively include one or more force sensing elements disposed between the cover  102 - 2  and the frame  102 - 1  (e.g., to sense a capacitance or resistance, or a change in capacitance or resistance, between the cover  102 - 2  and the frame  102 - 1  or electrodes coupled thereto or positioned therebetween), or within the interior volume  104  (e.g., to sense a pressure, or change in pressure, within the interior volume  104 ). 
     As also shown in  FIG.  1 B , an array of photodetectors  116  (or at least one photodetector), a processor  118 , and/or other components may also be positioned partly or wholly within the interior volume  104 . The array of photodetectors  116  may extend over most or all of the surface area of the display  108 , or may be limited to a particular one or more regions of the display  108 . The array of photodetectors  116  and/or processor  118  may be mounted to the frame  102 - 1  and/or the cover  102 - 2 . In some cases, the photodetectors in the array of photodetectors  116  may include organic photodetectors (OPDs). In some cases, the array of photodetectors  116  and/or processor  118  may be included in the stack  110 . Some of the components (e.g., the processor  118 ) may alternatively be positioned entirely outside the interior volume  104 , such as below a support plate or mid-plate of the frame  102 - 1  (not shown). 
     The processor  118  may be configured to operate one or more or all of the display  108 , the touch sensor  112 , the force sensor  114 , or the array of photodetectors  116 , and may be configured to receive, evaluate, propagate, or respond to signals obtained from the touch sensor  112 , force sensor  114 , and/or array of photodetectors  116 . 
     In some embodiments, the array of photodetectors  116  (or at least one photodetector) may be variously configured (e.g., by the processor  118 ) as an ambient light sensor, a light-emitting element (e.g., OLED) health sensor (e.g., age sensor), a touch sensor, a proximity sensor, a health sensor, a biometric sensor (e.g., a fingerprint sensor or facial recognition sensor), a camera, a depth sensor, and so on. In some embodiments, different parts of the array of photodetectors  116  may be configured to provide different types of optical sensing contemporaneously. In some embodiments, part or all of the array of photodetectors  116  may be configured to perform different types of optical sensing at different times. Although the array of photodetectors  116  is shown positioned behind the display  108 , the array of photodetectors  116  may alternatively be positioned in front of the display  108  (e.g., between the display  108  and the cover  102 - 2 ) or photodetectors in the array of photodetectors  116  may be interspersed with light-emitting elements of the display  108  (e.g., the photodetectors, and emissive regions of the display  108 ), may have axes that are perpendicular to the cover  102 - 2 , and the axes of the photodetectors may be interspersed with the axes of the emissive regions. 
     When part or all of the array of photodetectors  116  is configured as an ambient light sensor, one or more photodetectors in the array may be configured to sense a visible light wavelength or range of visible light wavelengths, or different photodetectors may be configured to sense different visible light wavelengths or ranges of visible light wavelengths. In some embodiments, only one photodetector may be used as an ambient light sensor, or a number of photodetectors that is far less than (e.g., an order of magnitude less than) the number of light-emitting elements included in the display  108  may be used as an ambient light sensor. 
     When part or all of the array of photodetectors  116  is configured as a light-emitting element (e.g., OLED) health sensor (e.g., age sensor), a number of photodetectors equal to a number of light-emitting elements in the display  108  may be used (e.g., in a one-to-one photodetector-to-light-emitting elements correspondence) to monitor the health or age of the light-emitting elements. In these embodiments, outputs of the photodetectors may be analyzed by the processor  118 , and the processor  118  may adjust aspects of the light-emitting elements (e.g., drive voltages, and so on) to compensate for aging or other health-related aspects of the light-emitting elements. In some cases, different photodetectors in the array may be filtered (e.g., color filtered) to detect different wavelengths of light emitted by differently filtered (e.g., differently color filtered) light-emitting elements. 
     When part or all of the array of photodetectors  116  is configured as a proximity, touch sensor, fingerprint sensor, and/or facial recognition sensor, the strengths of the signals output by the photodetectors in the array may vary based on the distance of an object (e.g., a finger) to the cover  102 - 2 , or based on whether ridges or valleys of a fingerprint are positioned over the photodetectors, or based on what portions of a face are positioned in the fields of view of the photodetectors. In some embodiments, part or all of the array of photodetectors  116  may be used as a touch sensor in lieu of the touch sensor  112  (i.e., the touch sensor  112  may not be provided). Changes in the signals output by the photodetectors of the array may be analyzed by the processor  118  to identify not only the proximity of an object and/or an object&#39;s touch on the cover  102 - 2 , but also movements of an object, on or off the cover  102 - 2 , which movements may be correlated with one or more gestures. Photodetectors used as a proximity sensor may in some cases be configured (e.g., filtered or constructed) to detect visible and/or near infrared (NIR) electromagnetic radiation. In some cases, a NIR electromagnetic radiation source (or sources) may be positioned within or outside the boundary of the display  108 , and may be activated to emit NIR electromagnetic radiation when part or all of the array of photodetectors  116  is activated to determine proximity and/or touch of an object. Photodetectors used as a fingerprint sensor may in some cases be configured (e.g., filtered or constructed) to detect blue and/or green light. When part or all of the array of photodetectors  116  is configured as a fingerprint sensor, a collimator may be positioned between the cover  102 - 2  and the array of photodetectors  116 . 
     When part or all of the array of photodetectors  116  is configured as a health sensor, the photodetectors of the array may in some cases be configured (e.g., filtered or constructed) to detect visible and/or NIR electromagnetic radiation. In some cases, a NIR electromagnetic radiation source (or sources) may be positioned within or outside the boundary of the display  108 , and may be activated to emit NIR electromagnetic radiation when part or all of the array of photodetectors  116  is activated to sense a health condition. Health conditions that may be sensed using part or all of the array of photodetectors  116  include, for example, a heart rate, a blood oxygenation level, or a vein image. 
       FIGS.  2 A and  2 B  show another example of a device that may include an array of photodetectors. The device&#39;s dimensions and form factor, including the ratio of the length of its long sides to the length of its short sides, suggest that the device  200  is a mobile phone (e.g., a smartphone). However, the device&#39;s dimensions and form factor are arbitrarily chosen, and the device  200  could alternatively be any portable electronic device including, for example a mobile phone, tablet computer, portable computer, portable music player, electronic watch, health monitoring device, portable terminal, vehicle navigation system, robot navigation system, or other portable or mobile device. The device  200  could also be a device that is semi-permanently located (or installed) at a single location (e.g., a door lock, thermostat, refrigerator, or other appliance).  FIG.  2 A  shows a front isometric view of the device  200 , and  FIG.  2 B  shows a rear isometric view of the device  200 . The device  200  may include a housing  202  that at least partially surrounds a display  204 . The housing  202  may include or support a front cover  206  or a rear cover  208 . The front cover  206  may be positioned over the display  204 , and may provide a window through which the display  204  (including images displayed thereon) may be viewed by a user. In some embodiments, the display  204  may be attached to (or abut) the housing  202  and/or the front cover  206 . 
     The display  204  may include one or more light-emitting elements or pixels, and in some cases may be an LED display, an OLED display, an LCD, an EL display, a laser projector, or another type of electronic display. In some embodiments, the display  204  may include, or be associated with, one or more touch and/or force sensors that are configured to detect a touch and/or a force applied to a surface of the front cover  206 . 
     The various components of the housing  202  may be formed from the same or different materials. For example, a sidewall  218  of the housing  202  may be formed using one or more metals (e.g., stainless steel), polymers (e.g., plastics), ceramics, or composites (e.g., carbon fiber). In some cases, the sidewall  218  may be a multi-segment sidewall including a set of antennas. The antennas may form structural components of the sidewall  218 . The antennas may be structurally coupled (to one another or to other components) and electrically isolated (from each other or from other components) by one or more non-conductive segments of the sidewall  218 . The front cover  206  may be formed, for example, using one or more of glass, a crystal (e.g., sapphire), or a transparent polymer (e.g., plastic) that enables a user to view the display  204  through the front cover  206 . In some cases, a portion of the front cover  206  (e.g., a perimeter portion of the front cover  206 ) may be coated with an opaque ink to obscure components included within the housing  202 . The rear cover  208  may be formed using the same material(s) that are used to form the sidewall  218  or the front cover  206 , or may be formed using a different material or materials. In some cases, the rear cover  208  may be part of a monolithic element that also forms the sidewall  218  (or in cases where the sidewall  218  is a multi-segment sidewall, those portions of the sidewall  218  that are non-conductive). In still other embodiments, all of the exterior components of the housing  202  may be formed from a transparent material, and components within the device  200  may or may not be obscured by an opaque ink or opaque structure within the housing  202 . 
     The front cover  206  may be mounted to the sidewall  218  to cover an opening defined by the sidewall  218  (i.e., an opening into an interior volume in which various electronic components of the device  200 , including the display  204 , may be positioned). The front cover  206  may be mounted to the sidewall  218  using fasteners, adhesives, seals, gaskets, or other components. 
     A display stack or device stack (hereafter referred to as a “stack”) including the display  204  (and in some cases the front cover  206 ) may be attached (or abutted) to an interior surface of the front cover  206  and extend into the interior volume of the device  200 . In some cases, the stack may also include a touch sensor (e.g., a grid of capacitive, resistive, strain-based, ultrasonic, or other type of touch sensing elements), or other layers of optical, mechanical, electrical, or other types of components. In some cases, the touch sensor (or part of a touch sensor system) may be configured to detect a touch applied to an outer surface of the front cover  206  (e.g., to a display surface of the device  200 ). 
     The stack may also include an array of photodetectors  216 , with the photodetectors positioned in front of or behind, or interspersed with, the light-emitting elements of the display  204 . The array of photodetectors  216  may extend across an area equal in size to the area of the display  204 . Alternatively, the array of photodetectors  216  may extend across an area that is smaller than or greater than the area of the display  204 . Although the array of photodetectors  216  is shown to have a rectangular boundary, the array could alternatively have a boundary with a different shape, including, for example, an irregular shape. The array of photodetectors  216  may be variously configured as an ambient light sensor, a light-emitting element (e.g., OLED) health sensor (e.g., age sensor), a touch sensor, a proximity sensor, a health sensor, a biometric sensor (e.g., a fingerprint sensor or facial recognition sensor), a camera, a depth sensor, and so on. The array of photodetectors  216  may also function as a proximity sensor, for determining whether an object (e.g., a finger, face, or stylus) is proximate to the front cover  206 , or as any of the sensor types described with reference to  FIGS.  1 A- 1 B . In some embodiments, the array of photodetectors  216  may provide the touch sensing capability (i.e., touch sensor) of the stack. 
     In some cases, a force sensor (or part of a force sensor system) may be positioned within the interior volume below and/or to the side of the display  204  (and in some cases within the stack). The force sensor (or force sensor system) may be triggered in response to the touch sensor detecting one or more touches on the front cover  206  (or indicating a location or locations of one or more touches on the front cover  206 ), and may determine an amount of force associated with each touch, or an amount of force associated with the collection of touches as a whole. 
     As shown primarily in  FIG.  2 A , the device  200  may include various other components. For example, the front of the device  200  may include one or more front-facing cameras  210  (including one or more image sensors), speakers  212 , microphones, or other components  214  (e.g., audio, imaging, and/or sensing components) that are configured to transmit or receive signals to/from the device  200 . In some cases, a front-facing camera  210 , alone or in combination with other sensors, may be configured to operate as a bio-authentication or facial recognition sensor. Additionally or alternatively, the array of photodetectors  216  may be configured to operate as a front-facing camera  210 , a bio-authentication sensor, or a facial recognition sensor. 
     The device  200  may also include buttons or other input devices positioned along the sidewall  218  and/or on a rear surface of the device  200 . For example, a volume button or multipurpose button  220  may be positioned along the sidewall  218 , and in some cases may extend through an aperture in the sidewall  218 . The sidewall  218  may include one or more ports  222  that allow air, but not liquids, to flow into and out of the device  200 . In some embodiments, one or more sensors may be positioned in or near the port(s)  222 . For example, an ambient pressure sensor, ambient temperature sensor, internal/external differential pressure sensor, gas sensor, particulate matter concentration sensor, or air quality sensor may be positioned in or near a port  222 . 
     In some embodiments, the rear surface of the device  200  may include a rear-facing camera  224 . A flash or light source  226  may also be positioned along the rear of the device  200  (e.g., near the rear-facing camera). In some cases, the rear surface of the device  200  may include multiple rear-facing cameras. 
       FIG.  3    shows an example plan view of arrays  300  of light-emitting elements and photodetectors that may be included in a stack positioned under the cover of the device described with reference to  FIG.  1 A- 1 B or  2 A- 2 B . 
     A first array  302  may include a set of photodetectors  304 . The set of photodetectors  304  may be coupled to an image processor  306 . The set of photodetectors  304  may detect the same wavelength of electromagnetic radiation or different wavelengths of electromagnetic radiation. In the illustrated embodiment, the set of photodetectors  304  is arranged in rows and columns. However, the set of photodetectors  304  may alternatively be arranged in any suitable configuration, such as, for example, a hexagonal configuration. 
     The first array  302  may be in communication with a column select circuit  308  through one or more column select lines  310 , and with a row select circuit  312  through one or more row select lines  314 . The row select circuit  312  may selectively activate a particular photodetector  304  or group of photodetectors, such as all of the photodetectors  304  in a row. The column select circuit  308  may selectively receive the data output from a selected photodetector  304  or group of photodetectors  304  (e.g., all of the photodetectors  304  in a row). 
     The row select circuit  312  and/or column select circuit  308  may be in communication with the image processor  306 . The image processor  306  may process data received from the photodetectors  304  and provide that data to another processor (e.g., a system processor) and/or other components of a device (e.g., other components of the device described with reference to  FIG.  1 A- 1 B or  2 A- 2 B ). 
     In some embodiments, the first array  302  may be configured as a rolling shutter image sensor, in which different rows or columns of photodetectors  304  are sequentially enabled and read out. In other embodiments, the first array  302  may be configured as a global shutter image sensor, in which all of the photodetectors  304  are enabled at once, charges integrated by the photodetectors  304  are locally stored, and then the charges are read out by row or column. 
     A second array  316  may include a set of light-emitting elements  318  defining a display. The first and second arrays  302 ,  316  may be stacked, such that the first array  302  is positioned in front of or behind the second array  316  when an image projected by the display is viewed by a user. Alternatively, photodetectors and light-emitting elements of the first and second arrays  302 ,  316  may be interspersed. In these latter embodiments, the photodetectors  304  may be positioned in front of, behind, or alongside the light-emitting elements  318  of the display. 
       FIG.  4    shows an example of a stack  400  (e.g., a display stack or device stack). In some embodiments, the stack  400  may be part or all of the stack described with reference to  FIG.  1 A- 1 B or  2 A- 2 B . 
     By way of example, the stack  400  may include one or more thin-film transistor (TFT) layers (e.g., a TFT backplane  402 , and in some cases a Low-Temperature Polycrystalline Oxide (LTPO) backplane). A planarization (PLN) layer  404  (e.g., a thin-film PLN) may be deposited directly or indirectly on, or formed on or above, the TFT backplane  402 . A pixel define layer (PDL)  406  (e.g., a thin-film PDL) may be deposited directly or indirectly on, or formed on or above, the PLN layer  404 . An organic material  408  (e.g., a thin-film organic material) may be deposited directly or indirectly on, or formed on or above, the PDL  406 . A thin-film encapsulation (TFE) layer  410  may be deposited directly or indirectly on, or formed on or above, the organic material  408 . a touch sensor PLN (T-PLN) layer  412  may be deposited directly or indirectly on, or formed on or above, the TFE layer  410 . An optional touch sensor  414  (e.g., a touch-on-encapsulation (TOE) thin-film touch sensor) may be deposited directly or indirectly on, or formed on or above, the T-PLN layer  412 . Alternatively, another type of touch sensor technology may be used (e.g., a dual indium tin oxide (DITO) touch sensor or other type of touch sensor), and the touch sensor may be positioned where the touch sensor  414  is shown, or in other locations (e.g., on top of the cover  416 ). In other embodiments, a touch sensor may not be included in the stack  400 . The layers  402 - 414  may be attached to (e.g., adhesively bonded to) a cover  416 . 
     In some embodiments, the stack  400  may include more, fewer, or different layers or components. For example, a polarizer may be deposited directly or indirectly on the touch sensor  414  or interior surface of the cover  416 . A number of electrodes (e.g., conductive traces in metal layers) may also be included in the stack  400 . In some embodiments, the layers  402 - 416  of the stack  400  may have different orders, or may include multiple layers. For example, the TFT backplane  402  may include multiple layers, the PLN layer  404  may include multiple layers, and so on. 
     The TFT backplane  402 , PDL  406 , and organic material  408  may define an array of light-emitting and/or light-sensing elements (or units). In some embodiments, the TFT backplane  402 , PDL  406 , and organic material  408  may define an array of OLEDs having an array of emissive EL regions (e.g., one emissive EL region per OLED). Each OLED  418  may include an emissive EL region  420 , from which electromagnetic radiation (e.g., visible light or NIR electromagnetic radiation) is emitted toward the cover  416 . 
     The stack  400  may also include at least one photodetector  422 , or an array of photodetectors  422 . Each photodetector  422  may be provided at various locations in the stack  400 . For example, one or more photodetectors  422  may be provided between the touch sensor  414  and the cover  416 , at a location  422 - 1 . Alternatively, one or more photodetectors  422  may be provided between the organic material  408  and the TFE layer  410 , at a location  422 - 2 . Alternatively, one or more photodetectors  422  may be provided between the PLN layer  404  or PDL layer  406  and the organic material  408 , at a location  422 - 3 . Alternatively, one or more photodetectors  422  may be provided alongside emissive EL regions  420 . For example, the organic material  408  may include different types of organic material, including organic material configured to emit electromagnetic radiation having one or more wavelengths, and organic material configured to detect electromagnetic radiation having one or more wavelengths. The detected electromagnetic radiation may have the same or different wavelengths as the emitted electromagnetic radiation. In some embodiments, photodetectors  422  may be provided at more than one of the locations  422 - 1 ,  422 - 2 ,  422 - 3 , and may be configured to detect different wavelengths of electromagnetic radiation (and/or may be configured for different functional purposes, such as touch sensing, health sensing, or OLED health sensing). In some cases, the photodetectors  422  may be constructed as OPDs. 
     Examples of how OPDs (or other types of photodetectors) may be incorporated into the stack  400 , or into other stacks, are illustrated with reference to  FIGS.  5 - 9   . 
       FIG.  5    shows a portion of a first example stack  500  including an OLED  502  and an OPD  504 . The OPD  504  is an example of a photodetector positioned at location  422 - 1  in  FIG.  4   . In some embodiments, the OLED  502  may be replaced by another type of light-emitting element, or the OPD  504  may be replaced by another type of photodetector. 
     In the stack  500 , the OPD  504  is disposed between a device cover  506  (or other exterior structural component) and an emissive EL region  508  of the OLED  502 , and may fully or partially overlap the emissive EL region  508 . In alternative embodiments, the OPD  504  may have a greater width or depth, and may be positioned between the cover  506  and emissive EL regions  508  of multiple (i.e., two or more) OLEDs  502 . The emissive EL region(s)  508  over which the OPD  504  is positioned may emit electromagnetic radiation through the OPD  504 . 
     The stack  500  may be representative of a stack including an array of OLEDs  502 . The stack  500  may also include an array of OPDs  504 , which may have a one-to-one, one-to-many, or many-to-one correspondence with the OLEDs  502 . The OPDs  504  may be disposed uniformly or non-uniformly over the OLEDs  502 . For example, in some embodiments, an array of OPDs  504  may include OPDs  504  positioned over some or all of the OLEDs  502  in a particular region (or regions) of a display. 
     One or more intermediate layers or components, such as an OLED encapsulation layer  510  and/or touch sensor  512 , may be positioned between the OLED  502  and OPD  504 . Similarly, the one or more intermediate layers or components may be positioned between an array of such OLEDs  502  and one or an array of such OPDs  504 . The OLED encapsulation layer  510  and touch sensor  512  are examples of the TFE layer and touch sensor described with reference to  FIG.  4   . Other layers, such as a T-PLN layer, may also be disposed between the OLED  502  (or array of OLEDs  502 ) and the OPD  504  (or array of OPDs  504 ). 
     In some embodiments of the stack  500 , a first electrode  514  may be electrically connected to a first surface of the OPD  504  (e.g., a surface of the OPD  504  closest to the cover  506 ), and a second electrode  516  may be electrically connected to a second surface of the OPD  504  (e.g., a surface of the OPD  504  closest to the OLED  502 ). One or both of the electrodes  514 ,  516  may be electrically connected to a backplane (e.g., a TFT backplane  518 ) of the stack  500 . In some embodiments, the second electrode  516  may be positioned between the OPD  504  and a touch sensor  512 , and may be electrically connected to both the second surface of the OPD  504  and the touch sensor  512 . 
     In some embodiments, a third electrode  520  may be electrically connected to a first surface of the OLED  502  (e.g., a surface of the OLED  502  closest to the OPD  504 ), and a fourth electrode  522  may be electrically connected to a second surface of the OLED  502  (e.g., a surface of the OLED  502  closest to the TFT backplane  518 ). One or both of the electrodes  520 ,  522  may be electrically connected to a backplane of the stack  500  (e.g., to the TFT backplane  518 ). 
     Each of the first, second, and third electrodes  514 ,  516 ,  520  may be semi-transparent or fully transparent, to allow electromagnetic radiation emitted by the OLED  502  to pass through the electrodes  514 ,  516 ,  520 . The OPD  504  may also be constructed of semi-transparent or transparent materials. 
       FIG.  6 A  shows a portion of a second example stack  600  including an OLED  602  and an OPD  604 . The OPD  604  is an example of a photodetector positioned at location  422 - 2  in  FIG.  4   . In some embodiments, the OLED  602  may be replaced by another type of light-emitting element, or the OPD  604  may be replaced by another type of photodetector. 
     Similarly to the OPD described with reference to  FIG.  5   , the OPD  604  is disposed between a device cover  606  (or other exterior structural component) and an emissive EL region  608  of the OLED  602 , and may fully or partially overlap the emissive EL region  608 . In alternative embodiments, the OPD  604  may have a greater width or depth, and may be positioned between the cover  606  and emissive EL regions  608  of multiple (i.e., two or more) OLEDs  602 . The emissive EL region(s)  608  over which the OPD  604  is positioned may emit electromagnetic radiation through the OPD  604 . 
     The stack  600  may be representative of a stack including an array of OLEDs  602 . The stack  600  may also include an array of OPDs  604 , which may have a one-to-one, one-to-many, or many-to-one correspondence with the OLEDs  602 . The OPDs  604  may be disposed uniformly or non-uniformly over the OLEDs  602 . For example, in some embodiments, an array of OPDs  604  may include OPDs  604  positioned over some or all of the OLEDs  602  in a particular region (or regions) of a display. 
     In contrast to the stack described with reference to  FIG.  5   , the stack  600  may include fewer layers between the OLED  602  and OPD  604 . In some cases, there may only be an electrode  612  between the OLED  602  and OPD  604 . In some embodiments of the stack  600 , a first electrode  610  may be electrically connected to a first surface of the OPD  604  (e.g., a surface of the OPD  604  closest to the cover  606 ), and a second electrode  612  may be electrically connected to a second surface of the OPD  604  (e.g., a surface of the OPD  604  closest to the OLED  602 ). One or both of the electrodes  610 ,  612  may be electrically connected to a backplane (e.g., a TFT backplane  614 ) of the stack  600 . In some embodiments, the second electrode  612  may be positioned between the OPD  604  and the emissive EL region  608  of the OLED  602 , and may be electrically connected to both the second surface of the OPD  604  and the emissive EL region  608  of the OLED  602 . 
     In some embodiments, a third electrode  616  may be electrically connected to a surface of the OLED  602  opposite the OPD  604 . The third electrode  616  may also be electrically connected to a backplane of the stack  600  (e.g., to the TFT backplane  614 ). 
     The first and second electrodes  610 ,  612  may be semi-transparent or fully transparent, to allow electromagnetic radiation emitted by the OLED  602  to pass through the electrodes  610 ,  612 . The OPD  604  may also be constructed of semi-transparent or transparent materials. 
       FIG.  6 B  shows a variation of the example stack  600  described with reference to  FIG.  6 A . The stack  640  differs from the stack  600  in that an additional one or more layers  642  are included between the OLED  602  and OPD  604 . In some embodiments, the additional one or more layers may include one or more of a spacer or planarization layer, a layer that blocks a range of electromagnetic radiation wavelengths detected by the OPD  604  but not intended for the OLED  602 , a lens (or lens array), and so on. Given the additional separation between the OLED  602  and the OPD  604 , the OPD  604  may be coupled to a set of electrodes  644 ,  646  that is mutually exclusive of a set of electrodes  648 ,  650  coupled to the OLED  602 . 
       FIG.  6 C  shows another variation of the example stack  600  described with reference to  FIG.  6 A . The stack  680  differs from the stack  600  in that the second electrode  612  is replaced by a charge generation layer (CGL)  682 . The CGL  682  may be used to discharge the OPD  604  and charge the emissive EL region  608 . In some embodiments, the CGL  682  may include metal, such as silver (Ag), gold (Au), lithium (Li), ytterbium (Yb), and/or caesium (Cs). In other embodiments, the CGL  682  may be an all-organic interlayer. In some embodiments, one of the OLED  602  or OPD  604  may have an n-type active layer (or organic material), and the other of the OLED  602  or OPD  604  may have a p-type active layer (or organic material). 
       FIG.  7    shows a portion of a third example stack  700  including an OLED  702  and an OPD  704 . The OPD  704  is an example of a photodetector positioned at location  422 - 3  in  FIG.  4   . In some embodiments, the OLED  702  may be replaced by another type of light-emitting element, or the OPD  704  may be replaced by another type of photodetector. 
     In the stack  700 , the OLED  702  is disposed below a cover  706  (or other exterior structural component), and the OPD  704  is disposed below the OLED  702  (i.e., the OLED  702  is positioned between the OPD  704  and the cover  706 ). In some cases, and as shown, the OPD  704  may be positioned under an emissive EL region  708  of the OLED  702 , and may fully or partially overlap the emissive EL region  708 . In alternative embodiments, the OPD  704  may have a greater width or depth, and may extend under emissive EL regions  708  of multiple (i.e., two or more) OLEDs  702 . 
     The stack  700  may be representative of a stack including an array of OLEDs  702 . The stack  700  may also include an array of OPDs  704 , which may have a one-to-one, one-to-many, or many-to-one correspondence with the OLEDs  702 . The OPDs  704  may be disposed uniformly or non-uniformly over the OLEDs  702 . For example, in some embodiments, an array of OPDs  704  may include OPDs  704  positioned below some or all of the OLEDs  702  in a particular region (or regions) of a display. 
     One or more intermediate layers or components  710 , such as a reflector (e.g., a distributed Bragg reflector (DBR)), collimator, optical passband filter (e.g., color filter), or microlens may be positioned between the OLED  702  and OPD  704 . Similarly, the one or more intermediate layers or components  710  may be positioned between an array of such OLEDs  702  and one or an array of such OPDs  704 . When the one or more intermediate layers or components  710  include a reflector, such as a DBR, the reflector may be configured to reflect at least a first portion of a first range of electromagnetic radiation wavelengths emitted by the OLED  702 , and to pass at least a second portion of a second range of wavelengths sensed by the OPD  704 . In some embodiments, the first range of electromagnetic radiation wavelengths may be a visible range, and the second range may be a NIR range. In some embodiments, the first range includes a range of colored light (e.g., green light), and the second range may include a different range of colored light (e.g., red light). In some embodiments, the ranges of electromagnetic radiation wavelengths included in the first and second ranges may differ from pixel to pixel of a display. In some embodiments, the first and second ranges may be the same range or partially or fully overlapping ranges. For example, the OLED  702  and OPD  704  may be configured to sense the same or overlapping ranges of electromagnetic radiation. 
     When the one or more intermediate layers or components  710  include a collimator, the collimator may narrow the field of view of the OPD  704 , to limit the angular optical acceptance cone of the OPD  704 . When the one or more intermediate layers or components  710  include a microlens, the microlens may concentrate electromagnetic radiation on the OPD  704 . 
     In some embodiments of the stack  700 , the OPD  704  may have a material construction that configures the OPD  704  to absorb electromagnetic radiation in at least a first range of electromagnetic radiation wavelengths. The first range of electromagnetic radiation wavelengths may be outside a second range of electromagnetic radiation wavelengths emitted by the OLED  702 . In some embodiments, the material construction of the OPD  704  may be further configured to not absorb electromagnetic radiation in at least the second range of electromagnetic radiation wavelengths. Alternatively or additionally, a material positioned between the OLED  702  and the OPD  704  (e.g., a layer or component  710 ) may be configured to reflect or absorb the second range of electromagnetic radiation wavelengths. The first and second ranges of electromagnetic radiation wavelengths may be non-overlapping. 
     In some embodiments of the stack  700 , a first electrode  712  may be electrically connected to a first surface of the OLED  702  (e.g., to a surface of the emissive EL region  708  closest to the cover  706 ), and a second electrode  714  may be electrically connected to a second surface of the OLED  702  (e.g., to a surface of the emissive EL region  708  closest to the OPD  704 ). One or both of the electrodes  712 ,  714  may be electrically connected to a backplane (e.g., a TFT backplane  716 ) of the stack  700 . 
     In some embodiments, a third electrode  718  may be electrically connected to a first surface of the OPD  704  (e.g., a surface of the OPD  704  that is closest to the OLED  702 ), and a second electrode  720  may be electrically connected to a second surface of the OPD  704  (e.g., a surface of the OPD  704  that is closest to the TFT backplane  716 ). One or both of the electrodes  718 ,  720  may be electrically connected to a backplane of the stack  700  (e.g., to the TFT backplane  716 ). 
     Each of the first, second, and third electrodes  712 ,  714 ,  718  may be semi-transparent or fully transparent, to allow at least a portion of the electromagnetic radiation emitted by the OLED  702  to pass through the electrodes  712 ,  714 ,  718 . When the OPD  704  is measuring light received through the cover  706 , the OLED  702  may also be constructed of semi-transparent or transparent materials. 
       FIG.  8 A  shows a portion of a fourth example stack  800  including an OLED  802  and an OPD  804 . The OPD  804  is an example of a photodetector positioned at location  422 - 3  in  FIG.  4   . In some embodiments, the OLED  802  may be replaced by another type of light-emitting element, or the OPD  804  may be replaced by another type of photodetector. 
     Similarly to the OLED and OPD described with reference to  FIG.  7   , the OLED  802  is disposed below a cover  806  (or other exterior structural component), and the OPD  804  is disposed below the OLED  802  (i.e., the OLED  802  is positioned between the OPD  804  and the cover  806 ). In some cases, and as shown, the OPD  804  may be positioned under an emissive EL region  808  of the OLED  802 , and may fully or partially overlap the emissive EL region  808 . In alternative embodiments, the OPD  804  may have a greater width or depth, and may extend under emissive EL regions  808  of multiple (i.e., two or more) OLEDs  802 . 
     The stack  800  may be representative of a stack including an array of OLEDs  802 . The stack  800  may also include an array of OPDs  804 , which may have a one-to-one, one-to-many, or many-to-one correspondence with the OLEDs  802 . The OPDs  804  may be disposed uniformly or non-uniformly over the OLEDs  802 . For example, in some embodiments, an array of OPDs  804  may include OPDs  804  positioned below some or all of the OLEDs  802  in a particular region (or regions) of a display. 
     In contrast to the stack described with reference to  FIG.  7   , the stack  800  may include fewer layers between the OLED  802  and OPD  804 . In some cases, there may only be an electrode  812  between the OLED  802  and OPD  804 . In some embodiments of the stack  800 , a first electrode  810  may be electrically connected to a first surface of the OLED  802  (e.g., to a surface of the emissive EL region  808  closest to the cover  806 ), and a second electrode  812  may be electrically connected to a second surface of the OLED  802  (e.g., to a surface of the emissive EL region  808  closest to the OPD  804 ). One or both of the electrodes  810 ,  812  may be electrically connected to a backplane (e.g., a TFT backplane  814 ) of the stack  800 . In some embodiments, the second electrode  812  may be electrically connected to both the emissive EL region  808  and a first surface of the OPD  804 . 
     In some embodiments, a third electrode  816  may be electrically connected to a second surface of the OPD  804  (e.g., to a surface of the OPD  804  that is closest to the TFT backplane  814 ). The third electrode  816  may also be electrically connected to a backplane of the stack  800  (e.g., to the TFT backplane  814 ). 
     Each of the first and second electrodes  810 ,  812  may be semi-transparent or fully transparent, to allow at least a portion of the electromagnetic radiation emitted by the OLED  802  to pass through the electrodes  810 ,  812 . When the OPD  804  is measuring light received through the cover  806 , the OLED  802  may also be constructed of semi-transparent or transparent materials. 
       FIG.  8 B  shows a variation of the example stack  800  described with reference to  FIG.  8 A . The stack  850  differs from the stack  800  in that the second electrode  812  is replaced by a CGL  852 . The CGL  852  may be used to discharge the OPD  804  and charge the emissive EL region  808 . In some embodiments, the CGL  852  may include metal, such as Ag, Au, Li, Yb, and/or Cs. In other embodiments, the CGL  852  may be an all-organic interlayer. In some embodiments, one of the OLED  802  or OPD  804  may have an n-type active layer (or organic material), and the other of the OLED  802  or OPD  804  may have a p-type active layer (or organic material). 
       FIG.  9    shows a portion of a fifth example stack  900  including an array of OLEDs  902 ,  904  and at least one OPD  906 . The at least one OPD  906  is an example of a photodetector positioned at location  422 - 1  in  FIG.  4   . In some embodiments, the OLEDs  902 ,  904  may be replaced by another type of light-emitting element, or the at least one OPD  906  may be replaced by another type of photodetector. 
     In the stack  900 , the at least one OPD  906  is disposed between a device cover  908  (or other exterior structural component) and the array of OLEDs  902 ,  904 , but emissive EL regions  910 ,  912  of the OLEDs  902 ,  904  are offset horizontally as well as vertically with respect to the at least one OPD  906 , with the emissive EL regions  910 ,  912  and OPD(s)  906  including respective organic materials in different layers. Stated differently, the array of emissive EL regions  910 ,  912  may have a first set of axes perpendicular to the cover  908  (e.g., emission axes  914 ,  916 ), and the at least one OPD  906  may have a second set of axes (e.g., detection axis  918 ) perpendicular to the cover  908 , and axes of the OPDs  906  may be interspersed with (i.e., not coincident with) the axes of the emissive EL regions  910 ,  912 . 
     The stack  900  may be representative of a stack including an array of OLEDs  902 ,  904  and an array of OPDs  906 , which may be provided in equal or different numbers. The OPDs  906  may be interspersed uniformly or non-uniformly with the OLEDs  902 ,  904 . For example, in some embodiments, an array of OPDs  906  may include OPDs  906  interspersed with the OLEDs  902 ,  904  in a particular region (or regions) of a display. 
     Because they are provided in separate layers, the at least one OPD  906  and array of OLEDs  902 ,  904  may have separate hole and electron transport layers. In some cases, the at least one OPD  906  and array of OLEDs  902 ,  904  may be fabricated by solution processing, with techniques such as ink jet printing. One or more intermediate layers or components  920  may be positioned between the OLEDs  902 ,  904  and OPD  906  as described with reference to  FIG.  5   . Electrodes may also be disposed in the stack  900  and electrically connected to the OLEDs  902 ,  904  and OPD  906 , as described, for example, with reference to  FIG.  5   . 
     In a variation of the stack  900 , the at least one OPD  906  may be moved closer to the array of OLEDs  902 ,  904 , similarly to what is described with reference to  FIG.  6 A , but with the emissive EL regions  910 ,  912  and OPDs  906  both horizontally and vertically offset. 
       FIG.  10 A  shows a portion of a sixth example stack  1000  including an array of OLEDs  1002 ,  1004  and at least one OPD  1006 . The at least one OPD  1006  is an example of a photodetector positioned adjacent emissive EL regions in the organic material  408  described with reference to  FIG.  4   . In some embodiments, the OLEDs  1002 ,  1004  may be replaced by another type of light-emitting element, or the at least one OPD  1006  may be replaced by another type of photodetector. 
     In the stack  1000 , the OLEDs  1002 ,  1004  and at least one OPD  1006  are disposed under a device cover  1008  (or other exterior structural component). The array of OLEDs  1002 ,  1004  includes an array of emissive EL regions  1010 ,  1012 , as described with reference to  FIG.  9   , and the emissive EL regions  1010 ,  1012  are offset horizontally with respect to the at least one OPD  1006 , with the emissive EL regions  1010 ,  1012  and OPD(s)  1006  including respective organic materials in the same layer. Stated differently, the array of emissive EL regions  1010 ,  1012  may have a first set of axes perpendicular to the cover  1008  (e.g., emission axes  1014 ,  1016 ), and the at least one OPD  1006  may have a second set of axes (e.g., detection axis  1018 ) perpendicular to the cover  1008 , and axes of the OPDs  1006  may be interspersed with (i.e., not coincident with) the axes of the emissive EL regions  1010 ,  1012 . The OPD(s)  1006  may replace portions or all of a PDL layer. 
     The stack  1000  may be representative of a stack including an array of OLEDs  1002 ,  1004  and an array of OPDs  1006 , which may be provided in equal or different numbers. The OPDs  1006  may be interspersed uniformly or non-uniformly with the OLEDs  1002 ,  1004 . For example, in some embodiments, an array of OPDs  1006  may include OPDs  1006  interspersed with the OLEDs  1002 ,  1004  in a particular region (or regions) of a display. 
     The at least one OPD  1006  may have an active layer that includes a mixture of materials (e.g., a bulk heterojunction), a few layers or material that form one or more heterojunctions, or a single layer of material. The at least one OPD  1006  may share the hole and electron transport layers of the array of OLEDs  1002 ,  1004 , thereby reducing the number of fine metal masks needed to produce the stack  1000 . In some cases, the at least one OPD  1006  and array of OLEDs  1002 ,  1004  may be fabricated by solution processing, with techniques such as ink jet printing. Electrodes may be electrically connected to the OLEDs  1002 ,  1004  and at least one OPD  1006  as described with reference to  FIG.  6 A , or in other ways. 
       FIG.  10 B  shows a variation of the example stack  1000  described with reference to  FIG.  10 A . The stack  1040  differs from the stack  1000  in that the stack includes a PDL layer  1042  (e.g., a PDL layer similar to the PDL layer  406  described with reference to  FIG.  4   ), and the OPD  1006  is positioned under (or within) the PDL layer  1042  (or between the PDL layer  1042  and another layer, such as a PLN layer  1044 ). 
       FIG.  10 C  shows a variation of the example stack  1040  described with reference to  FIG.  10 B . The stack  1080  differs from the stack  1040  in that the OPD  1006  is positioned on (and above) the PDL layer  1042 . Similarly to what is described with reference to  FIG.  9   , the stack  1080  both horizontally and vertically offsets the emissive EL regions  1010 ,  1012  with respect to the at least one OPD  1006 . However, the OPD(s)  1006  may be positioned much closer to the emissive EL regions  1010 ,  1012  in the stack  1080 . 
       FIG.  11    shows an example plan view of the stack described with reference to  FIG.  9  or  10   . The stack includes an array of OLEDs  1102 , including red OLEDs  1102 - 1 , blue OLEDs  1102 - 2 , and green OLEDs  1102 - 3 . In some embodiments, and as shown, each of the red, blue, and green OLEDs  1102 - 1 ,  1102 - 2 ,  1102 - 3  may be more or less uniformly distributed with respect to the surface of the stack, and an array of OPDs  1104  may replace ones of the OLEDs  1102 - 1 ,  1102 - 2 ,  1102 - 3  in a uniform or non-uniform manner across the surface of the stack. Alternatively, one or more OPDs may be positioned at uniform or non-uniform locations, across the surface of the stack, without replacing any of the uniformly-distributed OLEDs  1102 - 1 ,  1102 - 2 ,  1102 - 3 . 
     Any of the stacks described with reference to  FIGS.  5 - 11    may be incorporated into an electronic device such as the device described with reference to  FIG.  1 A- 1 B or  2 A- 2 B , or into other types or forms of devices. When controlled by a processor, an array of OLEDs (or other light-emitting elements) and array of OPDs (or other photodetectors, or at least one photodetector) may be activated alternately or contemporaneously. Alternate activation may be useful for reducing optical interference during ambient or externally-reflected electromagnetic radiation sensing. Contemporaneous activation may be useful for OLED health sensing. 
     In some embodiments, a processor may operate an array of OPDs (or at least one OPD) in different modes. For example, the processor may be configured to operate an array of OPDs (or at least one OPD) in an OLED emission measurement mode, in which the processor activates the array of OPDs contemporaneously with the array of OLEDs or, alternatively, in at least one of an ambient electromagnetic radiation sensing mode or a reflective sensing mode (e.g., an externally-reflected electromagnetic radiation sensing mode), in which the processor activates the array of OPDs and array of OLEDs at different times. 
     In some embodiments, a processor may activate different sub-arrays of OPDs for different purposes—either alternately or contemporaneously. For example, upon use of a first sub-array of OPDs to authenticate a user (e.g., by face recognition or a fingerprint match), the processor may activate a second sub-array (or the first sub-array) to sense a health condition (e.g., a user&#39;s heart rate). 
     In some embodiments, an array of OPDs may include different sub-arrays of OPDs that are configured to detect different wavelengths of electromagnetic radiation. For example, an array of OPDs may include a first sub-array of OPDs configured to detect a first range of electromagnetic radiation wavelengths, and a second sub-array of OPDs configured to detect a second range of electromagnetic radiation wavelengths, in which the first and second ranges of electromagnetic radiation wavelengths differ. The first and second sub-arrays of OPDs may be operated contemporaneously (e.g., when the first and second sub-arrays are used to sense different wavelengths of ambient light) or alternately (e.g., when the different sub-arrays are used for fingerprint sensing and OLED health sensing, respectively). 
     The transparent or semi-transparent electrodes described with reference to  FIGS.  5 - 11   , or any of the electrodes included in the stacks described with reference to  FIGS.  5 - 11   , may be formed, for example, using thin metal layers, transparent conductive oxides, conductive polymers, metal nanowires, and so on. 
     The active layer of the OPDs described with reference to  FIGS.  5 - 11    may in some cases be deposited by vacuum or by solution, depending on the stack architecture and the deposition technique&#39;s compatibility with the stack&#39;s OLEDs. The active layer of the OPDs may include, for example, a mixture of materials (e.g., a bulk heterojunction), a few layers or material that form one or more heterojunctions, or a single layer of material. OPD transport properties may be optimized independent of OLED transport properties. 
     The active layer of the OLEDs described with reference to  FIGS.  5 - 11    may in some cases be deposited by vacuum or by solution, depending on the stack architecture. In some cases, the OLEDs may be optimized at the expense of OPD optimization, or vice versa. 
     In any of the stacks described with reference to  FIGS.  5 - 11   , crosstalk between OLEDs and OPDs can be mitigated by absorption tuning of the OPDs or OLEDs (e.g., through material and/or cavity tuning, by insertion of a color filter, and/or, when appropriate, by insertion of other electromagnetic radiation-absorbing elements that can block electromagnetic radiation leakage from OLEDs that might interfere with an intended function (or functions) of the OPDs). When relevant, a DBR may also or alternatively be used between an OPD and an OLED. When an OPD is used to measure the health of an OLED, absorption of an OPD may be tuned to match the emission of the OLED positioned above or near the OPD. When an OPD is used to measure electromagnetic radiation other than that emitted by an OLED, the OPD absorption may be tuned to exclude the emission of the OLED and/or an intermediary layer or component (e.g., a DBR) may be tuned to reflect the OLED&#39;s emission. 
       FIG.  12    shows a sample electrical block diagram of an electronic device  1200 , which electronic device may in some cases be implemented as the device described with reference to  FIG.  1 A- 1 B or  2 A- 2 B . The electronic device  1200  may include an electronic display  1202  (e.g., a light-emitting display), a processor  1204 , a power source  1206 , a memory  1208  or storage device, a sensor system  1210 , or an input/output (I/O) mechanism  1212  (e.g., an input/output device, input/output port, or haptic input/output interface). The processor  1204  may control some or all of the operations of the electronic device  1200 . The processor  1204  may communicate, either directly or indirectly, with some or all of the other components of the electronic device  1200 . For example, a system bus or other communication mechanism  1214  can provide communication between the electronic display  1202 , the processor  1204 , the power source  1206 , the memory  1208 , the sensor system  1210 , and the I/O mechanism  1212 . 
     The processor  1204  may be implemented as any electronic device capable of processing, receiving, or transmitting data or instructions, whether such data or instructions is in the form of software or firmware or otherwise encoded. For example, the processor  1204  may include a microprocessor, a central processing unit (CPU), an application-specific integrated circuit (ASIC), a digital signal processor (DSP), a controller, or a combination of such devices. As described herein, the term “processor” is meant to encompass a single processor or processing unit, multiple processors, multiple processing units, or other suitably configured computing element or elements. In some cases, the processor  1204  may be the processor described with reference to any of  FIG.  1 A- 1 B,  2 A- 2 B,  3   , or other figures. 
     It should be noted that the components of the electronic device  1200  can be controlled by multiple processors. For example, select components of the electronic device  1200  (e.g., the sensor system  1210 ) may be controlled by a first processor and other components of the electronic device  1200  (e.g., the electronic display  1202 ) may be controlled by a second processor, where the first and second processors may or may not be in communication with each other. 
     The power source  1206  can be implemented with any device capable of providing energy to the electronic device  1200 . For example, the power source  1206  may include one or more batteries or rechargeable batteries. Additionally or alternatively, the power source  1206  may include a power connector or power cord that connects the electronic device  1200  to another power source, such as a wall outlet. 
     The memory  1208  may store electronic data that can be used by the electronic device  1200 . For example, the memory  1208  may store electrical data or content such as, for example, audio and video files, documents and applications, device settings and user preferences, timing signals, control signals, and data structures or databases. The memory  1208  may include any type of memory. By way of example only, the memory  1208  may include random access memory, read-only memory, Flash memory, removable memory, other types of storage elements, or combinations of such memory types. 
     The electronic device  1200  may also include one or more sensor systems  1210  positioned almost anywhere on the electronic device  1200 . In some cases, the sensor systems  1210  may include one or more photodetectors, positioned as described with reference to any of  FIGS.  1 A- 11   . The sensor system(s)  1210  may be configured to sense one or more types of parameters, such as but not limited to, vibration; light; touch; force; heat; movement; relative motion; biometric data (e.g., biological parameters) of a user; air quality; proximity; position; connectedness; matter type; and so on. By way of example, the sensor system(s)  1210  may include one or more of (or multiple of) a heat sensor, a position sensor, a proximity sensor, a light or optical sensor (e.g., an electromagnetic radiation emitter and/or detector), an accelerometer, a pressure transducer, a gyroscope, a magnetometer, a health monitoring sensor, and an air quality sensor, and so on. Additionally, the one or more sensor systems  1210  may utilize any suitable sensing technology, including, but not limited to, interferometric, magnetic, pressure, capacitive, ultrasonic, resistive, optical, acoustic, piezoelectric, or thermal technologies. 
     In some embodiments, the electronic display  1202  and one or more photodetectors of a sensor system  1210  may be incorporated into a stack (e.g., a device stack or display stack) as described with reference to any of  FIGS.  1 A- 11   . 
     The I/O mechanism  1212  may transmit or receive data from a user or another electronic device. The I/O mechanism  1212  may include the electronic display  1202 , a touch sensing input surface, a crown, one or more buttons (e.g., a graphical user interface “home” button), one or more cameras (including an under-display camera), one or more microphones or speakers, one or more ports such as a microphone port, and/or a keyboard. Additionally or alternatively, the I/O mechanism  1212  may transmit electronic signals via a communications interface, such as a wireless, wired, and/or optical communications interface. Examples of wireless and wired communications interfaces include, but are not limited to, cellular and Wi-Fi communications interfaces. 
     The foregoing description, for purposes of explanation, uses specific nomenclature to provide a thorough understanding of the described embodiments. However, it will be apparent to one skilled in the art, after reading this description, that the specific details are not required in order to practice the described embodiments. Thus, the foregoing descriptions of the specific embodiments described herein are presented for purposes of illustration and description. They are not targeted to be exhaustive or to limit the embodiments to the precise forms disclosed. It will be apparent to one of ordinary skill in the art, after reading this description, that many modifications and variations are possible in view of the above teachings. 
     As described above, one aspect of the present technology may be the gathering and use of data available from various sources, including biometric data (e.g., the presence and/or proximity of a user to a device, a user&#39;s fingerprint, and so on). The present disclosure contemplates that, in some instances, this gathered data may include personal information data that uniquely identifies or can be used to identify, locate, or contact a specific person. Such personal information data can include demographic data, location-based data, telephone numbers, email addresses, home addresses, data or records relating to a user&#39;s health or level of fitness (e.g., vital signs measurements, medication information, exercise information), date of birth, or any other identifying or personal information. 
     The present disclosure recognizes that the use of such personal information data, in the present technology, can be used to the benefit of users. For example, the personal information data can be used to activate or deactivate various functions of the user&#39;s device, or gather performance metrics for the user&#39;s device or the user. Further, other uses for personal information data that benefit the user are also contemplated by the present disclosure. For instance, health and fitness data may be used to provide insights into a user&#39;s general wellness, or may be used as positive feedback to individuals using technology to pursue wellness goals. 
     The present disclosure contemplates that the entities responsible for the collection, analysis, disclosure, transfer, storage, or other use of such personal information data will comply with well-established privacy policies and/or privacy practices. In particular, such entities should implement and consistently use privacy policies and practices that are generally recognized as meeting or exceeding industry or governmental requirements for maintaining personal information data private and secure. Such policies should be easily accessible by users, and should be updated as the collection and/or use of data changes. Personal information from users should be collected for legitimate and reasonable uses of the entity and not shared or sold outside of those legitimate uses. Further, such collection/sharing should occur after receiving the informed consent of the users. Additionally, such entities should consider taking any needed steps for safeguarding and securing access to such personal information data and ensuring that others with access to the personal information data adhere to their privacy policies and procedures. Further, such entities can subject themselves to evaluation by third parties to certify their adherence to widely accepted privacy policies and practices. In addition, policies and practices should be adapted for the particular types of personal information data being collected and/or accessed and adapted to applicable laws and standards, including jurisdiction-specific considerations. For instance, in the US, collection of or access to certain health data may be governed by federal and/or state laws, such as the Health Insurance Portability and Accountability Act (HIPAA); whereas health data in other countries may be subject to other regulations and policies and should be handled accordingly. Hence different privacy practices should be maintained for different personal data types in each country. 
     Despite the foregoing, the present disclosure also contemplates embodiments in which users selectively block the use of, or access to, personal information data. That is, the present disclosure contemplates that hardware and/or software elements can be provided to prevent or block access to such personal information data. For example, in the case of advertisement delivery services, the present technology can be configured to allow users to select to “opt in” or “opt out” of participation in the collection of personal information data during registration for services or anytime thereafter. In another example, users can select not to provide mood-associated data for targeted content delivery services. In yet another example, users can select to limit the length of time mood-associated data is maintained or entirely prohibit the development of a baseline mood profile. In addition to providing “opt in” and “opt out” options, the present disclosure contemplates providing notifications relating to the access or use of personal information. For instance, a user may be notified upon downloading an app that their personal information data will be accessed and then reminded again just before personal information data is accessed by the app. 
     Moreover, it is the intent of the present disclosure that personal information data should be managed and handled in a way to minimize risks of unintentional or unauthorized access or use. Risk can be minimized by limiting the collection of data and deleting data once it is no longer needed. In addition, and when applicable, including in certain health related applications, data de-identification can be used to protect a user&#39;s privacy. De-identification may be facilitated, when appropriate, by removing specific identifiers (e.g., date of birth, etc.), controlling the amount or specificity of data stored (e.g., collecting location data at a city level rather than at an address level), controlling how data is stored (e.g., aggregating data across users), and/or other methods. 
     Therefore, although the present disclosure broadly covers use of personal information data to implement one or more various disclosed embodiments, the present disclosure also contemplates that the various embodiments can also be implemented without the need for accessing such personal information data. That is, the various embodiments of the present technology are not rendered inoperable due to the lack of all or a portion of such personal information data. For example, content can be selected and delivered to users by inferring preferences based on non-personal information data or a bare minimum amount of personal information, such as the content being requested by the device associated with a user, other non-personal information available to the content delivery services, or publicly available information.

Metadata:
Filing Date: 20200828
Publication Date: 20221213
Grant Date: 20221213
Priority Date: 20190924
Inventors: Ran, Niva A.
POLYAKOV, ALEKSANDR N.
TSAI, LUN
HO, MENG-HUAN
YEKE YAZDANDOOST, MOHAMMAD
Assignee: APPLE INC
CPC Classifications: [{"code": "H01L27/3209", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01L27/3227", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01L27/307", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01L27/323", "inventive": true, "first": false, "tree": "[]"}, {"code": "H10K59/60", "inventive": true, "first": true, "tree": "[]"}, {"code": "H10K59/32", "inventive": true, "first": false, "tree": "[]"}, {"code": "H10K39/32", "inventive": true, "first": false, "tree": "[]"}, {"code": "H10K59/40", "inventive": true, "first": false, "tree": "[]"}, {"code": "H10K65/00", "inventive": true, "first": true, "tree": "[]"}, {"code": "H10K59/40", "inventive": true, "first": false, "tree": "[]"}, {"code": "H10K39/32", "inventive": true, "first": false, "tree": "[]"}, {"code": "H10K59/871", "inventive": false, "first": false, "tree": "[]"}, {"code": "H10K59/873", "inventive": false, "first": false, "tree": "[]"}]
Family ID: 84426591