PATENT DOCUMENT

Publication Number: US-11067884-B2
Application Number: US-201916723850-A
Country: US
Kind Code: B2

Title: Through-display optical transmission, reception, or sensing through micro-optic elements

Abstract:
A device includes a display stack and an optical receiver. The display stack includes a set of opaque elements defining a translucent aperture. The translucent aperture extends through the display stack. The optical receiver is spaced apart from and behind a back surface of the display stack. At least one micro-optic element is formed on the back surface of the display stack, between the display stack and the optical receiver. The at least one micro-optic element includes a micro-optic element having a focal point located within the translucent aperture. The optical receiver is configured to receive light through the translucent aperture and the at least one micro-optic element.

Claims:
What is claimed is: 
     
       1. A device, comprising:
 a display stack including a set of opaque elements defining a translucent aperture extending through the display stack; 
 an optical receiver spaced apart from and behind a back surface of the display stack; and 
 at least one micro-lens formed on the back surface of the display stack, between the display stack and the optical receiver, the at least one micro-lens including a micro-lens having a focal point located within the translucent aperture; wherein: 
 the optical receiver is configured to receive light through the translucent aperture and the at least one micro-lens. 
 
     
     
       2. The device of  claim 1 , wherein the display stack comprises an organic light-emitting diode (OLED) array. 
     
     
       3. The device of  claim 1 , wherein the display stack includes different sets of opaque elements defining different translucent apertures extending through the display stack. 
     
     
       4. The device of  claim 3 , wherein:
 the at least one micro-lens formed on the back surface of the display stack comprises a micro-lens array formed on the back surface of the display stack; wherein: 
 the micro-lens having the focal point located within the translucent aperture comprises a first micro-lens of the micro-lens array. 
 
     
     
       5. The device of  claim 3 , wherein:
 the translucent aperture is a first translucent aperture; 
 the micro-lens is a first micro-lens; 
 the different translucent apertures comprise a second translucent aperture; 
 the at least one micro-lens comprises the first micro-lens and a second micro-lens; 
 the second micro-lens has a focal point located within the second translucent aperture; and 
 the optical receiver is configured to receive light through the first translucent aperture and the first micro-lens, and through the second translucent aperture and the second micro-lens. 
 
     
     
       6. A device, comprising:
 a multi-layer display stack including a set of opaque elements; 
 an optical module spaced apart from and behind a back surface of the display stack; and 
 at least one micro-optic element formed on the back surface of the display stack, between the display stack and the optical module; wherein, 
 different subsets of the opaque elements define different translucent apertures extending from a front surface to the back surface of the display stack; 
 a first translucent aperture of the different translucent apertures has a first aperture size; 
 a second translucent aperture of the different translucent apertures has a second aperture size; 
 a first micro-optic element of the at least one micro-optic element is aligned with the first translucent aperture and has a first size; and 
 a second micro-optic element of the at least one micro-optic element is aligned with the second translucent aperture and has a second size. 
 
     
     
       7. The device of  claim 6 , wherein the at least one micro-optic element includes a micro-optic element having a focal point located within one of the translucent apertures. 
     
     
       8. The device of  claim 6 , wherein the optical module comprises an optical receiver positioned to receive light through the display stack and at least the first micro-optic element. 
     
     
       9. The device of  claim 8 , wherein the optical module comprises a condensing lens positioned between the first micro-optic element and the optical receiver. 
     
     
       10. The device of  claim 8 , wherein the optical module further comprises an optical transmitter positioned to transmit light through at least the second micro-optic element and the display stack. 
     
     
       11. The device of  claim 10 , wherein the optical module comprises:
 a condensing lens positioned between the first micro-optic element and the optical receiver; and 
 a collimating lens positioned between the optical transmitter and the second micro-optic element. 
 
     
     
       12. The device of  claim 6 , wherein the optical module comprises an optical transmitter positioned to transmit light through at least the first micro-optic element and the display stack. 
     
     
       13. The device of  claim 12 , further comprising:
 a diffraction grating that shapes the light transmitted by the optical transmitter as the light exits the first micro-optic element. 
 
     
     
       14. The device of  claim 6 , wherein:
 the optical module comprises at least two optical transmitters positioned to transmit light through at least the first micro-optic element and the display stack; and 
 light transmitted through the first micro-optic element is shaped by at least two translucent apertures of the different translucent apertures. 
 
     
     
       15. The device of  claim 6 , wherein the at least one micro-optic element comprises a micro-lens array. 
     
     
       16. The device of  claim 6 , wherein the at least one micro-optic element comprises at least one gradient-index (GRIN) lens. 
     
     
       17. The device of  claim 6 , wherein at least one translucent aperture of the different translucent apertures is transparent. 
     
     
       18. The device of  claim 6 , wherein:
 the optical module comprises an optical transmitter positioned to transmit light through multiple translucent apertures of the different translucent apertures; 
 the transmitted light is transmitted through the at least one micro-optic element and the display stack; and 
 the transmitted light provides diffuse illumination in at least a first conjugated focal plane, and a structured light pattern in at least a second conjugated focal plane. 
 
     
     
       19. The device of  claim 18 , further comprising:
 a cover disposed over the multi-layer display stack; wherein,
 the first conjugated focal plane is at an exterior surface of the cover or within a first distance from the exterior surface of the cover; and 
 the second conjugated focal plane is at a second distance from the exterior surface of the cover, the second distance greater than the first distance. 
 
 
     
     
       20. The device of  claim 18 , further comprising:
 a camera configured to acquire an image of an object illuminated by the optical transmitter; and 
 a processor configured to generate a three-dimensional map of the object using,
 the image of the object; and 
 parameters of the structured light pattern in at least the second conjugated focal plane. 
 
 
     
     
       21. The device of  claim 6 , further comprising:
 a processor; wherein, 
 the optical module comprises an optical transmitter positioned to transmit light through multiple translucent apertures of the different translucent apertures; 
 the transmitted light is transmitted through the at least one micro-optic element and the display; 
 the processor is configured to activate a first subset of emitters of the optical transmitter during a first time period, and activate a second subset of emitters of the optical transmitter during a second time period; 
 activation of the first subset of emitters produces a first structured light pattern in a conjugated focal plane; and 
 activation of the second subset of emitters produces a second structured light pattern in the conjugated focal plane. 
 
     
     
       22. A method of sensing a proximity of an object to a device having a light-emitting display, comprising:
 emitting light from an optical transmitter; 
 collimating the emitted light; 
 focusing the collimated emitted light toward a first translucent aperture in a display surface of the light-emitting display; 
 receiving light through a second translucent aperture in the display surface; 
 collimating the received light; 
 condensing the collimated received light toward an optical receiver; 
 quantifying an output of the optical receiver; and 
 correlating the quantified output of the optical receiver to the proximity of the object to the device. 
 
     
     
       23. The method of  claim 22 , wherein the light focused toward the first translucent aperture has a predetermined set of one or more wavelengths, and the light received through the second translucent aperture by the optical receiver has the predetermined set of one or more wavelengths. 
     
     
       24. The method of  claim 23 , wherein the light emitted from the optical transmitter comprises an optical pulse, the method further comprising:
 recording an emission time of the optical pulse; 
 determining a reception time of a reflection of the optical pulse using the optical receiver; and 
 determining a distance between the object and the device using the emission time and the reception time. 
 
     
     
       25. The method of  claim 22 , wherein quantifying the output of the optical receiver comprises:
 quantifying a change in the output of the optical receiver.

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. 62/785,152, filed Dec. 26, 2018, the contents of which are incorporated herein by reference as if fully disclosed herein. 
    
    
     FIELD 
     The described embodiments relate generally to devices (e.g., smartphones, tablet computers, or other devices) having under-display optical transmitters, receivers, and/or sensors. More particularly, the described embodiments relate to through-display optical transmission or reception through micro-optic elements (e.g., a micro-lens array), and in some cases to through-display optical sensing through micro-optic elements. 
     BACKGROUND 
     In some cases, it may be desirable to determine whether an object or user is proximate to a device, to determine the distance between an object or user and a device, or to determine a velocity or acceleration of an object or user with respect to a device. It may also be desirable to capture a two-dimensional (2D) or three-dimensional (3D) image of an object or user that is proximate to a device. In some cases, the 2D or 3D image may be an image of a fingerprint, a face, or a scene in a field of view (FoV). In some cases, it may be useful to wirelessly transmit or receive information between devices. It may also be useful to acquire images or data pertaining to a device&#39;s environment. In all of these cases, the measurements, images, or other data may be sensed or acquired optically. 
     SUMMARY 
     Embodiments of the systems, devices, methods, and apparatus described in the present disclosure are directed to under-display optical transmission, reception, and/or sensing. In accordance with described techniques, an optical transmitter, optical receiver, optical transceiver, or multiple optical transmitters, receivers and/or transceivers may be positioned behind a device&#39;s display, and light may be transmitted or received through translucent apertures extending from a front surface to a back surface of a display stack of the device. In this manner, an optical transmitter, receiver, or sensor may transmit or receive “through” a display. The optical transmitter, receiver, or sensor may opportunistically transmit or receive light through available translucent apertures in the display stack, or the display stack may be configured to provide translucent apertures in a deterministic pattern. When an optical transmitter, receiver, or sensor is positioned under a device&#39;s display, a portion of the device&#39;s display surface does not have to be reserved for the optical transmitter, receiver, or sensor, and in some cases the size of the device&#39;s display may be increased. 
     In a first aspect, the present disclosure describes a device including a display stack and an optical receiver. The display stack may include a set of opaque elements defining a translucent aperture. The translucent aperture may extend through the display stack. An optical receiver may be spaced apart from and behind a back surface of the display stack. At least one micro-optic element may be formed on or abutted to the back surface of the display stack, between the display stack and the optical receiver. The at least one micro-optic element may include a micro-optic element having a focal point located within the translucent aperture. The optical receiver may be configured to receive light through the translucent aperture and the at least one micro-optic element. 
     In another aspect, the present disclosure describes a device including a multi-layer display stack and an optical module. The multi-layer display stack may include a set of opaque elements. The set of opaque elements may include a set of light-emitting elements, a set of drive circuits coupled to the set of light-emitting elements, and a multi-layer mesh of conductive traces. The multi-layer mesh of conductive traces may be configured to route electrical signals to the set of drive circuits. Different subsets of the opaque elements may define different translucent apertures extending from a front surface to a back surface of the display stack. The optical module may be spaced apart from and behind the back surface of the display stack. At least one micro-optic element may be formed on the back surface of the display stack, between the display stack and the optical module. The at least one micro-optic element may include a micro-optic element having a focal point located within one of the translucent apertures. The optical module may include an optical transmitter, an optical receiver, or an optical transceiver. When the optical module includes a transmitter (or a transceiver having a transmitting component), the transmitter may be configured to transmit light through the translucent aperture(s) with minimal transmission loss using the at least one micro-optic element. 
     In still another aspect of the disclosure, a method of sensing a proximity of an object to a device having a light-emitting display is described. The method may include receiving light through a translucent aperture in a display surface of the light-emitting display; collimating the received light; condensing the collimated received light toward an optical receiver; quantifying an output of the optical receiver; and correlating the quantified output of the optical receiver to the proximity of the object to the device. In some embodiments, the translucent aperture may be a first translucent aperture, and the method may also include emitting light from an optical transmitter; collimating the emitted light; and focusing the collimated emitted light toward a second translucent aperture in the display surface. In some embodiments, the emitted light may be focused and/or re-imaged to shape the light in a far-field. 
     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. 1A &amp; 1B  show an example embodiment of a device having a display; 
         FIGS. 2A and 2B  show an example embodiment of a display stack and optical module; 
         FIG. 3  shows an alternative plan view of the display stack described with reference to  FIGS. 2A and 2B ; 
         FIG. 4  shows an alternative elevation of the display stack shown in  FIGS. 2A and 2B , with an alternative configuration of optical module; 
         FIG. 5  shows another alternative elevation of the display stack shown in  FIGS. 2A and 2B , with an optical module configured as described with reference to  FIG. 4 ; 
         FIG. 6  shows yet another alternative elevation of the display stack shown in  FIGS. 2A and 2B , in which light may be emitted or received through a slanted translucent aperture in the display stack; 
         FIG. 7A  shows another alternative elevation of the display stack shown in  FIGS. 2A and 2B , with an optical module configured as described with reference to  FIG. 4  but including multiple optical transmitters; 
         FIG. 7B  shows an alternative to what is shown in  FIG. 7A , with the optical module including only a single optical transmitter, and the micro-optic elements defining a meta-surface that shapes light emitted by the optical transmitter as it exits the micro-optic element; 
         FIG. 8  shows an example pattern of illumination emitted by an array of optical transmitters, which optical transmitters may be positioned behind a display stack and transmit light through translucent apertures in the display stack; 
         FIGS. 9A-9F  illustrate an example method of forming a micro-lens array on the back surface of a display stack; 
         FIG. 10  shows another example embodiment of a display stack and optical module, in relation to near-field and far-field conjugated focal planes; 
         FIG. 11A  shows example illumination of a near-field conjugated focal plane by an under-display optical module; 
         FIG. 11B  shows example illumination of a far-field conjugated focal plane by an under-display optical module; 
         FIG. 12  shows an example plan view of a set of emitters included in an under-display optical modulate, in relation to an array of micro-optic elements; 
       Each of  FIGS. 13A and 13B  depicts illumination (e.g., normalized irradiance) along x and y axes of a conjugated focal plane parallel to the a plane passing through the set of emitters or array of micro-optic elements described with reference to  FIG. 12 ; 
         FIG. 14  illustrates an example method of sensing a proximity of an object to a device having a light-emitting display; 
         FIG. 15  illustrates an example method of illuminating a field of view; and 
         FIG. 16  shows an example electrical block diagram of an electronic device. 
     
    
    
     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. 
     The following disclosure relates to optical sensing, and more particularly to under-display optical sensing. When an optical sensor is positioned under a light-emitting display, a portion of the device&#39;s display surface does not have to be reserved for the optical sensor, and in some cases the size of the device&#39;s display may be increased. However, an impediment to positioning an optical sensor under a display is the inclusion of many opaque elements in the display&#39;s display stack. Opaque elements may include, for example, light-emitting elements, drive circuits, conductive traces that route electrical signals to the drive circuits, optical, electrical, physical, and/or chemical shielding or confining elements, and so on. For purposes of this disclosure, light-emitting elements are deemed to include semiconductor light-emitting elements, such as light-emitting diodes (LEDs); semiconductor-driven electroluminescent light-emitting elements, such as organic LEDs (LEDs) including organic materials charged by thin-film transistors; and other types of light-emitting elements. 
     The multiple layers of opaque elements in a display stack can reflect, absorb, diffuse, and diffract light entering the front or back surface of the display stack, and can provide high transmission loss (low throughput) for light passing through the display stack. In fact, the density of opaque elements in a display stack can make the display stack, as a whole, seem relatively opaque. In some cases, a display stack may allow approximately 1% of visible light to pass, and allow approximately 2-4% of infrared light to pass. One potential solution to this is to alternatively fabricate some of the display stack&#39;s opaque elements (e.g., the conductive traces) as transparent elements. For example, conductive traces may be made of indium-tin-oxide (ITO). However, transparent elements are often associated with a cost, such as higher sheet resistance. Furthermore, and in the case of an OLED display, a highly reflective surface is needed under the OLED emitter to maximize OLED optical extraction. Also, transparent conductive traces may allow organic material to be exposed to optical radiation from an under-display optical transmitter, which can cause the organic material to heat, glow, age, degrade, and so on. 
     Of particular concern for an under-display optical sensor, and especially an under-OLED display optical sensor, are the conductive traces (e.g., anode metal traces) that route electrical signals to the drive circuits for the light-emitting elements in the display stack. The conductive traces may provide power and control signals to the light-emitting elements (or pixels), and may read data from the pixels (e.g., from the thin-film transistor(s) (TFT(s)) of every of pixel). The conductive traces are typically included in multiple layers of the display stack, and may be oriented in different directions (e.g., orthogonal or otherwise overlapping directions) such that they form a mesh of conductive traces. In some cases, the conductive traces may cover 85-95% of the surface area of a display stack, and may thus prevent light from passing through approximately 85-95% of a display stack. This greatly reduces the signal-to-noise ratio (SNR) and dynamic range of an optical sensor positioned in an under-display configuration. The conductive traces are not only opaque, but in many cases are highly reflective. This can generate significant crosstalk between an optical transmitter and optical receiver, or between the transmit and receive components of an optical transceiver, and may further reduce the SNR and dynamic range of an optical sensor. Still further, the regular pitch of the anode metal traces (usually equal to an integer or fraction of the display&#39;s pixel pitch) can make the mesh of anode metal traces an effective diffraction grating. Regardless, there exist translucent (and sometimes transparent) apertures between the conductive traces, and some of these translucent apertures typically extend from the front surface to the back surface of a display stack. 
     Of particular concern for an under-display optical sensor that includes near-infrared (NIR) under-display transmitters (i.e., optical transmitters that transmit wavelengths of light in the range of 700-1100 nm or beyond) is that, when TFTs in the display stack are exposed to transmitter backlighting, control and drive operations of the TFTs may be significantly altered-both transiently and long-term—by the photo-absorption of TFT poly-silicon layers and other sensitive layers. Spatially maximizing the transmit power of optical transmitters through a display stack&#39;s translucent apertures (“open” areas) and minimizing direct backlighting to the display stack&#39;s TFTs, can greatly mitigate the negative impact of under-display optical transmitters on display performance. 
     The present disclosure describes systems, devices, methods, and apparatus in which micro-optic elements (e.g., micro-lenses or gradient-index (GRIN) lenses) are formed on (or abutted to) the back surface of a display stack. The micro-optic elements may be aligned with the translucent apertures that already exist in a display stack (e.g., the micro-optic elements may be opportunistically aligned), or aligned with translucent apertures that are formed by deterministically routing conductive traces to provide translucent apertures of predetermined size at predetermined locations. In some cases, the micro-optic elements may be formed by exposing the front surface of a display stack to electromagnetic radiation (e.g., ultraviolet (UV) radiation) that passes through the translucent apertures to pattern a photoresist applied to the back surface of the display stack. In this manner, the micro-optic elements may be considered self-aligned by the display stack. 
     An under-display optical sensor may variously include an optical transmitter, an optical receiver, an optical transceiver, or multiple optical transmitters, optical receivers and/or optical transceivers. In some cases, multiple optical sensors may be provided under a device&#39;s display, and may be used to perform the same or different functions. An under-display optical sensor may be used, for example, as a proximity sensor (or ranging sensor), an ambient light sensor, a fingerprint sensor, a camera (2D or 3D), a wireless communicator or controller, a time-of-flight (ToF) sensor (e.g., a short pulse optical source and a single-photon avalanche-diode (SPAD) detector or SPAD array), and so on. One or more optical transmitters, without corresponding optical receives, may also be positioned under a display (e.g., for providing flood illumination, a flashlight, or an optical pointer (e.g., an infrared (IR) pointer)). In some embodiments, an optical transmitter and/or receiver may be provided under a display, and an optical transmitter and/or receiver may be provided adjacent the display. 
     The provision of an under-display optical sensor can maximize the display surface real-estate available for providing a display, and in some cases may enable an edge-to-edge display (i.e., a display that spans 100% of the display surface). Also, the display-integrated micro-optic elements described herein can enhance through-display optical transmission, reduce display back-reflection and diffraction, reduce backlighting-induced display distortion, and improve through-display optical reception efficiency. 
     These and other embodiments are discussed with reference to  FIGS. 1A-15 . 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. 
       FIGS. 1A and 1B  show an example of a device  100  having a display  104 . More particularly,  FIG. 1A  shows a perspective view of the front of the device  100 , and  FIG. 1B  shows an elevation of a side of the device  100 . 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  100  is a mobile phone (e.g., a smartphone). However, the device&#39;s dimensions and form factor are arbitrarily chosen, and the device  100  could alternatively be any portable electronic device including, for example, a mobile phone, tablet computer, portable computer, portable music player, health monitoring device, portable terminal, or other portable or mobile device. The device  100  could also be a device that is semi-permanently located or installed at a single location. 
     The device  100  may include a housing  102  that at least partially surrounds or supports a display  104 . In some examples, the housing  102  may include or support a front cover  106  and/or a rear cover  108 . The front cover  106  may be positioned over the display  104 , and may provide a window through which the display  104  may be viewed. In some embodiments, the display  104  may be attached to (or abut) the housing  102  and/or the front cover  106 . 
     As shown primarily in  FIG. 1A , the device  100  may include various other components. For example, the front of the device  100  may include one or more front-facing cameras  110 , speakers  112 , microphones, or other components  114  (e.g., audio, imaging, or sensing components) that are configured to transmit or receive signals to/from the device  100 . In some cases, a front-facing camera  110 , alone or in combination with other sensors, may be configured to operate as a bio-authentication or facial recognition sensor. The device  100  may also include various input devices, including a mechanical or virtual button  116 , which may be accessible from the front surface (or display surface) of the device  100 . In some cases, the front-facing camera  110 , virtual button  116 , and/or other sensors of the device  100  may be integrated with a display stack of the display  104  and moved under the display  104 . 
     The device  100  may also include buttons or other input devices positioned along a sidewall  118  of the housing  102  and/or on a rear surface of the device  100 . For example, a volume button or multipurpose button  120  may be positioned along the sidewall  118 , and in some cases may extend through an aperture in the sidewall  118 . By way of example, the rear surface of the device  100  may include a rear-facing camera or other optical sensor. A flash or light source may also be positioned along the rear of the device  100  (e.g., near the rear-facing camera). In some cases, the rear surface of the device  100  may include multiple rear-facing cameras. 
     The display  104  may include one or more light-emitting elements including, for example, LEDs, OLEDs, a liquid crystal display (LCD), an electroluminescent display (EL), or other types of light-emitting elements. The display  104  may also 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  106 . 
     The various components of the housing  102  may be formed from the same or different materials. For example, the sidewall  118  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  118  may be a multi-segment sidewall including a set of antennas. The antennas may form structural components of the sidewall  118 . 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  118 . The front cover  106  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  104  through the front cover  106 . In some cases, a portion of the front cover  106  (e.g., a perimeter portion of the front cover) may be coated with an opaque ink to obscure components included within the housing  102 . The rear cover  108  may be formed using the same material(s) that are used to form the sidewall  118  or the front cover  106 . In some cases, the rear cover  108  may be part of a monolithic element that also forms the sidewall  118  (or in cases where the sidewall  118  is a multi-segment sidewall, those portions of the sidewall  118  that are non-conductive). In still other embodiments, all of the exterior components of the housing  102  may be formed from a transparent material, and components within the device  100  may or may not be obscured by an opaque ink or opaque structure within the housing  102 . 
     The front cover  106  may be mounted to the sidewall  118  to cover an opening defined by the sidewall  118  (i.e., an opening into an interior volume in which various electronic components of the device  100 , including the display  104 , may be positioned). The front cover  106  may be mounted to the sidewall  118  using fasteners, adhesives, seals, gaskets, or other components. 
     A display stack or device stack (hereafter referred to as a “stack”) including the display  104  may be attached (or abutted) to an interior surface of the front cover  106  and extend into the interior volume of the device  100 . In some cases, the stack may 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 sensing system) may be configured to detect a touch applied to an outer surface of the front cover  106  (e.g., to a display surface of the device  100 ). 
     In some cases, a force sensor (or part of a force sensing system) may be positioned within the interior volume below and/or to the side of the display  104 . The force sensor (or force sensing system) may be triggered in response to the touch sensor detecting one or more touches on the front cover  106  (or a location or locations of one or more touches on the front cover  106 ), 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. 
     In some embodiments, one or more micro-optic elements may be formed on (or abutted to) a back surface  122  of the display stack, under the display  104 . Each of the micro-optic elements may be respectively aligned with one or more (i.e., one or multiple) translucent apertures that extend from a front surface to the back surface  122  of the display stack. Some or all of the micro-optic elements may focus light emitted by one or more under-display optical transmitters in one or more of the translucent apertures, to increase the percentage of light that passes through the translucent apertures, reduce TFT exposure to backlighting, and reduce back reflections. Also or alternatively, some or all of the micro-optic elements may collimate light received through the translucent apertures, so that the light does not scatter behind the display and can be focused onto one or more optical receivers, thereby increasing the light collection efficiency of the device  100 . 
       FIG. 1B  shows light  124  being emitted from an optical transmitter positioned behind the back surface  122  of the display stack of the device  100 . The emitted light  124  may travel from the back surface  122  toward the front cover  106 , and may pass through the front cover  106 . After passing through the front cover  106 , the emitted light  124  may travel toward an object  126 , such as a user&#39;s ear, reflect from the object  126 , and travel back toward the device  100  as reflected light  128 . The reflected light  128  may pass through the display stack and be received by an optical receiver positioned behind the back surface  122  of the display stack. A processor of the device  100  may then determine a proximity of the object  126  to the device  100 . The processor may also or alternatively make other determinations, based on light emitted and received by the device  100 , or based on light received (but not emitted) by the device  100 . 
       FIGS. 2A and 2B  show an example embodiment of a display stack  200  and optical module  202 . In some cases, the display stack  200  and optical module  202  may be included in the device  100  described with reference to  FIGS. 1A and 1B .  FIG. 2A  shows an elevation of the display stack  200  and optical module  202 , and  FIG. 2B  shows a plan view of the display stack  200  (with the optical module  202  being hidden from view by the display stack  200 ). 
     The display stack  200  may be attached or abutted to a cover  214  (e.g., a glass cover or “cover glass”), and may include multiple layers (e.g., layers  204 ,  206 ,  208 ,  210 , and  212 ). In other words, the display stack  200  may be a multi-layer display stack  200 . The layers  204 - 212  of the display stack  200  may include a set of opaque elements. The opaque elements may variously include a set of light-emitting elements  216  (e.g., a set of OLEDs in a light-emitting layer  208  (e.g., an organic layer)), a set of drive circuits (e.g., a set of TFTs in a drive layer  210 , which TFTs may be employed as OLED drive circuits to drive the set of light-emitting elements  216  (e.g., the set of OLEDs in the light-emitting layer  208 ), a set of conductive traces in one or more layers  212  (e.g., bottom high reflectors for the light-emitting elements  216 , electrical contacts for the drive circuits in the drive layer  210 , and/or interconnect traces for the drive circuits), optical, electrical, physical, and/or chemical shielding or confining elements, and so on. Different opaque elements may be included in the same or different layers, and in some cases may span two or more layers. The display stack  200  may also include a set of materials associated with partial transmission, absorption, and/or reflection of optical wavelengths of interest, and/or a set of opaque and/or transparent materials, such as dielectric material between the light-emitting elements, a cathode electrode in a cathode layer  206 , and a polarizer, touch sensor electrodes, and/or other elements in one or more layers  204 . 
     The conductive traces in layer(s)  212  may be configured to route electrical signals for (i.e., to and/or form) the drive circuits in the drive layer  210  (e.g., to and/or from the TFTs in the drive layer  210 ). In some cases, the conductive traces may be made of metal, such as copper, gold, silver, aluminum, or a metal alloy. The conductive traces may form a multi-layer mesh of conductive traces in the layers  212 . For example, the conductive traces in a first one or more layers may extend substantially parallel to one another in a first direction, and the conductive traces in a second one or more layers may extend substantially parallel to one another in a second direction, orthogonal to the first direction. In some embodiments, the back surfaces of the conductive traces (or both the front surfaces and the back surfaces of the conductive traces) may be treated to reduce their reflectivity. For example, an opaque ink or other layer may be applied to the back surface of the layers  212  (or to the front and back surfaces of the layers  212 ), but for the openings to the translucent apertures  218 . Alternatively, the conductive traces, or a dielectric that covers the layers  212 , may be coated or treated to reduce the reflectivity of the display stack  200 , but for the openings to the translucent apertures  218 . Such an ink, roughening, or other treatment may also help to reduce optical crosstalk between an optical transmitter and optical receiver positioned under the display stack  200 . 
     The set of opaque elements may define one or more translucent apertures  218 . The translucent apertures  218  may extend through the display stack  200  (e.g., from a front surface (or user-facing surface) of the display stack  200  to a back surface of the display stack  200 ). For example, a translucent aperture  218  having a rectangular or square cross-section may be bounded on a first set of opposite sides by conductive traces in a first set of one or more layers of the display stack  200 , and on a second set of opposite sides by conductive traces in a second set of one or more layers of the display stack  200 . In some cases, other opaque elements (e.g., light-emitting elements  216 , optical, electrical, physical, and/or chemical shielding or confining elements, and so on) may also or alternatively bound and define a translucent aperture  218 . In some cases, part or all of a translucent aperture  218  may be filled by a dielectric (or multiple dielectrics) used to form one or more substrate or intermediate layers on which (or in which) the opaque elements are formed. The dielectric(s) may allow light having one or more predetermined wavelengths to pass through a translucent aperture  218 . In some cases, light within a predetermined range of wavelengths, or light of any wavelength, may pass through a translucent aperture  218 . In some embodiments, a translucent aperture  218  may be transparent to some or all of the wavelengths of light that it passes. 
     In some embodiments, the set of opaque elements may include elements that are opaque to some wavelengths of light (e.g., opaque to visible, infrared, and/or other wavelengths of light), but translucent or transparent to other wavelengths of light. As used herein, the term “light” is broadly used to refer to visible and invisible forms of electromagnetic radiation. 
     The translucent apertures  218  in the display stack  200  may be evenly or unevenly distributed across the display stack  200 . The translucent apertures  218  may have the same or different sizes (e.g., dimensions). Different subsets of the display stack&#39;s opaque elements may define different ones of the translucent apertures  218 . In some cases, the display stack  200  may include translucent apertures  218  that are slanted with respect to the front and back surfaces of the display stack  200  (i.e., translucent apertures  218  that intersect the front and back surfaces of the display sack  200  at other than a ninety degree angle). In some cases, a slanted aperture may intersect one or more perpendicular apertures. 
     The optical module  202  may be positioned behind the back surface  220  of the display stack  200 , and may be spaced apart from the back surface  220  of the display stack  200  (e.g., positioned in a plane parallel to the back surface  220  of the display stack  200 , and facing the back surface  220  of the display stack  200 ). The optical module  202  may include an optical receiver  224  and/or an optical transmitter  226 , and in some cases may include multiple optical receivers and/or optical transmitters (or an optical transceiver). Alternatively, a plurality of optical modules may be positioned behind and spaced apart from the back surface  220  of the display stack  200 , with each optical module including an optical receiver, an optical transmitter, or both (e.g., an optical transceiver). 
     At least one micro-optic element  228  (e.g., one or more micro-lenses or GRIN lenses) may be formed on the back surface  220  of the display stack  200 , between the display stack  200  and the optical module  202 . Each micro-optic element  228  may have a focal point located within, aligned with, or near one of the translucent apertures  218 . 
     The optical receiver  224  may be positioned to receive light through the display stack  200  (e.g., through one or more of the translucent apertures  218 ) and at least a first of the micro-optic elements  228 . In some cases, the optical module  202  may include a condensing lens  242  positioned between the at least first micro-optic element  228  and the optical receiver  224 . 
     In some embodiments, the optical receiver  224  may receive light through at least first and second translucent apertures  218 , which apertures are respectively aligned with first and second micro-optic elements  228  having focal points located within, aligned with, or near the first and second translucent apertures  218 . In these embodiments, the optical receiver  224  may be configured to receive light through the first translucent aperture  218  and the first micro-optic element  228 , and through the second translucent aperture  218  and the second micro-optic element  228 . Receiving light through more translucent apertures  218  can increase the light collection capability of the optical receiver  224  and increase SNR. 
     The optical transmitter  226  may be positioned to transmit light through at least a second micro-optic element  228  and the display stack  200  (e.g., through one or more of the translucent apertures  218 ). In some cases, the optical module  202  may include a collimating lens  232  positioned between the optical transmitter  226  and the at least second micro-optic element  228 . 
     In some embodiments, the optical transmitter  226  may transmit light through at least first and second translucent apertures  218 , which apertures are respectively aligned with first and second micro-optic elements  228  having focal points located within, aligned with, or near the first and second translucent apertures  218 . In these embodiments, the optical transmitter  226  may be configured to transmit light through the first translucent aperture  218  and the first micro-optic element  228 , and through the second translucent aperture  218  and the second micro-optic element  228 . Transmitting light through more translucent apertures  218  can increase the transmission power. 
     In some embodiments, the display stack  200  may be mounted to a backplate  234  (or vice versa). The optical module  202  may also be mounted to the backplate  234 . As shown, the optical module  202  may include a substrate  236  having one or more walls extending perpendicularly therefrom. The walls may be used to mount the optical module to the backplate  234  or to the display stack  200 . A wall  238  may be provided between the optical receiver  224  and optical transmitter  226 , or walls may surround each of the optical receiver  224  and optical transmitter  226 , to mitigate optical crosstalk between the optical receiver  224  and optical transmitter  226 . Optical crosstalk may occur, for example, when light emitted by the optical transmitter  226  reflects from the micro-optic elements  228 , a layer of the display stack  200 , or the cover  214 , and impinges on the optical receiver  224  before first exiting the cover  214 . 
     As previously mentioned,  FIG. 2B  shows a plan view of the display stack  200 . By way of example, the display stack  200  is shown to include a mesh of conductive traces  240  (e.g., conductive traces that cross over or under other traces in other layers of the display stack  200 ). Only some of the conductive traces  240  are specifically shown in  FIG. 2B . 
     The display stack  200  also includes light-emitting elements  216 , and in some cases may include other elements. The conductive traces  240  may be opaque, such that light (or light of a desired wavelength) is only able to pass through the display stack  200  between the conductive traces  240 . In some cases, the mesh of conductive traces  240  may be the primary opaque elements that define the bounds of a plurality of translucent apertures  218  extending from the front surface to the back surface of the display stack  200 . However, other opaque elements may also define portions of some or all of the translucent apertures  218 . 
     An array of micro-optic elements  228  may be aligned with some or all of the translucent apertures  218 . For example, in some cases, a micro-lens array may be formed on the back surface of the display stack  200 . Each micro-lens in the array may have a focal point located within, aligned with, or near one of the translucent apertures  218 . 
     The layout of the conductive traces  240  shown in  FIG. 2B  is optimized to provide somewhat larger, more equally spaced, and linear translucent apertures  218  through the display stack  200 . Such an optimized layout of conductive traces  240  can make it easier to form an array of micro-optic elements  228  on the back surface of the display stack  200  (e.g., an array of same size micro-lenses). However, in some cases, the conductive traces  240  in a display stack  200  may not have an optimized layout, as shown in  FIG. 3 . 
       FIG. 3  shows an alternative plan view of the display stack  200  described with reference to  FIGS. 2A and 2B . Similarly to the display stack  200  shown in  FIG. 2B , the display stack  200  shown in  FIG. 3  includes a mesh of conductive traces  240 . The display stack  200  also includes light-emitting elements  216 , and in some cases may include other elements. However, in contrast to the layout described with reference to  FIG. 2B , the opaque elements of the light-emitting layer  208 , drive layer  210 , and layers  212  of conductive traces  240  shown in  FIG. 3  are not optimized and the translucent apertures  218  in the display stack  200  have varying sizes (e.g., different widths, different lengths, and so on). The different sizes are due to variances in the spacing and density of the conductive traces  240 , in combination with the overlapping shapes opaque elements in the light-emitting layer  208  and drive layer  210 , which variances may be due to the positions of thin-film transistors and their connections, and other components associated with the light-emitting elements  216 . 
     An array of micro-optic elements  228  may be aligned with some or all of the translucent apertures  218 , with the different micro-optic elements  228  of the array having the same or different sizes. In some cases, micro-optic elements  228  of smaller size (e.g., smaller diameter) may be formed on (or abutted to) the back surface of the display stack  200  and aligned with smaller size translucent apertures. Similarly, micro-optic elements  228  of larger size (e.g., larger diameter) may be formed on (or abutted to) the back surface of the display stack  200  and aligned with larger size translucent apertures  218 . Additionally or alternatively, a collection of multiple micro-optic elements  228  may be formed on (or abutted to) the back surface of the display stack  200  and tiled over a single translucent aperture  218 . Similarly, a single micro-optic element  228  may be formed on (or abutted to) the back surface of the display stack  200  and span (or cover, or be aligned with) a collection of multiple translucent apertures  218 . 
       FIG. 4  shows an alternative elevation of the display stack  200  shown in  FIGS. 2A and 2B , with an alternative configuration of optical module  202 . The alternative elevation is similar to the elevation shown in  FIG. 2A , but has micro-optic elements  228  of different size formed on (or abutted to) the back surface  230  of the display stack  200 . By way of example, the micro-optic elements  228  are shown to be micro-lenses having different diameters. 
     In some cases, the micro-optic elements  228  may be sized differently to focus or distribute more or less light in different portions of a field or view (e.g., to shape a beam or beams of light emitted into the field of view). In some cases, the size or dimensions of different translucent apertures  218  may differ, and the micro-optic elements  228  aligned with differently sized translucent apertures  218  may be sized differently to ensure that the focal points of differently sized micro-optic elements  228  are all located at a same or desired position with the differently sized translucent apertures  218 . Alternatively, different micro-optic elements  228  may be sized differently to move the focal points of different micro-optic elements  228  to different locations, within or outside a translucent aperture  218 . For example, a first translucent aperture  218  may have a first aperture size, and a second translucent aperture  218  may have a second aperture size, different from the first aperture size. In these embodiments, a first micro-optic element  228  may be aligned with the first translucent aperture  218  and have a first size, and a second micro-optic element may be aligned with the second translucent aperture  218  and have a second size. Parameters of one or more micro-optic elements  228  (e.g., focal points, numerical apertures (NAs), and so on) may be adjusted to provide a uniform or non-uniform distribution of light (or more or less uniform distribution of light) at a particular distance from the front surface of the display stack  200 . 
     The optical module  202  may be similar to the optical module described with reference to  FIG. 2A , but by way of example is shown to only include an optical transmitter  226 . Also, the optical transmitter  226  is shown to receive light through a greater number of translucent apertures  218  and micro-optic elements  228 . 
     In some embodiments, beams emitted through the display stack  200  may be further or alternatively shaped by elements included in one or more layers of the display stack  200 . In some cases, these elements may be wavelength-targeted, such that they shape light having one or more predetermined wavelengths, but have no effect on other light (e.g., no effect on the visible light emitted by the light-emitting elements  216 ). 
       FIG. 5  shows another alternative elevation of the display stack  200  shown in  FIGS. 2A and 2B , with an optical module  202  configured as described with reference to  FIG. 4 . The alternative elevation is similar to the elevation shown in  FIG. 2A , but has micro-optic elements  228  in the form of a GRIN lens array (instead of a micro-lens array) formed on (or abutted to) the back surface  220  of the display stack  200 . A GRIN lens may have a changing optical index, such as an optical index that changes from the periphery to the center of the lens. The changing optical index can bend light in different ways as it passes through the lens. 
     Flat optics, such as GRIN lenses, can be fabricated by using the conductive traces of the display stack  200  as a mask for performing ion implantation. The beam shaping provided by GRIN lenses can be customized, for example, by changing the index profile, thickness, and/or z-position of a GRIN lens. 
     In alternatives to what is shown in  FIG. 5 , the micro-optic elements  2   12828  could include Fresnel lenses, diffractive optic elements, and so on. In some embodiments, micro-optic elements  228  may be integrated into existing layers of the display stack  200  or included in additional layers of the display stack  200  (e.g., within the translucent apertures  218 ). Flat optics are sometimes easier to integrate into a layer of a display stack. 
       FIG. 6  shows yet another alternative elevation of the display stack  200  shown in  FIGS. 2A and 2B , in which light may be emitted or received through a slanted translucent aperture  218  in the display stack  200 . The slanted translucent aperture  218  may have an axis that extends from the front surface to the back surface of the display stack  200  at an angle other than a 90 degree angle (i.e., the slanted translucent aperture  218  is not perpendicular to the front and rear surfaces of the display stack  200 ). The slanted translucent aperture  218  may be bounded by (and defined by) opaque elements in the display stack  200  similarly to the translucent apertures described with reference to  FIGS. 2A, 2B, 3, 4, and 5 . 
     An optical module  202  may be positioned behind the back surface  220  of the display stack  200  and spaced apart from the back surface  220  of the display stack  200  (e.g., positioned in a plane parallel to the back surface  220  of the display stack  200  and facing the back surface  220  of the display stack  200 ). The optical module  202  may include an optical receiver and/or an optical transmitter, but in  FIG. 6  is shown to only include an optical transmitter  226 . In some cases, the optical module  202  may include a lens  232 . A micro-optic element  228  may be formed on the back surface  220  of the display stack  200 , between the display stack  200  and the optical module  202 . The micro-optic element  228  may be aligned, or at least partially aligned with, an end of the slanted translucent aperture  218 . 
     When the optical module includes an optical transmitter  226 , the micro-optic element  228  and/or the lens  232  may be configured to redirect (e.g., bend and collimate, or steer) light emitted by the optical transmitter  226  so that it can be emitted through the slanted translucent aperture  218 . When the optical module  202  includes an optical receiver, the micro-optic element  228  and/or the lens  232  may be configured to redirect (e.g., bend and condense, or steer) light received through the slanted translucent aperture  218  so that it can be received by the optical receiver. In some cases, the micro-optic element  228  or lens  232  may include a diffractive optical element. 
     In an alternative to the optical module placement shown in  FIG. 6 , an optical module could be mounted on a slanted surface and receive light from, or emit light into, the slanted translucent aperture  218  similarly to how the optical receiver or optical transmitter described with reference to  FIG. 2A  receives or emits light through a translucent aperture that is oriented perpendicular to a display stack. 
     In an alternative to the slanted translucent aperture  218  described with reference to  FIG. 6 , the micro-optic element  228  and/or lens  232  described with reference to  FIG. 6  may be used to receive or emit light, at an angle, through a translucent aperture oriented perpendicular to the display stack  200 . 
       FIG. 7A  shows another alternative elevation of the display stack  200  shown in  FIGS. 2A and 2B , with an optical module  202  configured as described with reference to  FIG. 4  but including multiple optical transmitters  226  (e.g., a first optical transmitter  226 - 1 , a second optical transmitter  226 - 2 , and a third optical transmitter  226 - 3 ).  FIG. 7A  shows the display stack  200  as a singular structure and does not call out the various display stack layers described with reference to other figures. However, the display stack  200  shown in  FIG. 7A  may include the layers described in other figures, and/or other or different layers. 
     Illustrated in  FIG. 7A  is a pixel  700  having at least one dimension of width “d”. A micro-optic element  228  may be aligned with the width of the pixel  700 , but need not be. In alternative embodiments, more than one micro-optic element  228  may be aligned with or overlap the pixel  700 . The opaque elements within the display stack  200  may define multiple translucent apertures  218  extending from the front surface to the back surface  220  of the display stack  200 , as generally illustrated by the openings in a layer  702 . Each micro-optic element  228  may be positioned behind multiple translucent apertures  218 . A plurality of pixels may be distributed in an array oriented parallel to the display surface of the display stack  200 , and each pixel may be configured similarly to (or different from) the pixel  700 . 
     Light emitted by each of the optical transmitters  226 - 1 ,  226 - 2 ,  226 - 3  may pass through a same or different set of one or more micro-optic elements  228 , and the light passing through a single micro-optic element  228  may pass through a same or different set of multiple translucent apertures  218 . If the optically clear portions of the translucent apertures  218  are generally rectangular or square, the beams of light passing through each translucent aperture  218  in the display stack  200  may have a generally rectangular or square cross-section in a far-field. The rectangular or square cross-sectioned beams may overlap or not overlap, depending on the configuration of various elements within the optical module  202  and display stack  200 , and depending on the distance from the cover  214  to the far-field. 
     In some embodiments, all of the optical transmitters  226 - 1 ,  226 - 2 ,  226 - 3  may be operated to emit light at the same time. In other embodiments, the optical transmitters  226 - 1 ,  226 - 2 ,  226 - 3  may be operated to emit light singularly, or in different combinations with other optical transmitters  226 - 1 ,  226 - 2 ,  226 - 3 . Configuring the optical transmitters  226 - 1 ,  226 - 2 ,  226 - 3  to be individually addressed and operated can enable beam shaping or beam scanning in a far-field. 
     In some embodiments, the optical transmitters  226 - 1 ,  226 - 2 ,  226 - 3  may emit light having the same wavelength (or color). In other embodiments, different optical transmitters  226 - 1 ,  226 - 2 ,  226 - 3  may emit light having different wavelengths (or colors). The light emitted by different optical transmitters may pass through the same or different translucent apertures  218  in the display stack  200 . 
     In some embodiments, the collimating lens  232  may have a focal length of “F”, and the micro-optic elements  228  may have focal lengths of “f”. In these embodiments, and in some cases, the ratio between F and f may match the magnification ratio from the optical transmitter pitch to the translucent aperture pitch, such that the optical transmitters may be re-imaged through translucent apertures  218  for every pixel  700 . In some cases, the best re-imaging beam quality and lowest optical transmission loss through the translucent apertures  218  may be achieved when the working distance between the collimating lens  232  and the micro-optic elements  228  is F+f. Lateral alignment between the collimating lens  232  and micro-optic elements  228  is not necessary. An example far-field image generated using the display stack  200 , micro-optic elements  228 , and optical module  202  described with reference to  FIG. 7A  is shown in  FIG. 8 . 
     In some embodiments, the F/f ratio, display pixel diameter (d), translucent aperture size, micro-optic element pitch (D), and/or emitter aperture/pitch/segmentation/array size may be configured to allow one or multiple general or specific emitters, segments, arrays to be focused through one or multiple general or specific translucent apertures  218 . 
     The display stack  200 , micro-optic elements  228 , and optical module  202  described with reference to  FIG. 7A  may be used to emit light through the multiple translucent apertures  218  per pixel described with reference to  FIG. 3 . 
       FIG. 7B  shows an alternative to what is shown in  FIG. 7A , with the optical module  202  including only a single optical transmitter  226 , and the micro-optic elements  228  defining a meta-surface  706  that shapes light emitted by the optical transmitter  226  as it exits the micro-optic elements  228 . For example, a micro-optic element  228  may have a meta-surface  706  (e.g., a diffraction grating) positioned between the micro-optic element  228  and the display stack  200 , which meta-surface  706  splits light focused by the micro-optic element  228 . Alternatively, a micro-optic element  228  could have a different configuration, or have a meta-surface formed on a different surface of the micro-optic element  228 . 
       FIG. 8  shows a pattern of illumination  800  emitted by one or more optical transmitters, which optical transmitters may be positioned behind a display stack and transmit light through translucent apertures in the display stack, as described with reference to  FIGS. 2A-2B, 3, 4, 5, 6 , and  7 A- 7 B. As shown, the light projected through each translucent aperture may have a generally rectangular or square aspect ratio in a far-field of view. For example, light emitted through a first translucent aperture may have the shape  802 , light emitted through a second translucent aperture may have the shape  804 , and light emitted through a third translucent aperture may have the shape  806 . The shapes  802  and  804  overlap each other, but neither of the shapes  802  or  804  overlap the shape  806 . The dimensions of various aspects of the pattern on a surface or object, including the dimensions or skew of individual light beams (e.g., dimension  808 ), or the dimensions or skew between different light beams (e.g., a distance between beams or an amount of overlap of beams, such as the dimension  810 ), may be used to determine a proximity or distance of the object to the optical transmitter. 
       FIGS. 9A-9F  illustrate an example method of forming a micro-lens array on the back surface of a display stack. Turning to  FIG. 9A , the method begins with a display stack  200  including a set of opaque elements (e.g., a mesh of conductive traces, which traces are coupled to the TFTs of a set of light-emitting elements  216 ). The mesh of conductive traces may include anode traces connected to a back side of the light-emitting elements  216 . An additional set of elements, including a cathode contact for the set of light-emitting elements  216 , a mesh of conductive traces forming a touch sensor, a polarizer, and so on, may be formed on a front side (i.e., a light-emitting side) of the light-emitting elements. In some embodiments, the light-emitting elements may include OLEDs. By way of example, the display stack  200  is shown to include the same layers included in the display stack described with reference to  FIG. 2A . 
     As described with reference to  FIGS. 2A, 2B, 3, 4, 5, 6, and 7A-7B , a set of translucent apertures  218  may be defined by the opaque elements of the display stack  200 , and may extend from a front surface to a back surface  220  of the display stack  200 . 
       FIG. 9B  shows an inversion of the display stack  200  described with reference to  FIG. 9A , and shows the application of a photoresist  900  to the back surface  220  of the display stack  200 . The photoresist  900  may include a translucent (or transparent) material, which material is used to grow a micro-lens array on the display stack  200 . 
       FIG. 9C  shows the front surface of the display stack  200  being exposed to electromagnetic radiation  902  (e.g., ultraviolet (UV) radiation). The opaque elements of the display stack  200 , and particularly the mesh of conductive traces connected to the back side of the light-emitting elements, serves as a photomask, such that the electromagnetic radiation  902  passes through the translucent apertures  218  and cures the portions  904  of the photoresist  900  that are aligned with the translucent apertures  218 . Use of the opaque elements within the display stack  200  as a photomask provides for self-alignment of micro-lenses with the translucent apertures  218 , as explained further with reference to  FIGS. 9D-9F . 
     As shown in  FIG. 9D , the uncured portions of the photoresist  900  may be removed (e.g., by etching), leaving a plurality of seeds  906  for growing a micro-lens array.  FIG. 9E  shows the micro-lens array (including micro-lenses or micro-optic elements  228 ) after it has been grown, with each micro-lens in the array being centered about one of the seeds  906 . In some cases, the micro-lens array may be grown using a reflow process (e.g., by reflowing the seeds  906  or material that is added to the seeds  906 ). 
       FIG. 9F  shows the display stack  200  after it has been inverted again and attached to the underside (interior side) of a cover  214 . In some embodiments, the cover  214  may be a glass or plastic cover. In some embodiments, the display stack  200  may be attached to the cover  214  using a transparent adhesive. Following attachment of the display stack  200  to the cover  214 , one or more optical modules may be positioned behind and spaced apart from the display stack  200 , as described with reference to  FIG. 2A, 2B, 3, 4, 5, 6 , or  7 A- 7 B. 
     In other embodiments, the micro-optic elements  228  may be constructed or formed apart from the display stack  200 , and then actively or passively aligned with the translucent apertures  218  in the display stack  200 . 
       FIG. 10  shows another example embodiment of a display stack  200  and optical module  202 . The display stack  200  and optical module  202  are shown in relation to near-field and far-field conjugated focal planes  1000 ,  1002  of the optical module  202 . 
     By way of example, the display stack  200  is configured as shown in  FIGS. 2A and 2B . The display stack  200  may also be configured in other ways, and may include the layers described in other figures and/or other or different layers. 
     The optical module  202  is shown to include multiple optical transmitters  226  (e.g., a first optical transmitter  226 - 1 , a second optical transmitter  226 - 2 , and a third optical transmitter  226 - 3 ), but may alternatively include a single optical transmitter (e.g., as described with reference to  FIG. 4 ). 
     One or more micro-optic elements  228  may be formed on the back surface of the display stack  200 . By way of example, an array of micro-optic elements  228  is shown. In some embodiments, the micro-optic elements  228  may be or include micro-lenses or GRIN lenses. The micro-optic elements  228  may be spherical or have other shapes (e.g., squares, rounded corner squares, and so on). 
     The opaque elements within the display stack  200  may define multiple translucent apertures  218  extending from the front surface to the back surface  220  of the display stack  200 . Each micro-optic element  228  may be positioned behind, or aligned with, one translucent aperture  218  or multiple translucent apertures  218 . The passage of light through one or more micro-optic elements  228 , and multiple translucent apertures  218 , may cause the light to diffract (i.e., the apertures  218  may operate as a diffraction grating). Light from the same coherent emitters, that diffracts as it passes through the micro-optic element(s)  228  and translucent apertures  218 , may constructively and de-constructively combine to produce a structured light pattern in one or more conjugated focal planes of the optical module  202 . Geometric re-imaging and/or diffraction of the light that passes through the apertures  218  may at the same time provide diffuse illumination (e.g., uniform or substantially uniform illumination) in one or more other conjugated focal planes of the optical module  202 . For example, diffuse or uniform illumination may be provided in at least a first conjugated focal plane  1000  intersecting the translucent apertures  218 , and a structured light pattern may be provided in at least a second conjugated focal plane  1002  external to the cover  214 . In this manner, the display stack  200  and optical module  202  may function as a multi conjugated focal plane projection system. 
     In some embodiments, the first conjugated focal plane  1000  may be at a distance Z 1  from the micro-optic elements, and may intersect the translucent apertures  218 . In alternative embodiments, the first conjugated focal plane may be located somewhat interior or exterior from the translucent apertures  218  (e.g., closer or farther from the optical transmitters  226 ). The second conjugated focal plane  1002  may be at a distance Z 2  from the first conjugated focal plane, and by way of example is shown to be exterior to the cover  214  (and external to the device that includes the cover  214 ). The apertures of the optical transmitters  226  may be at a distance from the micro-optic elements  228 . In other embodiments, the various arrays and conjugated focal planes may be positioned at other distances from each other and/or at other distances from components of the display stack  200 . In some other cases, the pitch (D) of the micro-optic elements  228 , the module working distance (Z 0 ), and/or emitter aperture/pitch/segmentation/array size may be configured to allow one or multiple general or specific emitters, segments, or arrays to be focused through one or multiple general or specific translucent apertures  218 , and to optimize the structured light pattern arrangement and/or contrast at a far-field interface. 
     Light emitted by each of the optical transmitters  226 - 1 ,  226 - 2 ,  226 - 3  may pass through a same or different set of one or more micro-optic elements  228 , and the light passing through a single micro-optic element  228  may pass through a same or different set of multiple translucent apertures  218 . 
     In some embodiments, all of the optical transmitters  226 - 1 ,  226 - 2 ,  226 - 3  may be operated to emit light at the same time. In other embodiments, the optical transmitters  226 - 1 ,  226 - 2 ,  226 - 3  may be operated to emit light singularly, or in different combinations with other optical transmitters  226 - 1 ,  226 - 2 ,  226 - 3 . Configuring the optical transmitters  226 - 1 ,  226 - 2 ,  226 - 3  to be individually addressed and operated, or to be addressed in two or more overlapping (interspersed) or non-overlapping (non-interspersed) subsets, can enable the optical module  202  to provide different types of structured light patterns in a near and/or far-field (e.g., in the second conjugated focal plane  1002 ). 
     In some embodiments, the optical transmitters  226 - 1 ,  226 - 2 ,  226 - 3  may emit light having the same wavelength (or color). In other embodiments, different optical transmitters  226 - 1 ,  226 - 2 ,  226 - 3  may emit light having different wavelengths (or colors). The light emitted by different optical transmitters may pass through the same or different translucent apertures  218  in the display stack  200 . 
       FIGS. 11A and 11B  show examples of near-field and far-field illumination, which illumination may be provided by an under-display optical module similar to the one described with reference to  FIG. 10 . More specifically,  FIG. 11A  shows example illumination  1100  (intensity of illumination) of a near-field conjugated focal plane, and  FIG. 11B  shows example illumination  1110  (intensity of illumination) of a far-field conjugated focal plane. As can be seen in  FIG. 11A , the near-field conjugated focal plane is illuminated diffusely (e.g., in a substantially uniform manner), while the far-field conjugated focal plane is illuminated with a structured light pattern. 
     In some examples, a device may include one or more under-display light receivers (e.g., photodetectors) that sense the amount of emitted light that reflects from an object that enters or moves within the near-field conjugated focal plane, and determines a presence, proximity, location, or size of the object (or objects) from the sensed amount(s) of reflected light. Additionally or alternatively, the device may include a camera that senses the amount(s) of reflected light, a color or pattern of the reflected light, and so on, and uses parameters of the sensed light to determine a presence, proximity, location, size, or other parameters of an object (or objects) that enters or moves within the near-field conjugated focal plane. In some examples, the same device may use a camera (e.g., an under-display camera) to acquire an image, or set of images, of an object that is illuminated by an optical transmitter of the under-display optical module, and the processor may be configured to determine parameters of the object using the image(s) of the object and parameters of the structured light pattern in at least the far-field conjugated focal plane. For example, the processor may generate a three-dimensional map of the object using the image(s) of the object and the parameters of the structured light pattern in at least the far-field conjugated focal plane. 
       FIG. 12  shows an example plan view  1200  of a set of emitters  1202  that may be included in an under-display optical module. The set of emitters  1202  is shown in relation to an array of micro-optic elements  1204 . 
     The design considerations described with reference to  FIG. 12  may be applied to a device that includes a larger or smaller set of emitters and/or a larger or smaller array of micro-optic elements. The relative size of the emitters  1202  in relation to the micro-optic elements  1204  is also just an example, and may be varied in other embodiments. Also, different emitters  1202  may have the same or different shapes or sizes, and different micro-optic elements  1204  may have the same or different shapes or sizes. 
     In some embodiments, a processor may use the emitters  1202  shown in  FIG. 12  to provide different structured light patterns in a conjugated focal plane at different times (e.g., to provide multi-frame projection in which the structured light pattern can differ from one frame to another). For example, a processor may be configured to activate a first subset  1206  of the emitters  1202  during a first time period (during a first frame), and activate a second subset  1208  of the emitters  1202  during a second time period (e.g., during a second frame). Activation of the first subset  1206  of emitters  1202  may produce a first structured light pattern (e.g., the structured light pattern  1300  shown in  FIG. 13A ), and activation of the second subset  1208  of emitters  1202  may produce a second structured light pattern (e.g., the structured light pattern  1310  shown in  FIG. 13B ). 
     By way of example, the second subset  1208  of emitters  1202  is shown to include the same number and pattern of emitters as the first subset  1206  of emitters  1202 , but is rotated and spatially offset from the first subset  1206  of emitters  1202 . In some embodiments, the emitters  1202  of both the first and second subsets  1206 ,  1208  may be configured and positioned to provide diffuse or uniform illumination in a first conjugated focal plane (e.g., a near-field conjugated focal plane), but provide different structured light patterns in one or more other conjugated focal planes (e.g., in the same or different far-field conjugated focal planes). 
     In some embodiments, the first and second subsets  1206 ,  1208  of emitters  1202 , and/or their different structured light patterns in a far-field conjugated focal plane, may be spatially multiplexed (e.g., spatially offset from one another). In other embodiments, the first and second subsets  1206 ,  1208  of emitters  1202 , and/or their different structured light patterns in a far-field conjugated focal plane, may be interspersed or overlapping. 
       FIG. 12  shows how different structured light patterns can be achieved by varying the placement of an array of emitters  1202  with respect to an array of micro-optic elements  1204 . Additionally or alternatively, different structured light patterns can be achieved by varying the apertures or pitch of emitters  1202  (e.g., varying VCSEL apertures or pitch); varying emitter-to-micro-optic element working distance (e.g., varying VCSEL to MLA working distance); varying micro-optic element parameters (e.g., varying MLA curvature); and so on. In some embodiments, different subsets of emitters  1202  may be individually addressable. In some embodiments, each emitter  1202  may be individually addressable. Individual addressability of emitters  1202  can enable the generation of a large number of structured light patterns, through various constructive/de-constructive interference effects. Individual addressability (or an ability to address more granular subsets of emitters  1202 ) can assist in reducing the footprint (or die area) of an under-display optical transmitter capable of producing multiple structured light patterns. 
     In some embodiments, far-field structured light pattern differences (or irregularities, or different structured light pattern uniqueness) and distance-dependent (or distance-independent) structured light patterns may be achieved while maintaining optimal through-display efficiency in a near-field conjugated focal plane. 
     Different structured light patterns may be generated sequentially (e.g., in different frames), simultaneously, or on demand. In some cases, a camera may acquire images that indicate how an object is illuminated by the different structured light patterns, and more accurately determine parameters of the object (e.g., generate a more precise or finer resolution three-dimensional map of the object) using the images. Alternatively, environmental conditions or object parameters may be sensed or provided, and the processor may activate one or multiple subsets of emitters  1202  such that the object is properly illuminated for the sensed or provided environmental conditions or object parameters. In some embodiments, multi-frame projection, and/or addressable emitters or subsets of emitters, can enable power and time-efficient three-dimensional sensing or other three-dimensional sensing/display projection taks. 
     Each of  FIGS. 13A and 13B  depict illumination (e.g., normalized irradiance) along x and y axes of a conjugated focal plane parallel to the a plane passing through the set of emitters  1202  or array of micro-optic elements  1204  described with reference to  FIG. 12 , or parallel to the exterior surface of the cover described with reference to  FIG. 10  and other figures. Each of  FIGS. 13A and 13B  represent normalized irradiance on a scale of 0 to 1, in Watts per square meter (W/m 2 ). 
     In some embodiments of the display stacks and optical modules described herein, micro-optic elements disposed under a display stack may not be attached or formed on a back surface of the display stack, but may instead be abutted to a display stack or otherwise positioned between an under-display optical module and a display stack. In some of these embodiments, the micro-optic elements may be provided as part of the optical module. In some embodiments, the micro-optic elements may be formed (or grown) on individual ones or groups of optical emitters (e.g., VCSELs) or optical detectors (e.g., photodiodes). In some cases, micro-optic elements may be precisely aligned with optical emitters or optical detectors (or vice versa). In other cases, micro-optic elements may be loosely aligned with optical emitters or optical detectors, and a device may be calibrated based on the actual alignment of parts in a particular device or set of devices. 
       FIG. 14  illustrates a method  1400  of sensing a proximity of an object to a device having a light-emitting display. The method  1400  may be performed using any of the display stacks and optical modules described herein, in combination with a processor such as the processor described with reference to  FIG. 16 . 
     At block  1402 , the method  1400  may optionally include emitting light from an optical transmitter. The emitted light may be collimated at block  1404 , and the collimated emitted light may be focused toward a first translucent aperture in a display surface of a light-emitting display at block  1406 . 
     At block  1408 , the method  1400  may include receiving light through a second translucent aperture in the display surface. The received light may be collimated at block  1410 , and the collimated received light may be condensed toward an optical receiver at block  1412 . An output of the optical receiver may be quantified (e.g., by a processor of the device) at block  1414 , and the quantified output of the optical receiver may be correlated to the proximity of the object to the device at block  1416 . 
     The light focused toward the first translucent aperture, at block  1406 , may have a predetermined set of one or more wavelengths. The predetermined set of wavelengths (or single wavelength) may be established by the configuration of the optical transmitter, or by filtering performed by a collimating lens or focusing lens. Similarly, the light received by the optical receiver may have the predetermined set of one or more wavelengths (or single wavelength). The predetermined set of wavelengths (or single wavelength) received by the optical receiver may be established by filtering performed by a collimating lens or condensing lens, or by the configuration of the optical receiver. 
     In embodiments in which the operations at blocks  1402 - 1406  are performed, and the light emitted from the optical transmitter includes an optical pulse, the method  1400  may further include recording an emission time of the optical pulse; determining a reception time of a reflection of the optical pulse using the optical receiver; and determining a distance between the object and the device using the emission time and the reception time (e.g., based on a ToF of the optical pulse and the speed of light). 
     In some embodiments of the method  1400 , quantifying the output of the optical receiver may include quantifying a change in the output of the optical receiver. 
     In some cases, the method  1400  may be modified to emit and/or receive light through a plurality of translucent apertures in the display surface. The method  1400  may also be modified to make other determinations, to acquire an image (including an image of a fingerprint or face), to make measurements (e.g., ambient light measurements), or to transmit and receive wireless communications. 
       FIG. 15  illustrates an example method of illuminating a field of view. The method  1400  may be performed using any of the display stacks and optical modules described herein (so long as the optical module includes an optical transmitter), in combination with a processor such as the processor described with reference to  FIG. 16 . 
     At block  1502 , the method  1500  may include emitting light from an array of optical transmitters. The light may be emitted through an array of micro-optic elements attached to (or otherwise positioned behind) the back of a display stack (e.g., a display stack of a light-emitting display), and the array of micro-optic elements may direct at least a portion of the emitted light through an array of translucent apertures in the display stack. 
     At block  1504 , an amount of the emitted light that is reflected from a first object (e.g., a finger or stylus positioned on or proximate a cover disposed over the display stack) may be sensed. In some embodiments, the reflected light may be sensed by an optical receiver positioned under or behind the display stack. The optical receiver may include an array of photodiodes. 
     At block  1506 , and before, after, or in parallel with the operations at block  1504 , at least one image of a second object (e.g., a user&#39;s face or head, or a component of a user&#39;s face, or a user&#39;s hand) may be acquired. In some embodiments, the image(s) may be acquired by an image sensor (e.g., a camera) disposed under or behind the display stack. In some embodiments, the micro-optic elements positioned between the optical transmitter and display stack may not be positioned between the display stack and the image sensor, so that the image sensor may adequately identify irregularities in a structured light pattern that illuminates the second object. The second object may be illuminated by a structured light pattern, or by multiple structured light patterns, as the image(s) are acquired. The structured light pattern(s) may be formed by constructive and deconstructive interference of the light emitted at block  1502 . 
     At block  1508 , the method  1500  may include determining a proximity and/or location of the first object, using the sensed amount of reflected light. 
     At block  1510 , the method  1500  may include generating a three-dimensional map of the second object using the acquired image(s). 
     In some cases, the determination made at block  1508  and three-dimensional map generated at block  1510  may be performed for the same object and/or used as part of a biometric authentication function. 
       FIG. 16  shows a sample electrical block diagram of an electronic device  1600 , which electronic device may in some cases take the form of the device described with reference to  FIGS. 1A and 1B  and/or have a display stack and under-display optical sensor as described with reference to  FIGS. 1A-15 . The electronic device  1600  may include a display  1602  (e.g., a light-emitting display), a processor  1604 , a power source  1606 , a memory  1608  or storage device, a sensor system  1610 , or an input/output (I/O) mechanism  1612  (e.g., an input/output device, input/output port, or haptic input/output interface). The processor  1604  may control some or all of the operations of the electronic device  1600 . The processor  1604  may communicate, either directly or indirectly, with some or all of the other components of the electronic device  1600 . For example, a system bus or other communication mechanism  1614  can provide communication between the display  1602 , the processor  1604 , the power source  1606 , the memory  1608 , the sensor system  1610 , and the I/O mechanism  1612 . 
     The processor  1604  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  1604  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. 
     It should be noted that the components of the electronic device  1600  can be controlled by multiple processors. For example, select components of the electronic device  1600  (e.g., the sensor system  1610 ) may be controlled by a first processor and other components of the electronic device  1600  (e.g., the display  1602 ) 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  1606  can be implemented with any device capable of providing energy to the electronic device  1600 . For example, the power source  1606  may include one or more batteries or rechargeable batteries. Additionally or alternatively, the power source  1606  may include a power connector or power cord that connects the electronic device  1600  to another power source, such as a wall outlet. 
     The memory  1608  may store electronic data that can be used by the electronic device  1600 . For example, the memory  1608  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  1608  may include any type of memory. By way of example only, the memory  1608  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  1600  may also include one or more sensor systems  1610  positioned almost anywhere on the electronic device  1600 . However, at least one optical sensor, or an optical receiver or optical transmitter, may be positioned under the display  1602  and may transmit and/or receive light through the display  1602 . The sensor system(s)  1610  may be configured to sense one or more type of parameters, such as but not limited to, light; touch; force; heat; movement; relative motion; biometric data (e.g., biological parameters) of a user; and so on. By way of example, the sensor system(s)  1610  may include a heat sensor, a position sensor, a light or optical sensor, an accelerometer, a pressure transducer, a gyroscope, a magnetometer, a health monitoring sensor, and so on. Additionally, the one or more sensor systems  1610  may utilize any suitable sensing technology, including, but not limited to, capacitive, ultrasonic, resistive, optical, ultrasound, piezoelectric, and thermal sensing technology. 
     The I/O mechanism  1612  may transmit or receive data from a user or another electronic device. The I/O mechanism  1612  may include the display  1602 , 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  1612  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.

Metadata:
Filing Date: 20191220
Publication Date: 20210720
Grant Date: 20210720
Priority Date: 20181226
Inventors: CHEN, TONG
WINKLER, MARK T.
HO, MENG-HUAN
LIU, RUI
XIANG, Xiao
CAI, WENRUI
Assignee: APPLE INC
CPC Classifications: [{"code": "G03B21/56", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B3/0068", "inventive": false, "first": false, "tree": "[]"}, {"code": "G03B21/625", "inventive": true, "first": false, "tree": "[]"}, {"code": "G03B21/62", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F3/044", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04B10/40", "inventive": false, "first": false, "tree": "[]"}, {"code": "G03B21/10", "inventive": true, "first": false, "tree": "[]"}, {"code": "G03B11/00", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B5/128", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04B10/116", "inventive": true, "first": false, "tree": "[]"}, {"code": "G03B17/02", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04N9/3141", "inventive": true, "first": false, "tree": "[]"}, {"code": "G03B15/03", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04B10/1143", "inventive": true, "first": true, "tree": "[]"}, {"code": "G03B21/10", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/044", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01L51/50", "inventive": true, "first": false, "tree": "[]"}, {"code": "G03B21/62", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04N9/3141", "inventive": true, "first": false, "tree": "[]"}, {"code": "G03B21/625", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B5/128", "inventive": true, "first": false, "tree": "[]"}, {"code": "G03B21/56", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04B10/40", "inventive": false, "first": false, "tree": "[]"}, {"code": "H10K50/00", "inventive": true, "first": false, "tree": "[]"}, {"code": "H10K59/65", "inventive": false, "first": false, "tree": "[]"}, {"code": "G01B11/2513", "inventive": true, "first": false, "tree": "[]"}, {"code": "H10K59/879", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 71122920