PATENT DOCUMENT

Publication Number: US-11289051-B2
Application Number: US-202017001444-A
Country: US
Kind Code: B2

Title: Electronic devices having light sensor modules overlapped by displays

Abstract:
An electronic device may have a display with an array of pixels configured to display images for a user. The electronic device may have an ambient light sensor for gathering ambient light information. Control circuitry in the electronic device may adjust the brightness level of an image being displayed by the display based on ambient light measurements from the ambient light sensor. The ambient light sensor may be formed from an ambient light sensor module that is aligned with an opening in an opaque masking layer in the display. One or more antireflection layers may be interposed between an inwardly facing surface of the display and an opposing external surface of the ambient light sensor module. The ambient light sensor module may have a light attenuator and other optical structures.

Claims:
What is claimed is: 
     
       1. An electronic device, comprising:
 a display having an array of pixels configured to display an image with a brightness level; 
 an opaque masking layer in a portion of the display, wherein the opaque masking layer has an ambient light sensor opening; 
 an ambient light sensor module configured to make an ambient light sensor measurement on ambient light received through the ambient light sensor opening, wherein the ambient light sensor module comprises:
 an ambient light sensor semiconductor die; 
 a package in which the ambient light sensor semiconductor die is mounted; and 
 a light attenuator mounted in the package that is configured to attenuate the received ambient light before the received ambient light is provided to the ambient light sensor semiconductor die; and 
 
 control circuitry configured to adjust the brightness level based on the ambient light sensor measurement. 
 
     
     
       2. The electronic device defined in  claim 1  wherein the light attenuator comprises a substrate and a layer of light-absorbing ink on the substrate. 
     
     
       3. The electronic device defined in  claim 1  wherein the light attenuator comprises a dark diffuser formed from a light-absorbing polymer with light-scattering structures. 
     
     
       4. The electronic device defined in  claim 3  wherein the light-scattering structures comprise black particles that absorb light. 
     
     
       5. The electronic device defined in  claim 3  wherein the light-absorbing polymer comprises black colorant. 
     
     
       6. The electronic device defined in  claim 1  wherein the light attenuator comprises a thin-film interference filter having a stack of dielectric layers configured to attenuate visible light. 
     
     
       7. The electronic device defined in  claim 6  wherein the stack of dielectric layers is configured to block infrared light. 
     
     
       8. The electronic device defined in  claim 1  wherein the ambient light sensor module comprises an infrared-light-blocking filter configured to block infrared light passing through the ambient light sensor opening in the opaque masking layer. 
     
     
       9. The electronic device defined in  claim 1  wherein the ambient light sensor module comprises a light diffuser. 
     
     
       10. The electronic device defined in  claim 1  wherein the display comprises a transparent layer overlapping the array of pixels, wherein the array of pixels forms an active area of the display in which the image is displayed, and wherein the opaque masking layer is formed on a surface of the transparent layer in an inactive area of the display that does not overlap the array of pixels. 
     
     
       11. The electronic device defined in  claim 10  further comprising a layer of adhesive that attaches the ambient light sensor module to the inner surface of the transparent layer in alignment with the ambient light sensor opening. 
     
     
       12. The electronic device defined in  claim 1  wherein the display comprises a color filter layer and a thin-film transistor layer and a layer of liquid crystal material between the color filter layer and the thin-film transistor layer and wherein the opaque masking layer is between the color filter layer and the thin-film transistor layer. 
     
     
       13. The electronic device defined in  claim 12  further comprising an antireflection layer on an inner surface of the thin-film transistor layer between the ambient light sensor opening and the ambient light sensor module. 
     
     
       14. The electronic device defined in  claim 12  further comprising an antireflection layer on an exterior surface of the ambient light sensor module. 
     
     
       15. The electronic device defined in  claim 12  further comprising a first antireflection layer on the thin-film transistor layer, a second antireflection layer on the ambient light sensor module, and an air gap between the first and second antireflection layers. 
     
     
       16. The electronic device defined in  claim 1  wherein the display has a transparent layer with an inwardly facing surface, the electronic device further comprising:
 an antireflection coating on a portion of the inwardly facing surface of the transparent layer. 
 
     
     
       17. The electronic device defined in  claim 16  wherein an air gap separates the antireflection coating from the ambient light sensor module and wherein the light attenuator has a light transmission of 2-16%.

Description:
FIELD 
     This relates generally to electronic devices, and, more particularly, to electronic devices with light sensors. 
     BACKGROUND 
     Electronic devices such as laptop computers, cellular telephones, and other equipment are sometimes provided with light sensors. For example, ambient light sensors may be incorporated into a device to provide the device with information on current lighting conditions. Ambient light readings may be used in controlling the device. If, for example bright daylight conditions are detected, an electronic device may increase display brightness to compensate. Color ambient light sensors can detect changes in the color of ambient light so that compensating color cast adjustments can be made to displayed content. 
     SUMMARY 
     An electronic device may have a display with an array of pixels forming an active display area. During operation of the device, the array of pixels may be used to display an image for the user. In an inactive border area or other inactive display area that is free of pixels, an opaque masking layer may be included in the display to block internal device components from view from the exterior of the electronic device. Ambient light may pass through an opening in the opaque masking layer. 
     The electronic device may have an ambient light sensor module aligned with the opening in the opaque masking layer. Control circuitry in the electronic device may adjust a brightness level associated with an image being displayed by the display based on ambient light measurements from the ambient light sensor module. 
     In some configurations, one or more antireflection layers may be interposed between an inwardly facing surface of the display and an opposing external surface of the ambient light sensor module. 
     The ambient light sensor module may have a light attenuator and other optical structures. The light attenuator may provide the ambient light sensor module with a dark appearance that matches surrounding portions of the opaque masking layer. If desired, light diffuser structures, infrared-light-blocking structures, light guide structures, and/or other optical structures may be included in the ambient light sensor module. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic diagram of an illustrative electronic device having an ambient light sensor module in accordance with an embodiment. 
         FIGS. 2 and 3  are perspective views of illustrative electronic devices in accordance with embodiments. 
         FIGS. 4 and 5  are cross-sectional side views of illustrative ambient light sensor modules under clear apertures in opaque masking layers in displays in accordance with embodiments. 
         FIG. 6  is a cross-sectional side view of an illustrative ambient light sensor module coupled to a printed circuit in accordance with an embodiment. 
         FIG. 7  is a cross-sectional side view of an illustrative light attenuator for an ambient light sensor module in accordance with an embodiment. 
         FIG. 8  is a cross-sectional side view of an illustrative light diffuser for an ambient light sensor module in accordance with an embodiment. 
         FIG. 9  is a cross-sectional side view of an illustrative thin-film interference filter for blocking visible and/or infrared light for an ambient light sensor module in accordance with an embodiment. 
         FIG. 10  is an illustrative optical waveguide for an ambient light sensor module in accordance with an embodiment. 
         FIGS. 11, 12, 13, 14, 15, and 16  are cross-sectional side views of illustrative optical layers for ambient light sensor modules in accordance with embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     An illustrative electronic device of the type that may be provided with one or more optical components such as ambient light sensor modules is shown in  FIG. 1 . Electronic device  10  of  FIG. 1  may be a computing device such as a laptop computer, a computer monitor containing an embedded computer, a tablet computer, a cellular telephone, a media player, or other handheld or portable electronic device, a smaller device such as a wristwatch or other device worn on a user&#39;s wrist, a pendant device, a headphone or earpiece device, a device embedded in eyeglasses or other equipment worn on a user&#39;s head, or other wearable or miniature device, a television, a computer display that does not contain an embedded computer, a gaming device, a navigation device, an embedded system such as a system in which electronic equipment with a display is mounted in a kiosk or automobile, equipment that implements the functionality of two or more of these devices, or other electronic equipment. 
     As shown in  FIG. 1 , electronic device  10  may have control circuitry  16 . Control circuitry  16  may include storage and processing circuitry for supporting the operation of device  10 . The storage and processing circuitry may include storage such as hard disk drive storage, nonvolatile memory (e.g., flash memory or other electrically-programmable-read-only memory configured to form a solid state drive), volatile memory (e.g., static or dynamic random-access-memory), etc. Processing circuitry in control circuitry  16  may be used to control the operation of device  10 . The processing circuitry may be based on one or more microprocessors, microcontrollers, digital signal processors, baseband processors, power management units, audio chips, application specific integrated circuits, etc. Control circuitry  16  may include communications circuitry for supporting wired and/or wireless communications between device  10  and external equipment. For example, control circuitry  16  may include wireless communications circuitry such as cellular telephone communications circuitry and wireless local area network communications circuitry. 
     Input-output circuitry in device  10  such as input-output devices  12  may be used to allow data to be supplied to device  10  and to allow data to be provided from device  10  to external devices. Input-output devices  12  may include buttons, joysticks, scrolling wheels, touch pads, key pads, keyboards, microphones, speakers, tone generators, vibrators, cameras, light-emitting diodes and other status indicators, data ports, etc. A user can control the operation of device  10  by supplying commands through input-output devices  12  and may receive status information and other output from device  10  using the output resources of input-output devices  12 . 
     Input-output devices  12  may include one or more displays such as display  14 . Display  14  may be a touch screen display that includes a touch sensor for gathering touch input from a user or display  14  may be insensitive to touch. A touch sensor for display  14  may be based on an array of capacitive touch sensor electrodes, acoustic touch sensor structures, resistive touch components, force-based touch sensor structures, a light-based touch sensor, or other suitable touch sensor arrangements. 
     Input-output devices  12  may also include sensors  18 . Sensors  18  may include a capacitive sensor, a light-based proximity sensor, a magnetic sensor, an accelerometer, a force sensor, a touch sensor, a temperature sensor, a pressure sensor, a compass, a microphone, a radio-frequency sensor, a three-dimensional image sensor, a camera, a light-based position sensor (e.g., a lidar sensor), and other sensors. Sensors  18  may also include one or more light detectors that are configured to detect ambient light. Sensors  18  may, for example, include one or more monochrome ambient light sensors and one or more color ambient light sensors that are configured to measure ambient light from the environment in which device  10  is operated. A monochrome ambient light sensor may be used to measure ambient light intensity. A color ambient light sensor may be used to measure the color (color spectrum, color temperature, color coordinates, etc.) of ambient light and may be used to measure ambient light intensity. 
     To make color measurements, a color ambient light sensor in device  10  may have a light detector such as a photodiode that is overlapped by a tunable wavelength filter and/or may have multiple channels each of which has a light detector such as a photodiode that is overlapped by a filter that passes a different color of light (e.g., a different wavelength band) to that light detector. Photodetectors such as photodiodes may be formed in a semiconductor die. By processing the readings from each of the multiple channels, the relative intensity of each of the different colors of light can be determined. Using data from the different channels in a color ambient light sensor, control circuitry  16  can therefore produce ambient light color temperature measurements and other color measurements (e.g., colors represented in color coordinates, etc.). The ambient light color information may be used in controlling display  14  and/or in taking other actions in device  10 . As an example, the color cast of images displayed on display  14  can be adjusted based on ambient light color measurements (e.g., to make the images on display  14  yellower in warm ambient lighting conditions and to make the images on display  14  bluer in cold ambient lighting conditions). If desired, display brightness may be automatically increased by control circuitry  16  in response to detection of bright ambient light conditions and may be automatically decreased by control circuitry  16  in response to detection of dim ambient light conditions. Adjustments to the brightness of the image on display  14  in this way based on ambient light sensor measurements from an ambient light sensor in device  10  may help enhance user comfort when viewing images. 
     Electronic device  10  may include one or more ambient light sensors. Illustrative arrangements in which device  10  includes a single ambient light sensor are sometimes described herein as an example. In some configurations, the ambient light sensor may be located directly under or nearly under display  14  (e.g., under an active display area or under an inactive border of a display, in an inactive notch formed along an edge of an active display area, in an inactive island that forms a window area within an active display area, etc.). 
     Display  14  may be an organic light-emitting diode display, a liquid crystal display, or other display. In some configurations, organic light-emitting diode pixel light emission or backlight unit light emission in a backlit liquid crystal display may be temporarily dimmed to help prevent backlight leakage that could generate stray light. This may help reduce noise during ambient light measurements. Ambient light measurements can also be gathered while a display backlight is active. To help reduce crosstalk while a backlight is active, an ambient light sensor module may be provided with a light attenuator. The light attenuator may attenuate stray light to help reduce stray light noise. The light attenuator may also help provide the ambient light sensor module with a dark outward appearance that matches surrounding opaque masking material that is used in the inactive area of the display. A clear aperture may be formed in an opaque masking layer to allow ambient light to reach the ambient light sensor module. 
     A perspective view of an illustrative electronic device of the type that may include an ambient light sensor is shown in  FIG. 2 . In the example of  FIG. 2 , device  10  includes a display such as display  14  mounted in housing  22 . Display  14  may be a liquid crystal display, a light-emitting diode display such as an organic light-emitting diode display or a display formed from crystalline semiconductor light-emitting diode dies, or other suitable display. Display  14  may have an array of pixels  26  extending across some or all of front face F of device  10  and/or other external device surfaces. The pixel array may be rectangular or may have other suitable shapes. Display  14  may be protected using a display cover layer (e.g., a transparent front housing layer) such as a layer of transparent glass, clear plastic, sapphire, or other clear layer. The display cover layer may overlap the array of pixels  26 . 
     Housing  22 , which may sometimes be referred to as an enclosure or case, may be formed of plastic, glass, ceramics, fiber composites, metal (e.g., stainless steel, aluminum, etc.), other suitable materials, or a combination of any two or more of these materials. Housing  22  and display  14  may separate an interior region of device  10  from an exterior region surrounding device  10 . Housing  22  may be formed using a unibody configuration in which some or all of housing  22  is machined or molded as a single structure or may be formed using multiple structures (e.g., an internal frame structure, one or more structures that form exterior housing surfaces, etc.). If desired, a wristband or other strap may be coupled to a main portion of housing  22  (e.g., in configurations in which device  10  is a wristwatch). Internal electrical components  28  (e.g., integrated circuits, discrete components, etc.) for forming control circuitry  16  and input-output devices  12  may be mounted in the interior of housing  22 . In some configurations, components  28  may be attached to display  14  (e.g., display driver circuitry may be mounted to the inner surface of display  14 ). 
     Pixels  26  may cover all of the front face of device  10  or display  14  may have inactive areas (e.g., notches, rectangular islands, or other regions) that are free of pixels  26 . The inactive areas may be used to accommodate an opening for a speaker and windows for optical components such as image sensors, an ambient light sensor, an optical proximity sensor, a three-dimensional image sensor such as a structured light three-dimensional image sensor, a camera flash, etc. An ambient light sensor may be formed under a window opening in housing  22  (e.g., a sensor may be mounted under a hole in a metal housing wall), may be formed under the active area of display  14 , or may be formed under an inactive display area. For example, an ambient light sensor may be formed on front face F along one of the edges of device  10  such as illustrative ambient light sensor region  30  of  FIG. 2 . 
     Device  10  of  FIG. 2  may be a cellular telephone, tablet computer, wristwatch, or other portable device (as examples). If desired, ambient light sensors may be provided in other electronic equipment. In the example of  FIG. 3 , device  10  is a laptop computer. Housing  22  of device  10  of  FIG. 3  includes upper housing portion  22 - 1  and lower housing portion  22 - 2 , which are joined by a hinge to allow these portions to rotate with respect to each other. Display  14  may be mounted in upper housing portion  22 - 1 . Keyboard  32  and trackpad  34  may be mounted in lower housing portion  22 - 2 . Ambient light sensors may be mounted on housing  22  facing the exterior of device  10 . As an example, an ambient light sensor module may be mounted under an active area of display  14  that is configured to display an image or an inactive area of display  14  (see, e.g., illustrative ambient light sensor region  30 ). 
     To help hide internal components in the interior of housing  22  from view, the inactive area of display  14  may be provided with an opaque masking layer. The opaque masking layer may be any suitable color (e.g., black, gray, white, a non-neutral color such as blue, etc.). In an illustrative example, display  14  has an inactive area with an opaque masking layer formed from black ink. Other opaque materials may be used, if desired. 
     To permit light to reach an ambient light sensor in region  30 , an opening (e.g., a clear aperture, sometimes referred to as an ambient light sensor window or ambient light sensor opening) may be formed in the opaque masking layer in region  30 . The shape of region  30  (e.g., the outline of the opaque masking layer opening when viewed from the exterior of device  10 ) may be circular, rectangular, or may have other suitable shapes. The opening may be completely free of opaque masking material (e.g., the opening may be a circular hole, etc.), thereby allowing close to 100% of ambient light to pass through the opening (e.g., at least 95% or other suitable amount of light). In the interior of device  10 , an ambient light sensor module may be aligned with the ambient light sensor aperture in the opaque masking layer. To enhance the uniform appearance of the inactive area of display  14  and prevent the ambient light sensor opening from being overly noticeable to a user of device  10 , the ambient light sensor module that is mounted under the opening may be provided with a light attenuator (e.g., a visible-light-absorbing structure with a light transmission of about 2-16%, at least 3%, 5-10%, 8%, at least 4%, at least 6%, less than 20%, less than 10%, or other suitable light transmission value). The dark appearance of the light attenuator in the ambient light sensor module may help absorb ambient light and reduce ambient light reflections to make the ambient light sensor module visually blend with adjacent portions of the opaque masking layer. 
       FIGS. 4 and 5  are cross-sectional side views of illustrative displays with ambient light sensors. Display  14  of  FIGS. 4 and 5  has an active area AA that displays images and an inactive area IA that is covered with opaque masking material and does not display images. 
     In the example of  FIG. 4 , display  14  has a transparent display cover layer such as display cover layer  36 . Display cover layer  36  may be formed from glass, polymer, sapphire or other crystalline materials, and/or other transparent materials. In active area AA, display  14  has an array of pixels P for displaying an image. Pixels P may, for example, form a light-emitting diode display panel such as a thin-film organic light-emitting diode display panel or a display panel having a pixel array formed from crystalline semiconductor light-emitting diode dies (as examples). Configurations in which display  14  is a liquid crystal display may also be used. As shown in  FIG. 4 , in inactive area IA of display  14 , pixels P are not present. Opaque making layer  38  may be formed on the underside (inner surface) of display cover layer  36  in inactive area IA to hide internal components in interior region  48  from view from a user in the external environment (exterior region  46 ) surrounding device  10 . 
     Ambient light sensor module  40  may be mounted in alignment with an opening in opaque masking layer  38  in ambient light sensor region  30 . This allows ambient light sensor module  40  to receive and measure ambient light  44  that passes through display cover layer  36  and the opening in layer  38  within ambient light sensor region  30 . If desired, a layer of clear adhesive such as adhesive layer  42  may be used to attach ambient light sensor module  40  to the interior of display cover layer  38  over the opening in layer  38 . Other mounting arrangements may be used, if desired. 
     In the illustrative configuration of  FIG. 5 , display  14  is a liquid crystal display. In active area AA, an array of pixels P is formed from a layer of liquid crystal material  54  sandwiched between a color filter layer such as color filter layer  56  and a thin-film transistor layer such as thin-film transistor layer  58 . Layers  56  and  58  may have glass substrates or other transparent supporting layers. Color filter elements  50  for the pixels of display  14  may be formed on the inner surface of the color filter layer and thin-film transistor pixel circuits  52  for the pixels of display  14  may be formed on the outer surface of the thin-film transistor layer. 
     In inactive area IA of display  14  of  FIG. 5 , opaque masking layer  38  may help block interior components in interior region  48  from view from exterior region  46 . Opaque masking layer  38  may be formed on the underside of color filter layer  56  or at other locations between color filter layer  56  and thin-film transistor layer  58  (as an example). One or more transparent layers (e.g., an overcoat layer formed from polymer) such as layer  39  may be formed between layer  38  and layer  58 . An ambient light sensor opening is formed in region  30  of layer  38  to permit ambient light  44  to pass through layers  56  and  58  to ambient light sensor module  40 . If desired, module  40  may be surrounded by stray light blocking structures  60  (e.g., gaskets, opaque walls, etc.). 
     Stray light may also be reduced by coating one or more surfaces with antireflection coatings (e.g., single-layer or multi-layer dielectric thin-film stacks forming antireflection layers). In the example of  FIG. 5 , a first optional antireflection coating (antireflection coating  62 ) has been formed on the inner surface of thin-film transistor layer  58  to help suppress light reflections at the interface between layer  58  and air gap  68  and a second optional antireflection coating (antireflection coating  64 ) has been formed on the upper (outwardly facing) exterior surface of ambient light sensor module  40  to help suppress light reflections at the interface between air gap  68  and module  40 . If desired, a layer of clear adhesive (e.g., optional adhesive  66 ) may be interposed between coatings  62  and  64  to help mount module  40  in alignment with the ambient light senor opening in masking layer  38  in region  30 . 
     An illustrative ambient light sensor module that includes a light attenuator is shown in the cross-sectional side view of  FIG. 6 . As shown in  FIG. 6 , ambient light sensor module  40  may have a module housing such as ambient light sensor module package  70 . Package  70  may have sidewall portion  70 - 1  and base portion  70 - 2 . Portions such as portions  70 - 1  and  70 - 2  may be formed from opaque polymer (e.g., black polymer), ceramic, and/or other materials. Portion  70 - 2  may contain signal lines formed from metal traces. The metal traces may include contacts such as solder pads that are soldered or otherwise electrically connected to corresponding contacts in ambient light sensor semiconductor die  72 . Die  72  contains circuitry such as photodetectors PD (e.g., photodiodes) and/or other circuitry for gathering ambient light measurements. Light filters configured to pass desired wavelengths (e.g., bands of wavelengths of different associated colors in a color ambient light sensor) and/or to optionally block infrared light may overlap the photodetectors on die  72  (and/or may be formed as part of optical structure  74 ). There may be any suitable number of photodetectors PD on die  72  (e.g., at least 3, at least 6, at least 10, fewer than 25, fewer than 12, fewer than 9, 1, 2, etc.). The metal traces in portion  70 - 2  may, if desired, form through-hole vias that are electrically connected to contacts on the lower surface of portion  70 - 2 . Optional additional signal paths (e.g., signal paths in printed circuit  78  or other signal lines) may be connected to the downwardly facing contacts on the lower surface of portion  70 - 2 . If desired, portion  70 - 2  may have an integral tail (e.g. a flexible printed circuit tail) that is used in connecting to other printed circuits in device  10  and/or may have a board-to-board connector or other connector structure for interconnecting the photodiodes and other circuitry of the ambient light sensor formed from die  72  to control circuitry  16  and/or other circuitry in device  10 . The electrical interconnection arrangement of  FIG. 6  is illustrative. 
     To provide module  40  with desired optical properties, such as desired amounts of visible light transmission, desired amounts of optional infrared-light blocking, desired amounts of light diffusion (e.g., to avoid angular dependence in ambient light readings that might otherwise arise when using device  10  in an environment with one or more specular light sources), desired amounts of light guiding, and/or other desired optical proprieties, optical module  40  may be provided with one or more stacked optical layers, transparent polymer or glass members, and/or other optical structures such as such as optical structure  74 . Structure  74 , which may sometimes be referred to as an optical module window structure or optical module cover, may exhibit sufficient transparency to allow a fraction of ambient light  44  to pass to ambient light sensor die  72  so that module  40  may be used in making ambient light intensity and/or color measurements. Structure  74  may be attached to package portion  70 - 1  using attachment structures  76  (e.g., adhesive, interlocking engagement structures such as clips, fasteners such as screws, press-fit connections, ledges and other structures that help align and support structure  74 , etc.). An air gap such as optional air gap  79  may be present between the lower (inwardly facing) surface of structure  74  and the opposing upper (outwardly facing) surface of die  72  (and/or a filter layer and/or other structures on the surface of die  72 ) or air gap  79  of  FIG. 6  may be partly or fully filled with clear adhesive (as examples). Adhesive layers may, in general, be interposed between any adjacent optical layers (e.g., between structure  74  and a display cover layer, color filter layer, thin-film transistor layer, or other transparent layer of glass or other material in display  14 , between layers of material in structure  74 , between the lower surface of structure  74  and die  72 , etc.). If desired, one or more of these adhesive layers (e.g., clear polymer layers) may be index matched to surrounding layers. 
     Structure  74  may include structures that perform functions such as visible light attenuation (e.g., some or all of structure  74  may serve as a light attenuator), light diffusion (e.g., some or all of structure  74  may exhibit haze the helps to diffuse ambient light  44  as light  44  passes to ambient light sensor die  72 ), light filtering (e.g., to block infrared light and/or to pass a desired amount of visible light of one or more desired colors), and/or light guiding (e.g., to form a waveguide that confines light laterally while transporting light towards die  72  from the opening in masking layer  38 ). If desired, some or all of these functions may be performed by a layer that serves multiple functions. For example, a dark layer of material with light-scattering structures may serve as both a light attenuator and a diffuser. As another example, a thin-film interference filter may serve both as a light attenuator (passing a desired amount of visible ambient light) and an infrared-light-blocking filter. 
     Illustrative structures of the type that may be incorporated into structure  74  of module  30  are shown in  FIGS. 7, 8, 9, and 10 . 
     An illustrative light attenuator is shown in  FIG. 7 . As shown in  FIG. 7 , light attenuator  80  may have one or more layers such as layers  82  and  84 . Layer  84  may be, for example a substrate layer formed from a layer of polymer, glass, or other transparent material. The thickness of layer  84  may be, for example, at least 25 microns, at least 250 microns, at least 1 mm, less than 3 mm, less than 1.5 mm, or less than 750 microns (as examples). Layer  82  may be a coating layer (e.g., a coating with a thickness at least 1%, at least 10%, 20-100%, less than 50%, less than 30%, or other suitable fraction of the thickness of layer  84 ). A coating such as layer  82  may be, for example, a polymer coating layer that is applied to substrate layer  84  as a liquid and subsequently cured. Layers such as layer  82  may be formed on the upper and/or lower surfaces of substrate layer  84 . To perform light absorbing functions, layer  82  and/or layer  84  may be provided with light-absorbing material such as dye, pigment, and/or other colorant that is provided as an additive in the polymer, glass, or other material forming layer  82  and/or layer  84  and that causes layer  82  and/or layer  84  to absorb desired amounts of visible light, infrared light, and/or ultraviolet light). As an example, layer  82  and/or layer  84  may be provided with a black additive such as a carbon-based pigment, black dye, etc. that causes layer  82  and/or layer  84  to absorb visible light and thereby provide attenuator  80  with a desired amount of light transmission. If desired, substrate layer  84  may be omitted (e.g., in a configuration in which coating layer  82  is supported on another layer in structure  74  and/or in which light-absorbing material is formed in another portion of structure  74 ) and/or coating  82  may be omitted (e.g., in a configuration in which layer  84  serves as an uncoated light attenuator). 
     An illustrative light diffuser for structure  74  is shown in  FIG. 8 . As shown in  FIG. 8 , light diffuser  86  may have one or more layers such as layers  94  and  88 . Layer  88  may be, for example, a substrate layer formed from glass or polymer (as examples). The thickness of substrate layer  88  may be, for example, at least 25 microns, at least 250 microns, at least 1 mm, less than 3 mm, less than 1.5 mm, or less than 750 microns (as examples). Layer  94  may be a coating layer (e.g., a coating with a thickness at least 1%, at least 10%, 20-100%, less than 50%, less than 30%, or other suitable fraction of the thickness of layer  88 ) or layer  94  may be a substrate layer (e.g., in a configuration in which layer  88  is omitted). One or both of layers  88  and  94  may be provided with light-scattering structures (e.g., surface texture, embedded light-scattering structures such as light-scattering particles, etc.). In the example of  FIG. 8 , layer  94  includes light-scattering structures (e.g., particles)  92  embedded in polymer binder  90 . Structures  92  may have a refractive index that differs from the refractive index of the polymer of binder  90  so that ambient light  44  is scattered when passing through diffuser  86  (e.g., diffuser  86  exhibits haze of at least 10%, at least 40%, less than 100%, or other suitable haze value). Structures  92  may be inorganic light-scattering particles such as particles of oxides such as silica, alumina, titanium oxide, etc. or other particles with refractive index values that differ from binder  90  and/or light-scattering structures  92  may be formed from gas bubble or voids embedded in binder  90  (as examples). If desired, light-absorbing material (e.g., a colorant such as a dark dye and/or dark pigment) may be added to binder  90  and/or substrate layer  88  to provide light diffuser  86  with light absorbing properties (e.g., so that diffuser  86  can serve as both a light attenuator and a light diffuser). In some configurations, some or all of structures  92  may be dark particles (e.g., carbon particles or other particles that scatter and absorb light). Arrangements in which coating  94  is omitted (e.g., configurations in which light-scattering structures are formed only in substrate  88 ) and/or arrangements in which coating  94  is supported by other structures in structure  74  (e.g., a filter layer, waveguide, attenuator substrate, etc.) may be used, if desired. 
       FIG. 9  is a cross-sectional side view of an illustrative light filter structure that may be used in forming structure  74 . In the example of  FIG. 9 , light filter  96  includes a dielectric stack such as layer  98  and substrate layer  102 . The thickness of substrate layer  102  may be, for example, at least 25 microns, at least 250 microns, at least 1 mm, less than 3 mm, less than 1.5 mm, or less than 750 microns (as examples). Layer  98  may be a thin-film interference filter formed from a stack of thin-film dielectric layers  100  (e.g., a coating with a thickness at least 1%, at least 10%, 20-100%, less than 50%, less than 30%, or other suitable fraction of the thickness of layer  102 ). Layers  100  may be thin-film dielectric layers formed from inorganic layers (e.g., layers deposited by physical vapor deposition, as an example) and/or polymer layers. The refractive index values of layers  100  may alternate and/or may have other appropriate thicknesses and refractive index values to form a thin-film interference filter that blocks infrared light and/or configures filter  96  to attenuate visible light by a desired amount (e.g., filter  96  may be an infrared-light-blocking-and-visible-light-transmitting filter and may have a visible light transmission of at least 1%, at least 5%, at least 10%, at least 90%, 100%, less than 50%, less than 10%, or other suitable value). In this way, filter  96  may serve as an infrared-light-blocking filter (sometimes referred to as an infrared filter) and/or a light attenuator that helps match the darkness of the ambient light sensor window to the darkness of surrounding portions of opaque masking layer  38 . 
       FIG. 10  is a cross-sectional side view of an illustrative light-guide structure that may be used in forming structure  74 . Optical waveguide  104  of  FIG. 10  may have a transparent optical waveguide (light guide) core such as core  106  (e.g., glass, polymer, or other transparent dielectric) surrounded by material  108 . Material  108  may, as an example, be a transparent material such as polymer, glass, or other dielectric having a lower refractive index than the refractive index of material  106  so that material  108  promotes total internal reflection of ambient light  44 , thereby allowing light  44  to be confined to core  106  and guided along the length of waveguide  104 . If desired, material  108  may be formed from reflective materials such as metal or may include metal to help with light confinement. Materials  106  and/or  108  may be formed from dielectric such as clear polymer or glass and may include light-absorbing material (e.g., dye, pigment and/or other additives). 
     Structures of the types shown in  FIGS. 7, 8, 9 , and/or  10  may be used individually and/or in any combination to form structure  74  of  FIG. 6 . For example, waveguide  104  of  FIG. 10  may be used with one or more of the structures of  FIGS. 7, 8 , and/or  9  or the structures of  FIGS. 7, 8 , and/or  9  can be used without a waveguide. The structures of  FIGS. 7 and 8  may be combined with or without using the structures of  FIG. 9 , the structure of  FIGS. 7 and 9  may be used with or without using the structures of  FIG. 8 , and/or the structures of  FIGS. 8 and 9  may be used with or without using the structures of  FIG. 7  (as examples). 
       FIGS. 11, 12, 13, 14, 15, and 16  are cross-sectional side views of illustrative arrangements for forming all or part of structure  74  of  FIG. 6 . 
     In the example of  FIG. 11 , structure  74  includes a dark diffuser. Dark diffuser  110  may have a clear or dark substrate layer such as substrate layer  112  (e.g., a layer of polymer film or glass substrate) and may have a polymer coating formed by polymer  114  with embedded light-scattering structures  116 . Light-absorbing material (e.g., dye, pigment, or other colorant) in layer  112  and/or layer  114  may be configured to provide dark diffuser  110  with a desired amount of light attenuation. For example, light-scattering structures  116  may be formed from carbon-based particles (e.g., black pigment particles that absorb light while scattering light) and/or white and/or dark light-scattering structures  116  may be embedded in polymer that contains black dye. In this way, dark diffuser  110  may serve both as a light diffuser and as a light attenuator. Dark diffuser  110  may be attached to optional volume diffuser  122  (e.g., a molded polymer member such as a layer of polymer  120  in which light-scattering structures  118  have been embedded). Diffuser  122  may be thicker than diffuser  110  (as an example). 
     In the example of  FIG. 12 , structure  74  includes a dark layer such as dark layer  124  for providing a desired amount of light attenuation. Dark layer  124  may be a layer of glass or polymer with light-absorbing material (e.g., dye and/or pigment) that absorbs light so that dark layer  124  can serve as a light attenuator. Adhesive layer  126  may be used to attach layer  124  to diffuser  128 . 
     Diffuser  128  may be formed from polymer (or glass) substrate layer  130  coated with a layer of polymer such as polymer coating layer  132  in which light-scattering structures (e.g., particles)  134  have been embedded. Volume diffuser  136  may be formed from molded polymer or other clear material (e.g., polymer layer  138 ) in which light-scattering structures  140  (e.g. particles) have been embedded. The thickness of diffuser  136  may be greater than that of diffuser  128  (as an example). The thickness of volume diffusers such as diffuser  136  of  FIG. 12  and diffuser  122  of  FIG. 11  may be, for example, at least 0.1 mm, at least 0.5 mm, at least 1 mm, less than 3 mm, less than 2 mm, less than 0.8 mm, less than 0.4 mm, or other suitable thickness. If desired, diffusers  122  and  136  may be omitted. 
     In the example of  FIG. 13 , structure  74  has a light-absorbing layer such as light-absorbing layer  142 . Layer  142  may be a dark substrate layer or may be a black ink coating or other dark coating (e.g., a light-absorbing polymer) formed on a clear or dark substrate such as substrate layer  144  formed from polymer or glass. Diffuser layer  146  may be a coating formed from polymer  150  on the lower surface of substrate layer  144 . Light-scattering structures  148  may be embedded in polymer  150 . 
     Another illustrative set of layers that may be used to form all or part of structure  74  is shown in  FIG. 14 . In the example of  FIG. 14 , thin-film interference filter  152  (e.g., a visible-light attenuating filter and/or an infrared-light-blocking filter) may be formed from a stack of dielectric layers  154  on substrate layer  156  (e.g., a polymer or glass substrate). Diffuser  158  may be formed from a polymer coating (polymer layer  160 ) on the lower surface of substrate  156 . Light-scattering structures  162  may be embedded within polymer layer  160 . Optional waveguide  164  (see, e.g., waveguide  104  of  FIG. 10 ) may be interposed between layer  158  and layer  166  (as an example). Layer  166  may be a dark volume diffuser formed from molded polymer (layer  168 ) with embedded light-scattering structures. Light-absorbing material such as dye and/or pigment may be provided in layer  166  so that layer  166  serves as a light attenuator in addition to a light diffuser. 
     If desired, an infrared blocking filter may be included in structure  74  as shown in the examples of  FIGS. 15 and 16 . In the example of  FIG. 15 , infrared-light-blocking filter  176  has been formed from a thin-film interference filter such as filter  172  with a stack of dielectric layers  174  configured to pass visible light while blocking infrared light. Filter  172  may be formed as a thin-film coating on substrate  186  (e.g., a substrate formed from a glass or polymer layer). Optional adhesive layer  178  may be used to attach substrate  186  to volume diffuser  184 . Diffuser  184  may be formed from molded polymer  180  with embedded light-scattering structures  182 . Diffuser  184  may be a dark diffuser that is configured to attenuate visible light (e.g., diffuser  184  may include additives such as dye, pigment, and/or other colorant to absorb visible light). In this way, diffuser  184  may serve both as a light diffuser and as a light attenuator. 
     In the illustrative configuration of  FIG. 16 , infrared-light-blocking filter  192  is formed from a thin-film interference filter such as filter  200  that has a stack of dielectric layers  188  on substrate layer  190 . Layer  190  may be formed from clear polymer or glass. Layers  188  may be configured so that filter  192  passes visible light while blocking infrared light. If desired, filter  200  may be configured to attenuate visible light (e.g., so that filter  192  may optionally serve as a light attenuator). Adhesive layer  194  may be used to attach substrate layer  190  to underlying structures such as light-absorbing layer  196 . Light-absorbing layer  196  may be a layer of dark ink (e.g., black polymer), a thin-film interference filter layer, or other layer that forms a light attenuator. Layer  196  may be formed as a coating on substrate layer  198  (e.g., a layer of glass or polymer). Light diffuser layer  200  may be formed from a polymer coating on substrate layer  198  (polymer  204 ) into which light-scattering structures (e.g., particles)  202  have been embedded. 
     Device  10  may be operated in a system that uses personally identifiable information. It is well understood that the use of personally identifiable information should follow privacy policies and practices that are generally recognized as meeting or exceeding industry or governmental requirements for maintaining the privacy of users. In particular, personally identifiable information data should be managed and handled so as to minimize risks of unintentional or unauthorized access or use, and the nature of authorized use should be clearly indicated to users. 
     The foregoing is merely illustrative and various modifications can be made to the described embodiments. The foregoing embodiments may be implemented individually or in any combination. 
     
       
         
           
               
             
               
                   
               
               
                 Table of Reference Numerals 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
            
               
                 10 
                 Electronic Device 
                 12 
                 Input-Output Devices 
               
               
                 14 
                 Display 
                 16 
                 Control Circuitry 
               
               
                 18 
                 Sensors 
                 30 
                 Ambient light sensor 
               
               
                   
                   
                   
                 region 
               
               
                 22 
                 Housing 
                 26 
                 Pixels 
               
               
                 F 
                 Front face 
                 28 
                 Components 
               
               
                 22-1 and 
                 Housing portions 
                 37 
                 Keyboard 
               
               
                 22-2 
                   
                   
                   
               
               
                 34 
                 Trackpad 
                 AA 
                 Active area 
               
               
                 IA 
                 Inactive area 
                 44 
                 Ambient light 
               
               
                 36 
                 Display cover layer 
                 38 
                 Opaque masking 
               
               
                   
                   
                   
                 layer 
               
               
                 P 
                 Pixels 
                 14P 
                 Display panel 
               
               
                 48 
                 Interior region 
                 46 
                 Exterior region 
               
               
                 42 
                 Adhesive layer 
                 40 
                 Ambient light sensor 
               
               
                   
                   
                   
                 module 
               
               
                 50 
                 Color filter elements 
                 52 
                 Pixel circuits 
               
               
                 54 
                 Liquid crystal layer 
                 56 
                 Color filter layer 
               
               
                 58 
                 Thin-film transistor 
                 60 
                 Stray light blocking 
               
               
                   
                 layer 
                   
                 structures 
               
               
                 62, 64 
                 Antireflection 
                 66 
                 Adhesive 
               
               
                   
                 coatings 
                   
                   
               
               
                 70 
                 Package 
                 70-1, 70-2 
                 Package portions 
               
               
                 76 
                 Attachment structures 
                 72 
                 Ambient light sensor 
               
               
                   
                   
                   
                 die 
               
               
                 PD 
                 Photodetectors 
                 78 
                 Printed circuit 
               
               
                 79 
                 Air gap 
                 74 
                 Structure 
               
               
                 80 
                 Light attenuator 
                 82, 84  
                 Layers 
               
               
                 86 
                 Light diffuser 
                 94, 88 
                 Layers 
               
               
                 90 
                 Polymer 
                 92 
                 Light-scattering 
               
               
                   
                   
                   
                 structures 
               
               
                 96 
                 Filter 
                 100 
                 Dielectric layers 
               
               
                 98 
                 Layer 
                 102 
                 Substrate layer 
               
               
                 104 
                 Waveguide 
                 106 
                 Core 
               
               
                 108 
                 Material 
                 112 
                 Layer 
               
               
                 114 
                 Polymer 
                 116 
                 Light-scattering 
               
               
                   
                   
                   
                 structures 
               
               
                 110 
                 Dark diffuser 
                 124 
                 Dark layer 
               
               
                 126 
                 Adhesive 
                 128 
                 Diffuser 
               
               
                 130 
                 Substrate layer 
                 132 
                 Polymer 
               
               
                 134 
                 Light-scattering 
                 136 
                 Volume diffuser 
               
               
                   
                 structures 
                   
                   
               
               
                 138 
                 Polymer 
                 140 
                 Light-scattering 
               
               
                   
                   
                   
                 structures 
               
               
                 142 
                 Light-absorbing layer 
                 144 
                 Substrate layer 
               
               
                 146 
                 Diffuser layer 
                 150 
                 Polymer 
               
               
                 148 
                 Light-scattering 
                 152 
                 Thin-fihn 
               
               
                   
                 structures 
                   
                 interference filter 
               
               
                 154 
                 Layers 
                 156 
                 Substrate layer 
               
               
                 158 
                 Diffuser layer 
                 160 
                 Polirter 
               
               
                 162 
                 Light-scattering 
                 164 
                 Waveguide 
               
               
                   
                 structures 
                   
                   
               
               
                 166 
                 Dark diffuser 
                 168 
                 Polymer 
               
               
                 170 
                 Light-scattering 
                 174 
                 Layers 
               
               
                   
                 structures 
                   
                   
               
               
                 172 
                 Filter 
                 174 
                 Layers 
               
               
                 176 
                 Infrared-light- 
                 186 
                 Substrate layer 
               
               
                   
                 blocking filter 
                   
                   
               
               
                 178 
                 Adhesive 
                 184 
                 Volume diffuser 
               
               
                 180 
                 Polymer 
                 182 
                 Light scattering 
               
               
                   
                   
                   
                 structures 
               
               
                 200 
                 Filter 
                 188 
                 Layers 
               
               
                 192 
                 Infrared-light- 
                 190 
                 Substrate layer 
               
               
                   
                 blocking filter 
                   
                   
               
               
                 194 
                 Adhesive 
                 196 
                 Light-absorbing 
               
               
                   
                   
                   
                 layer 
               
               
                 198 
                 Substrate layer 
                 200 
                 Diffuser layer 
               
               
                 204 
                 Polymer 
                 202 
                 Light-scattering 
               
               
                   
                   
                   
                 structures

Metadata:
Filing Date: 20200824
Publication Date: 20220329
Grant Date: 20220329
Priority Date: 20200824
Inventors: THAREJA, VRINDA
MEHTA, ARPIT B.
Assignee: APPLE INC
CPC Classifications: [{"code": "G02F1/133512", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02F1/13318", "inventive": true, "first": false, "tree": "[]"}, {"code": "G09G2320/0626", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02B5/281", "inventive": false, "first": false, "tree": "[]"}, {"code": "G09G2360/144", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02B1/115", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B5/003", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02B1/11", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02B2207/123", "inventive": false, "first": false, "tree": "[]"}, {"code": "G09G3/36", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B5/281", "inventive": true, "first": true, "tree": "[]"}, {"code": "G02B5/223", "inventive": true, "first": false, "tree": "[]"}, {"code": "G09G2360/141", "inventive": false, "first": false, "tree": "[]"}, {"code": "G09G5/10", "inventive": true, "first": true, "tree": "[]"}, {"code": "G09G2320/0626", "inventive": false, "first": false, "tree": "[]"}, {"code": "G09G3/3208", "inventive": true, "first": false, "tree": "[]"}, {"code": "G09G2360/144", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F1/13318", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B5/281", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02B5/003", "inventive": false, "first": false, "tree": "[]"}, {"code": "G09G2360/141", "inventive": false, "first": false, "tree": "[]"}, {"code": "G09G2360/144", "inventive": false, "first": false, "tree": "[]"}, {"code": "G09G2320/0626", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F1/13318", "inventive": true, "first": false, "tree": "[]"}, {"code": "G09G5/10", "inventive": true, "first": true, "tree": "[]"}, {"code": "G02B1/11", "inventive": false, "first": false, "tree": "[]"}]
Family ID: 80270952