Ambient light sensors for electronic devices

Abstract

Ambient light sensor (30) configured to provide ambient light measurements to control circuits (16) in an electronic device (10), the ambient light sensor (30) comprising: an integrated light detector circuit (58); a light guide (132) configured to direct ambient light (54) to the integrated light detector circuit (58); an infrared blocking filter (60) through which the ambient light (54) passes; and a light diffuser (62) comprising first and second light diffuser layers (62L) separated by an air gap (88), with the light guide (132) being interposed between the light diffuser (62) and the infrared blocking filter (60).

Description

TECHNICAL FIELD

[0001] It generally concerns electronic devices and more specifically electronic devices with optical components, such as ambient light sensors. BACKGROUND

[0002] Electronic devices such as laptop computers, mobile phones, and other equipment are sometimes provided with optical components. For example, an electronic device may include an ambient light sensor, an optical proximity sensor, image sensors, and light sources.

[0003] The desire to incorporate multiple optical components into an electronic device can present challenges. It can be difficult to incorporate optical components into an electronic device when space is limited. There is also the potential for different optical components to interfere with each other during operation.

[0004] US 2016 / 0 231 174 A1 discloses a photometric device comprising a photometric sensor into which light, which is an object to be measured, is incident, a signal processing element for processing a sensor output by the photometric sensor.

[0005] US 2013 / 0 286 686 A1 discloses an optical light-guiding element having a first end portion with a light entry surface designed to face a light-transmissive opening, and having a second end portion with a light exit region designed to face a light sensor.

[0006] US 2016 / 0 232 828 A1 describes that an electronic device can be provided with a display mounted in a housing. A color-sensitive ambient light sensor can measure the color of the ambient light. The color-sensing ambient light sensor can be mounted in alignment with an ambient light sensor window formed in an inactive area of ​​the display.

[0007] US 2016 / 0 054 175 A1 discloses an electronic device with light sensors. SUMMARY

[0008] The invention is defined by the features of the independent claim. Preferred advantageous embodiments thereof are described by the sub-features of the dependent claims.

[0009] An electronic device may be provided with a display mounted in a housing. The display may include an active area with an array of pixels for forming images and may include an inactive area along one or more edges of the active area. Windows for optical components may be formed in the inactive area and other portions of the electronic device. Optical components, such as light-emitting diodes, image sensors, optical proximity sensors, and ambient light sensors, may be aligned with the optical component windows.

[0010] An ambient light sensor may include an integrated light detection circuit with photodetectors. To provide color sensing capabilities to the ambient light sensor, the photodetectors may each be provided with a respective color filter configured to transmit a different range of wavelengths.

[0011] A diffuser can be used to scatter incoming ambient light. Infrared light-blocking filter layers can be used to block infrared light, such as infrared light emitted by an infrared light-emitting diode in the electronic device, and other stray infrared light.

[0012] A light guide can be used to guide ambient light to the integrated light detector circuit. The light guide can be interposed between a light diffuser and an infrared blocking filter.

[0013] The operation of an ambient light sensor may be coordinated with an infrared light emitting component, such as an infrared light emitting diode, used to provide infrared light illumination for an infrared image sensor. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic diagram of an illustrative electronic device including optical components, according to one embodiment. Fig. 2 is a perspective view of an illustrative electronic device with a display having windows for optical components that overlap optical components, according to one embodiment. Fig. 3 is a cross-sectional side view of an illustrative electronic device including optical components such as a light source, an image sensor, and an ambient light sensor, according to one embodiment. Fig. 4 is a cross-sectional side view of an illustrative diffuser according to one embodiment. Fig. 5 is a cross-sectional side view of an illustrative thin film interference filter according to one embodiment. Fig. 6 is a cross-sectional side view of an illustrative ambient light sensor according to one embodiment. Fig. 7 is a graph showing how light transmittance may vary as a function of wavelength for illustrative organic ambient light sensing color filters according to one embodiment. Fig. Figure 8 is a graph showing how light transmittance may vary as a function of wavelength for a thin film infrared light blocking filter according to one embodiment. Fig. 9 is a cross-sectional side view of an illustrative electronic device having an ambient light sensor with a light guide, according to one embodiment. Fig. 10 is a cross-sectional side view of an illustrative ambient light sensor with a light guide according to one embodiment. Fig. 11 is a cross-sectional side view of an illustrative ambient light sensor integrated circuit having photodetectors overlapped by color filters formed from thin-film interference filters, according to one embodiment. Fig. 12 is a graph plotting light transmittance versus wavelength for illustrative color filters, such as thin film interference filters with different passbands, according to one embodiment. Fig. 13 is a top view of an illustrative ambient light sensor integrated circuit having a set of photodetectors with a round contour, according to one embodiment. Fig. 14 is a top view of an illustrative ambient light sensor having a set of photodetectors with a rectangular contour, according to one embodiment. Fig. 15 is a circuit diagram of illustrative circuits for an electronic device according to one embodiment. Fig. 16, Fig. 17 and Fig. 18 are timing diagrams illustrating signals that can be obtained when using circuits of the type shown in Fig. 15 to coordinate the use of an ambient light sensor and a component including an infrared light emitting diode, according to one embodiment. Fig. 19 and Fig. 20 are timing diagrams illustrating how a flag signal may be asserted during operation to collect ambient light sensor data according to one embodiment. DETAILED DESCRIPTION

[0014] An illustrative electronic device of the type that can be provided with optical components, such as ambient light sensors, is shown in Fig. 1. The electronic device 10 may be a computing device, such as a laptop computer, a computer monitor containing an embedded computer, a tablet computer, a mobile phone, a media player, or other handheld or portable electronic device; a smaller device, such as a wristwatch device, a pendant device, a headphone or earphone device, a device embedded in eyeglasses or other equipment worn on a user'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; or equipment that implements the functionality of two or more of these devices.or other electronic equipment.

[0015] As in Fig. 1, the electronic device 10 may include control circuitry 16. The control circuitry 16 may include storage and processing circuitry to support the operation of the device 10. The storage and processing circuitry may include a storage device, e.g., a hard disk drive storage device, non-volatile 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. The processing circuitry in the control circuitry 16 may be used to control the operation of the device 10. The processing circuitry may be implemented on one or more microprocessors, microcontrollers, digital signal processors, baseband processors, power management units, audio chips, application-specific integrated circuits, etc.based on.

[0016] Device 10 may include input / output circuitry, such as input / output devices 12. Input / output devices 12 may include user input devices that detect user input and output components that provide output to a user. Devices 12 may also include communication circuitry that receives data for device 10 and provides data from device 10 to external devices. Devices 12 may also include sensors that detect information from the environment.

[0017] Input / output devices 12 may include one or more displays, such as display 14. Display 14 may be a touchscreen display, which may include a touch sensor for detecting touch input from a user, or display 14 may be touch-insensitive. A touch sensor for display 14 may be based on an array of capacitive touch-sensing electrodes, acoustic touch-sensing structures, resistive touch components, force-based touch-sensing structures, a light-based touch sensor, or other suitable touch-sensing devices. Display 14 may be a liquid crystal display, a light-emitting diode display (e.g., an organic light-emitting diode display), an electrophoretic display, or other display.

[0018] The input / output devices 12 may include optical components 18. The optical components 18 may include light-emitting diodes and other light sources. As an example, the optical components 18 may include one or more visible light-emitting diodes, such as a light-emitting diode 20. The light-emitting diode 20 may provide constant illumination (e.g., to implement a flashlight function for the device 10) and / or may emit pulses of flash illumination for a visible light camera, such as a visible light image sensor 26. The optical components 18 may also include an infrared light source (e.g., a laser, a lamp, a light-emitting diode, etc.), such as an infrared light-emitting diode 22. The infrared light-emitting diode 22 may provide constant and / or pulsed illumination at an infrared wavelength, such as 940 nm, a wavelength in the range of 800 to 1100 nm, etc.For example, infrared light-emitting diode 22 may provide constant illumination for an infrared camera, such as infrared image sensor 28. As an example, infrared image sensor 28 may be configured to capture iris scan information from a user's eyes and / or may be used to capture images for a facial recognition process implemented in control circuitry 16.

[0019] The optical components 18 may also include an optical proximity detector 24 and an ambient light sensor 30.

[0020] The optical proximity detector 24 may include an infrared light source, such as an infrared light-emitting diode, and a corresponding light detector, such as an infrared photodetector, to detect when an external object illuminated by infrared light from the light-emitting diode is in proximity to the device 10.

[0021] The ambient light sensor 30 may be a monochrome ambient light sensor that measures the intensity of ambient light, or may be a color ambient light sensor that measures ambient light color and intensity by making light measurements with multiple photodetectors, each of which is provided with a corresponding color filter (e.g., a corresponding bandpass filter that passes red light, blue light, yellow light, green light, or light of other colors) and each of which therefore responds to ambient light in a different wavelength range.

[0022] In addition to the optical components 18, the input / output devices 12 may include buttons, joysticks, scroll wheels, touchpads, keypads, keyboards, microphones, speakers, sound generators, vibrators, cameras, light-emitting diodes and other status indicators, non-optical sensors (e.g., temperature sensors, microphones, capacitive touch sensors, force sensors, gas sensors, pressure sensors, sensors that monitor device orientation and movement, such as inertial measurement units formed from accelerometers, compasses, and / or gyroscopes), data ports, etc. A user may control the operation of the device 10 by providing commands through the input / output devices 12 and may receive status information and other outputs from the device 10 using the output resources of the input / output devices 12.

[0023] The device 10 may include a housing. The housing may form a laptop computer case, a wristwatch case, a mobile phone case, a tablet computer case, or other suitable device case. A perspective view of a portion of an illustrated electronic device is shown in Fig. 2. In the example of Fig. 2, the device 10 includes a display, such as the display 14 mounted in housing 32. The housing 32, which may sometimes be referred to as an enclosure or shell, may be formed from plastic, glass, ceramic, fiber composites, metal (e.g., stainless steel, aluminum, etc.), other suitable materials, or a combination of two or more of these materials. The housing 32 may be formed using a one-piece configuration in which part or all of the housing 32 is machined or formed as a single structure, or may be formed using multiple structures (e.g., an internal frame structure, one or more structures forming external housing surfaces, etc.). The housing 32 may have any suitable shape. In the example of Fig. 2, the housing 32 has a rectangular contour (base when viewed from above) and includes four peripheral edges (e.g., opposite top and bottom edges and opposite left and right edges). Sidewalls may extend along the perimeter of the housing 32. The display 14 may be protected using a display cover layer, such as a layer of transparent glass, clear plastic, sapphire, or other transparent layer (e.g., a transparent planar member that forms part or all of a front surface of the device 10 or that is mounted in other portions of the device 10). Openings may be formed in the display cover layer. For example, an opening may be formed in the display cover layer to accommodate a button, a speaker terminal, such as speaker terminal 34, or other components.Openings may be formed in the housing 32 to form communication ports (e.g., an audio jack port, a digital port, etc.), to form openings for buttons, etc. In some configurations, the housing 32 may have a housing backplane formed from a planar glass member or other transparent layer (e.g., a planar member formed on a back surface of the device 10 opposite a front surface of the device 10 that includes a display cover layer).

[0024] The display 14 may include an array of pixels 38 in an active area AA (e.g., pixels of a liquid crystal display, pixels of an organic light-emitting diode, pixels of an electrophoretic display, etc.). The pixels 38 of the active area AA may display images to a user of the device 10. The active area AA may be rectangular, may have notches along one or more of its edges, may be circular, may be oval, may be rectangular with rounded corners, and / or may have other suitable shapes.

[0025] Inactive portions of the display 14, such as the inactive edge region IA, may be formed along one or more edges of the active region AA. The inactive edge region IA may overlap circuits, signal lines, and other structures that do not emit light to form images. To conceal inactive circuits and other components in the edge region IA from the view of a user of the device 10, the underside of the outermost layer of the display 14 (e.g., the display cover layer or another display layer) may be coated with an opaque masking material, such as a layer of black ink (e.g., polymer-containing black dye and / or black pigment, opaque materials of other colors, etc.) and / or other layers (e.g., metal, dielectric, semiconductor, etc.).Opaque masking materials such as these may also be formed on an interior surface of a planar case back formed of glass, ceramic, polymer, crystalline transparent materials such as sapphire, or other transparent material.

[0026] In the example of Fig. 2, the speaker port 34 is formed from an elongated opening (e.g., a strip-shaped opening) that extends along a dimension parallel to the upper peripheral edge of the housing 32. A speaker may be aligned within the device housing 32 with the speaker port opening 34. During operation of the device 10, the speaker port 34 serves as an ear speaker port for a user of the device 10 (e.g., a user may place the opening 34 near the user's ear during telephone calls).

[0027] The optical components 18 (e.g., a visible digital image sensor, an infrared digital image sensor, a light-based proximity sensor, an ambient light sensor, visible light and / or infrared light-emitting diodes providing constant and / or pulsed illumination, etc.) may be mounted beneath one or more optical component windows, such as optical component windows 40 and 42. In the example of Fig. 2, the window 40 has round contours (e.g., circular bases when viewed from above) and the window 42 has an elongated strip-shaped opening (e.g., an elongated strip-shaped base when viewed from above). The window 42 is mounted between the side wall along the upper peripheral edge of the device 10 and the speaker terminal 34 and extends parallel to the upper peripheral edge of the housing 32. If desired, windows, such as the optical windows 40 and 42, may have shapes other than circular and rectangular. The examples of Fig. 2 are merely illustrative.

[0028] Windows for optical components, such as windows 40 and 42, may be formed in an inactive area 1A of the display 14 (e.g., an inactive edge area in a display cover layer, such as an inactive display area extending along the upper peripheral edge of the housing 32) or may be formed in other portions of the device 10, such as portions of a housing backplane formed from a transparent member coated with an opaque masking material, portions of a metal housing wall, polymer wall structures, etc. In the example of Fig. 2, windows 40 and 42 are formed adjacent the upper peripheral edge of housing 32 between the speaker terminal opening 34 in the display cover layer for display 14 and the sidewall along the top edge of housing 32. In some configurations, an opaque masking layer is formed on the underside of the display cover layer in an inactive area 1A, and optical windows 40 and 42 are formed from openings within the opaque masking layer. To help optical windows 40 and 42 visually blend with the opaque masking layer, a dark ink layer, a metal layer, a thin-film interference filter formed from a stack of dielectric layers, and / or other structures may overlap windows 40 and 42.

[0029] In some operating modes, device 10 may emit infrared light, which has the potential to interfere with the operation of the ambient light sensor. As an example, consider a scenario in which the control circuitry 16 of device 10 uses infrared image sensor 28 to capture eye scan information and / or facial images (e.g., images of a user's face for use in performing facial recognition operations to authenticate the user of device 10). As described in Fig. 3, to ensure that a user's eyes and / or face are adequately illuminated, device 10 may utilize an infrared light source 22 (e.g., an infrared light-emitting diode, an infrared laser, etc.) to generate infrared light 48. Light 48 may illuminate external objects proximate device 10, such as an external object 44 (e.g., a user's face and / or eyes). Reflected infrared light 50 from external object 44 may be received and imaged using an infrared digital image sensor 28 to generate infrared images of the face and / or eyes.

[0030] While reflected infrared light 50 is being imaged, scattered infrared light reflected from object 44, such as scattered infrared light 52, may be present at ambient light sensor 30. To ensure that scattered infrared light 52 does not interfere with the ambient light measurements taken with ambient light sensor 30, ambient light sensor 30 may include an infrared blocking filter, such as filter 60. Filter 60 may be formed from materials that are transparent to visible light and that block infrared light, such as blue glass (e.g., blue borosilicate glass or other infrared-blocking glass) and / or thin-film interference filters formed from stacks of dielectric layers configured to block infrared light (e.g., infrared light at the wavelengths associated with scattered light 52 and, if desired, additional infrared wavelengths) while transmitting visible light.

[0031] Ambient light 54 may be present in the environment of device 10 and may include light emitted from a light source, such as light source 46 (e.g., the sun, a lamp, etc.). In some situations, ambient light 54 may be directional (e.g., the rays of light 54 from light source 46 may be oriented in a particular direction due to the nature of light source 46). To ensure that the response of ambient light detector 30 is consistent across a range of different orientations relative to light source 46 and ambient light 54, a light diffuser, such as diffuser 62, may be integrated into ambient light sensor 30. Ambient light sensor 30 may include one or more photodetectors (e.g., photodiodes) and associated amplification and digitization circuitry implemented on light detector integrated circuit 58.Diffuser 62 may overlap visible light transmitting and infrared light blocking filter layer 60 and integrated circuit 58. Diffuser 62 may be formed from polymer, glass, or other suitable materials. Diffuser 62 may be formed from one or more diffuser layers, such as the illustrative diffuser 62L of FIG. Fig. 4. If desired, each diffuser layer 62L may include a substrate, such as substrate 64. Substrate 64 may be formed of clear glass, transparent polymer, or other suitable substrate material. Diffuser coatings, such as bottom coating layer 66 and top coating layer 66', may be formed on both sides of substrate 64, only on the top side of substrate 64 (see, e.g., coating layer 66'), or only on the bottom side of substrate 64 (see, e.g., coating layer 66). Coating layers 66 and 66' may include a polymer (e.g., a transparent binder, such as a transparent polymer resin), such as polymer 70, and may include light-scattering particles 68 embedded in polymer 70.The light-scattering particles 68 may be titanium oxide particles or other particles with a refractive index greater (or less) than the refractive index of the polymer 70. If desired, the light-scattering particles 68 may be incorporated into the substrate 64. Light-scattering coatings formed from a polymer with embedded light-scattering particles may also be formed on a display cover layer, light guide structures, filter layers, and / or other transparent materials in the device 10. If desired, light-scattering features, such as protrusions and / or depressions, may also be included in one or more of the material layers forming the diffuser 62. In one exemplary configuration, the diffuser 62 may comprise a pair of diffuser layers 62L (e.g., first and second diffusers 62) stacked above the integrated light detector circuit 58 (. Fig. 3). In general, any suitable number of diffuser layers 62L may be included in the diffuser 62 (e.g., one, at least two, at least three, etc.).

[0032] The filter 60, which transmits visible light and blocks infrared light (sometimes referred to as infrared light blocking filter, infrared cut filter, etc.) may consist of one or more layers, such as the infrared light blocking layer 60L of Fig. 5, be educated. As in Fig. 5, layer 60L may include a substrate, such as substrate 76. Substrate 76 may be a polymer or glass layer that is transparent at visible wavelengths. Substrate 76 may be transparent at infrared wavelengths or may block infrared light. Thin-film interference filters 72 configured to transmit visible light and block infrared light may be formed on the top and / or bottom surfaces of substrate 76. Filters 72 may each include a dielectric stack of thin-film dielectric layers 74, such as inorganic dielectric layers with alternating higher and lower refractive index values. Layers 74 may, for example, be formed from inorganic dielectric materials such as silicon oxide, silicon nitride, niobium oxide, tantalum oxide, aluminum oxide, etc., and / or may be formed from organic dielectric materials.There may be any suitable number of layers 74 in each dielectric stack (e.g., at least 5, at least 10, at least 30, at least 40, 20 to 90, less than 100, etc.).

[0033] In general, sensor 30 may include one or more infrared blocking filters, such as filters 60, and each filter 60 may include one or more infrared blocking layers 60L. Each layer 60L may include one or more dielectric stacks 72 of thin-film layers 74. If desired, infrared blocking thin-film filters may be implemented from dielectric stacks formed on a display cover layer, a light guide layer, a lens, a diffuser, an integrated circuit, and / or other structures in ambient light sensor 30 through which ambient light passes. Fig. Figure 6 shows an illustrative configuration for a color ambient light sensor in the device 10. In the example of Fig. 6, the color ambient light sensor 30 is formed in alignment with the optical component window 40 (sometimes referred to as the ambient light sensor window) in the display 14. The display 14 has an array of pixels formed by the display cover layer 78 in an active area (AA) of the display 14 (in Fig. 6 not shown). In an inactive area 1A, portions of the underside of the display cover layer 78 may be coated with a layer of opaque masking material 80 (e.g., black ink, etc.) to obscure the view of internal components from the outside of the device 10. The window 40 may be formed from an opening in the opaque masking material 80. A thin layer of black ink 82 or other material that is at least partially transparent to visible light (e.g., a layer having a light transmittance of at least 1%, at least 2%, at least 5%, 1 to 10%, less than 30%, etc.) may be present in the window 40 to help visually match the appearance of the window 40 to the visual appearance of surrounding portions of the display cover layer 78 (e.g., toadjust the appearance of the opaque obscuring material 80) while still allowing the ambient light sensor 30 to measure ambient light.

[0034] The color ambient light sensor 30 may include support structures, such as a support structure 86 (sometimes referred to as a sensor wall, a sensor body structure, a sensor housing structure, etc.). A transparent adhesive, such as a layer of pressure-sensitive adhesive 84, may be used to couple the support structure 86 to the underside of the display cover layer 78 in alignment with the optical component window 40. The support structure 86 may form walls surrounding the light diffuser 62, the infrared light blocking filter 60, and the light detector integrated circuit 58. When viewed from above through the layer 78, the support structure 86 may extend around the perimeter of the optical window 40. The support structure 86 may be formed from an opaque material that blocks visible and infrared light, such as black plastic and / or other opaque materials.The support structure 86 can be used to form a single-piece or multi-piece housing for the sensor 30. In the example of FIG. Fig. 6, the support structure 86 has an upper portion that houses components such as the light diffuser 62 and the infrared light blocking filter 60, and a lower portion that houses the integrated light detector circuit 58. The upper and lower portions may be connected using a pressure-sensitive adhesive 112 or other suitable attachment mechanism.

[0035] The Diffuser 62 from Fig. 6 has an upper diffuser layer 62L and a lower diffuser layer 62L. In the upper diffuser layer, the substrate 64 ( Fig. 4) be coated with an upper diffuser coating 66' and may not have a lower diffuser coating. In the lower diffuser layer, the substrate 64 may be coated with a lower diffuser coating 66, and the coating 66' may be omitted. Air gaps 88 may separate the diffuser layers 62L from each other and from adjacent layers in the ambient light sensor 30 (e.g., to increase the space available for light mixing).

[0036] The infrared light-blocking filter 60 may be formed from upper and lower infrared light-blocking layers 60L. Each layer may include a substrate and a thin-film filter dielectric stack on one or both sides of the substrate, configured to block infrared light while transmitting visible light.

[0037] Pressure-sensitive adhesive rings 90 can separate layers 62L and 60L. A pressure-sensitive adhesive ring 116 can be used to couple a printed circuit board 94 to the support structures 86.

[0038] The integrated light detector circuit 58 may be formed from a silicon die or another semiconductor die. Wire bonds 100 may be used to couple wire bond pads on the integrated circuit 58 to a wire bond pad on the printed circuit 94. Solder bonds 98 may be used to couple signal paths formed from metal traces 112 in a flexible printed circuit 96 to signal paths 114 in the printed circuit 94 (e.g., signal paths formed from metal lines in the printed circuit 94 that are coupled to the wire bonds 100). In this way, the circuits of the integrated light detector circuit 58 are coupled to the signal paths in the flexible printed circuit 96 (e.g., such that these signal paths can carry signals to and from the control circuits 16). If desired, the integrated light detector circuit 58 may be Fig. 6 may be provided with silicon vias to electrically couple circuits in the integrated circuit 58 to the printed circuit 94 without the use of bond wires.

[0039] The integrated light detector circuit 58 may include multiple photodetectors 102 (e.g., photodiodes). Each photodetector 102 may be overlapped by a respective color filter 108. Each color filter may be formed from a colored ink or other material that selectively transmits a desired range of wavelengths to a corresponding overlapped photodetector 102 (e.g., an organic color filter material, such as a polymer containing dyes and / or pigments). For example, a red-transmissive color filter may overlap a first photodetector 102 to form a red-detecting channel in the ambient light sensor 30, a blue-transmissive color filter may overlap a second photodetector 102 to form a blue-detecting channel in the ambient light sensor 30, etc. Scattered infrared light may be filtered out using a thin-film interference filter, such as a filter 104 composed of a stack of dielectric layers (e.g.,B. inorganic thin-film layers with alternating higher and lower refractive indices). For example, the filter 104 may have a configuration of the type used in conjunction with the dielectric stack 72 of FIG. Fig. 5. The filter 104 may be formed from any suitable number of dielectric layers 100 (e.g., at least 5, at least 10, at least 20, 20 to 80, less than 100, etc.). The layers 100 may be formed on top of the integrated light detector circuit 58, overlapping each of the photodetectors 102, and sandwiched between the color filters 108 and the photodetectors 102. An encapsulant 92 (e.g., a transparent polymer such as epoxy) may be used to protect the silicon integrated circuit die forming the integrated circuit 58 from environmental contaminants.

[0040] The light transmission curves 120 and 122 of Fig. 7 depict illustrative light transmission properties (passband properties) for the color filters 108. Curve 120 may, as an example, be associated with a blue color filter and may cover a range of blue wavelengths, while curve 122 may be associated with a green color filter and may cover green wavelengths (as an example). As shown in Fig. 7, dye- and / or pigment-based color filters formed from organic materials (e.g., a polymer colored with a dye and / or pigment) may be transparent at infrared wavelengths. To ensure that scattered infrared light passing through the color filters 108 does not reach the photodetectors 102, the visible light-transmitting and infrared-blocking layer (filter) 104 may have a light transmission property of the material represented by the curve 124 of Fig. 8, which blocks infrared light. Configurations can also be used for the ambient light sensor 30, in which the color filter for each channel in the color ambient light sensor 30 of Fig. 6 is formed of a thin film interference filter configured to serve as a bandpass filter for a range of wavelengths associated with that channel.

[0041] If desired, an ambient light sensor may include a light guide. The light guide may help guide incoming ambient light past an electrical component, such as a speaker, to the integrated light detector circuit 58. As an example, the Fig. The arrangement shown in Figure 9 must be taken into account. Fig. Figure 9 is a cross-sectional side view of the upper edge portion of the device 10 of Fig. 2. As in Fig. 9, the display cover layer 78 may overlap an array of pixels 38 for the display 14 in an active area AA. In an inactive area IA, the speaker 126 may be mounted in alignment with the speaker terminal 34 in the display cover layer 78. The speaker 126 may be relatively wide, and the space between the speaker 126 and the adjacent side wall of the housing 32 (e.g., the uppermost peripheral edge of the housing 32 of Fig. 2) can be relatively small accordingly. This limits the available side space to accommodate the color ambient light sensor 30 near the display cover layer 78.

[0042] The color ambient light sensor 30 may have a lower portion, such as portion 30L, that is relatively wide to accommodate the integrated light detector circuit 58, and a narrower upper portion, such as portion 30T, that contains a light guide and can therefore be accommodated in the relatively narrow space between the speaker 126 and the sidewall 32W of the housing 32. The light guide in portion 30T is inserted between the speaker 126 and the housing sidewall 32SW along the upper peripheral edge of the housing 32.To help provide incident ambient light 54 to the photodetectors in the integrated light detector circuit 58 in the limited space available between the speaker terminal 34 and the package sidewall 32SW of the package 32, the light guide of the ambient light sensor portion 30T may be configured to direct incident light 54 from the optical component window 34 to photodetectors on the integrated light detector circuit 58 past the speaker 126. Fig. 10 is a cross-sectional side view of an illustrative color ambient light sensor with a light guide of the type shown in Fig. 9. As shown in Fig. As shown in Figure 10, the color ambient light sensor 30 may include the support structure 86 (sometimes referred to as an ambient light sensor housing structure, housing, body, etc.). The support structure 86 may be formed from an opaque material, such as a black polymer. An upper portion of the support structure 86 in the section 30T of the sensor 30 may be coupled to a lower portion of the support structure 86 in the section 30L of the sensor 30 using a pressure-sensitive adhesive 130.

[0043] The light guide 132, which may sometimes be referred to as a light tube, waveguide, or light guide structure, may include a core, such as core 134, and a cladding, such as cladding 136, surrounding the core 134. The core 134 may have a higher refractive index than the cladding 136 to promote total internal reflection and guidance of ambient light 54 within the light guide 132. For example, the core 134 may have a refractive index of 1.5 to 2.0, and the cladding 136 may have a refractive index of 1.1 to 1.5 (as examples). The core 134 and the cladding 136 may be formed from glass, polymer, sapphire, or another transparent crystalline material. As an example, the core 134 may be formed of glass and the cladding 136 may be formed of a polymer having a lower refractive index than the glass of the core 134.Configurations in which the cladding 136 is omitted and in which the core 134 is surrounded by an air gap to ensure that light is guided within the core 134 according to the principle of total internal reflection can also be used if desired. In arrangements in which the cladding 136 is present, dust and other contaminants that would otherwise contact the outer surface of the core 134 can be prevented from contacting the core 134. This can improve the reliability of the light guide 132. The presence of the cladding 136 can also help support the light guide 132 within the support structure 86 and can thereby help improve the ability of the light guide 132 to withstand damage during a drop event.

[0044] The diffuser 62 may scatter incident ambient light 54 and may be located between the top of the light guide 132 and the bottom of the display cover layer 78 ( Fig. 9). After ambient light 54 has propagated through the light guide 132, it may pass through the visible light transmitting and infrared light blocking filter 60. The filter 60 may be mounted in a recessed portion of the support structure 86 in the lower portion 30L and may be coupled to the support structure 86 using a ring of pressure-sensitive adhesive 90. The rings of pressure-sensitive adhesive 90 may also separate the diffuser layers 62L from each other and from the light guide 132 to form air gaps 88. The filters 60 may comprise a substrate, such as the substrate 76 of Fig. 5, (e.g., an infrared light-blocking glass layer, such as a blue borosilicate glass layer or other glass layer that prevents the passage of infrared light) and may include upper and lower dielectric stacks 72 on the glass layer formed from inorganic dielectric thin-film layers or other dielectric layers 74 with alternating higher and lower refractive index values. The stacks 72 form a thin-film interference filter that transmits visible light while blocking infrared light. Because the filter 60 is located near the integrated light detector circuit 58 (e.g., because the filter 60 is disposed between the light guide 132 and the integrated circuit 58), stray infrared light entering the interior of the support structure 86 (e.g., at locations near the adhesive 130) is blocked and prevented from reaching the integrated light detector circuit 58.If desired, infrared filters such as filter 60 may be placed elsewhere in the color ambient light sensor 30, such as between the diffuser 62 and the light guide 132.

[0045] The color filters 108 (e.g., bandpass filters having passbands in different wavelength ranges) may be formed over respective photodetectors 102 in the integrated circuit 58 to provide color light sensitivity for the ambient light sensor 30. The encapsulant 92 (e.g., one or more layers of transparent polymer, such as epoxy, etc.) may be used to cover the integrated circuit 58. Wire bonds 100, the traces 114 in the printed circuit 94, the solder connections 98, and the traces 112 in the flexible printed circuit 96 may be used to conduct signals between the control circuits 16 and the integrated circuit 58. If desired, the integrated light detector circuit 58 may be Fig. 10 may be provided with silicon vias to electrically couple circuits in the integrated circuit 58 to the printed circuit 94 without the use of bond wires.

[0046] As in Fig. 11, the color filters 108 of Fig. 10 thin-film interference filters. Each color filter 108 for the color ambient light sensor 30 of Fig. 10 may, for example, comprise a stack of 5 to 100 dielectric layers 170 (e.g., inorganic dielectric layers such as silicon oxide, niobium oxide, aluminum oxide, tantalum oxide, titanium oxide, silicon nitride, etc., and / or organic dielectric layers) with alternating refractive index values ​​to form desired bandpass color filters for respective photodetectors 102 in the integrated circuit 58. Transmittance versus wavelength properties for illustrative color filters 108 of the Fig. 11 are represented by curves 172 and 174 in Fig. 12. As shown in Fig. 12, the thin film interference filter structures used in forming the filters 108 may be configured to block infrared light.

[0047] An illustrative circular photodetector array for the photodetectors 102 of the integrated circuit 58 of Fig. 6 is in Fig. 13. An illustrative rectangular arrangement for the photodiodes 102 of the integrated circuit 58 of Fig. 10 is in Fig. 14. Other configurations can be used if desired. In arrangements of the Fig. 13 and Fig. 14, photodetectors for different color channels may be distributed throughout the sensor 30, and, if desired, redundant photodetectors (e.g., photodetectors that measure the same color of the ambient light) may be included in the ambient light sensor 30. As an example, the photodetectors 102 of Fig. 13 and / or Fig. 14 photodetectors for 3 to 10 different color channels (including an optional transparent color channel), and each color channel may have 1 to 5 different individual photodetectors 102 for acquiring ambient light color measurements for that color channel. Circuitry in the integrated circuit 58 (e.g., switching circuitry, amplifier circuitry, analog-to-digital conversion circuitry, communication circuitry for supporting communications with control circuitry elsewhere in the device 10, etc.) may be incorporated into the integrated circuit 58 with the photodetectors 102, or, if desired, some or all of this supporting circuitry for the photodetectors 102 may be formed in one or more integrated circuits separate from the integrated circuit 58.Ambient light sensor measurements from ambient light sensor 30 can be used to control the operation of device 10. For example, control circuitry 16 can adjust the intensity of images displayed on display 14 in response to measured changes in the intensity of the ambient light. As an example, if a user moves device 10 into a bright outdoor environment, control circuitry 16 increases the brightness of display 14 to overcome glare. Color changes (e.g., white point adjustments) can also be made based on ambient light sensor measurements. For example, if ambient light color measurements indicate that the ambient lighting has become warm (e.g., if a user moves device 10 indoors), the white point of display 14 can be adjusted by control circuitry 16 so that display 14 displays correspondingly warmer content.

[0048] If desired, the acquisition of ambient light sensor measurements and the illumination of external objects can be coordinated using light sources, such as infrared light-emitting diode 22. In one illustrative arrangement, ambient light sensor measurements can be temporarily paused each time light-emitting diode 22 emits a pulse of light. In another illustrative arrangement, a flag can be set each time light-emitting diode 22 is activated during the acquisition of ambient light sensor measurements (e.g., so that those measurements, which may be contaminated by noise from the light from diode 22, can be discarded). In yet another embodiment, potential light contamination from adjacent electronic devices can be detected using a light sensor (e.g., an infrared light sensor).If light is detected from adjacent devices, ambient light sensor measurements may be discarded.

[0049] Fig. 15 is a circuit diagram of illustrative circuits for device 10 that may be used in coordinating the operation of ambient light sensing circuits and light emitting circuits according to one embodiment. As shown in Fig. 15, the ambient light sensor 30 may be formed from a photodetector, such as a photodiode. The output of the photodetector (ambient light sensor) 30 may be provided to the integrating analog-to-digital converter 190. During operation, the integrating analog-to-digital converter 190 may integrate the photodiode current associated with the photodetector of the ambient light sensor 30 and may provide corresponding digital ambient light sensor measurement data to the control circuits 16. The periods during which the ambient light sensor 30 collects ambient light data may be controlled by the control circuits 16. For example, the control circuits 16 may provide control signals (sometimes referred to as a HOLD signal) to circuit logic, such as switches 192 and 194.When the HOLD signal is asserted, switch 192 is closed, shorting node N to ground, thereby shunting the photodiode current from the photodiode of ambient light sensor 30 to ground. Simultaneously, the assertion of the HOLD signal opens switch 194, disconnecting node N from the input to the integrating analog-to-digital converter 190. When the HOLD signal is deasserted, switch 192 is opened, and switch 194 is closed, allowing the integrating analog-to-digital converter 190 to acquire ambient light data.

[0050] The control circuitry 16 may also control the operation of circuitry 196, such as the infrared light-emitting diode 22 and the infrared image sensor 28 (e.g., using enable signals). For example, the control circuitry 16 may cause the light-emitting diode 22 to emit a pulse of light while the image sensor 28 is caused to capture an image frame (e.g., an image frame containing facial information or other user biometric information). In some configurations, the control circuitry 16 may capture light measurements from a light sensor, such as an infrared light sensor 198 (e.g., an infrared photodetector such as a photodiode).

[0051] In one illustrative arrangement, control circuits 16 use switches 192 and 194 to temporarily interrupt the integration of ambient light sensor signals each time infrared light-emitting diode 22 is used to emit a pulse of infrared illumination. This helps prevent infrared-induced noise from being introduced into the visible ambient light measurements with ambient light sensor 30. As an example, consider the scenario of Fig. 16 and Fig. 17. In this arrangement, the control circuits 16 use the ambient light sensor 30 to measure ambient light over a period of time extending from time t5 to time t5. The duration of this period (e.g., t5 to t5) may be, for example, 100 to 700 ms, at least 25 ms, at least 40 ms, at least 75 ms, at least 150 ms, at least 300 ms, less than 150 ms, less than 500 ms, less than 700 ms, less than 900 ms, or another suitable period.

[0052] The control circuitry 16 may capture images during ambient light sensor data collection with the infrared image sensor 28. For example, a user may switch the device 10 from a standby state to a ready state to use the device 10. Immediately after switching the device 10 to a ready state (e.g., at a time such as time t ), the control circuitry 16 may begin capturing image data with the circuitry 196 (e.g., to enable a user to biometrically authenticate as an authorized user of the device 10) while beginning to capture ambient light sensor measurements with the ambient light sensor 30 (e.g., so that the screen brightness of the display 14 can be adjusted based on the ambient light sensor data when the device 10 exits sleep mode).Because the infrared illumination generated by LED 22 has the potential to introduce noise into the signal measurements acquired by ambient light sensor 30, control circuitry 16 may synchronize the operation of circuitry 196 and ambient light sensor 30. Each time control circuitry 16 causes LED 22 to emit infrared light (to illuminate external objects imaged by image sensor 28), control circuitry 16 may also cause ambient light sensor 30 to temporarily stop collecting (integrating) ambient light sensor data.

[0053] As in Fig. 18, the infrared (IR) light output of the light-emitting diode 22 may be delivered in one or more sets of pulses 200. Each set of pulses 200 may include one or more light pulses (e.g., at least 1, at least 2, at least 4, at least 8, at least 15, less than 20, less than 100, less than 25, less than 10, etc.). The pulses may each have a duration of 3 ms, at least 1 ms, less than 5 ms, or another suitable duration. During each pulse (or multiple pulses), a corresponding image frame may be captured by the image sensor 28. The use of pulsed light may enable the light-emitting diode 22 to produce a higher peak light output than would be possible if continuous illumination were used, thereby reducing the signal-to-noise ratio during image acquisition operations with the infrared image sensor 28.Pulsed light can also help reduce thermal stress and improve battery life. The light intensity generated by the LED 22 can be relatively high, so that the control circuitry 16 can interrupt ambient light sensor data acquisition (e.g., integration by integrating the analog-to-digital converter 190) each time the LED 22 generates an output, as indicated by the complementary shapes of the pulses. Fig. 16 and Fig. 17 shown.

[0054] To ensure that integration operations of the ambient light sensor have been successfully interrupted before infrared light is emitted by the LED 22, the control circuits 16 may activate the HOLD signal before the LED 22 is turned on. As shown in Fig. For example, as shown in Figure 18, HOLD may be enabled at time ta. After a short delay (e.g., a delay of approximately 5 microseconds), switch 192 is closed, switch 194 is opened, and converter 190 interrupts integration (e.g., at time tb). LED 22 may then generate an output at time tc without risk of generating interference for the ambient light sensor. Similarly, LED 22 may be turned off (time te) before ambient light sensor integration resumes (time tf). There may be a short delay between the enablement of the HOLD signal and the continuation of ambient light sensing (switch 192 open, switch 194 closed, and converter 190 integrating).This allows the hold signal HOLD to be deactivated, if desired, at a time td slightly before the LED 22 is turned on to generate the infrared output IR at the time te, provided that the ambient light sensor 30 becomes active (interruption is terminated) at a time tf later than the time te.

[0055] If desired, the control circuits 16 may use the ambient light sensor 30 without interrupting the ambient light sensor 30 during light emission from the light-emitting diode 22. In the event that the infrared light-emitting diode 22 is activated during operation of the ambient light sensor 30 (e.g., in the event that the control circuits 16 use the light-emitting diode 22 and the image sensor 28 to capture images while the ambient light sensor 30 provides an output that is integrated by the integrating analog-to-digital converter 190), the control circuits 16 may indicate that potential contamination of the ambient light sensor reading by emitted light from the diode 22 has occurred (e.g., by setting a flag).The control circuits 16 may then discard the ambient light sensor reading potentially contaminated by light from the diode 22, or may assert a bit to indicate that ambient light sensor data may be contaminated by infrared light. Fig. Figure 19 shows how ambient light data can be acquired by integrating an ambient light sensor photodiode current over a period 210 (shown by the period that an ALS is switched on in Fig. 19). Fig. Figure 20 illustrates how a flag (FLAG) may be activated during the ambient light sensor integration period (e.g., at time tflag) to indicate that the light emitting diode 22 has emitted infrared light during use of the ambient light sensor 30 to capture an ambient light sensor measurement. In response to determining that FLAG is activated during an ambient light sensor integration period (e.g., period 210 of Fig. 19) has been activated, the control circuits may discard the potentially contaminated ambient light sensor data from the sensor 30 and may acquire a new ambient light sensor measurement.

[0056] Another way to avoid potential infrared light contamination involves using an infrared light sensor, such as sensor 198, to determine when infrared light is emitted. Sensor 198 may, for example, be used by control circuitry 16 to monitor for the presence of infrared light pulses from external light-emitting circuitry. As one example, sensor 198 may detect that infrared light has been emitted by circuitry 196 (e.g., an infrared light-emitting diode 22 providing illumination of external objects imaged by a corresponding infrared light sensor 28) in a device other than device 10. These potentially contaminating infrared light pulses may be emitted by adjacent electronic devices (e.g.,one or more electronic devices other than device 10), such as devices operated by other users. When infrared light pulses or other potentially contaminating infrared light are detected in the vicinity of device 10 using sensor 198, a flag, such as the FLAG signal from . Fig. 20, can be activated. Ambient light sensor data integrated over a period that overlaps the activated flag can then be discarded.

[0057] According to one embodiment, an ambient light sensor is provided that is configured to provide ambient light measurements to control circuits in an electronic device that includes an integrated light detector circuit, a light guide configured to guide ambient light to the integrated light detector circuit, and an infrared cut filter through which the ambient light passes.

[0058] According to another embodiment, the ambient light sensor includes a light diffuser, wherein the light guide is inserted between the light diffuser and the infrared blocking filter.

[0059] According to another embodiment, the light guide includes a core and a cladding surrounding the core, wherein the core has a first refractive index and the cladding has a second refractive index that is less than the first refractive index.

[0060] According to another embodiment, the jacket includes a polymer and the ambient light sensor includes an opaque support structure surrounding the integrated light detector circuit and the light guide.

[0061] According to another embodiment, the integrated light detector circuit includes a plurality of photodetectors.

[0062] According to another embodiment, the ambient light sensor includes a plurality of color filters, each color filter transmitting a different respective range of wavelengths of visible light to a respective one of the plurality of photodetectors.

[0063] According to another embodiment, the light diffuser includes a plurality of light diffuser layers, each light diffuser layer comprising a substrate and a polymer coating having embedded light scattering particles on the substrate.

[0064] According to another embodiment, the plurality of light diffuser layers includes a first and a second light diffuser layer separated by an air gap.

[0065] According to another embodiment, the infrared blocking filter includes at least one stack of dielectric thin film layers having alternating refractive index values.

[0066] According to another embodiment, the infrared cut filter includes a glass substrate on which the dielectric thin film layers are formed.

[0067] According to another embodiment, the glass substrate includes infrared light blocking glass.

[0068] According to another embodiment, the color filters each include a stack of inorganic dielectric thin film layers configured to transmit a respective range of wavelengths of visible light while blocking infrared light.

[0069] According to one embodiment, an electronic device is provided that includes an array of pixels, a display cover layer overlapping the pixels, a window for optical components in a portion of the display cover layer through which ambient light passes, and a color ambient light sensor aligned with the window for optical components, wherein the color ambient light sensor includes an opaque support structure, a light diffuser coupled to the opaque support structure through which the ambient light passes, an integrated light detector circuit at least partially surrounded by the opaque support structure, wherein the integrated light detector circuit includes a plurality of photodetectors, each overlapped by a color filter configured to transmit a different respective range of wavelengths of visible light,and an infrared light blocking filter coupled to the support structure and located between the light diffuser and the integrated light detector circuit.

[0070] According to another embodiment, the color filters each include an organic material, and the color ambient light sensor includes an infrared light-blocking thin-film interference filter having inorganic dielectric thin-film layers between the color filters and the integrated light detector circuit. According to another embodiment, the light diffuser includes a plurality of light diffuser layers, each of the light diffuser layers including a substrate layer coated with a polymer containing light-scattering particles of an inorganic dielectric.

[0071] According to another embodiment, the infrared light blocking filter includes a plurality of infrared light blocking layers, each infrared light blocking layer including a substrate and a thin film interference filter formed from a stack of alternating refractive index dielectric layers on the substrate.

[0072] According to another embodiment, the electronic device includes an infrared light-emitting diode configured to emit infrared light blocked by the infrared light-blocking filter and an infrared sensor configured to capture images illuminated by the emitted infrared light.

[0073] According to another embodiment, the electronic device includes control circuitry configured to adjust a white point of images displayed on the array of pixels in response to color ambient light sensor information measured with the color ambient light sensor.

[0074] According to one embodiment, an electronic device is provided including a display having a display cover layer, an ambient light sensor window in the display cover layer, and an ambient light sensor configured to receive ambient light through the ambient light sensor window, wherein the ambient light sensor includes an integrated light detector circuit having a plurality of photodetectors, each overlapped by a color filter configured to transmit a different respective range of visible light wavelengths, and a visible light transmitting and infrared light blocking thin-film interference filter interposed between the color filters and the ambient light sensor window.

[0075] According to another embodiment, the electronic device includes an infrared light-emitting diode configured to emit infrared light blocked by the visible light transmitting and infrared light blocking thin-film interference filter, and an infrared sensor configured to capture images illuminated by the emitted infrared light.

[0076] According to one embodiment, an electronic device is provided that includes an ambient light sensor photodetector, an integrating analog-to-digital converter configured to integrate an output from the ambient light sensor photodetector, an infrared light-emitting diode, and control circuitry configured to interrupt integration of the output when the infrared light-emitting diode is turned on.

[0077] According to another embodiment, the electronic device includes circuit logic coupled to the ambient light sensor photodetector, wherein the control circuit logic is configured to adjust the circuit logic when the infrared light-emitting diode is used to emit infrared light.

[0078] According to another embodiment, the circuit logic includes a first switch coupled between a node and an input of the integrating analog-to-digital converter and a second switch coupled between the node and ground.

[0079] According to another embodiment, the ambient light sensor photodetector has a first terminal coupled to ground and a second terminal coupled to the node.

[0080] According to another embodiment, the circuit logic is configured to operate in a first mode in which the first switch is closed to couple the output of the ambient light sensor photodetector to the input of the integrating analog-to-digital converter to enable the integrating analog-to-digital converter to integrate the output from the ambient light sensor photodetector, and the second switch is open to isolate the node to ground, and a second mode in which the first switch is open to disconnect the output of the ambient light sensor photodetector from the input of the integrating analog-to-digital converter, and the second switch is closed to short the node to ground.According to another embodiment, the electronic device includes an infrared image sensor configured to capture an image of an external object illuminated by infrared light emitted by the infrared light-emitting diode while the switching circuitry operates in the second mode. According to one embodiment, an electronic device is provided that includes an ambient light sensor configured to capture an ambient light sensor measurement during an integration period, an infrared light-emitting diode, and control circuitry configured to discard the ambient light sensor measurement in response to determining that the infrared light-emitting diode has emitted infrared light during the integration period.

[0081] According to another embodiment, the electronic device includes an infrared image sensor configured to capture an image of an external object illuminated by infrared light emitted by the infrared light-emitting diode.

[0082] According to another embodiment, the ambient light sensor includes an integrated light detector circuit having a plurality of photodetectors, each overlapped by a color filter configured to transmit a different respective range of wavelengths of visible light.

[0083] According to one embodiment, an electronic device is provided that includes an ambient light sensor configured to acquire an ambient light sensor measurement during an integration period, an infrared light sensor, and control circuitry configured to discard the ambient light sensor measurement in response to determining that the infrared light sensor has acquired infrared light during the integration period.

[0084] According to another embodiment, the ambient light sensor includes an integrated light detector circuit having a plurality of photodetectors, each overlapped by a color filter configured to transmit a different respective range of wavelengths of visible light.

[0085] According to another embodiment, the electronic device includes a display and the control circuit is configured to adjust a white point of images displayed on the display based on the ambient light sensor measurement.

[0086] According to one embodiment, an electronic device is provided that includes a rectangular housing having four peripheral edges, including a top peripheral edge, an electrical component, an optical component window, a photodetector, and a light guide interposed between the electrical component and a side wall of the rectangular housing and configured to guide ambient light from the optical component window past the electrical component to the photodetector.

[0087] According to another embodiment, the electronic device includes an array of pixels and a display cover layer overlapping the pixels, wherein the window for optical components is formed in a portion of the display cover layer.

[0088] According to another embodiment, the window for optical components has an elongated shape extending parallel to the upper peripheral edge and located between the electrical component and the side wall of the rectangular housing.

[0089] According to another embodiment, the electrical component includes a speaker aligned with a speaker formed in the display cover layer, and the speaker terminal has an elongated shape extending parallel to the optical component window. According to another embodiment, the electronic device includes an integrated light detector circuit on which the photodetector is formed. According to another embodiment, the photodetector is one of a plurality of photodetectors, each of which is configured to measure ambient light of a different color.

[0090] According to another embodiment, the electronic device includes thin film interference filters having different respective passbands, each of which overlaps a respective one of the plurality of photodetectors.

[0091] According to another embodiment, the electronic device includes an opaque support structure surrounding the light guide, the light guide having a core with a first refractive index and a cladding with a second refractive index lower than the first refractive index.

[0092] According to another embodiment, the electronic device includes a light diffuser interposed between the optical component window and the photodetector.

[0093] According to another embodiment, the electronic device includes an infrared digital image sensor mounted adjacent to the upper peripheral edge and an infrared light-emitting diode configured to provide illumination for infrared images captured with the infrared digital image sensor. According to another embodiment, the photodetector is one of a plurality of photodetectors, each configured to measure ambient light of a different color, and each of the plurality of photodetectors is overlapped by a respective thin-film interference filter having a different respective visible light passband.

[0094] According to another embodiment, the thin film interference filters are configured to block infrared light.

[0095] According to another embodiment, the electronic device includes an infrared light blocking filter interposed between the light guide and the photodetectors.

Claims

[1] An ambient light sensor (30) configured to provide ambient light measurements to control circuits (16) in an electronic device (10), the ambient light sensor (30) comprising: an integrated light detector circuit (58); a light guide (132) configured to guide ambient light (54) to the integrated light detector circuit (58); an infrared blocking filter (60) through which the ambient light (54) passes; and a light diffuser (62) comprising first and second light diffuser layers (62L) separated by an air gap (88), the light guide (132) being interposed between the light diffuser (62) and the infrared blocking filter (60). [2] The ambient light sensor (30) of claim 1, wherein the light guide (132) includes a core (134) and a cladding (136) surrounding the core (134), the core (134) having a first refractive index and the cladding (136) having a second refractive index less than the first refractive index. [3] The ambient light sensor (30) of claim 2, wherein the casing (136) comprises a polymer, the ambient light sensor (30) further comprising an opaque support structure (86) surrounding the integrated light detector circuit (58) and the light guide (132). [4] The ambient light sensor (30) of claim 3, wherein the integrated light detector circuit (58) includes a plurality of photodetectors (102). [5] The ambient light sensor (30) of claim 4, further comprising a plurality of color filters (108), each color filter (108) transmitting a different respective range of wavelengths of visible light to a respective one of the plurality of photodetectors (102). [6] The ambient light sensor (30) of claim 5, wherein each of the first and second light diffuser layers (62L) comprises a substrate (64) and a polymer coating on the substrate (64) having embedded light scattering particles. [7] The ambient light sensor (30) of claim 5, wherein the infrared blocking filter (60) includes at least one stack of dielectric thin film layers having alternating refractive index values. [8] The ambient light sensor (30) of claim 6, wherein the infrared cut filter (60) includes a glass substrate on which the dielectric thin film layers are formed. [9] The ambient light sensor (30) of claim 8, wherein the glass substrate comprises infrared light blocking glass. [10] The ambient light sensor (30) of claim 9, wherein the color filters (108) each include a stack of inorganic dielectric thin film layers configured to transmit a respective range of wavelengths of visible light while blocking infrared light. [11] The ambient light sensor (30) of claim 1, wherein the electronic device (10) includes an array of pixels (38), a display cover layer (78) covering the pixels, and an optical component window (40, 42) in a portion of the display cover layer (78) through which the ambient light (54) passes, the ambient light sensor (30) being aligned with the optical component window (40, 42), and the ambient light sensor (30) including: an opaque support structure (86); wherein the light diffuser (62) is coupled to the opaque support structure (86), wherein the integrated light detector circuit (58) is at least partially surrounded by the opaque support structure (86), wherein the integrated light detector circuit (58) comprises a plurality of photodetectors (102) each covered by a color filter (108) configured to transmit a different respective band of visible light wavelengths, and wherein the infrared blocking filter (60) is coupled to the opaque support structure (86) and is located between the light diffuser (62) and the integrated light detector circuit (58). [12] The ambient light sensor (30) of claim 11, wherein the color filters (108) each include an organic material, and wherein the ambient light sensor (30) further comprises an infrared light blocking thin film interference filter having inorganic dielectric thin film layers between the color filters (108) and the integrated light detector circuit (58). [13] The ambient light sensor (30) of claim 11, wherein the first and second light diffuser layers (62L) each comprise a substrate layer coated with a polymer containing light-scattering particles of an inorganic dielectric.

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