Electronic device with relative humidity sensor

Abstract

An electronic device may include a housing and a relative humidity sensor in the housing. A relative humidity sensor may include an optical layer, a relative humidity sensitive layer coupled to a surface of the optical layer, a light emitter that emits light into the optical layer, and a light detector that detects light that has been reflected within the optical layer and exits the relative humidity sensitive layer. The relative humidity may be determined based on light detected by the light detector. The optical layer may be a layer with an inclined edge, a prism, a Bragg reflector, or a waveguide. A reference light detector and / or a temperature sensor may be included in the relative humidity sensor, and measurements from the additional sensors may be used to determine the relative humidity. In this manner, an optical relative humidity sensor may be formed in an electronic device.

Description

[0001] This application claims priority to U.S. Patent Application No. 18 / 752,306 filed on June 24, 2024 and U.S. Provisional Patent Application No. 63 / 585,823 filed on September 27, 2023, which are hereby incorporated by reference in their entirety. Technical Field

[0002] The present invention relates generally to electronic devices, and more particularly to electronic devices having environmental sensors. Background Art

[0003] Electronic devices such as laptop computers, cell phones, and other equipment are sometimes provided with environmental sensors such as ambient light sensors, image sensors, and microphones. Summary of the invention

[0004] An electronic device such as a wristwatch device or other wearable electronic device may include a housing and a display in the housing. The electronic device may also include a relative humidity sensor in the housing. For example, the housing may have an opening, and the relative humidity sensor may be covered by the opening to receive moisture from outside the device.

[0005] The relative humidity sensor may include an optical layer, a relative humidity-sensitive layer coupled to a surface of the optical layer, a light emitter that emits light into the optical layer, and a light detector that detects light that has been reflected within the optical layer and leaves the relative humidity-sensitive layer. The relative humidity-sensitive layer may have a refractive index or other property that changes based on relative humidity. Thus, relative humidity may be determined based on the light detected by the light detector.

[0006] As an example, the optical layer can be a layer with a sloped edge, a prism, a Bragg reflector, or a waveguide. A reference light detector and / or a temperature sensor can be included in the relative humidity sensor, and measurements from these additional sensors can also be used to determine the relative humidity. In this way, an optical relative humidity sensor can be formed in an electronic device. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 is a perspective view of an illustrative wearable electronic device according to some embodiments.

[0008] Figure 2 is a perspective view of an illustrative portable electronic device according to some embodiments.

[0009] Figure 3 is a diagram of an illustrative electronic device according to some embodiments.

[0010] Figure 4 is a side view of an illustrative electronic device with a relative humidity sensor according to some embodiments.

[0011] Figure 5 is a graph of an illustrative relationship between relative humidity and power received by a photodetector in a relative humidity sensor, according to some embodiments.

[0012] Figure 6 is a side view of an illustrative electronic device with a relative humidity sensor having light emitters and light detectors on the same side of an optical layer according to some embodiments.

[0013] Figure 7 is a side view of an illustrative electronic device having a relative humidity sensor formed by a Bragg reflector according to some embodiments.

[0014] Figure 8 is a graph of an exemplary relationship between wavelength and reflectivity of a Bragg reflector according to some embodiments.

[0015] Fig. 9 is a side view of an illustrative electronic device having a relative humidity sensor formed by a prism and a collimated light source according to some embodiments.

[0016] Fig.10 is a side view of an illustrative electronic device having a relative humidity sensor formed by a prism and a diverging light source according to some embodiments.

[0017] Fig.11 is a side view of an illustrative electronic device with a relative humidity sensor formed by a waveguide according to some embodiments. DETAILED DESCRIPTION

[0018] Electronic devices are often carried by users as they conduct daily activities. For example, a user may carry an electronic device with them throughout the day while walking, commuting, working, exercising, etc. In some cases, a user may desire to know the relative humidity in the environment of the device. For example, relative humidity may be used in combination with fitness applications (e.g., to determine whether a user is experiencing low temperatures, which is more likely at high relative humidity levels), weather sensing and / or forecasting, and / or other desired functionality.

[0019] In order to perform relative humidity measurements, an electronic device may include a relative humidity sensor. The relative humidity sensor may include a light source, an optical layer (through which the light source emits light), a relative humidity sensitive layer on the optical layer, and a light detector. The relative humidity sensitive layer may change the light before it reaches the light detector. In particular, the relative humidity sensitive coating may have different refractive indices at different relative humidity levels. Therefore, the relative humidity can be determined based on the amount / intensity of light that reaches the light detector after the light has been reflected by the relative humidity sensitive layer.

[0020] Generally, any suitable electronic device may include a relative humidity sensor. Figure 1 As shown, the wearable electronic device 10, which may be a wristwatch device, may have a housing 12, a display 14, and a strap 16. Specifically, the display 14 may be on the front of the wearable device 10. The wristwatch may be attached to the user's wrist via the strap 16. When worn on the user's wrist, the back of the wearable device 10 (i.e., the back surface of the housing 12) may contact the user's wrist or be oriented toward the user's wrist. In some embodiments, the device 10 may include various sensors that contact the user's wrist, and the sensors may collect the user's health or activity data (e.g., heart rate data or blood oxygen data). Additionally or alternatively, the device 10 may include an opening 13. The opening 13 may allow moisture to pass through the wall of the housing 12 (e.g., the side wall of the housing 12), thereby allowing the relative humidity sensor covered by the opening to determine the relative humidity outside the device 10. The opening 13 may be covered by a net or other material, or may not be covered.

[0021] although Figure 1 The electronic device 10 is shown as a wristwatch device, but this is merely illustrative. In general, the electronic device 10 can be any desired device. For example, in Figure 2 In the illustrative example of , device 10 may be a cellular telephone (e.g., a smart phone) having a display 14 on the front of a housing 22 and an opening 23 for a relative humidity sensor on a side wall of the housing 22. Alternatively, device 10 may be a media player (e.g., a smart speaker) or other handheld or portable electronic device, a laptop computer, a desktop computer, a wristband device, a hanging device, a headset, a speaker, an earbud or a handset device, a head-mounted device such as glasses, goggles, a helmet, or other equipment worn on a user's head, or other wearable or miniature device, a navigation device or other accessory, and / or equipment that implements the functionality of two or more of these devices.

[0022] Illustrative configurations in which electronic device 10 is a portable electronic device such as a cellular phone, a head-mounted device, earbuds, a wristwatch, or a portable computer may sometimes be described herein as an example. Regardless of the form factor of device 10, Figure 3 An illustrative schematic diagram of the device 10 is shown in FIG.

[0023] like Figure 3As shown, an electronic device such as electronic device 10 may have a control circuit 112. Control circuit 112 may include storage and processing circuits for controlling the operation of device 10. Circuit 112 may include storage devices, such as hard disk drive storage devices, non-volatile memory (e.g., 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 circuits in control circuit 112 may be based on one or more microprocessors, microcontrollers, digital signal processors, baseband processors, power management units, audio chips, graphics processing units, application-specific integrated circuits, and other integrated circuits. Software code may be stored on a storage device in circuit 112 and run on processing circuits in circuit 112 to implement control operations for device 10 (e.g., data acquisition operations, operations involving the use of control signals to adjust components of device 10, etc.).

[0024] Electronic device 10 may include communication circuitry 114, which may include wired and / or wireless communication circuitry. For example, electronic device 10 may include radio frequency transceiver circuitry, such as cellular telephone transceiver circuitry, wireless local area network transceiver circuitry (e.g., circuits), short-range RF transceiver circuits that use ultra-high frequency radio waves to communicate over short distances (e.g., circuits or other short-range transceiver circuits), millimeter wave transceiver circuits, and / or other wireless communication circuits.

[0025] Device 10 may include input-output devices 116. Input-output devices 116 may be used to allow a user to provide user input to device 10. Input-output devices 116 may also be used to gather information about the environment in which device 10 operates. Output components in device 116 may allow device 10 to provide output to a user, and may be used to communicate with external electrical equipment.

[0026] Input-output devices 116 may include one or more optional displays, such as display 14. Display 14 may be an organic light emitting diode display or other display having light emitting diodes, a liquid crystal display, a micro-LED display, or other display. Display 14 may be touch sensitive (e.g., display 14 may include a two-dimensional touch sensor for capturing touch input from a user) and / or display 14 may not be touch sensitive.

[0027] The input-output devices 116 may include sensors 118. The sensors 118 may include, for example, temperature sensors (e.g., thermistors or thermocouples), three-dimensional sensors (e.g., three-dimensional image sensors such as structured light sensors that emit a light beam and use a two-dimensional digital image sensor to collect image data for a three-dimensional image from light points generated when a target is illuminated by the light beam, a binocular three-dimensional image sensor that uses two or more cameras in a binocular imaging arrangement to collect a three-dimensional image, a three-dimensional lidar (light detection and ranging) sensor, a three-dimensional radio frequency sensor, or other sensors that collect three-dimensional image data), cameras (e.g., infrared and / or visible light digital image sensors), gaze tracking sensors (e.g., gaze tracking systems based on image sensors and, if necessary, also based on light sources that emit one or more light beams that are reflected from the user's eyes using an image sensor). tracking), touch sensors, capacitive proximity sensors, light-based (optical) proximity sensors, other proximity sensors, force sensors, sensors such as switch-based contact sensors, gas sensors, pressure sensors, humidity sensors, magnetic sensors (e.g., magnetometers), audio sensors (microphones), ambient light sensors, microphones for collecting voice commands and other audio inputs, sensors configured to collect information about motion, position and / or orientation (e.g., accelerometers, gyroscopes, pressure sensors, compasses, and / or inertial measurement units including all of these sensors or a subset of one or both of these sensors), health sensors that measure various biometric information (e.g., heart rate sensors such as photoplethysmography sensors, electrocardiogram sensors, and perspiration sensors), and / or other sensors.

[0028] Sensors 118 may also include one or more relative humidity sensors 120. Relative humidity sensor 120 may be incorporated into device 10 and may measure the relative humidity of an environment external to electronic device 10.

[0029] If desired, input-output devices 116 may include other devices 124, such as tactile output devices (e.g., vibrating components), light emitting diodes and other light sources, speakers such as ear speakers for producing audio output, circuits for receiving wireless power, circuits for wirelessly transmitting power to other devices, batteries and other energy storage devices (e.g., capacitors), joysticks, buttons, and / or other components.

[0030] Figure 4 An illustrative example of a device having a relative humidity sensor is shown in FIG. Figure 4 As shown, device 10 may include relative humidity sensor 120. In particular, relative humidity sensor 120 may be positioned behind opening 25 of layer 24. Layer 24 may be a housing of device 10, such as Figure 1Housing 12 or Figure 2 Alternatively, layer 24 may be another layer that overlaps relative humidity sensor 120 and separates interior 11 from exterior 15. Figure 1 Opening 13 or Figure 2 The opening 25 of the opening 23 may allow moisture from the environment at the exterior 15 to reach the relative humidity sensor 120 in the interior 11. The opening 25 may overlap with the sensor 120, such as Figure 4 As shown, or the sensor 120 can be partially or completely offset from the opening 25. In other words, the relative humidity sensor 120 can be in the interior 11 and can be exposed to the environment at the exterior 15. A protective mesh 26 can be included in the opening 25 to protect the relative humidity sensor 120 and / or other components in the interior 11 from various particles or other intrusive materials. The protective mesh 26 can be a metal mesh, a polymer mesh, or a mesh of any other suitable material. In some embodiments, the protective mesh 26 can be coated with a hydrophobic material to protect the sensor 120 from liquid water while still allowing the sensor 120 to react to changes in relative humidity in the exterior 15.

[0031] Relative humidity sensor 120 may include light emitter 28 (also referred to herein as light source 28), which may be a laser diode, a light emitting diode, or any other desired light emitter. Sensor 120 may also include optical layer 35, which may be formed of glass, polymer (e.g., polycarbonate), sapphire, ceramic, or other suitable material. Optical layer 35 may have sloped edges 37 and 39 (also referred to herein as beveled and / or faceted edges 37 and 39). In some embodiments, optical layer 35 may be an optical film.

[0032] A light detector 34, which may be a photodiode or other light-sensitive device, may be included within the sensor 120 at an end opposite the light emitter 28. A mirror coating 36 may be formed on the sloped edge 39 and may reflect light to the light detector 34. The mirror coating 36 may be formed of a reflective material such as a metal; a reflective coating such as a stack of thin-film dielectric layers having a reflectivity of at least 75%, at least 80%, at least 90%, or other suitable reflectivity; or other suitable reflective material.

[0033] A relatively humidity-sensitive layer 30 (also referred to herein as a relatively humidity-sensitive material 30) may be formed on the surface of the optical layer 35, and an absorbing coating 32 may be formed on the relatively humidity-sensitive layer 30. The relatively humidity-sensitive layer 30 may be an inorganic porous film that may include voids and / or nanoparticles. The layer 30 may have a thickness of at least 1 micron, between 1 micron and 100 microns, less than 150 microns, at least 50 microns, or other suitable thicknesses. The nanoparticles may be inorganic, such as metal oxide nanoparticles. As some illustrative examples, the nanoparticles may include silicon dioxide nanoparticles, titanium dioxide nanoparticles, zinc oxide nanoparticles, or other suitable nanoparticles. At different relative humidities, the nanoparticles and / or voids in the layer 30 may exhibit changes, such as changes in the refractive index, thereby affecting the light reflected from the layer 30.

[0034] Alternatively, the relatively humidity sensitive layer 30 may be formed of a holographic layer. For example, the relatively humidity sensitive layer 30 may be formed of a photopolymer such as dichromated gelatin, in which or on which a holographic pattern is recorded. The holographic pattern may be an interference pattern including a plurality of gratings and / or may include a lens or a mirror. The photopolymer may be sensitive to relative humidity and / or temperature, and may have a refractive index change or a thickness change at different relative humidities. When exposed to different relative humidity levels, the holographic interference pattern (e.g., the distance between the gratings of the interference pattern) may change, thereby affecting the reflection of light from the relatively humidity sensitive layer 30.

[0035] The absorptive coating 32 may be a black coating (e.g., black ink or black frit), a thin film interference filter coating having, for example, at least 50%, at least 75%, at least 80%, or at least 90% absorption, or any other suitable absorptive coating. A mirror coating 36 may optionally be included on the surface of the optical layer 35 opposite the light source 28.

[0036] In operation, light source 28 may emit light 38 into optical layer 35 through beveled edge 37. Light 38 may reflect within optical layer 35 and exit relatively humidity-sensitive layer 30 until it is detected by light detector 34. Mirror coating 36 may reflect light that reaches beveled edge 39 toward light detector 34. However, the presence of relatively humidity-sensitive layer 30 may affect the amount of light that reaches light detector 34.

[0037] Specifically, at low relative humidity, the refractive index of relatively humidity-sensitive layer 30 may be between the refractive index of the air outside device 10 (e.g., a refractive index of approximately 1.0) and the refractive index of the nanoparticles within layer 30 due to the presence of voids within layer 30. Thus, at low relative humidity levels, a high percentage of light 38 will be reflected within optical layer 35 and reach light detector 34.

[0038] However, when relative humidity increases, water may accumulate on the surface of the nanoparticles and / or fill voids in layer 30. The presence of water may therefore increase the refractive index of layer 30, redirecting some of the light 40 passing through layer 30 to be absorbed by absorptive coating 32. Thus, at high relative humidity levels, a lower percentage of light 38 will reach photodetector 34.

[0039] In an exemplary embodiment in which a sol-gel coated silica porous film is used for layer 30, when the relative humidity changes from 30% to 90%, the refractive index of the relative humidity sensitive layer 30 may change from 1.38 to 1.43. However, this is merely exemplary. In general, the refractive index of layer 30 may change according to the relative humidity based on the material forming layer 30.

[0040] As a result of the change in refractive index, more light 40 will pass through the relative humidity sensitive layer 30 and be absorbed by the absorptive coating 32. The amount of light 40 absorbed by the absorptive coating 32 increases as the relative humidity increases, and the amount of light reaching the light detector 34 decreases as the relative humidity increases. Therefore, the relative humidity can be determined by determining the amount of light reaching the light detector 34. Figure 5 An illustrative example of the relationship between the amount of light detected by a light detector in a relative humidity sensor and the relative humidity is shown in FIG.

[0041] like Figure 5 As shown, the graph 42 may include a graph of relative humidity versus relative humidity as measured by a relative humidity sensor (e.g., Figure 4 The relative humidity sensor 120) includes a light detector (e.g., Figure 4 44. In particular, Figure 5 As shown, a high power A can be detected by the light detector at a relative humidity of 30%. In contrast, a low power B can be detected by the light detector at a relative humidity of 90%. As an example, power A can be at least 175 μW, at least 190 μW, or another high power value, while power B can be less than 150 μW, less than 160 μW, or another low power value. However, these examples are merely illustrative. Typically, high power A and low power B will be detected based on the relative humidity sensor provided by the light source (e.g., Figure 4 The power emitted by the light source 28) changes.

[0042] As an example, the relationship between relative humidity and power for a given relative humidity sensor can be determined by calibrating the relative humidity sensor using at least two different relative humidity conditions. In operation, a known relationship between relative humidity and power (e.g., Figure 5 The exemplary relationship 44 of can be used to determine relative humidity based on the power measurement from the light detector. For example, processing circuitry and / or control circuitry (such as Figure 3The control circuit 112 of the optical relative humidity sensor can be used to determine the relative humidity based on the power measurement from the light detector. In this way, an optical relative humidity sensor such as Figure 4 A relative humidity sensor 120) may be used to measure the relative humidity in the environment of the device.

[0043] exist Figure 5 In the example of FIG. 1 , the relationship between received power and relative humidity is shown between 30% and 90%. However, this is merely an illustrative relationship across an illustrative range of relative humidity levels. In general, depending on the relative humidity sensitive material used in the relative humidity sensor, the relative humidity sensitive material can detect relative humidity changes across any suitable range of relative humidity levels.

[0044] although Figure 4 Light emitter 28 and light detector 34 are shown on opposite sides of sensor 120, but this arrangement is merely exemplary. In some embodiments, light emitters and light detectors may be incorporated on the same side of a relative humidity sensor. Figure 6 An illustrative example is shown in .

[0045] like Figure 6 As shown, the light emitter 28 and the light detector 34 can be included on the same side of the sensor 120. In operation, the light emitter 28 can emit light 52 into the optical layer 35. When the light 52 reaches the opposite side of the optical layer 35, the light can be reflected by the mirror coating 36. The light 52 can then be reflected back through the optical layer 35 and reach the light detector 34 as light 54. The power of the light 54 reaching the light detector 34 can be related to the relative humidity because the refractive index of the relative humidity sensitive material 30 can change based on the relative humidity, thereby allowing more light to pass through to the absorptive coating 32 (e.g., as the relative humidity increases). Figure 4 Thus, by measuring light 54 (e.g., the power of light 54) using light detector 34, relative humidity can be determined. In other words, relative humidity sensor 120 can directly determine relative humidity based on the measurement of light 54, or control circuitry (such as Figure 3 The control circuit 112) can be used to determine the relative humidity based on the measurement of light 54.

[0046] By combining the light emitter 28 and the light detector 34 on the same side of the optical layer 35, the path of the light 52 through the optical layer 35 can be doubled (e.g., with Figure 4If the optical layer 35 is maintained at the same length, this can increase the sensitivity of the sensor 120. Alternatively, the length of the optical layer 35 can be reduced, and space can be saved in the device 10. Additionally or alternatively, the light emitter 28 and the light detector 34 can be mounted on the same control board (e.g., a printed circuit board), which can save additional space in the device 10.

[0047] In addition to incorporating the light emitter 28 and the light detector 34 on the same side of the optical layer 35, the sensor 120 may optionally include a reference light detector 46 and a temperature sensor 56. The reference light detector 46, which may be a photodiode or other light-sensitive component, may detect light 50 emitted by the light emitter 28 and reflected by the sloped edge 37 before the remainder of the light 48 enters the optical layer 35. By measuring the light 50, light intensity fluctuations (e.g., light fluctuations of the light emitter 28 or fluctuations of ambient light) may be detected and corrected. Additionally or alternatively, the temperature sensor 56, which may be a thermistor or a thermocouple, may measure the temperature near the relatively humidity-sensitive material 30. Because the refractive index of the relatively humidity-sensitive material 30 may change in response to changes in temperature as well as changes in relative humidity, changes due to temperature changes may be corrected based on the temperature measurement of the temperature sensor 56.

[0048] Although the temperature sensor 56 is shown adjacent to the light detector 34, this is merely illustrative. In general, the temperature sensor 56 may be formed in any suitable location in the relative humidity sensor 120. For example, the temperature sensor 56 may be formed near the relative humidity sensitive layer 30, adjacent to the relative humidity sensitive layer 30, in contact with the relative humidity sensitive layer 30, or otherwise close to the layer 30 to determine a temperature change of the layer 30. Alternatively or additionally, multiple temperature sensors 56 may be incorporated into the sensor 120.

[0049] The sensor 120 may also optionally include a heater 58. As an example, the heater 58 may be a resistive heating element that can be heated to evaporate moisture from the relative humidity sensitive layer 30 if the device 10 has been subjected to high humidity or immersion. Alternatively or additionally, in some embodiments, the heater 58 may dry the relative humidity sensitive layer 30 between relative humidity measurements. The heater 58 may dry the layer 30 between each relative humidity measurement or between selected relative humidity measurements. In other words, the heater 58 may ensure that the relative humidity sensitive layer 30 returns to a refractive index state that reflects the current relative humidity outside the device 10.

[0050] However, in Figure 6 Reference light detector 46, temperature sensor 56 and / or heater 58 (with Figure 4 The arrangement of the comparison is only illustrative. Generally, it can be Figure 6 Any of the reference light detector 46, the temperature sensor 56, and / or the heater 58 may be omitted from the sensor 120. Additionally or alternatively, any of the reference light detector 46, the temperature sensor 56, and / or the heater 58 may be incorporated into Figure 4 In the sensor 120.

[0051] exist Figure 4 and Figure 6 In the example of , light emitted by light emitter 28 travels through optical layer 35 having a sloped edge before reaching light detector 34. However, Figure 4 and Figure 6 The use of the medium optical layer 35 is merely exemplary. In some embodiments, other layers can be used to form the optical layer. Figure 7 An illustrative example in which a Bragg reflector is used is shown in .

[0052] like Figure 7 As shown, the relative humidity sensor 120 may include Bragg reflectors 58A and 58B as optical layers. The Bragg reflectors 58A and 58B may include a stack of thin film dielectric layers having alternating high and low refractive indices. These thin film dielectric layers may destructively interfere with light incident on the Bragg reflectors 58A and 58B, and the Bragg reflectors 58A and 58B may therefore reflect light based on its wavelength. The relative humidity sensitive layer 30 may be included on the top surface of the Bragg reflector 58A, while the Bragg reflector 58B may not be coated with the layer 30.

[0053] Light emitter 28 may emit light 59 toward Bragg reflector 58A, which in turn may reflect the light as light 61. Light 61 may be detected by light detector 34. At the same time, light emitter 28 may emit light 63 toward reference Bragg reflector 58B, which in turn may reflect the light as light 65. Light 65 may be detected by reference light detector 46.

[0054] Due to the presence of the relatively humidity-sensitive layer 30 on the Bragg reflector 58A, the light detector 34 may detect a different amount of light than the reference light detector 46, even though the lights 59 and 63 have the same wavelength and power when emitted by the light emitter 28. The difference between the measurements obtained by the light detector 34 and the reference light detector 46 may correspond to the refractive index of the relatively humidity-sensitive material 30, and therefore to the relative humidity (as measured in conjunction with the relative humidity). Figures 4 to 6In particular, relative humidity may be determined based on measurements of light detector 34 and reference light detector 46, such as by comparing the measurement from light detector 34 to the measurement from reference light detector 46. In other words, relative humidity sensor 120 may determine relative humidity directly based on measurements of light detector 34 and reference light detector 46, or control circuitry (such as Figure 3 The control circuit 112 of the light detector 34 can be used to determine the relative humidity based on the measurements of the reference light detector 46.

[0055] Bragg reflectors 58A and 58B may be designed to reflect light of a desired wavelength (eg, corresponding to the wavelength of light emitted by light emitter 28 ) and may be sensitive to changes in the refractive index near that wavelength. Figure 8 A graph of an exemplary relationship between wavelength and reflectivity of a Bragg reflector is shown in FIG.

[0056] like Figure 8 As shown, the graph 60 may include a Bragg reflector (such as Figure 7 6A and 67). As shown in the exemplary relationship 62, the Bragg reflector can have peaks and valleys in reflectivity at different wavelengths of light incident on the Bragg reflector. In the regions between the peaks and valleys, the Bragg reflector can have a very sensitive response to changes in wavelength. In particular, across the wavelength ranges 64 and 67, the Bragg reflector can have large changes in reflectivity with small changes in the wavelength of the incident light.

[0057] Therefore, the Bragg reflector in the relative humidity sensor can be designed to have a wavelength range 64 and / or 67 of a suitable value, such as approximately 880 nm, between 870 and 900 nm, between 800 and 840 nm, or other suitable values, and the light emitter in the sensor (e.g., light emitter 28) can emit light within the wavelength range 64 or 67. Therefore, any change in the refractive index of the relative humidity sensitive material 30 overlapping with the Bragg reflector 58A may have a large effect on the reflectivity of the light leaving the Bragg reflector 58A. By comparing the light sensed by the light detector 34 and the light sensed by the light detector 46, the refractive index change of the relative humidity sensitive material 30 can be determined, and the relative humidity can be determined based on the refractive index change. In this way, Figure 7 The relative humidity sensor 120 may be used to determine the relative humidity.

[0058] Although Figure 7The use of a single light source emitting light to both Bragg reflectors is shown, but this arrangement is merely illustrative. In some embodiments, two light sources having different wavelengths may be used with a single Bragg reflector (or multiple Bragg reflectors) and a photodetector. For example, one light source may emit light with wavelengths in wavelength range 64, while another light source may emit light with wavelengths in wavelength range 67. The ratio of light reflected by a Bragg reflector (with a relative humidity-sensitive material 30 overlapping the Bragg reflector) at the two wavelengths may be acquired (e.g., the reflected light at the two wavelengths may be compared) and used to determine the refractive index of the relative humidity-sensitive material 30 and, therefore, the relative humidity. For example, the method may have a ratio of Figure 7 The arrangement shown in higher resolution.

[0059] As another option, a single light source can emit light at a single Bragg reflector (with the relative humidity-sensitive material 30 overlapping the Bragg reflector). Multiple light detectors sensitive to different wavelengths (e.g., light detectors with different color filters) can detect the reflected light. Based on the reflected light of different wavelengths, such as by comparing the reflected light of different wavelengths, the refractive index and relative humidity of the relative humidity-sensitive material 30 can be determined.

[0060] In some embodiments, polarized light can be used in a relative humidity sensor, which can increase the sensitivity of the sensor. Fig. 9 An illustrative example is shown in .

[0061] like Fig. 9 As shown, relative humidity sensor 120 may include relative humidity sensitive layer 30 on optical layer 66, which may be a prism. Light emitter 28 may emit light 68 through collimating lens 69. Light 68 may be transverse magnetic (TM) polarized light or may be light having another suitable polarization. Light 72 may be light reflected from optical layer 66 to reference light detector 46, while light 70 may enter optical layer 66. Light 70 may be reflected from relative humidity sensitive layer 30 at angle 71, and may be reflected and exit optical layer 66 as light 73. Light detector 34 may detect light 73.

[0062] The reflection of the relative humidity-sensitive layer 30 between the Brewster's angle and the total internal reflection (TIR) ​​angle may be very sensitive to small changes due to the polarization and collimation of the light 68. Therefore, the light emitter 28 may be configured to emit light 68 so that the light 70 strikes the relative humidity-sensitive layer 30 between the Brewster's angle and the TIR angle. In other words, the angle 71 may be between the Brewster's angle and the TIR angle. Therefore, any changes in the relative humidity-sensitive layer 30 (e.g., the refractive index of the layer 30) due to changes in relative humidity may have a large effect on the reflectivity of the layer 30, and the relative humidity may be determined based on the light detected by the light detector 34. In other words, the relative humidity sensor 120 may determine the relative humidity directly based on the light detected by the light detector 34, or a control circuit (such as a Figure 3 The control circuit 112 can be used to determine the relative humidity based on the light detected by the light detector 34.

[0063] The sensor 120 may also include a temperature sensor 56, which may be used to correct the determined relative humidity for changes in the relative humidity sensitive layer 30 due to temperature. If desired, the light emitter 28, the reference light detector 46, the light detector 34, and / or the temperature sensor 56 may be formed on the same control board, such as the same printed circuit board.

[0064] Instead of using Fig. 9 By using collimated light in a layer, a refractometer can be used to measure the light that has been reflected at different angles based on the changes in the relative humidity sensitive layer. Fig.10 An illustrative example is shown in .

[0065] like Fig.10 As shown, the light emitter 28 can emit light 78 into the optical layer 66, which can be a prism. Fig. 9 The light 68 is different, Fig.10 The light 78 is non-collimated. The light 78 may be reflected off the interface between the relatively humidity sensitive layer 30 and the air as light 79. The light 79 may pass out of the optical layer 66 and may be focused by the lens 80 before being detected by the line detector 82.

[0066] Because light 78 is divergent, non-collimated light, the light may be reflected from layer 30 at a range of incident angles below and above the TIR angle. The spread of light reflected from layer 30 may vary based on the refractive index of layer 30. For example, in Fig.10In an exemplary embodiment of , light 78 may illuminate an area of ​​line detector 82 between line 84 and line 86. By determining the extent to which line detector 82 is illuminated (e.g., by detecting the angular spread of light detected by line detector 82), the refractive index of layer 30 may be determined, which may be used to determine relative humidity. In this manner, a refractometer formed using line detector 82 (or another suitable light detector) may be used to measure relative humidity. In other words, relative humidity sensor 120 may determine relative humidity directly based on measurements of line detector 82, or control circuitry (such as a Figure 3 The control circuit 112) can be used to determine the relative humidity based on the measurements of the line detector 82.

[0067] Although in Fig.10 Not shown, but a reference light detector and / or a temperature sensor may be incorporated into relative humidity sensor 120 if desired.

[0068] In some exemplary embodiments, integrated photonics may be used in combination with one or more relative humidity sensitive layers to determine relative humidity. Fig.11 An illustrative example of a relative humidity sensor using integrated photonics is shown in FIG.

[0069] like Fig.11 As shown, the relative humidity sensor 120 may include multiple optical layers, such as waveguides 88 and 90. The relative humidity sensitive layer 30 may surround both waveguides 88 and 90. The light emitter 28, which may be a laser source, may excite an electromagnetic wave 94 in the waveguide 88. Due to field coupling, the power of the electromagnetic wave 94 may be exchanged from the waveguide 88 to the waveguide 90 as the electromagnetic wave moves through the sensor 120. In particular, as shown by wave 95, some of the power has been transferred to the waveguide 90, and at the end of the sensor 120, most, if not all, of the power has been transferred to the waveguide 90, as shown by wave 96.

[0070] The coupling length of the electromagnetic power in waveguides 88 and 90 sensed by detectors 34 and 41, respectively, may be a function of relative humidity due to the presence of relative humidity sensitive layer 30 on waveguides 88 and 90. Thus, by measuring the amount of power that has been transferred to waveguide 90 (using detectors 41 and 34), relative humidity may be determined. In other words, relative humidity sensor 120 may determine relative humidity directly based on measurements of detectors 34 and 41, or control circuitry (such as Figure 3 The control circuit 112) can be used to determine the relative humidity based on the measurements of the detectors 34 and 41.

[0071] If desired, an optional light emitter 29, which may be a second laser source, may excite waveguide 90. Light emitter 29 may operate at the same wavelength as light emitter 28, or light emitters 28 and 29 may operate at different wavelengths. Electromagnetic power in waveguides 88 and 90 may be exchanged, and a detector may determine the amount of power that has been exchanged. As an example, using two laser sources may allow sensor 120 to cover a larger relative humidity range.

[0072] although Fig.11 A relatively humidity sensitive layer 30 is shown on both sides of two waveguides 88 and 90, but this is merely illustrative. In some embodiments, a single relatively humidity sensitive layer 30 may be bonded between waveguides 88 and 90, while the upper surface of waveguide 88 and the lower surface of waveguide 90 may be free of relatively humidity sensitive material.

[0073] As described above, one aspect of the present technology is to collect and use information, such as information from input-output devices. The disclosure contemplates that, in some cases, data including personal information data may be collected that uniquely identifies or can be used to contact or locate a specific person. Such personal information data may include demographic data, location-based data, phone numbers, email addresses, Twitter IDs, home addresses, data or records related to the user's health or fitness level (e.g., vital sign measurements, medication information, exercise information), date of birth, user name, password, biometric information, or any other identification or personal information.

[0074] The present disclosure recognizes that the use of such personal information in the present technology can be used to benefit users. For example, the personal information data can be used to deliver targeted content that users are more interested in. Therefore, the use of such personal information data enables users to have planned control over the content delivered. In addition, the present disclosure also anticipates other uses of personal information data that benefit users. For example, health and fitness data can be used to provide insights into the user's overall health status, or can be used as positive feedback to individuals who use technology to pursue health goals.

[0075] The disclosure anticipates that entities responsible for the collection, analysis, disclosure, transmission, storage or other purposes of such personal information data will comply with sound privacy policies and / or privacy measures. Specifically, such entities should implement and adhere to the use of privacy policies and practices that are recognized as meeting or exceeding the industry or government requirements for maintaining the privacy and security of personal information data. Such policies should be easy for users to access and should be updated as changes in the collection and / or use of data occur. Personal information from users should be collected for legal and reasonable entity purposes and should not be shared or sold outside these legal purposes. In addition, such collection / sharing should be carried out after receiving the informed consent of the user. In addition, such entities should consider taking any necessary steps to protect and safeguard access to such personal information data, and ensure that other entities with access to personal information data comply with their privacy policies and procedures. In addition, such entities can subject themselves to third-party assessments to prove that they comply with widely accepted privacy policies and practices. In addition, policies and practices should be adapted to specific types of personal information data collected and / or accessed, and to applicable laws and standards including considerations of special jurisdictions. For example, in the United States, the collection or access of certain health data may be governed by federal and / or state laws such as the Insurance Portability and Accountability Act (HIPAA), while health data in other countries may be subject to other regulations and policies and should be handled accordingly. Therefore, different privacy measures should be advocated for different types of personal data in each country.

[0076] Regardless of the foregoing, the present disclosure also contemplates implementation schemes in which users selectively block the use or access of personal information data. That is, the present disclosure contemplates hardware elements and / or software elements to prevent or block access to such personal information data. For example, the technology of the present invention may be configured to allow users to choose to "opt in" or "opt out" to participate in the collection of personal information data at any time during or after registration for a service. For another example, a user may choose not to provide certain types of user data. For another example, a user may choose to limit the length of time that user-specific data is retained. In addition to providing "opt-in" and "opt-out" options, the present disclosure also contemplates providing notifications related to access or use of personal information. For example, a user may be notified that their personal information data will be accessed when downloading an application ("app"), and then the user may be reminded again before the personal information data is accessed by the app.

[0077] In addition, it is the intention of the present disclosure that personal information data should be managed and processed in a manner that minimizes the risk of unintentional or unauthorized access or use. Once the data is no longer needed, the risk can be minimized by limiting the collection of data and deleting the data. In addition, and when applicable, including in certain health-related applications, data de-identification can be used to protect the privacy of users. Where appropriate, de-identification can be facilitated by removing specific identifiers (e.g., date of birth, etc.), controlling the amount or characteristics of stored data (e.g., collecting location data at the city level rather than the address level), controlling how the data is stored (e.g., aggregating data between users), and / or other methods.

[0078] Thus, while the present disclosure broadly encompasses the use of information that may include personal information data to implement one or more of the various disclosed embodiments, the present disclosure also contemplates that various embodiments may be implemented without requiring access to personal information data. That is, various embodiments of the present technology will not fail to function properly due to the lack of all or a portion of such personal information data.

[0079] According to one embodiment, an electronic device having an interior and an exterior exposed to an environment is provided, the electronic device comprising: a housing that separates the interior from the environment, the housing having an opening; and a relative humidity sensor that is in the interior and exposed to the environment, the relative humidity sensor comprising: an optical layer; a relative humidity-sensitive layer that is coupled to a surface of the optical layer; a light emitter that is configured to emit light into the optical layer; and a light detector that is configured to detect light that has been reflected within the optical layer and leaves the relative humidity-sensitive layer.

[0080] According to another embodiment, a relative humidity sensor includes an absorptive coating on a relatively humidity sensitive layer, the relatively humidity sensitive layer being disposed between the absorptive coating and a surface of the optical layer.

[0081] According to another embodiment, the relative humidity sensor is configured to determine the relative humidity based on an amount of light detected by the light detector.

[0082] According to another embodiment, the optical layer has a first side and an opposing second side, the light emitter is configured to emit light into the first side, and the light detector is adjacent to the second side.

[0083] According to another embodiment, the optical layer has a first side and an opposing second side, the light emitter is configured to emit light into the first side and the light detector is configured to detect light at the first side, and the relative humidity sensor includes a mirror coating on the second side.

[0084] According to another embodiment, a relative humidity sensor includes a reference light detector and a temperature sensor adjacent to a first side of an optical layer.

[0085] According to another embodiment, the relative humidity sensor includes a heater configured to dry the relative humidity sensitive layer between relative humidity measurements.

[0086] According to another embodiment, the optical layer is a Bragg reflector comprising a stack of thin film dielectric layers.

[0087] According to another embodiment, a relative humidity sensor includes a reference Bragg reflector and a reference light detector, the light emitter being configured to emit additional light toward the reference Bragg reflector, the reference light detector being configured to detect light that has been reflected from the reference Bragg reflector, the relative humidity sensor being configured to determine the relative humidity by comparing a first measurement from the light detector and a second measurement from the reference light detector.

[0088] According to another embodiment, the light emitter is configured to emit light of a first wavelength, and the relative humidity sensor includes an additional light source configured to emit additional light of a second wavelength different from the first wavelength into the Bragg reflector, the light detector is further configured to detect the additional light that has been reflected within the Bragg reflector and leaves the relative humidity sensitive layer, and the relative humidity sensor is configured to determine the relative humidity by comparing the detected light and the detected additional light.

[0089] According to another embodiment, the light detector is configured to detect light of a first wavelength, the relative humidity sensor includes an additional light detector configured to detect light of a second wavelength different from the first wavelength, and the relative humidity sensor is configured to determine the relative humidity by comparing the detected light of the first wavelength with the detected light of the second wavelength.

[0090] According to another embodiment, the optical layer is a prism and the relative humidity sensor includes: a collimating lens configured to collimate light emitted by the light emitter; and a reference light detector configured to detect reflected light emitted from the light emitter and reflected off an edge of the prism.

[0091] According to another embodiment, the relative humidity sensor is configured to determine the relative humidity based on the intensity of the detected light.

[0092] According to another embodiment, the optical layer is a prism, the light detector is a line detector, and the relative humidity sensor is configured to determine the relative humidity based on the angular spread of light detected by the line detector.

[0093] According to another embodiment, the optical layer is a first waveguide, the light emitter is a laser configured to excite electromagnetic power within the first waveguide, the light detector is a first light detector configured to measure the electromagnetic power at the end of the first waveguide, and the relative humidity sensor includes: a second waveguide; and a second light detector configured to measure additional electromagnetic power at the end of the second waveguide, and the relative humidity sensor is configured to determine the relative humidity based on the electromagnetic power at the end of the first waveguide and the additional electromagnetic power at the end of the second waveguide.

[0094] According to another embodiment, the relatively humidity sensitive layer includes a film including voids and metal oxide nanoparticles.

[0095] According to one embodiment, a relative humidity sensor is provided, which includes an optical layer, a relative humidity sensitive layer on a surface of the optical layer, a light emitter configured to emit light into the optical layer, and a light detector configured to detect light that has been reflected within the optical layer and leaves the relative humidity sensitive layer, the relative humidity sensor being configured to determine the relative humidity based on the detected light.

[0096] According to another embodiment, the optical layer includes a sloped edge configured to direct light emitted by the light emitter into the optical layer and to direct light that has been reflected within the optical layer out of the optical layer.

[0097] According to another embodiment, the optical layer is a prism.

[0098] According to one embodiment, an electronic device is provided, the device comprising: a housing; a relative humidity sensor located in the housing, the relative humidity sensor comprising: an optical layer; a relative humidity sensitive layer located on a surface of the optical layer, the relative humidity sensitive layer being configured to exhibit a change in refractive index in response to a change in relative humidity; a light emitter configured to emit light into the optical layer; and a light detector configured to detect light that has been reflected within the optical layer and leaves the relative humidity sensitive layer; and a control circuit configured to determine the relative humidity based on the light detected by the light detector.

[0099] The foregoing is exemplary and various modifications may be made to the embodiments described. The foregoing embodiments may be implemented independently or in any combination.

Claims

1. An electronic device having an interior and an exterior exposed to an environment, the electronic device comprising: an enclosure separating the interior from the environment, wherein the enclosure has an opening; and a relative humidity sensor within the interior and exposed to the environment, wherein the relative humidity sensor comprises: Optical layer; a relatively humidity-sensitive layer coupled to a surface of the optical layer; a light emitter configured to emit light into the optical layer; and A light detector is configured to detect light that has been reflected within the optical layer and exits the relatively humidity-sensitive layer.

2. The electronic device according to claim 1, wherein the relative humidity sensor further comprises: An absorbing coating on the relatively humidity sensitive layer, wherein the relatively humidity sensitive layer is disposed between the absorbing coating and the surface of the optical layer. 3 . The electronic device of claim 2 , wherein the relative humidity sensor is configured to determine relative humidity based on the amount of the light detected by the light detector. 4 . The electronic device of claim 3 , wherein the optical layer has a first side and an opposing second side, the light emitter is configured to emit the light into the first side, and the light detector is adjacent to the second side.

5. The electronic device of claim 3, wherein the optical layer has a first side and an opposing second side, the light emitter is configured to emit the light into the first side, and the light detector is configured to detect the light at the first side, and the relative humidity sensor further comprises: A mirror coating on the second side.

6. The electronic device according to claim 5, wherein the relative humidity sensor further comprises: A reference light detector and a temperature sensor are adjacent to the first side of the optical layer.

7. The electronic device according to claim 2, wherein the relative humidity sensor further comprises: A heater is configured to dry the relative humidity sensitive layer between relative humidity measurements.

8. The electronic device of claim 1, wherein the optical layer is a Bragg reflector comprising a stack of thin film dielectric layers.

9. The electronic device according to claim 8, wherein the relative humidity sensor further comprises: a reference Bragg reflector, wherein the light emitter is configured to emit additional light toward the reference Bragg reflector; and a reference light detector configured to detect light that has been reflected from the reference Bragg reflector, wherein the relative humidity sensor is configured to determine relative humidity by comparing a first measurement from the light detector and a second measurement from the reference light detector.

10. The electronic device of claim 8, wherein the light emitter is configured to emit the light at a first wavelength, and the relative humidity sensor further comprises: an additional light source configured to emit additional light of a second wavelength different from the first wavelength into the Bragg reflector, wherein the light detector is further configured to detect the additional light that has been reflected within the Bragg reflector and exits the relative humidity sensitive layer, and the relative humidity sensor is configured to determine the relative humidity by comparing the detected light and the detected additional light.

11. The electronic device of claim 8, wherein the light detector is configured to detect light of a first wavelength, the relative humidity sensor further comprising: An additional light detector is configured to detect light at a second wavelength different from the first wavelength, wherein the relative humidity sensor is configured to determine relative humidity by comparing the detected light at the first wavelength to the detected light at the second wavelength.

12. The electronic device of claim 1, wherein the optical layer is a prism, the relative humidity sensor further comprising: a collimating lens configured to collimate the light emitted by the light emitter; and A reference light detector is configured to detect reflected light emitted from the light emitter that reflects off an edge of the prism.

13. The electronic device of claim 12, wherein the relative humidity sensor is configured to determine the relative humidity based on an intensity of the detected light.

14. The electronic device of claim 1, wherein the optical layer is a prism, the light detector is a line detector, and the relative humidity sensor is configured to determine relative humidity based on an angular spread of the light detected by the line detector.

15. The electronic device of claim 1, wherein the optical layer is a first waveguide, the light emitter is a laser configured to excite electromagnetic power within the first waveguide, and the light detector is a photodetector configured to measure the electromagnetic power at an end of the first waveguide. a first light detector, and the relative humidity sensor further comprises: Second waveguide; and a second light detector configured to measure additional electromagnetic power at an end of the second waveguide, wherein the relative humidity sensor is configured to determine relative humidity based on the electromagnetic power at the end of the first waveguide and the additional electromagnetic power at the end of the second waveguide.

16. The electronic device of claim 1, wherein the relatively humidity sensitive layer comprises a film including voids and metal oxide nanoparticles.

17. A relative humidity sensor, comprising: Optical layer; a relatively humidity-sensitive layer located on a surface of the optical layer; a light emitter configured to emit light into the optical layer; and A light detector is configured to detect light that has been reflected within the optical layer and exits the relative humidity sensitive layer, wherein the relative humidity sensor is configured to determine relative humidity based on the detected light.

18. The relative humidity sensor of claim 17, wherein the optical layer comprises a sloped edge configured to guide the light emitted by the light emitter into the optical layer and to guide the light having been reflected within the optical layer out of the optical layer. The relative humidity sensor of claim 18 , wherein the optical layer is a prism.

20. An electronic device, comprising: shell; a relative humidity sensor located in the housing, wherein the relative humidity sensor comprises: Optical layer; a relatively humidity-sensitive layer on a surface of the optical layer, wherein the relatively humidity-sensitive layer is configured to exhibit a change in refractive index in response to a change in relative humidity; a light emitter configured to emit light into the optical layer; and a light detector configured to detect light that has reflected within the optical layer and exited the relatively humidity-sensitive layer; and A control circuit is configured to determine relative humidity based on the light detected by the light detector.

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