Patent Publication Number: US-11640144-B2

Title: Watch with optical sensor for user input

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. application Ser. No. 16/523,815, filed Jul. 26, 2019, now patented as U.S. Pat. No. 11,209,783, which claims the benefit of U.S. Provisional Application No. 62/712,169, entitled “WATCH WITH OPTICAL SENSOR FOR USER INPUT,” filed Jul. 30, 2018, the entirety of each of which is incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The present description relates in general to user input components, and more particularly to, for example and without limitation, optical sensors of watches for user input. 
     BACKGROUND 
     Portable electronic devices, such as watches, have become increasingly popular, and the features and functionality provided by portable electronic devices continue to expand to meet the needs and expectations of many consumers. User interface features are often provided on electronic devices to allow a user to provide commands for execution by the devices. Many devices include input components, such as crowns, that receive and detect tactile input from a user during operation. Such input components may be prominently featured on the device for ready access by a user. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Certain features of the subject technology are set forth in the appended claims. However, for purpose of explanation, several embodiments of the subject technology are set forth in the following figures. 
         FIG.  1    illustrates a perspective view of a watch on a wrist of a user, according to some embodiments of the present disclosure. 
         FIG.  2    illustrates a perspective view of a watch, in accordance with some embodiments of the present disclosure. 
         FIG.  3    illustrates a side view of a watch, in accordance with some embodiments of the present disclosure. 
         FIG.  4    illustrates a front view of a watch, in accordance with some embodiments of the present disclosure. 
         FIG.  5    illustrates a sectional view of a portion of the watch of  FIG.  4   , in accordance with some embodiments of the present disclosure. 
         FIG.  6    illustrates a sectional view of a portion of the watch of  FIG.  4   , in accordance with some embodiments of the present disclosure. 
         FIG.  7    illustrates a front view of the watch of  FIG.  4   , in accordance with some embodiments of the present disclosure. 
         FIG.  8    illustrates a front view of the watch of  FIG.  4   , in accordance with some embodiments of the present disclosure. 
         FIG.  9    illustrates a front view of the watch of  FIG.  4   , in accordance with some embodiments of the present disclosure. 
         FIG.  10    illustrates a sectional view of a portion of the watch of  FIG.  9   , in accordance with some embodiments of the present disclosure. 
         FIG.  11    illustrates a side view of a watch, in accordance with some embodiments of the present disclosure. 
         FIG.  12    illustrates a sectional view of a portion of the watch of  FIG.  11   , in accordance with some embodiments of the present disclosure. 
         FIG.  13    illustrates a sectional view of a portion of the watch of  FIG.  11   , in accordance with some embodiments of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     The detailed description set forth below is intended as a description of various configurations of the subject technology and is not intended to represent the only configurations in which the subject technology may be practiced. The appended drawings are incorporated herein and constitute a part of the detailed description. The detailed description includes specific details for the purpose of providing a thorough understanding of the subject technology. However, it will be clear and apparent to those skilled in the art that the subject technology is not limited to the specific details set forth herein and may be practiced without these specific details. In some instances, well-known structures and components are shown in block diagram form in order to avoid obscuring the concepts of the subject technology. 
     The present description relates in general to assemblies for user input components, and more particularly to, for example and without limitation, optical sensors of watches for user input. Electronic devices, such as watches, can include one or more user input components, such as crowns, dials, and/or buttons, at an external surface thereof for receiving input from a user. The input components can provide the user with the ability to interact with and provide instructions to the electronic device. 
     However, user input components, such as crowns, can occupy space on a watch that could otherwise be occupied by other components of the watch. Some user input components include moving parts, which are susceptible to wear. User input components can also be susceptible to damage resulting from impact during normal use or when the watch is inadvertently dropped. 
     Embodiments of the present disclosure can provide a watch with user input components that employ an optical sensor to receive input from a user. The input components provide an ability for a user to interact with the watch in a manner similar to how a user would interact with a crown that is rotatable and/or translatable. For example, the user can provide motions and gestures near the input component that the input component can detect and interpret and user inputs to control an aspect of the watch. The motions and gestures provided by the user can be directly detected with optical systems of the input component, so that the number of moving parts are reduced and space within the watch is more efficiently utilized. While providing these benefits, the input component provides a user experience that simulates user interactions with a crown that is rotatable and/or translatable. 
     These and other embodiments are discussed below with reference to  FIGS.  1 - 12   . However, those skilled in the art will readily appreciate that the detailed description given herein with respect to these Figures is for explanatory purposes only and should not be construed as limiting. 
     Referring to  FIG.  1   , a wearable electronic device, such as a watch  10 , is shown. The watch  10  is worn on a wrist of a user  2  with a watch band  18 . The watch  10  can be portable and also attached to other body parts of the user or to other devices, structures, or objects. The watch band  18  can be flexible and encircle at least a portion of the wrist of a user  2 . By securing the watch  10  to the person of the user, the watch band  18  provides security and convenience. 
     While  FIG.  1    illustrates the device as the watch  10 , it will be recognized that features described herein with respect to the watch  10  can be applied to a variety of other devices, such as other wearable devices, other electronic devices, portable computing devices, cell phones, smart phones, tablet computers, laptop computers, cameras, timekeeping devices, virtual reality devices, augmented reality devices, mixed reality devices, computerized glasses, and other wearable devices navigation devices, displays, sports devices, accessory devices, health-monitoring devices, medical devices, wristbands, bracelets, jewelry, and/or the like. 
     The watch  10  can include one or more I/O systems. For example, a display  20  can be configured to visually output information. The display  20  of the watch  10  can also be configured to receive touch input from a user. The housing  30  can support the display  20 . The display  20  can include or be provided with a cover glass that defines an outermost surface of the display  20 . The housing  30  can serve to surround a peripheral region as well as support the internal components of the watch  10  in their assembled position. For example, the housing  30  encloses and supports various internal components (including for example integrated circuit chips, processors, memory devices and other circuitry) to provide computing and functional operations for the watch  10 . 
     Referring to  FIG.  2   , the watch  10  can utilize a watch band  18  for attaching the watch  10  to a wrist. For example, as shown in  FIG.  2   , the watch band  18  can include a first band strap  62  attached to a first attachment unit  12  of the watch  10  and a second band strap  64  attached to a second attachment unit  12  of the watch  10 . In some embodiments, free ends of the first band strap  62  and the second band strap  64  can be configured to be releasably attached or secured to one another using a clasp  66  or other attachment mechanism to form a loop. This loop can then be used to attach the watch  10  to a user&#39;s wrist. 
     Although a single attachment unit  12  is discussed herein, a plurality of attachment units  12  can be coupled to the housing  30 . When multiple attachment units  12  are used, as shown in  FIG.  2   , the housing  30  can have a band retaining feature  16  (e.g., channel, latch, clip, recess, lock or other such coupling node) on a first side and a second side, opposite the first side, of the housing  30 . While the band retaining feature  16  of  FIG.  2    is shown as a channel, it will be understood that other retention mechanisms can be applied. The band retaining feature  16  on the first side of the housing  30  can receive one of the attachment units  12  and the band retaining feature  16  on the second side of the housing  30  can receive another attachment unit  12 . The attachment units  12  can have a same or different size and/or shape, wherein the size and/or shape corresponds to a size and/or shape of the respective band retaining feature  16 . As shown in FIG.  2 , the housing  30  includes one or more band retaining features  16  that mechanically engage a corresponding attachment unit  12 . The band retaining features  16  include an opening while the attachment unit  12  includes a lug that fits within the opening. The opening can be configured in a variety of different shapes and orientations. 
     The housing  30  can have multiple sides that are formed together to define a periphery of the housing  30 . The housing  30  can have a front side  22  and a rear side  24  opposite the front side  22 . The front side  22  faces away from a wrist of the user when the watch  10  is worn. The display  20  can be provided on the front side  22  of the housing  30  for displaying images to the user. The rear side  24  faces toward the wrist of the user when the watch  10  is worn. Other components, such as one or more sensors, can be provided on the rear side  24  of the housing  30  for monitoring biometric characteristics of the user. 
     The housing  30  can further include multiple lateral sides  26  that join together the front side  22  and the rear side  24  of the housing  30 . For example, one or more of the lateral sides  26  (e.g., opposing lateral sides  26 ) can include a band retaining feature  16 . At least one of the lateral sides  26  can include one or more input components  40 . As used herein, an input component can be any device that is configured to receive and detect input from a user. The input component  40  can detect motion, position, orientation, speed, acceleration, contact, and/or proximity of the user (e.g., finger, hand, or limb of the user). As discussed further herein, the input component  40  can include an optical sensor for detecting user input. 
     While the input component  40  of  FIG.  2    is represented as being round and positioned on a lateral side  26 , it will be understood that the input component  40  can be of any size, shape, and/or arrangement. For example, the input component  40  can be square, rectangular, polygonal, round, curved, arcuate, circular, semi-circular, flat, or another shape. By further example, the input component  40  can be positioned on any surface of the housing  30 , including the front side  22 , the rear side  24 , and/or a lateral side  26 . 
     Operation of the input component  40  can have one or more of a variety of effects. The input component  40  can be used to accept input from the user, which may be used to control aspects of the watch  10 . For example, in response to a user input received by an input component  40 , the watch can perform one or more of a variety of actions, as discussed further herein. 
     Referring to  FIG.  3   , the watch  10  can include components for performing various functions, including interacting with a user. For example, the display  20  can provide visual (e.g., image or video) output for the watch  10  and include an input surface for one or more touch input devices such as a touch sensor, force sensor, temperature sensor, and/or a fingerprint sensor. As discussed herein, the watch  10  can further include the input component  40  for receiving input from a user. 
     Additionally or alternatively, the watch  10  can include one or more other I/O components  76  for receiving input from and/or providing output to a user. I/O components  76  can include buttons, crowns, keys, dials, switches, trackpads, and the like. The user input can depress, rotate, move, tilt, flex, or deform the I/O component  76  in a manner that is detectable by the I/O component  76 . The I/O component  76  can include or be connected to one or more sensors that detect the input. Sensors can include, for example, force sensors, pressure sensors, optical sensors, or proximity sensors. Where multiple I/O component  76  are provided, the input components can be of the same or different types (e.g., depressable and/or rotatable). By further example, an I/O component  76  can include a speaker, a microphone, and/or a haptic device. A haptic device can be implemented as any suitable device configured to provide force feedback, vibratory feedback, tactile sensations, and the like. The haptic device can be implemented as a linear actuator configured to provide a punctuated haptic feedback, such as a tap or a knock. 
     As further shown in  FIG.  3   , the watch  10  includes one or more processors  72  that include or are configured to access a memory having instructions stored thereon. The instructions or computer programs can be configured to perform one or more of the operations or functions described with respect to the watch  10 . The processors  72  can be implemented as any electronic device capable of processing, receiving, or transmitting data or instructions. For example, the processors  72  can include one or more of: a microprocessor, a central processor (CPU), an application-specific integrated circuit (ASIC), a digital signal processor (DSP), or combinations of such devices. As described herein, the term “processor” is meant to encompass a single processor or processor, multiple processors, multiple processors, or other suitably configured computing element or elements. The memory can store electronic data that can be used by the watch  10 . For example, a memory can store electrical data or content such as, for example, audio and video files, documents and applications, device settings and user preferences, timing and control signals or data for the various modules, data structures or databases, and so on. The memory can be configured as any type of memory. By way of example only, the memory can be implemented as random access memory, read-only memory, Flash memory, removable memory, or other types of storage elements, or combinations of such devices. 
     As further shown in  FIG.  3   , the watch  10  can include a communication component  74  that facilitates transmission of data and/or power to or from other electronic devices across standardized or proprietary protocols. For example, a communication component  74  can transmit electronic signals via a wireless and/or wired network connection. Examples of wireless and wired network connections include, but are not limited to, cellular, Wi-Fi, Bluetooth, infrared, RFID, and Ethernet. 
     As further shown in  FIG.  3   , the watch  10  can also include one or more sensors  78 , such as biosensors. The one or more sensors  78  can be configured to sense substantially any type of characteristic such as, but not limited to, images, pressure, light, touch, force, temperature, position, motion, and so on. For example, the sensor(s)  78  can be a photodetector, a temperature sensor, a light or optical sensor, an atmospheric pressure sensor, a humidity sensor, a magnet, a gyroscope, an accelerometer, and so on. In other examples, the watch  10  can include one or more health sensors. In some examples, the health sensors can be disposed on a rear side of the housing  30  of the watch  10 . The one or more sensors  78  can include optical and/or electronic biometric sensors that can be used to compute one or more biometric characteristics. A sensor  78  can include a light source and a photodetector to form a photoplethysmography (PPG) sensor. Light can be transmitted from the sensor  78 , to the user, and back to the sensor  78 . For example, the housing  30  can provide one or more windows (e.g., opening, transmission medium, and/or lens) to transmit light to and/or from the sensor  78 . The optical (e.g., PPG) sensor or sensors can be used to compute various biometric characteristic including, without limitation, a heart rate, a respiration rate, blood oxygenation level, a blood volume estimate, blood pressure, or a combination thereof. One or more of the sensors  78  can also be configured to perform an electrical measurement using one or more electrodes. The electrical sensor(s) can be used to measure electrocardiographic (ECG) characteristics, galvanic skin resistance, and other electrical properties of the user&#39;s body. Additionally or alternatively, a sensor  78  can be configured to measure body temperature, exposure to UV radiation, and other health-related information. 
     The watch  10  can include other components to support those described herein. For example, the watch  10  can include a battery that is used to store and provide power to the other components of the watch  10 . The battery can be a rechargeable power supply that is configured to provide power to the watch  10 . The watch  10  can also be configured to recharge the battery using a wireless charging system. 
     Referring to  FIG.  4   , the input component  40  can be provided along a side of the housing, such as the lateral side  26 . Such a configuration allows the input component  40  to be readily accessible by a user without interfering with a user&#39;s view and usage of the display  20 . While the input component  40  of  FIG.  4    is shown with an outer periphery that is flush with an exterior surface of the housing  30 , it will be understood that the input component  40  can protrude beyond the exterior surface of the housing  30 , as discussed further herein. Additionally or alternatively, the input component  40  can be recessed within the exterior surface of the housing  30 . Where the input component  40  is flush or recessed with respect to the housing  30 , the input component can be protected from impact resulting from normal use and/or inadvertent drops. For example, the housing  30  can present an outermost periphery that protects the input component  40 , even when forces are applied to a side that contains the input component  40 . 
     Referring to  FIGS.  5  and  6   , the input component  40  can be used to optically detect user inputs. The input component  40  can include a light source  44 , such as light emitting diodes (LEDs). Additionally or alternatively, laser diode can be used. The light source  44  can include a single emitter or multiple emitters. The light source  44  can emit a single frequency, multiple frequencies (e.g., RGB), and/or invisible frequencies (e.g., infrared, UV). 
     The input component  40  can further include an optical sensor  46 , such as a photodiode or a photodiode array. Additionally or alternatively, the input component  40  can include one or more of various types of optical sensors that are arranged in various configurations for detecting user inputs described herein. For example, motion of a user can be detected by an image sensor, a light sensor such as a CMOS light sensor, CCD sensor, a photovoltaic cell, a photo resistive component, a laser scanner, and the like. 
     The input component  40  can provide one or more windows  42  (e.g., opening, transmission medium, and/or lens) to transmit light from the light source  44  and/or to the optical sensor  46 . The window  42  can include a light transmitting material that provides a surface to which a user can apply tactile input. The window  42  can form at least part of an enclosure that contains the light source  44  and/or the optical sensor  46 . The window  42  can provide optical effects for the transmitted light. For example, the window  42  can include a diffuser, and/or a lens. While the input component  40  of  FIGS.  5  and  6    is represented as including a light source  44  and an optical sensor  46  within a single enclosure and having a single window  42 , it will be understood that a light source  44  and an optical sensor  46  can be provided in separate enclosures and/or with separate windows  42  for transmitting light. It will also be understood that any one enclosure can contain any number of light sources  44  and optical sensors  46 . 
     In use, the input component  40  can optically track motion of a user (e.g., finger). The light source  44  can emit light through the window  42  onto the finger. The light can be reflected off of the finger and through the window  42  to the optical sensor  46 . The optical sensor  46  can capture a series of images across a period of time. 
     The watch can be configured to optimize operational efficiency of the light source  44  and/or the optical sensor  46 . The watch can include a proximity sensor  58  that detects a presence of a user (e.g., finger, hand, or limb of the user) within a certain distance of the input component  40 . For example, the proximity sensor  58  can detect when a finger is applied to the input component  40  or a vicinity thereof. The proximity sensor  58  can include a touch sensing device, a force sensing device, a temperature sensing device, a capacitive sensing device, a resistive sensing device, and/or an optical sensing device. The proximity sensor  58  can extend at least partially about a periphery of the input component  40 . For example the proximity sensor  58  can include a ring that surrounds the input component  40 . 
     The proximity sensor  58  can be in communication with the processor of the watch to indicate when the user is within a certain distance of the input component  40 . The processor can control operation of the light source  44  and/or the optical sensor  46  accordingly. For example, when the presence of the user is not detected within a certain distance of the input component  40 , the light source  44  and/or the optical sensor  46  can operate in a reduced power mode or not at all to conserve power. In the reduced power mode, the light source  44  can emit less light or no light. In the reduced power mode, the optical sensor  46  can acquire fewer images or no images. By further example, when the presence of the user is detected within a certain distance of the input component  40 , the light source  44  and/or the optical sensor  46  can operate in a higher power mode. In the higher power mode, the light source  44  can emit more light. In the higher power mode, the optical sensor  46  can acquire a greater number of images, for example, with greater frequency (e.g., frame rate), or images with higher resolution. 
     The watch can include a switch for accepting translational input from the user. As shown in  FIGS.  5  and  6   , a force sensor assembly can include the input component  40  and a force sensor  48 . The force sensor  48  can include a dome switch that is configured to provide a tactile feedback when actuated. The actuation of a dome switch can be perceived by the user as a click or release as the force sensor  48  is actuated. Once the force has been removed from the input component  40 , the dome switch resiliently returns to its original position, providing a biasing force to return the input component  40  to its original position. Additionally or alternatively, the force sensor  48  may include a separate biasing element, such as a spring, that exerts a force (either directly or indirectly) against the input component  40 .  FIG.  5    depicts the force sensor  48  when there is no force applied (i.e., un-actuated).  FIG.  6    depicts the force sensor  48  when there is a translational force applied to the input component  40  (i.e., actuated). As shown in  FIGS.  5  and  6   , the input component  40  is translatable relative to the housing  30 , providing an ability for the user to translate the input component  40  and apply a translating force to the force sensor  48 . Actuation of the force sensor  48  can provide a binary output (actuated/not actuated) and/or a non-binary output that corresponds to the amount of translation along the axis of motion. 
     Referring to  FIGS.  7  and  8   , the input component  40  can be used to detect a user input. More specifically, the example provided below with respect to  FIGS.  7  and  8    may use its optical sensor to detect motion, position, orientation, speed, acceleration, contact, and/or proximity of the user (e.g., finger, hand, or limb of the user. Once the user input has been detected, this information may be used to output or change information and images that are presented on a display or user interface of the watch. 
     Integrating a rotary input device (e.g., crown) into the space constraints of a typical wearable electronic device may be particularly challenging. Specifically, some traditional rotary input configurations may be undesirably large or delicate for use in a portable electronic device. The optical sensor described below may provide certain advantages over some traditional rotary input configurations and may be particularly well suited for use with a watch. 
     As shown in  FIGS.  7  and  8   , a user  2  can move a portion of a finger, hand, or limb past the input component  40 , which detects the motion. As discussed herein, the light source of the input component  40  can emit light through the window onto the finger, and the light can be reflected off of the finger and through the window to the optical sensor of the input component  40 . The input component  40  can capture a series of images across a period of time. A feature of the finger can be detected and tracked to determine its position in each image. For example, the finger can include visible features such as ridges, grooves, textures, patterns, colors, and/or variations of one or more of these across an area of the finger. As the optical sensor  46  determines the location of any given feature across multiple images, the input component  40  can determine the motion, position, orientation, speed, acceleration, contact, and/or proximity of the finger with respect to the input component  40 . Once this information is determined, it can be used to output or change information or images that are presented on the display  20  or another user interface of the watch  10 . 
     The input component  40  can be configured to detect motion in one dimension, two dimensions, or three dimensions. For example, the input component  40  can detect motion of a finger along an axis that passes by the input component  40 . While the motion may include other directions, the input component  40  can filter to exclude directions other than those along the axis. By further example, the input component  40  can detect motion of a finger within a two-dimensional plane, such as a plane of or parallel to an outer surface of the window. By further example, the input component  40  can detect motion of a finger within a three-dimensional space, including variations in distance from the input component  40 . 
     Operation of the input component  40  can have one or more of a variety of effects. For example, in response to a user input received by an input component  40 , the watch can perform one or more of a variety of actions. While such actions can include any preprogrammed or user-selected action, various examples are provided herein by way of illustration and not limitation. 
     The input component  40  can be operated by the user to scroll the display  20  or select from a range of values. The input component  40  can be rotated to move a cursor or other type of selection mechanism from a first displayed location to a second displayed location in order to select an icon or move the selection mechanism between various icons that are output on the display  20 . In a time keeping application, the input component  40  can be used to adjust the position of watch hands or index digits displayed on the display  20  of the watch  10 . The input component  40  can also be used to control the volume of a speaker, the brightness of the display screen, or control other hardware settings. Other actions can include one or more of launching a program, displaying particular information, changing an aspect of the display, communicating with an external device, initiating a call, sending a message, activating a microphone for receiving and recognizing voice input from the user, providing a sound, initiating a financial transaction, restarting the watch, turning off the watch, taking a screenshot, activating the screen, tracking activity of the user, taking a biometric reading, recording a location of the user, and/or modifying settings of the watch. 
     Where an action relates to a setting (volume of a speaker, brightness of the display screen, etc.) of the watch, the input component  40  can detect motion in a single axis and provide an output that corresponds to an effect on the setting. For example, detected motion of a finger in a first direction (e.g., up) can increase a quantitative setting (e.g., increase volume, brightness). By further example, detected motion of a finger in a second direction (e.g., down), opposite the first direction, can decrease a quantitative setting (e.g., decrease volume, brightness). 
     An action can be general across an operating system of a watch, such that the action can be performed at any time during operation of the watch. Additionally or alternatively, an action can be specific to an application that is actively operating on the watch, such that the action can only be performed when the application is active. An action can be specific to a particular combination of input components receiving user input simultaneously or in a particular sequence. Accordingly, a user input can include input provided to more than one input component. An action can be specific to other contextual factors, such as an attribute of a user input or an operational parameter of the watch. 
     Referring to  FIGS.  9  and  10   , the input component  40  can be configured to detect user input at one or more distances  90  away from the input component  40 . The distance  90  can be zero (e.g., contacting the input component  40 ) or non-zero. The distance  90  can be determined based on the light source  44 , the window  42 , and/or the optical sensor  46 . 
     For example, as shown in  FIG.  10   , the light source  44  can be configured to emit light sufficient to track user motion only to a certain distance. The window  42  and/or the optical sensor  46  can include one or more lenses  98  that produces a finite focal length, so that only objects at a certain distance  90  are in focus. Each of the lenses can have a different focal length. Accordingly, the input component  40  can be configured to detect only objects at a given distances  90  away from the input component  40 . 
     As further shown in  FIG.  10   , the input component  40  can include multiple light sources  44 , windows  42 , lenses  98 , and/or optical sensors  46 , such that each of the optical sensors  46  is configured to detect motions of a finger at different distances  90  away from the corresponding optical sensor  46 . For example, a first optical sensor  46  can be configured (e.g., by parameters of a first light source  44 , a first window  42  or lens  98 , and/or a first optical sensor  46 ) to detect user input at a first distance away from the input component  40 , and a second optical sensor  46  can be configured (e.g., by parameters of a second light source  44 , a second window  42  or lens  98 , and/or a second optical sensor  46 ) to detect user input at a second distance, different than the first distance, away from the input component  40 . At least one of the distances can be zero (e.g., contacting the input component  40 ). Accordingly, different outputs and/or actions can be assigned to user inputs detected at different distances away from the input component  40 . 
     Referring to  FIG.  11   , an input component  40  can be provided on a protrusion  50  that extends away from other portions of a housing  30  of a watch  10 . The protrusion  50  can extend from a side of the housing  30 , such as the lateral side  26 . The position of the input component  40  on the protrusion  50  allows the input component  40  to be readily accessible by a user without interfering with a user&#39;s view and usage of the display  20 . Furthermore, the shape, size, and other characteristics of the protrusion  50  can simulate characteristics of a rotary crown on a watch, such that the user can interact with the protrusion  50  in a manner similar to how a user would interact with a rotary crown. 
     As shown in  FIG.  11   , the protrusion  50  can extend away from and beyond an exterior surface of the housing  30 , for example, at the lateral side  26 . While the protrusion  50  of  FIG.  11    is represented as being cylindrical and positioned on a lateral side  26 , it will be understood that the protrusion  50  can be of any size, shape (e.g., cross-sectional shape), and/or arrangement. For example, the protrusion  50  can be square, rectangular, polygonal, round, curved, arcuate, circular, semi-circular, flat, or another shape in cross-section. By further example, the protrusion  50  can be positioned on any surface of the housing  30 , including the front side  22 , the rear side  24 , and/or a lateral side  26 . 
     As shown in  FIG.  12   , the protrusion  50  can extend along a first axis  92  that intersects an interior of the housing  30 . The input component  40  positioned on the protrusion  50  can face in a direction along a second axis  94  that is different than the first axis  92 . For example, while the protrusion  50  extends along the first axis  92  away from an interior of the housing  30 , the input component  40  can face in a direction (e.g., along the second axis  94 ) that is orthogonal or transverse to the first axis  92 . The extension of the protrusion along the first axis  92  provides a surface for supporting the input component  40 . For example, the input component  40  can face in a direction that is parallel to a direction in which the display is facing on the front side of the housing  30 . Such a configuration allows the input component  40  to be accessible on a front side of the protrusion  50  so that both the display and the input component  40  can face the user when the user is observing the watch. 
     As shown in  FIG.  12   , the protrusion  50  can extend from the housing  30 . For example, the protrusion  50  can be unitary with the housing  30 , integrally formed with the housing, and/or part of a monolithic structure that includes the housing  30 . Alternatively, the protrusion  50  can be separate from the housing and joined (e.g., connected, coupled, attached, fixed, etc.) thereto. Some or all of the elements of the input component  40  can be housed within the protrusion  50 , so that other space within an interior of the housing  30  is available for other components of the watch. Furthermore, the protrusion  50  can have sufficient rigidity and strength to protect the components contained therein during normal use and inadvertent drops of the watch. Where the outermost periphery and/or edges of the protrusion  50  are fixed with respect to the housing  30 , the protrusion  50  can be resilient against impact, despite presenting an exposed and protruding profile. 
     Referring to  FIGS.  12  and  13   , the input component  40  can be used to optically detect user inputs. The input component can include elements that are similar to or identical to the elements described above with respect to  FIGS.  5  and  6   . For example, the input component  40  can include a light source  44 , such as light emitting diodes (LEDs), within the protrusion  50 . The input component  40  can further include an optical sensor  46 , such as a photodiode or a photodiode array, within the protrusion  50 . The input component  40  can provide one or more windows  42  (e.g., opening, transmission medium, and/or lens) on a side (e.g., front side) of the protrusion  50  to transmit light from the light source  44  and/or to the optical sensor  46 . In use, the input component  40  can optically track motion of a user (e.g., finger). The light source  44  can emit light through the window  42  onto a finger. The light can be reflected off of the finger and through the window  42  to the optical sensor  46 . The optical sensor  46  can capture a series of images across a period of time. The watch can also include a proximity sensor  58  on the protrusion  50  for detecting a presence of a user (e.g., finger, hand, or limb of the user) within a certain distance of the input component  40 . 
     The watch can include a button  52  on the protrusion  50  and a force sensor  48  for accepting translational input from the user. As shown in  FIGS.  12  and  13   , a force sensor assembly can include the button  52  at an end of the protrusion  50  and a force sensor  48 . The button can be positioned along the first axis  92 , so that it forms a surface at an end of the protrusion  50 . The force sensor  48  can include a dome switch that is configured to provide a tactile feedback when actuated. The actuation of a dome switch can be perceived by the user as a click or release as the force sensor  48  is actuated. Once the force has been removed from the button  52 , the dome switch resiliently returns to its original position, providing a biasing force to return the button  52  to its original position. Additionally or alternatively, the force sensor  48  may include a separate biasing element, such as a spring, that exerts a force (either directly or indirectly) against the button  52 .  FIG.  12    depicts the force sensor  48  when there is no force applied (i.e., un-actuated).  FIG.  13    depicts the force sensor  48  when there is a translational force applied to the button  52  (i.e., actuated). As shown in  FIGS.  12  and  13   , the button  52  is translatable relative to the housing  30  and/or the protrusion  50 , providing an ability for the user to translate the button  52  and apply a translating force to the force sensor  48 . Actuation of the force sensor  48  can provide a binary output (actuated/not actuated) and/or a non-binary output that corresponds to the amount of translation along the axis of motion. Such a configuration provides an ability for a user to interact with the button  52  in a manner similar to how a user would interact with a crown that is translatable. 
     Accordingly, embodiments of the present disclosure provide a watch with user input components that employ an optical sensor to receive input from a user. The input components provide an ability for a user to interact with the watch in a manner similar to how a user would interact with a crown that is rotatable and/or translatable. The user can provide motions and gestures near the input component that the input component can detect and interpret and user inputs to control an aspect of the watch. The motions and gestures provided by the user can be directly detected with optical systems of the input component, so that the number of moving parts are reduced and space within the watch is more efficiently utilized. While providing these benefits, the input component provides a user experience that simulates user interactions with a crown that is rotatable and/or translatable. 
     A reference to an element in the singular is not intended to mean one and only one unless specifically so stated, but rather one or more. For example, “a” module may refer to one or more modules. An element proceeded by “a,” “an,” “the,” or “said” does not, without further constraints, preclude the existence of additional same elements. 
     Headings and subheadings, if any, are used for convenience only and do not limit the invention. The word exemplary is used to mean serving as an example or illustration. To the extent that the term include, have, or the like is used, such term is intended to be inclusive in a manner similar to the term comprise as comprise is interpreted when employed as a transitional word in a claim. Relational terms such as first and second and the like may be used to distinguish one entity or action from another without necessarily requiring or implying any actual such relationship or order between such entities or actions. 
     Phrases such as an aspect, the aspect, another aspect, some aspects, one or more aspects, an implementation, the implementation, another implementation, some implementations, one or more implementations, an embodiment, the embodiment, another embodiment, some embodiments, one or more embodiments, a configuration, the configuration, another configuration, some configurations, one or more configurations, the subject technology, the disclosure, the present disclosure, other variations thereof and alike are for convenience and do not imply that a disclosure relating to such phrase(s) is essential to the subject technology or that such disclosure applies to all configurations of the subject technology. A disclosure relating to such phrase(s) may apply to all configurations, or one or more configurations. A disclosure relating to such phrase(s) may provide one or more examples. A phrase such as an aspect or some aspects may refer to one or more aspects and vice versa, and this applies similarly to other foregoing phrases. 
     A phrase “at least one of” preceding a series of items, with the terms “and” or “or” to separate any of the items, modifies the list as a whole, rather than each member of the list. The phrase “at least one of” does not require selection of at least one item; rather, the phrase allows a meaning that includes at least one of any one of the items, and/or at least one of any combination of the items, and/or at least one of each of the items. By way of example, each of the phrases “at least one of A, B, and C” or “at least one of A, B, or C” refers to only A, only B, or only C; any combination of A, B, and C; and/or at least one of each of A, B, and C. 
     It is understood that the specific order or hierarchy of steps, operations, or processes disclosed is an illustration of exemplary approaches. Unless explicitly stated otherwise, it is understood that the specific order or hierarchy of steps, operations, or processes may be performed in different order. Some of the steps, operations, or processes may be performed simultaneously. The accompanying method claims, if any, present elements of the various steps, operations or processes in a sample order, and are not meant to be limited to the specific order or hierarchy presented. These may be performed in serial, linearly, in parallel or in different order. It should be understood that the described instructions, operations, and systems can generally be integrated together in a single software/hardware product or packaged into multiple software/hardware products. 
     In one aspect, a term coupled or the like may refer to being directly coupled. In another aspect, a term coupled or the like may refer to being indirectly coupled. 
     Terms such as top, bottom, front, rear, side, horizontal, vertical, and the like refer to an arbitrary frame of reference, rather than to the ordinary gravitational frame of reference. Thus, such a term may extend upwardly, downwardly, diagonally, or horizontally in a gravitational frame of reference. 
     The disclosure is provided to enable any person skilled in the art to practice the various aspects described herein. In some instances, well-known structures and components are shown in block diagram form in order to avoid obscuring the concepts of the subject technology. The disclosure provides various examples of the subject technology, and the subject technology is not limited to these examples. Various modifications to these aspects will be readily apparent to those skilled in the art, and the principles described herein may be applied to other aspects. 
     All structural and functional equivalents to the elements of the various aspects described throughout the disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. No claim element is to be construed under the provisions of 35 U.S.C. § 112, sixth paragraph, unless the element is expressly recited using the phrase “means for” or, in the case of a method claim, the element is recited using the phrase “step for”. 
     The title, background, brief description of the drawings, abstract, and drawings are hereby incorporated into the disclosure and are provided as illustrative examples of the disclosure, not as restrictive descriptions. It is submitted with the understanding that they will not be used to limit the scope or meaning of the claims. In addition, in the detailed description, it can be seen that the description provides illustrative examples and the various features are grouped together in various implementations for the purpose of streamlining the disclosure. The method of disclosure is not to be interpreted as reflecting an intention that the claimed subject matter requires more features than are expressly recited in each claim. Rather, as the claims reflect, inventive subject matter lies in less than all features of a single disclosed configuration or operation. The claims are hereby incorporated into the detailed description, with each claim standing on its own as a separately claimed subject matter. 
     The claims are not intended to be limited to the aspects described herein, but are to be accorded the full scope consistent with the language of the claims and to encompass all legal equivalents. Notwithstanding, none of the claims are intended to embrace subject matter that fails to satisfy the requirements of the applicable patent law, nor should they be interpreted in such a way.