Abstract: Hat, helmet, and other headgear apparatus includes dry electrophysiological electrodes and, optionally, other physiological and/or environmental sensors to measure signals such as ECG from the head of a subject. Methods of use of such apparatus to provide fitness, health, or other measured or derived, estimated, or predicted metrics are also disclosed.

Abstract: Earphone apparatus includes dry electrophysiological electrodes and, optionally, other physiological and/or environmental sensors to measure signals such as ECG from the head of a subject. Methods of use of such apparatus to provide fitness, health, or other measured or derived, estimated, or predicted metrics are also disclosed.

Abstract: A watch can include a watch body and a band for securing the watch to the user. The watch body can detect an identification of the band or combination of band portions, which can serve as an input to initiate actions performed by the watch body. For example, a type, model, color, size, or other characteristic of a band can be determined and used to select a corresponding action performed by the watch body. Identification of the band can be performed by components of the watch body that also serve other purposes. The watch body can respond to the identification of a particular band by performing particular functions, such as changing an aspect of a user interface or altering settings of the watch body.

Abstract: An electronic device may be attached to an external item. The electronic device may include an optical identification sensor configured to sense a color-encoded tag in the external item when the item is attached to the device. The optical identification sensor may include a board layer, a protective filter layer, wall structures for supporting the protective filter layer on the board layer, a linear array of photodetectors disposed between the board layer and the protective filter layer, a field-of-view restriction filter interposed between the photodetectors and the protective filter layer, and a light source having multiple emitters for illuminating the color-encoded tag. The emitters may be activated sequentially to produce multiple images that are combined to reconstruct an accurate reading of the color-encoded tag, which can then be used to identify the type of external item currently attached to the electronic device.

Abstract: Eyewear apparatus includes dry electrophysiological electrodes and, optionally, other physiological and/or environmental sensors to measure signals such as EOG and ECG from the head of a subject. Methods of use of such apparatus to provide fitness, health, or other measured or derived, estimated, or predicted metrics are also disclosed.

Abstract: An electronic device may be attached to an external item. The electronic device may include an optical identification sensor configured to sense a color-encoded tag in the external item when the item is attached to the device. The optical identification sensor may include a board layer, a protective filter layer, wall structures for supporting the protective filter layer on the board layer, a linear array of photodetectors disposed between the board layer and the protective filter layer, a field-of-view restriction filter interposed between the photodetectors and the protective filter layer, and a light source having multiple emitters for illuminating the color-encoded tag. The emitters may be activated sequentially to produce multiple images that are combined to reconstruct an accurate reading of the color-encoded tag, which can then be used to identify the type of external item currently attached to the electronic device.

Abstract: A watch body includes a housing at least partially defining an interior of the watch body. A retaining feature is formed in or extends from the housing. A watch crown is retained by the retaining feature and is operable to be rotated by a user. The watch crown has a surface facing the housing. The watch crown is entirely external to the interior of the watch body. An electromagnetic radiation source is disposed within the housing and is operable to emit a beam of electromagnetic radiation toward the surface. A sensor is disposed within the housing and is operable to characterize a movement of the watch crown based at least in part on a portion of the beam of electromagnetic radiation that impinges on the surface and is redirected by the surface.

Abstract: An electronic device is described. The electronic device may include a housing, a rotatable crown, and a self-mixing interferometry (SMI) sensor positioned within the housing. The rotatable crown may include an array of retroreflective surface features that reflect incident light back to a light source. Each retroreflective surface feature of the array of retroreflective surface features may be formed as a corner-cube with three perpendicular faces. The SMI sensor or associated processing electronics may compare originally emitted light with reflected light to identify a movement or distance of the rotatable crown with respect to the SMI sensor.

Abstract: A method includes imaging, with an optical read head attached to a second mechanical component, a portion of an encoder track disposed on a first mechanical component. The encoder track has a first encoder scale extending along the encoder track and a second encoder scale extending along the encoder track, and the imaged portion of the encoder track includes a first portion of the first encoder scale and a second portion of the second encoder scale. The method further includes transforming an imaged portion of the encoder track to a spatial frequency domain; identifying a pair of frequency bins in the spatial frequency domain; determining a phase difference between a first frequency bin and a second frequency bin in the pair of frequency bins; and mapping the phase difference to a positional relationship between the first mechanical component and the second mechanical component.

Abstract: An electronic device is described. The electronic device may include a housing, a rotatable crown, and a self-mixing interferometry (SMI) sensor positioned within the housing. The rotatable crown may include an array of retroreflective surface features that reflect incident light back to a light source. Each retroreflective surface feature of the array of retroreflective surface features may be formed as a corner-cube with three perpendicular faces. The SMI sensor or associated processing electronics may compare originally emitted light with reflected light to identify a movement or distance of the rotatable crown with respect to the SMI sensor.

Abstract: An electronic watch includes a housing, a user-operable watch crown mounted to the housing, an electromagnetic radiation source emitting a beam of electromagnetic radiation toward a watch crown surface, and a sensor. The beam of electromagnetic radiation depends on a coherent mixing of electromagnetic radiation within a resonant cavity of the electromagnetic radiation source. The coherent mixing includes a mixing of a first amount of electromagnetic radiation generated by the electromagnetic radiation source and a second amount of electromagnetic radiation redirected into the resonant cavity by the watch crown surface. The sensor measures a first parameter of the beam of electromagnetic radiation and determines, using the measurement of the first parameter, a value of a second parameter characterizing movement of the watch crown. The second parameter may include a direction of rotation or speed of rotation of the watch crown, or other parameters.

Abstract: An electronic device is described. The electronic device may include a housing, a rotatable crown, and a self-mixing interferometry (SMI) sensor positioned within the housing. The rotatable crown may include an array of retroreflective surface features that reflect incident light back to a light source. Each retroreflective surface feature of the array of retroreflective surface features may be formed as a corner-cube with three perpendicular faces. The SMI sensor or associated processing electronics may compare originally emitted light with reflected light to identify a movement or distance of the rotatable crown with respect to the SMI sensor.

Abstract: An electronic device may be attached to an external item. The electronic device may include an optical identification sensor configured to sense a color-encoded tag in the external item when the item is attached to the device. The optical identification sensor may include a board layer, a protective filter layer, wall structures for supporting the protective filter layer on the board layer, a linear array of photodetectors disposed between the board layer and the protective filter layer, a field-of-view restriction filter interposed between the photodetectors and the protective filter layer, and a light source having multiple emitters for illuminating the color-encoded tag. The emitters may be activated sequentially to produce multiple images that are combined to reconstruct an accurate reading of the color-encoded tag, which can then be used to identify the type of external item currently attached to the electronic device.

Abstract: Earphone apparatus includes dry electrophysiological electrodes and, optionally, other physiological and/or environmental sensors to measure signals such as ECG from the head of a subject. Methods of use of such apparatus to provide fitness, health, or other measured or derived, estimated, or predicted metrics are also disclosed.

Abstract: Eyewear apparatus includes dry electrophysiological electrodes and, optionally, other physiological and/or environmental sensors to measure signals such as EOG and ECG from the head of a subject. Methods of use of such apparatus to provide fitness, health, or other measured or derived, estimated, or predicted metrics are also disclosed.

Abstract: Hat, helmet, and other headgear apparatus includes dry electrophysiological electrodes and, optionally, other physiological and/or environmental sensors to measure signals such as ECG from the head of a subject. Methods of use of such apparatus to provide fitness, health, or other measured or derived, estimated, or predicted metrics are also disclosed.

Abstract: An electronic watch includes a housing, a user-operable watch crown mounted to the housing, an electromagnetic radiation source emitting a beam of electromagnetic radiation toward a watch crown surface, and a sensor. The beam of electromagnetic radiation depends on a coherent mixing of electromagnetic radiation within a resonant cavity of the electromagnetic radiation source. The coherent mixing includes a mixing of a first amount of electromagnetic radiation generated by the electromagnetic radiation source and a second amount of electromagnetic radiation redirected into the resonant cavity by the watch crown surface. The sensor measures a first parameter of the beam of electromagnetic radiation and determines, using the measurement of the first parameter, a value of a second parameter characterizing movement of the watch crown. The second parameter may include a direction of rotation or speed of rotation of the watch crown, or other parameters.

Abstract: A self-mixing interference sensor may be positioned within an electronic device and may be configured to detect a gesture on a user input surface of the electronic device. A beam of electromagnetic radiation may be emitted from the self-mixing interference sensor toward the user input surface. When an object with a suitable refractive index is not in contact with the user input surface, the beam of electromagnetic radiation may reflect away from the self-mixing interference sensor. When an object with a suitable refractive index is in contact with the user input surface, the beam of electromagnetic radiation may reflect back into the self-mixing interference sensor and may undergo a self-mixing process. A property of the object in contact with the surface of the user input device may be detected by measuring a change in an optical property of the beam of electromagnetic radiation.

Abstract: Earphone apparatus includes dry electrophysiological electrodes and, optionally, other physiological and/or environmental sensors to measure signals such as ECG from the head of a subject. Methods of use of such apparatus to provide fitness, health, or other measured or derived, estimated, or predicted metrics are also disclosed.

Abstract: Hat, helmet, and other headgear apparatus includes dry electrophysiological electrodes and, optionally, other physiological and/or environmental sensors to measure signals such as ECG from the head of a subject. Methods of use of such apparatus to provide fitness, health, or other measured or derived, estimated, or predicted metrics are also disclosed.