Abstract: A pair of eyeglasses may include one or more adjustable lenses that are each configured to align with a respective one of a user's eyes. The adjustable lenses may each include electrically modulated optical material such as one or more liquid crystal cells, each having a phase profile that is adjusted using patterned electrodes. Analog voltages may be provided to the patterned electrodes through variable-resistance conductive paths that are each coupled to a subset of the patterned electrodes. Digital voltage selection circuitry may be used to select which analog voltage to apply to each of the variable-resistance conductive paths from a predetermined set of analog voltages that are generated off of the lens. The digital voltage selection circuitry may include an array of multiplexers, each of which selects a desired voltage based on control signals received from digital control circuitry such a shift register and/or a decoder.

Abstract: An electronic device may include one or more ultrasonic temperature sensors. The ultrasonic temperature sensors may be formed in openings or cavities in a housing of the electronic device. The ultrasonic temperature sensors may include ultrasonic transmitters that transmit signals at different ultrasonic frequencies and ultrasonic receivers that receive the transmitted signals. Phase differences between the received ultrasonic signals may be used to determine the speed of sound of ambient air and therefore calculate the temperature of the ambient air. The ultrasonic transmitters and receivers may include piezoelectric micromachined ultrasound transducers (PMUTs). Each transmitter and receiver may be a dedicated transmitter or receiver, or may transmit and receive ultrasonic signals. Each receiver may include an array of PMUTs that receive ultrasonic signals of different frequencies. The PMUTS may be formed on complementary metal-oxide semiconductors (CMOS).

Abstract: A pair of eyeglasses may include one or more adjustable lenses. An adjustable lens may include electrically modulated optical material such as one or more liquid crystal cells having a phase profile that is adjusted using patterned electrodes. Digital-to-analog converter circuits may provide voltages to the electrodes. To save space on the lens, a smaller number of digital-to-analog converter circuits may provide voltages to a greater number of electrodes by sequentially coupling and decoupling the digital-to-analog converter circuits to different groups of electrodes, advancing from group-to-group with each clock cycle by a number of electrodes that is less than the number of digital-to-analog converter circuits. At least one of the electrodes in each group may be driven at the same voltage for two consecutive clock cycles to avoid erroneous voltages resulting from the parasitic capacitance between adjacent fingers.

Abstract: An electronic device may have back-to-back displays. A user-facing display may have microlenses, tunable lens structures, holograms, lasers, and other structures for displaying images in multiple eye boxes while the electronic device is being worn on the head of a user. In some configurations, a switchable diffuser may be incorporated into the user-facing display. In one mode, the switchable diffuser allows microlenses of the pixels of the user-facing display to provide images to eye boxes in which images from the display are viewable. In another mode, the switchable diffuser diffuses light from the pixels so that the user-facing display may be used while the device is being held in the hand of the user.

Abstract: Image-sensing devices include odd-symmetry gratings that cast interference patterns over a photodetector array. Grating features offer considerable insensitivity to the wavelength of incident light, and to the manufactured distance between the grating and the photodetector array. Photographs and other image information can be extracted from interference patterns captured by the photodetector array. Images can be captured without a lens, and cameras can be made smaller than those that are reliant on lenses and ray-optical focusing.

Abstract: A pair of eyeglasses may include one or more adjustable lenses that are each configured to align with a respective one of a user's eyes. The adjustable lenses may each include electrically modulated optical material such as one or more liquid crystal cells. The liquid crystal cells may include arrays of electrodes that extend along one, two, three, four, or more than four directions. Control circuitry may apply control signals to the array of electrodes in each liquid crystal cell to produce a desired phase profile. Each lens may be foveated such that portions of the lens within the user's gaze exhibit a different phase profile than portions of the lens outside of the user's gaze. The control circuitry may adjust the location of the optically distinct area so that it remains aligned with the user's gaze.

Abstract: A pair of eyeglasses may include one or more adjustable lenses that are each configured to align with a respective one of a user's eyes. The adjustable lenses may include a foveated liquid crystal adjustable lens stacked with a non-liquid-crystal adjustable lens such as a fluid-filled lens or an Alvarez lens. The foveated adjustable lens may include electrically modulated optical material such as one or more liquid crystal cells. The liquid crystal cells may include arrays of electrodes that extend along one, two, three, four, or more than four directions. Control circuitry may apply control signals to the array of electrodes in each liquid crystal cell to produce a desired phase profile. Each lens may be foveated such that portions of the lens within the user's gaze exhibit a different phase profile than portions of the lens outside of the user's gaze.

Abstract: Image-sensing devices include odd-symmetry gratings that cast interference patterns over a photodetector array. Grating features offer considerable insensitivity to the wavelength of incident light, and to the manufactured distance between the grating and the photodetector array. Photographs and other image information can be extracted from interference patterns captured by the photodetector array. Images can be captured without a lens, and cameras can be made smaller than those that are reliant on lenses and ray-optical focusing.

Abstract: A pair of eyeglasses may include one or more adjustable lenses that are each configured to align with a respective one of a user's eyes. The adjustable lenses may each include electrically modulated optical material such as one or more liquid crystal cells. The liquid crystal cells may include arrays of electrodes that extend along one, two, three, four, or more than four directions. Control circuitry may apply control signals to the array of electrodes in each liquid crystal cell to produce a desired phase profile. Each lens may be foveated such that portions of the lens within the user's gaze exhibit a different phase profile than portions of the lens outside of the user's gaze. The control circuitry may adjust the location of the optically distinct area so that it remains aligned with the user's gaze.

Abstract: An imaging system includes a phase grating overlying a two-dimensional array of pixels, which may be thermally sensitive pixels for use in infrared imaging. The phase grating comprises a two-dimensional array of identical subgratings that define a system of Cartesian coordinates. The subgrating and pixel arrays are sized and oriented such that the pixels are evenly distributed with respect to the row and column intersections of the subgratings. The location of each pixel thus maps to a unique location beneath a virtual archetypical subgrating. Portions of the phase grating extend beyond the edges of the pixels array to interference pattern in support of Fourier-domain imaging.

Abstract: Image-sensing devices include odd-symmetry gratings that cast interference patterns over a photodetector array. Grating features offer considerable insensitivity to the wavelength of incident light, and also to the manufactured distance between the grating and the photodetector array. Photographs and other image information can be extracted from interference patterns captured by the photodetector array. Images can be captured without a lens, and cameras can be made smaller than those that are reliant on lenses and ray-optical focusing.

Abstract: An array of diffraction-pattern generators employ phase anti-symmetric gratings to projects near-field spatial modulations onto a closely spaced array of photoelements. Each generator in the array of generators produces point-spread functions with spatial frequencies and orientations of interest. The generators are arranged in an irregular mosaic with little or no short-range repetition. Diverse generators are shaped and placed with some irregularity to reduce or eliminate spatially periodic replication of ambiguities to facilitate imaging of nearby scenes.

Abstract: An optical method of measuring motion employs a phase grating that produces a diffraction pattern responsive to light from an imaged scene. First and second images of the diffraction pattern are captured and compared to produce an image comparison. Apparent motion is then calculated from the image comparison.

Abstract: A sensing device with an odd-symmetry grating projects near-field spatial modulations onto an array of closely spaced pixels. Due to physical properties of the grating, the spatial modulations are in focus for a range of wavelengths and spacings. The spatial modulations are captured by the array, and photographs and other image information can be extracted from the resultant data. Pixels responsive to infrared light can be used to make thermal imaging devices and other types of thermal sensors. Some sensors are well adapted for tracking eye movements, and others for imaging barcodes and like binary images. In the latter case, the known binary property of the expected images can be used to simplify the process of extracting image data.

Abstract: An imaging system with a diffractive optic captures an interference pattern responsive to light from an imaged scene to represent the scene in a spatial-frequency domain. The sampled frequency-domain image data has properties that are determined by the point-spread function of diffractive optic and characteristics of scene. An integrated processor can modified the sampled frequency-domain image data responsive to such properties before transforming the modified frequently-domain image data into the pixel domain.

Abstract: An optical smart sensor combines a phase grating with a rolling shutting to distinguish between modulated point sources. Employing a phase grating in lieu of a lens dramatically reduces size and cost, while using timing information inherent to imaging techniques that used a rolling shutter allows the smart sensor to distinguish point sources quickly and easily using a single frame of image data.

Abstract: The embodiments herein describe technologies of cryogenic digital systems with a power supply located in an ambient temperature domain and logic located in a cryogenic temperature domain. A pair of conductors is operable to carry current with a voltage difference between the power supply and the logic. The pair of conductors includes a first portion thermally coupled to a temperature-regulated or temperature-controlled intermediate temperature domain. The intermediate temperature domain is less than the ambient temperature domain and greater than the cryogenic temperature domain.

Abstract: Image-sensing devices include odd-symmetry gratings that cast interference patterns over a photodetector array. Grating features offer considerable insensitivity to the wavelength of incident light, and also to the manufactured distance between the grating and the photodetector array. Photographs and other image information can be extracted from interference patterns captured by the photodetector array. Efficient extraction algorithms based on Fourier deconvolution introduce barrel distortion, which can be removed by resampling using correction functions.

Abstract: An imaging device has an optical grating with a repealing pattern of similar subgratings, each of which produces a similar interference pattern responsive to an image scene. An underlying pixel array samples the similar images to obtain a collection of similar, low-resolution patterns. A processor sums these patterns, on a per-pixel basis, to produce a low-noise, low-resolution digest of the imaged scene. The digest simplifies some aspects of image processing and has application where active illumination power is a chief concern, either for power constraints or when excessive illumination would be undesirable or unsafe.

Abstract: An imaging system includes multiple diffractive optical gratings disposed over a two-dimensional array of photosensitive pixels. The different gratings present different patterns and features that are tailored to produce point-spread responses that emphasize different properties of an imaged scene. The different responses are captured by the pixels, and data captured from the responses can be used separately or together to analyze aspects of the scene. The imaging systems can include circuitry to analyze the image data, and to support modes that select between point-spread responses, selections of the pixels, and algorithms for analyzing image data.