Abstract: A top-down construction type assembly construction method for paved road surface, including the following steps: step I, manufacturing prefabricating slabs: using a top-down method to manufacture the prefabricating slabs, and providing bolt sleeves, inside the prefabricating slabs, which are evenly arranged in the prefabricating slabs; step II, mounting the prefabricating slabs: on a lower bearing plate, placing the prefabricating slabs in one step, performing a fine tuning on a position and an altitude of the prefabricating slabs, performing a grouting construction, finally forming the paved road surface; the prefabricating slabs are manufactured by laying bricks and pouring concrete, the prefabricating slabs are rolled over and mounted, thus eliminating on-site concrete bonding between bricks and the lower bearing plate, improving overall stability of the bricks and the prefabricating slabs after being mounted, assembled mounting for a paved road surface is implemented, and the construction period is shorte

Abstract: A method for establishing synchronization relationship, a chip, an electronic device, and a non-transitory computer-readable storage medium are provided. The method includes the following. A synchronization pulse of the master device is initiated according to a pulse period preset. A start time of a K1th synchronization pulse and a start time of a K2th connection event of a slave device are obtained, and an offset time is obtained according to the start time of the K1th synchronization pulse and the start time of the K2th connection event. First synchronization information is transmitted to the slave device for the slave device to start a local synchronization pulse synchronized with the synchronization pulse of the master device according to the first synchronization information. The first synchronization information carries a count value K1, a count value K2, the offset time, and the pulse period.

Abstract: Techniques are described for optical sightline tracking in a wearable system. Embodiments include a wearable structure that includes at least one integrated illuminator and at least one integrated imaging array. Each illuminator and imaging array is disposed in the periphery of an eye of a user wearing the structure. From the peripheral viewpoint, embodiments measure a three-dimensional origin point of one or both eyes and can compute angular coordinate measurements for one or both eyes based on the imaging to indicate the direction in which the user's eyes are looking (a sightline). Embodiments can track changes in the sightline to support various applications, such as positioning of display of virtual objects in virtual or augmented reality environments. Some embodiments can also use the obtained imagery for biometric verification and/or identification, detection of changes in pupillary response, etc.

Abstract: Techniques are described for non-invasive, dual-altitude-based measurement of blood pressure of a user using a portable electronic device having a sensor head. Illumination is projected into a body part and received by photodetectors. A changing amount of illumination received by the photodetectors changes corresponds to a changing amount of blood volume in elastic circulatory system pathways in the body part. Measurements of the received illumination are obtained at multiple altitudes relative to the user's heart. A linear fit is applied to the multiple measurements based on at least a predetermined slope-calibration factor to obtain a slope-corrected mean blood pressure measurement (BPM). Some embodiments use similar techniques to further measure pulse-to-mean (PTM) at multiple altitudes. The PTM measurements are used to simulate a systolic and/or diastolic BPM.

Abstract: Techniques are described for passive three-dimensional image sensing based on referential image blurring. For example, a filter mask is integrated with a lens assembly to provide one or more normal imaging bandpass (NIB) regions and one or more reference imaging bandpass (RIB) regions, the regions being optically distinguishable and corresponding to different focal lengths and/or different focal paths. As light rays from a scene object pass through the different regions of the filter mask, a sensor can detect first and second images responsive to those light rays focused through the NIB region and the RIB region, respectively (according to their respective focal lengths and/or respective focal paths). An amount of blurring between the images can be measured and correlated to an object distance for the scene object. Some embodiments project additional reference illumination to enhance blurring detection in the form of reference illumination flooding and/or spotted illumination.

Abstract: Techniques are described for passive three-dimensional image sensing based on referential image blurring. For example, a filter mask is integrated with a lens assembly to provide one or more normal imaging bandpass (NIB) regions and one or more reference imaging bandpass (RIB) regions, the regions being optically distinguishable and corresponding to different focal lengths and/or different focal paths. As light rays from a scene object pass through the different regions of the filter mask, a sensor can detect first and second images responsive to those light rays focused through the NIB region and the RIB region, respectively (according to their respective focal lengths and/or respective focal paths). An amount of blurring between the images can be measured and correlated to an object distance for the scene object. Some embodiments project additional reference illumination to enhance blurring detection in the form of reference illumination flooding and/or spotted illumination.

Abstract: Techniques are described for passive three-dimensional (3D) object authentication based on image sizing, such as for biometric facial recognition. For example, during a registration routine, an imaging system captures images of a registering user's face at multiple distances. The images can be processed to extract registration dimensions, including individual deterministic structural dimensions, dimensional relationships that are static over changes in imaging distance, and dimensional relationships that changes predictably over changes in imaging distance. During an authentication routine, the imaging system again captures authentication images of an authenticating user's face (purportedly the previously registered user) at some authentication imaging distance and processes the images to extract authentication dimensions.

Abstract: Devices and optical sensor modules are provided for on-screen optical sensing of fingerprints or other patterns by interleaving optical sensors with display pixels across a display panel for using a top surface above the display panel over the entire display surface as an optical sensing surface.

Abstract: Techniques are described for passive three-dimensional (3D) image sensing based on chromatic differentiation for use in object verification. For example, multiple sub-images correspond to 3D feature regions of an object. The sub-images can be analyzed to obtain respective sets of feature depth measurements (e.g., depth, textural signatures, etc.) based on multiple differentiated chromatic components of raw image sensor data captured from the object. A verification signal can be output as a function of comparing the respective sets of feature depth measurements from the plurality of characteristic sub-images to previously stored feature depth expectations, such that the verification signal indicates whether an identity of the object is verified and/or whether the object is a spoof.

Abstract: Methods, systems, and devices are disclosed for optical sensing and tracking of eye movement. In one aspect, a method for tracking the movement of an eye includes emitting a first modulated light and a second modulated light toward an eye of a user, wherein the first modulated light and the second modulated light have substantially the same modulation frequency, but the modulation phases of the two modulated lights are substantially opposite to each other; receiving at a photodetector module a returned light including at least a partial retroreflected light from the eye of the user based on the first and second modulated lights; and processing the output signal from the photodetector module to determine positional and dimensional parameters of the eye of the user based at least on the partial retroreflected light corresponding to the first and second modulated lights.

Abstract: A method for establishing synchronization relationship, a chip, an electronic device, and a non-transitory computer-readable storage medium are provided. The method includes the following. A synchronization pulse of the master device is initiated according to a pulse period preset. A start time of a K1th synchronization pulse and a start time of a K2th connection event of a slave device are obtained, and an offset time is obtained according to the start time of the Klth synchronization pulse and the start time of the K2th connection event. First synchronization information is transmitted to the slave device for the slave device to start a local synchronization pulse synchronized with the synchronization pulse of the master device according to the first synchronization information. The first synchronization information carries a count value K1, a count value K2, the offset time, and the pulse period.

Abstract: Disclosed are techniques and devices for optical eye tracking based on imaging the eye and tracking certain images of eye features in the eye. The disclosed techniques and devices can be implemented to use structured light to illuminate an eye for obtaining images of the eye to generate accurate eye movement information.

Abstract: Techniques are described for non-invasive, cuff-less measurement of blood pressure of a user using a portable electronic device. Illumination is projected through a body part and received by photodetectors on the other side of the body part. The body part includes elastic pathways of the circulatory system through which blood flows. Cycles of contraction and relaxation by the heart cause pulse waves to travel through the blood, which cause volumetric changes in the elastic pathways. The transient changes in blood volume result in corresponding transient changes in the amount of illumination that is absorbed by the body part versus the amount that passes through to the photodetectors, as manifest by a detection output signal. Calibration data can be used to convert the detection output signal to blood pressure measurements, such as including diastolic and systolic blood pressure readings.

Abstract: Techniques are described for passive three-dimensional (3D) image sensing based on chromatic differentiation. For example, an object can be imaged by using a photodetector array to detect light reflected off of the object and focused through a lens onto the array. Light components of different wavelengths tends to be focused through the lens to different focal lengths, which can tend to impact the brightness of each wavelength as detected. For example, if the detector array is closer to a shorter-wavelength focal plane, a white spot will tend to be detected with a higher magnitude of blue light components than of red light components. Ratios of brightness magnitudes for different wavelengths vary in a manner that strongly correlates to object distance from the lens. Embodiments exploit this correlation to passively detect object distance. Some embodiments further provide various types of distance and/or chromatic calibration to further facilitate such detection.

Abstract: Techniques are described for passive three-dimensional (3D) face imaging based on macro-structure and micro-structure image sizing, such as for biometric facial recognition. A set of images of a user's face is processed to extract authentication deterministic macro-structure (DMAS) measurements. A database includes profile DMAS measurements, profile location definitions for deterministic micro-structure (DMIS) feature regions, and profile DMIS signatures computed for the DMIS feature regions. A first-level authentication determination can be based on comparing the authentication DMAS measurements with the profile DMAS measurements. Authentication DMIS signatures can be computed from sub-images obtained for the DMIS feature regions at the profile location definitions. A second-level authentication determination can be based on comparing the authentication DMIS signatures with the profile DMIS signatures.

Abstract: Techniques are described for time-of-fly sensors with hybrid refractive gradient-index optics. Some embodiments are for integration into portable electronic devices with cameras, such as smart phones. For example, a time-of-fly (TOF) imaging subsystem can receive optical information along an optical path at an imaging plane. A hybrid lens can be coupled with the TOF imaging subsystem and disposed in the optical path so that the imaging plane is substantially at a focal plane of the hybrid lens. The hybrid lens can include a less-than-quarter-pitch gradient index (GRIN) lens portion, and a refractive lens portion with a convex optical interface. The portions of the hybrid lens, together, produce a combined focal length that defines the focal plane. The hybrid lens is designed so that the combined focal length is less than a quarter-pitch focal length of the GRIN lens portion and has less spherical aberration than either lens portion.

Abstract: Techniques are described for passive three-dimensional (3D) object authentication based on image sizing, such as for biometric facial recognition. For example, during a registration routine, an imaging system captures images of a registering user's face at multiple distances. The images can be processed to extract registration dimensions, including individual deterministic structural dimensions, dimensional relationships that are static over changes in imaging distance, and dimensional relationships that changes predictably over changes in imaging distance. During an authentication routine, the imaging system again captures authentication images of an authenticating user's face (purportedly the previously registered user) at some authentication imaging distance and processes the images to extract authentication dimensions.

Abstract: Techniques are described for integrating blood pressure measurement (BPM) into a portable electronic device. For example, an input interface of the device includes an integrated force sensor. Human-discernable feedback is output to the user, while using the force sensor to monitor fingertip pressure being applied by the user on the input interface, to guide the user into a first condition in which capillary fingertip blood flow (CFBF) is occluded. The human-discernable feedback is then output to the user, while continuing to use the force sensor to monitor the fingertip pressure, to guide the user into one or more subsequent conditions that allow non-occluded CFBF signals to be sensed by one or more sensors (e.g., the force sensor, an optical fingerprint sensor, etc.). The sensed non-occluded CFBF signals can be used to generate one or more CFBF-based BPM readings for the user (e.g., which can be calibrated to arterial BPM).

Abstract: An electronic device includes a display screen that includes a cover glass, and a display illumination layer. The display illumination layer includes an array of light-emitting elements that forms an array of pixels of the display screen. The electronic device further includes a light source disposed adjacent the cover glass and configured to emit a light beam to be coupled into the cover glass. A portion of the light beam may be transmitted through the top surface of the cover glass to illuminate a hand of a user. The electronic device further includes an optical ID sensing module that includes an array of photodetectors disposed under the array of light-emitting elements and spatially distributed across the array of pixels of the display screen, and electronic circuitry coupled to the array of photodetectors and configured to capture a fingerprint image or a palmprint image of the hand.

Abstract: An optical sensor module for sensing a face of a person for user identification and authentication, where a face illumination module is provided to use an array of face illumination light sources arranged in a regular array pattern to produce illumination light which may be invisible light such as infrared light and an optical diffraction element that is located to receive illumination light beams from the face illumination light sources and to transfer each illumination light beam from each face illumination light source in the array into a patterned light beam containing illumination light spots.