Abstract: Directive projection screens described herein are configured to selectively direct incident light depending upon an angle of incidence of the light. Such direction improves projection screen gain. Incident light within an acceptance cone is configured to be presented to a viewer. Light outside of the acceptance cone is directed away from the user or absorbed. As a result of this selectivity and the gain, presentation of images on the directive projection screen is improved in the presence of non-projector light sources.

Abstract: Techniques for transitioning an electronic device between device states. In one example, a voice-controlled device is configured to transition from a sleep state to an awake state in response to identifying a user speaking a predefined utterance. The techniques may determine whether the user has spoken the predefined utterance with reference to traditional speech-recognition techniques, as well as with reference to changes in the volume of a user's voice.

Abstract: A passive projection screen presents images projected thereon by a projection system. A surface of the screen includes elements that are reflective to non-visible light, such as infrared (IR) light. When non-visible light is directed to the screen, the non-visible light is reflected by the reflective elements back. Part of the reflected light may contact and reflect from a user's fingertip or hand (or other object, such as a stylus) while another part is reflected to the projection system. The projection system differentiates among distances to the surface and distances that include the additional travel to the fingertip. As the fingertip moves closer to the surface, the distances approach equality. When the distances are approximately equal, the finger is detected as touching the surface. In this manner, a projection surface equipped with reflective elements facilitates more accurate touch detection.

Abstract: An audio-based system may perform noise and echo suppression by initially processing an audio signal that is subject to acoustic echo or echo resulting from other system characteristics. The audio signal is processed in the time domain using an adaptive echo-cancellation filter. The audio is then further processed in the frequency domain to simultaneously reduce background noise and residual echo.

Abstract: A voice gesture is determined from characteristics of an audio signal based on sound uttered by a user. The voice gesture may represent a command or parameters or a command, and may be context sensitive. Upon determining a command and parameters of the command based on the received voice gesture, the command is executed in accordance with the determined parameters. The command may modify any number of attributes within an environment including, but limited to, an image projected within the environment.

Abstract: An architecture has one or more systems for generating augmented reality environments configured to access cloud services over a network. A user is authenticated within the environments, and once authenticated is permitted to interact with the cloud services using the augmented reality environments as well as client resources provided within the environments. The client resources may include devices or things that are primary intended for use within the environments, and devices or things that are not typically associated with augmented reality environments. The architecture enables the client resources to function as thin client interfaces to the cloud services.

Abstract: An audio-based system may perform echo cancellation by decomposing an input audio signal and a corresponding reference signal into sub-signals corresponding to different frequency bands and implementing adaptive filtering independently for each frequency band. Computational resources may be allocated differently for each of the frequency bands depending on observed conditions. Orders of adaptive FIR filters may be varied during operation. Double talk detection and echo path change detection may be implemented for some frequency bands and not others. Filter adaption rates may also be assigned independently to each of the FIR filters, and may be changed during operation.

Abstract: In some examples, a projection display surface is configured to reflect a first image or image portion in a first direction and a second image or image portion in a second direction. In some cases, first light corresponding to the first image is projected onto a display surface that includes a first plurality of reflectors configured to reflect the first light in a first direction, but not reflect second light corresponding to the second image. The display surface may further include a second plurality of reflectors to reflect the second light in a second direction, but not reflect the first light. In some examples, the first light is within a first wavelength range and the second light is within a second, different wavelength range. In other examples, the first light has a first polarization and the second light has a second, different polarization.

Abstract: Techniques for providing virtual assistants to assist users during a voice communication between the users. For instance, a first user operating a device may establish a voice communication with respective devices of one or more additional users, such as with a device of a second user. For instance, the first user may utilize her device to place a telephone call to the device of the second user. A virtual assistant may also join the call and, upon invocation by a user on the call, may identify voice commands from the call and may perform corresponding tasks for the users in response.

Abstract: An architecture for selecting and providing content items to a device includes cloud-based resources of a device management service and one or more content sources. The device is configured to receive instructions and a portion of the content item from the device management service. The instructions direct the device to obtain and buffer the content item from the content source, while simultaneously outputting the portion of the content item to a user.

Abstract: In some embodiments, distances associated with a surface may be calculated using time-of-flight (ToF) of a plurality of pulses of light occurring at a predetermined frequency. Reflected light from a light emitter may be captured by two or more light sensors. At least one light sensor may be located in a sensor pod that is separate from the light emitter, which may be housed in an emitter pod with or without a light sensor. The sensor pod may be synchronized with the emitter pod to enable ToF of light distance calculations. The calculated distance may be used to determine movement of a surface and/or one or more pixels of a surface. In some instances, the calculated distance may be used to identify a profile of a surface, which may then be used associate the profile with an object, a command, or another association.

Abstract: Techniques for providing audio services to multiple devices are described. For instance, connections between a hands-free unit and multiple wireless devices are established. The connections are themselves used to establish active communication channels, such as active audio communication channels, between the hands-free unit and the wireless devices, such as during a phone call. Upon establishment of an active communication channel with one of the wireless devices, the connections to the other wireless devices are disconnected—and/or additional connections refused—for the duration of the active communication channel. Furthermore, a routing module in various embodiments permits multiple hands-free units to route active communication channels to each other depending on user location.

Abstract: An augmented reality environment allows interaction between virtual and real objects. Multiple microphone arrays of different physical sizes are used to acquire signals for spatial tracking of one or more sound sources within the environment. A first array with a larger size may be used to track an object beyond a threshold distance, while a second array having a size smaller than the first may be used to track the object up to the threshold distance. By selecting different sized arrays, accuracy of the spatial location is improved.

Abstract: A directive projection screen is configured to present images projected from a remote projector in three dimensions (3D) to a viewer. The screen includes a plurality of passive optical elements arranged on a structural substrate. The optical elements are configured to receive incident light projected from the projector and reflect the light such that first portions of the image are directed in a first direction to be viewed by a first eye of the viewer and second portions of the image are directed in a second direction to be viewed by a second eye of the viewer.

Abstract: A stepper motor may be controlled by a controller to provide extended revolution of a motor shaft while operating in a first mode and to allow a user to manually intervene with an intended position or rotation of the motor shaft while operating in a second mode. In some embodiments, the controller may adjust a torque applied to the stepper mode during operation of the stepper motor. The controller may reduce a torque applied by the stepper motor to a lower torque while the user intervenes with the intended position or rotation of the motor and increase the torque to a holding torque after the user intervention has ended. Thus, the controller may dynamically adjust a torque of the stepper motor in response to detection of the user intervention.

Abstract: A voice controlled assistant has two speakers and stereo component configured to produce high quality stereo sound. The stereo component generates a first channel signal and a second channel signal used to produce stereo sound. The first channel signal is filtered to remove a range of frequencies, such as the low frequency range. The filtered first channel signal is passed to a first transducer associated with a first speaker to output a first part of the stereo sound. The second channel signal, together with the frequency portion removed from the first channel signal, are provided to a second transducer associated with a second speaker to output a second part of the stereo sound. In this manner, the two speaker arrangement plays stereo, without distortion, while preserving all frequencies in the signals.

Abstract: Structured light patterns are projected onto an object and images of the structured light interacting with the surface of the object are acquired, as well as grayscale information. Edges within the structured light patterns are detected and depth sample points on the edges are used to determine distance to those sample points. The grayscale information is used to construct surface normals. From these normals relative surface contours such as curves or slopes may be determined. A model of a surface of the object is generated using the distances and the contours.

Abstract: Techniques are described for detecting a hand gesture made by a user. Fingertips of a hand may be identified and tracked over time. When a user contracts the fingertips from an extended position, hand spread may be calculated based on the area of the hand and fingers. The hand spread over time may be compared to a Gaussian function to evaluate whether the observed motion represents a grasping motion.

Abstract: An anisotropic projection screen accepts light projected at non-normal angles and redirects the light as high quality images along a viewing path that is near normal to the screen. This allows side projection of images in a manner that avoids the potential viewer obstruction of the projection path. The images may be projected onto the screen from any angle (e.g., sides, top, bottom, etc.) relative to the screen surface, and then redirected to the viewer who is viewing the screen essentially normal to the screen surface. The screen has arrays of passive elements that are oriented to collect and redirect light from one direction, while rejecting or absorbing light received from another direction.

Abstract: An optical assembly includes an imaging element to generate an image and a module configured to adjust a throw ratio of the image which also forms an intermediate real image at an intermediate real image plane. A dynamic optical component positioned relative to the optical path to receive the intermediate real image is configured with one or more optical components which laterally translate a projected image without keystone distortion.