Abstract: An electronic device such as a head-mounted device may have displays. The display may have regions of lower and higher resolution to reduce data bandwidth and power consumption for the display while preserving satisfactory image quality. Data lines may be shared by lower and higher resolution portions of a display or different portions of a display with different resolutions may be supplied with different numbers of data lines. Data line length may be varied in transition regions between lower resolution and higher resolution portions of a display to reduce visible discontinuities between the lower and higher resolution portions. The lower and higher resolution portions of the display may be dynamically adjusted using dynamically adjustable gate driver circuitry and dynamically adjustable data line driver circuitry.

Abstract: Eyewear such as a head-mounted device may include display-optimized lenses. The lenses may be optimized for viewing an external display while also providing sun protection for the user's eyes. The external display may form part of a handheld electronic device that serves as a controller for the head-mounted device. The lenses in the head-mounted device may reduce ambient light brightness while maintaining the brightness of the external display so that the user can use the external display while wearing the head-mounted device. The user may, for example, provide touch input to the external display to adjust display content on the head-mounted display. The lenses may include a polarizer and a color filter having a transmission spectrum curve with peaks corresponding to the primary colors of the external display. The lenses may be removable clip-on lenses and the light filter may be an electrochromic filter.

Abstract: An electronic device may provide visual content at a virtual image distance that is farther from a user than the physical distance of the device from the user. A display in the device may have a transmissive spatial light modulator and beam steering device that are illuminated by a plane wave illumination system to provide computer-generated hologram images, may have a waveguide-based system that ensures that image content is presented at a desired virtual image distance, or may be a light-field display. The display may be used to display a left image in a left eye box and a right image in a right eye box. When viewed from the eye boxes, the left and right images fuse and are visible at a virtual image distance that is farther from the user than the distance physically separating the eye boxes from the display.

Abstract: An electronic device such as a head-mounted device may have displays. The display may have regions of lower and higher resolution to reduce data bandwidth and power consumption for the display while preserving satisfactory image quality. Data lines may be shared by lower and higher resolution portions of a display or different portions of a display with different resolutions may be supplied with different numbers of data lines. Data line length may be varied in transition regions between lower resolution and higher resolution portions of a display to reduce visible discontinuities between the lower and higher resolution portions. The lower and higher resolution portions of the display may be dynamically adjusted using dynamically adjustable gate driver circuitry and dynamically adjustable data line driver circuitry.

Abstract: Eyewear such as sunglasses may include display-optimized lenses. The lenses may be optimized for viewing an external display and/or for viewing a display in the head-mounted device while also providing sun protection for the user's eyes. The lenses may include a polarizer and a color filter that are designed for a given target display. Lenses that are optimized for a display that emits linearly polarized light may include a linear polarizer. Lenses that are optimized for a display that emits circularly polarized light may include a circular polarizer. The circular polarizer may include a quarter wave plate and a linear polarizer. The color filter may have a transmission spectrum curve with peaks corresponding to the primary colors of the target display so that the color and brightness of display light is preserved while the brightness of sunlight is reduced.

Abstract: Some implementations provide improved user experiences on head mounted devices (HMDs) that provide near eye viewing, e.g., HMDs that display distorted images and provide lenses that undistort the images for the user. The images are produced using distortion that is corrected dynamically based on context to conserve device resources. To do so, a context associated with a state of the user, the HMD, or content being viewed on the HMD is tracked during the user experience. For example, the device may predict pupil position, eye state, eye gaze direction, or eye fixation, content type, connection mode, and other context. The device uses the tracked context to determine how to correct distortion for the images at different points during the user experience. For example, new distortion corrections may be computed and used while the user's gaze is moving and previously-determined distortion corrections may be used while the user's gaze is fixed.

Abstract: Optical systems may have tunable lenses with focal lengths that are adjusted by control circuitry. A display may produce image light that is received by a tunable lens. The display may be transparent so that light from objects can pass through the display and be received by the tunable lens. The tunable lens may include a birefringent lens element and a polarization rotator and may receive light that has been linearly polarized by passing through a linear polarizer. The polarization rotator may be operable in a first state in which the polarization of light passing through the polarization rotator is not rotated and a second state in which the polarization of light passing through the polarization rotator is rotated by 90°. The birefringent lens element may be formed from a cured liquid crystal polymer or other polymer and may have a liquid crystal additive to enhance birefringence.

Abstract: Described herein are techniques that offer a class of user-interaction styles for indirect user interaction with a two-dimensional virtual space (“desktop”) using touch-sensitive control surface of a user-input device (such as a mobile phone). Some described techniques enable a user to point, pan and scale within a large virtual two-dimensional space with input from a touch surface of a handheld device, with the output of the user interaction being rendered on a visual display unit (other than the touch surface).

Abstract: An electronic device such as a head-mounted device may have displays. The display may have regions of lower and higher resolution to reduce data bandwidth and power consumption for the display while preserving satisfactory image quality. Data lines may be shared by lower and higher resolution portions of a display or different portions of a display with different resolutions may be supplied with different numbers of data lines. Data line length may be varied in transition regions between lower resolution and higher resolution portions of a display to reduce visible discontinuities between the lower and higher resolution portions. The lower and higher resolution portions of the display may be dynamically adjusted using dynamically adjustable gate driver circuitry and dynamically adjustable data line driver circuitry.

Abstract: An electronic device such as a head-mounted device may have displays. The display may have regions of lower (L) and higher (M, H) resolution to reduce data bandwidth and power consumption for the display while preserving satisfactory image quality. Data lines may be shared by lower and higher resolution portions of a display or different portions of a display with different resolutions may be supplied with different numbers of data lines. Data line length may be varied in transition regions between lower resolution and higher resolution portions of a display to reduce visible discontinuities between the lower and higher resolution portions. The lower and higher resolution portions of the display may be dynamically adjusted using dynamically adjustable gate driver circuitry and dynamically adjustable data line driver circuitry.

Abstract: An electronic device may have a display such as an organic light-emitting diode display. Electronic devices may also include a number of sensors such as accelerometers and gaze detection sensors. A graphics processing unit (GPU) may render digital pixel values for pixels in the device display. Frames (F2) with long rendering times may cause latency. To reduce latency, an image frame may be displayed for an extended period of time (68) to wait for the subsequent frame (F2) to finish rendering. Once the subsequent image frame (F2) has finished rendering, the subsequent image frame may be displayed without delay. To increase the lifespan of the display, variable persistence may be used. Sensor data and other factors may be used to dynamically determine persistence for minimal motion blur and maximum display lifespan. Sensor data may also be used to determine refresh rates for different portions of the display.

Abstract: An electronic device may have a display such as an organic light-emitting diode display. Electronic devices may also include a number of sensors such as accelerometers and gaze detection sensors. A graphics processing unit (GPU) may render digital pixel values for pixels in the device display. Frames (F2) with long rendering times may cause latency. To reduce latency, an image frame may be displayed for an extended period of time (68) to wait for the subsequent frame (F2) to finish rendering. Once the subsequent image frame (F2) has finished rendering, the subsequent image frame may be displayed without delay. To increase the lifespan of the display, variable persistence may be used. Sensor data and other factors may be used to dynamically determine persistence for minimal motion blur and maximum display lifespan. Sensor data may also be used to determine refresh rates for different portions of the display.

Abstract: An electronic device such as a head-mounted device may have displays. The display may have regions of lower (L) and higher (M, H) resolution to reduce data bandwidth and power consumption for the display while preserving satisfactory image quality. Data lines may be shared by lower and higher resolution portions of a display or different portions of a display with different resolutions may be supplied with different numbers of data lines. Data line length may be varied in transition regions between lower resolution and higher resolution portions of a display to reduce visible discontinuities between the lower and higher resolution portions. The lower and higher resolution portions of the display may be dynamically adjusted using dynamically adjustable gate driver circuitry and dynamically adjustable data line driver circuitry.

Abstract: Samples of a scene are acquired in synchronization with finely interleaved varying conditions such as lighting, aperture, focal length, and so forth. A time-varying sample at each pixel for each condition is reconstructed. Time multiplexed interleaving allows for real-time, live applications, while handling motion blur naturally. Effects such as real-time video relighting of a scene is possible. Time interleaved exposures also allow segmentation of a scene, and allows for constrained special effects such as triangulation matting using a multi-color interleaved chroma key.

Abstract: A method of calibrating a brightness value measured by a camera with an amount of light received by the camera includes creating a series of measurements, wherein for each measurement the amount of light received at an image plane in the camera is controlled to be a known ratio of two opposed irradiance values: a high irradiance value and a low irradiance value. Each ratio is correlated with the brightness value measured by the camera. A function is obtained describing the correlation.

Abstract: A method of calibrating a brightness value measured by a camera with an amount of light received by the camera includes creating a series of measurements, wherein for each measurement the amount of light received at an image plane in the camera is controlled to be a known ratio of two opposed irradiance values: a high irradiance value and a low irradiance value. Each ratio is correlated with the brightness value measured by the camera. A function is obtained describing the correlation.

Abstract: A method of calibrating a brightness value measured by a camera with an amount of light received by the camera includes creating a series of measurements, wherein for each measurement the amount of light received at an image plane in the camera is controlled to be a known ratio of two opposed irradiance values: a high irradiance value and a low irradiance value. Each ratio is correlated with the brightness value measured by the camera. A function is obtained describing the correlation.

Abstract: Described herein are techniques that offer a class of user-interaction styles for indirect user interaction with a two-dimensional virtual space (“desktop”) using touch-sensitive control surface of a user-input device (such as a mobile phone). Some described techniques enable a user to point, pan and scale within a large virtual two-dimensional space with input from a touch surface of a handheld device, with the output of the user interaction being rendered on a visual display unit (other than the touch surface).

Abstract: Samples of a scene are acquired in synchronization with finely interleaved varying conditions such as lighting, aperture, focal length, and so forth. A time-varying sample at each pixel for each condition is reconstructed. Time multiplexed interleaving allows for real-time, live applications, while handling motion blur naturally. Effects such as real-time video relighting of a scene is possible. Time interleaved exposures also allow segmentation of a scene, and allows for constrained special effects such as triangulation matting using a multi-color interleaved chroma key.

Abstract: Photodiode-based bi-directional reflectance distribution function (BRDF) measurement is described. Multiple photodiodes are distributed approximately symmetrically at a fixed distance from a surface to be measured. One or more of the photodiodes are directed to emit light, while readings are gathered from the other photodiodes that are not emitting light. The readings are processed based on previously measured calibration data to generate BRDF values.