Abstract: An in-situ test calibration system and method are disclosed where a perpetual out-of-band electrostatic force induced excitation is used to dither the proof-mass of a MEMS based accelerometer where the amount of deflection change is proportional to sensitivity changes. The supplier of the accelerometer would exercise the accelerometer in a calibration station to determine initial sensitivity values. After the calibration and before removing the accelerometer from the calibration station, the supplier would start the dither and calibrate the acceleration equivalent force (FG) to drive voltage transfer function (FG/V). After installation of the accelerometer into a system or sometime later in the field, any changes in the FG/V transfer function due to changes in the sensitivity are observable and can be used for re-calibrating the accelerometer.

Abstract: Aspects of the subject technology relate to an apparatus for self-mixing particulate-matter sensing using a vertical-cavity surface-emitting laser (VCSEL) with extrinsic photodiodes. The apparatus includes a dual-emitting light source disposed on a first chip and to generate a first light beam and a second light beam. The first light beam illuminates a particulate matter (PM), and a light detector extrinsic to the first chip measures the second light beam and variations of the second light beam and generates a self-mixing signal. The variations of the second light beam are caused by a back-scattered light resulting from back-scattering of the first light beam from the PM. The light detector is coupled to the dual-emitting light source. The direction of the second light beam is opposite to the direction of the first light beam, and the second light beam is directed to a sensitive area of the light detector.

Abstract: Aspects of the subject technology relate to an apparatus for self-mixing particulate-matter sensing using a vertical-cavity surface-emitting laser (VCSEL) with extrinsic photodiodes. The apparatus includes a dual-emitting light source disposed on a first chip and to generate a first light beam and a second light beam. The first light beam illuminates a particulate matter (PM), and a light detector extrinsic to the first chip measures the second light beam and variations of the second light beam and generates a self-mixing signal. The variations of the second light beam are caused by a back-scattered light resulting from back-scattering of the first light beam from the PM. The light detector is coupled to the dual-emitting light source. The direction of the second light beam is opposite to the direction of the first light beam, and the second light beam is directed to a sensitive area of the light detector.

Abstract: An electronic device may have components that experience performance variations as the device changes orientation relative to a user. Changes in the orientation of the device relative to the user can be monitored using a motion sensor. A camera may be used to periodically capture images of a user's eyes. By processing the images to produce accurate orientation information reflecting the position of the user's eyes relative to the device, the orientation of the device tracked by the motion sensor can be periodically updated. The components may include audio components such as microphones and speakers and may include a display with an array of pixels for displaying images. Control circuitry in the electronic device may modify pixel values for the pixels in the array to compensate for angle-of-view-dependent pixel appearance variations based on based on the orientation information from the motion sensor and the camera.

Abstract: An electronic device can include a force and touch sensing system. In one embodiment, an input force sensor device of an electronic device is disclosed.

Abstract: An in-situ test calibration system and method are disclosed where a perpetual out-of-band electrostatic force induced excitation is used to dither the proof-mass of a MEMS based accelerometer where the amount of deflection change is proportional to sensitivity changes. The supplier of the accelerometer would exercise the accelerometer in a calibration station to determine initial sensitivity values. After the calibration and before removing the accelerometer from the calibration station, the supplier would start the dither and calibrate the acceleration equivalent force (FG) to drive voltage transfer function (FG/V). After installation of the accelerometer into a system or sometime later in the field, any changes in the FG/V transfer function due to changes in the sensitivity are observable and can be used for re-calibrating the accelerometer.

Abstract: An electronic device may have components that experience performance variations as the device changes orientation relative to a user. Changes in the orientation of the device relative to the user can be monitored using a motion sensor. A camera may be used to periodically capture images of a user's eyes. By processing the images to produce accurate orientation information reflecting the position of the user's eyes relative to the device, the orientation of the device tracked by the motion sensor can be periodically updated. The components may include audio components such as microphones and speakers and may include a display with an array of pixels for displaying images. Control circuitry in the electronic device may modify pixel values for the pixels in the array to compensate for angle-of-view-dependent pixel appearance variations based on based on the orientation information from the motion sensor and the camera.

Abstract: An electronic device can include a force and touch sensing system. In one embodiment, an input force sensor device of an electronic device is disclosed.

Abstract: A personal audio device has a bone conduction pickup transducer, having a housing of which a rigid outer wall has an opening formed therein. A volume of yielding material fills the opening in the rigid outer wall. An electronic vibration sensing element is embedded in the volume of yielding material. The housing is shaped, and the opening is located, so that the volume of yielding material comes into contact with an ear or cheek of a user who is using the personal audio device. Other embodiments are also described and claimed.

Abstract: A personal audio device has a bone conduction pickup transducer, having a housing of which a rigid outer wall has an opening formed therein. A volume of yielding material fills the opening in the rigid outer wall. An electronic vibration sensing element is embedded in the volume of yielding material. The housing is shaped, and the opening is located, so that the volume of yielding material comes into contact with an ear or cheek of a user who is using the personal audio device. Other embodiments are also described and claimed.