Abstract: An electronic device may have a display with a brightness that is adjusted based on ambient light data from multiple ambient light sensors. Sensors that are shadowed can be ignored. A touch sensor array in the display may have electrodes that overlap ambient light sensors. When a touch sensor signal indicates that an external object is covering one of the ambient light sensors, data from that ambient light sensor can be discarded. The ambient light sensors may include a primary ambient light sensor such as a human-eye-response ambient light sensor and may include an array of secondary ambient light sensors such as non-human-eye-response sensors. The secondary ambient light sensors may be formed on a display layer such as a thin-film-transistor layer and may be formed from thin-film materials. An algorithm may be used to dynamically calibrate non-human-eye-response ambient light sensors to the human-eye-response ambient light sensor.

Abstract: A vibratory rotational rate gyroscope has a suspended assembly isolated from external vibrations by an arrangement of helical springs. This isolated assembly includes both the active components of the rotational rate gyroscope and a digital processing circuit. The digital processing circuit includes digital storage for both externally determined and internally determined unit-specific calibration values. These values provide seed values for startup processes, which improves loop startup time, and values for unit-specific electronic calibration. The digital processing circuit further converts all data to digital form. A digital communications protocol is used to transmit the calibration information and the outgoing data to and from the isolated assembly on only two conductors. Two additional conductors used for power. Four of the helical springs used in the suspension arrangement are used for these conductors such that no additional wiring is required.

Abstract: A dual-axis rotational rate sensor having two vibratory masses coupled to a restoring element and driven in a resonant counter-phase motion, wherein the two masses vibrate with equal but opposite amplitudes along a single axis. The vibratory structure also accommodates motion of the masses in a plane orthogonal to the vibratory axis. Measurement of the motion of the masses in two axes in this plane provides signals directly responsive to rotation of the sensor about two orthogonal axes. Measurement and drive is facilitated by the use of magnetic masses and electromagnetic drive and sense transducers.

Abstract: A synchronous signal processing circuit for a dual-axis vibratory rotation-rate sensor uses a hybrid analog/digital design to provide correction for parasitic quadrature errors by the addition of synthesized correction signals in the analog domain prior to digitization. Error correction, signal demodulation and data conversions are synchronized with a signal phase-locked to the measured motion of the vibratory mass. Similarly, cross-axis error correction signals are synthesized directly from the cross axis signals. Use of these precise phase references provides for various benefits in signal noise and error matching (tracking) over wide operation conditions.

Abstract: A signal-processing circuit for a dual-axis vibratory rotation-rate sensor has a digitally programmable bandwidth. An analog-to-digital converter (ADC) converts analog sense signals to digital signals at a high sampling rate. The results of successive ADC conversions are accumulated for a user-programmable number of conversions. By accumulating a number of samples, the sense signals are averaged which improves the signal-to-noise ratio and smoothes the output signal. Alternatively, accumulating a smaller number of samples allows the user to improve the response time of the sensor, allowing the user to set the number of samples that are averaged enables the user to control the effective bandwidth of the sensor. The accumulated conversions are also are scaled by unit-specific calibration factors in order to accommodate for unit to unit variations, so that the rate output will be consistent across a number of sensors.

Abstract: A vibrating gyroscope employs an electromagnetic transducer assembly which excites the vibration of the inertial element and senses its trajectory to provide an indication of movement relative to the plane of vibration of the inertial element. The transducer assembly allows for calibration of the gyroscope by positioning the transducer relative to the inertial element, thereby eliminating conventional requirements for selectively removing material from the inertial element during final calibration. Elastic members of the inertial element are manufactured in a monolithic structure to enhance the vibratory symmetry of the inertial element and the consistency and repeatability of its resonant properties. A phase-shifting circuit allows accurate extraction of rate information from the transducer while rejecting error signals. A mounting system facilitates mounting inertial elements to provide a simple implementations of multi-axis vibrating gyroscopes.