Abstract:
Actuators are used to move a variety of objects to desired positions. It is generally desirable that they can do this quickly without exhibiting overshoot or ringing. Some actuators are required to respond very quickly and examples of these are voice coil drivers used to move lenses in autofocus cameras provided in everyday devices such as smart phones and tablets. A rapid two step controller scheme had already been disclosed by Analog Devices Inc. Whilst the scheme works well, it can only be used reliably if the resonant frequency of the actuator is known to within 2 or 3%. The inventors have discovered that the resonant frequency of an actuator unexpectedly changes as a function of position. This disclosure provides ways of modifying the control scheme to cope with changes in resonant frequency.
Abstract:
Aspects of the embodiments are directed to systems, methods, and devices for eye gaze tracking. In embodiments, a projective surface, such as a virtual reality display screen or augmented reality projective surface, can project light towards a wearer's eyes. The light can be light representing the shape of the projective surface or can be a displayed shape. The light can be reflected from a cornea. The reflected light from the cornea can be received. A distortion of the shape of the projective surface or displayed shape can be used to determine an eye gaze position.
Abstract:
Accurately measuring bio-impedance is important for sensing properties of the body. Unfortunately, contact impedances can significantly degrade the accuracy of bio-impedance measurements. To address this issue, circuitry for implementing a four-wire impedance measurement can be configured to make multiple current measurements. The multiple current measurements set up a system of equations to allow the unknown bio-impedance and contact impedances to be derived. The result is an accurate bio-impedance measurement that is not negatively impacted by large contact impedances. Moreover, bad contacts with undesirably large impedances can be identified.
Abstract:
Aspects of the embodiments are directed to a time-of-flight imaging system and methods of using the same. The time-of-flight imaging system includes a light emitter comprising at least one one-dimensional array of laser diodes; a photosensitive element for receiving reflected light from an object; and a light deflection device configured to deflect light from the light emitter to the object. In embodiments, the time-of-flight imaging system includes a lens structure to deflect emitting light from the laser diodes at a predetermined angle towards a light steering device.
Abstract:
A magnetic device may include a magnetic structure, a device structure, and an associated circuit. The magnetic structure may include a patterned layer of material having a predetermined magnetic property. The patterned layer may be configured to, e.g., provide a magnetic field, sense a magnetic field, channel or concentrate magnetic flux, shield a component from a magnetic field, or provide magnetically actuated motion, etc. The device structure may be another structure of the device that is physically connected to or arranged relative to the magnetic structure to, e.g., structurally support, enable operation of, or otherwise incorporate the magnetic structure into the magnetic device, etc. The associated circuit may be electrically connected to the magnetic structure to receive, provide, condition or process of signals of the magnetic device.
Abstract:
An embodiment of a position sensing system includes a signal generation circuit to generate an excitation signal according to a selected characteristic signal, a drive circuit to drive an excitation source with the excitation signal, an input circuit to receive a sensor output while driving the excitation source, a signal detection circuit to identify a component of the sensor output corresponding to the characteristic signal, and a control circuit to determine the position of the movable object as a function of the identified component of the sensor output. The positioning system may be included an electronic camera, where the movable object may be a lens. The excitation source may be a conductive coil, the excitation a magnetic field, and the sensor a magneto resistive sensor. Alternatively, the excitation source may be an optical excitation source, the excitation an optical excitation, and the sensor an optical sensor.