Microvision, Inc.

University of Washington

Patrick J McVittie

Jonathan A Morarity

P Selvan Viswanathan

Les Atlas

Damon Marlow Domjan

Ru Chen

Justin R Zilke

A projection system emits light pulses in a field of view and measures properties of reflections. Properties may include time of flight and return amplitude. Foreground objects and background surfaces are distinguished, distances between foreground objects and background surfaces are determined based on reflections that are occluded by the foreground objects and other properties of the projection system.

Occlusion-based height estimation

A resonant scanning mirror includes a sensor to provide position information. A parameter estimation circuit estimates parameters from the position information. The parameter estimation circuit includes wideband analog circuits that have poles far removed from the resonant frequency of the scanning mirror. The parameter estimation circuit also includes an analog-to-digital converter that samples at a high sample rate, and digital filters that exhibit near perfect linearity.

Resonant MEMS mirror parameter estimation

A laser drive circuit compensates for laser diode dynamics. A compensation value is determined from a sum of weighted basis functions. The basis functions may be a function of current desired optical powers and/or past desired optical powers. The weights may be updated periodically based at least in part on accumulated basis function outputs and measured optical powers.

Dynamic laser diode compensation

Touch interactivity with occlusions in returned illumination data

A drive circuit for a resonant system provides an excitation signal having an amplitude and a phase. The resonant system provides a feedback signal representing an oscillation amplitude. The amplitude of the excitation signal is reduced for a substantially constant feedback signal amplitude by modifying the excitation signal phase.

Resonant system excitation power reduction using dynamic phase offset

Briefly, in accordance with one or more embodiments, a scanned beam projector comprises a laser diode to emit a beam, a scanning engine to scan the beam on a surface to project an image comprising virtual pixels on the surface, a digital-to-analog converter (DAC) coupled to the laser diode to cause the laser diode to emit the beam in response to a digital video signal provided to the DAC, and a pulsed pixel controller to provide the digital video signal to the DAC, the pulsed pixel controller to align the digital video signal provided to the DAC with the virtual pixels of the image, and to select an optimal waveform to be generated by the laser diode for each virtual pixel.

Scanned beam projector pulsed laser control

Objects in a cargo shipping container are detected by measuring vibration resonant frequency peaks of the container. The mass of an object on the floor of the container effects the vibration resonance of the container, enabling the object to be detected. A vibration source and a plurality of accelerometers are either attached to the steel structure of the container, or are disposed on a supporting structure, such as a cargo crane or lift, so that they contact the container. The vibration source causes the container to vibrate, and the accelerometers detect the vibration resonance of the container. A mismatch between a cargo manifest and an observed cargo, or detection of an object having relatively high mass, e.g., due to lead shielding, can justify a manual inspection. The process uses synchronous processing to achieve the sensitivity needed, is unobtrusive, and does not slow the flow of cargo through a facility.

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Seattle, WA, United States of America

Patrick J McVittie