Analog Devices,inc.

Analog Devices International Unlimited Company

Other

Erik D Barnes

Jonathan Ephraim David Hurwitz

Nicolas Le Dortz

Lawrence A Singer

Harvey Weinberg

Eoin Edward English

Ronald Alan Kapusta

Javier Calpe Maravilla

Scott Robert Davis

Andrew William Sparks

Junhua Shen

Tyler Adam Dunn

Alberto Marinas

Sefa Demirtas

Michael Ziemkiewicz

Charles Mathy

Daniel Peter Canniff

Paul O'Sullivan

Maurizio Zecchini

Krystian Balicki

Siwen Liang

Jonathan Ari Goldberg

Michael J Zylinski

Eric P Chojnacki

Monica Redon Segrera

A time-of-flight (ToF) transmitter with self-stabilized optical output phase with minimal overhead is described, where the transmitter may either function as a slave in that the laser pulse phase and width can be controlled by the master ToF receiver, or it can function as a master where the laser control pulse is generated on the same chip or a companion chip. When the ToF transmitter functions as a slave and receives the laser pulse control signal, the techniques of this disclosure can transform the receive path and the pre-driver circuit into part of a delay locked loop (DLL).

Time of flight transmitter with self-stabilized optical output phase

The present disclosure provides numerous applications for the use of liquid crystal polarization gratings (LCPGs) to controllably steer light. When combined with an image sensor, light generated or reflected from different fields of view (FOV) can be steered, allowing an increase in the FOV or the resolution of the image. Further, the LCPG can stabilize the resulting image, counteracting any movement of the image sensor. The combination of LCPGs and liquid crystal waveguides (LCWGs) allows fine deflection control of light (from the LCWG) over a wild field of view (from the LCPG). Further applications of LCPGs include object tracking and the production of depth images using multiple imaging units and independently steered LCPGs. The LCPG may be used in controlling both the projection and reception of light.

Beam steering device using liquid crystal polarization gratings

An image processing system for time-of-flight depth imaging includes a processor for determining depth measurements using different modes of operation. The processor determines depth measurements in a first set of frames using a second set of frames. The first mode is a continuous wave modulation mode without depth linearization and the second mode is a continuous wave modulation mode with depth linearization. The depth estimates collected in the second mode using depth linearization are used to correct the depth estimates collected in the first mode.

Depth non-linearity compensation in time-of-flight imaging

Time of Flight (ToF) image processing methods include collecting correlation samples to calculate a phase estimate. Systems and methods are provided for collecting correlation samples from multiple pixels. An image processing system for continuous waves includes a light source configured to emit light, an image sensor having a plurality of pixels, and a processor configured to collect correlation samples from a subset of the plurality of pixels in the image sensor.

Spatial correlation sampling in time-of-flight imaging

Time of Flight (ToF) image processing systems and methods for proximity detection are disclosed. In particular, use of a separate proximity detector can be eliminated by using the time of flight image processing system as disclosed herein. In particular, the time of flight image processing system has two modes: a low resolution proximity detection mode and a high resolution imaging mode.

Time-of-flight camera and proximity detector

Depth imagers can implement time-of-flight operations to measure depth or distance of objects. A depth imager can emit light onto a scene and sense light reflected back from the objects in the scene using an array of sensors. Timing of the reflected light hitting the array of sensors gives information about the depth or distance of objects in the scene. In some cases, corrupting light that is outside of a field of view of a pixel in the array of sensors can hit the pixel due to internal scattering or internal reflections occurring in the depth imager. The corrupting light can corrupt the depth or distance measurement. To address this problem, an improved depth imager can isolate and measure the corrupting light due to internal scattering or internal reflections occurring in the depth imager, and systematically remove the measured corrupting light from the depth or distance measurement.

Measuring and removing the corruption of time-of-flight depth images due to internal scattering

Optical systems can emit train(s) of light pulses onto objects to derive a distance between the light source and the object. Achieving meter or centimeter resolution may require very short light pulses. It is not trivial to design a circuit that can generate narrow current pulses for driving a diode that emits the light pulses. An improved driver circuit has a pre-charge path comprising one or more inductive elements and a fire path comprising the diode. Switches in the driver circuit are controlled with predefined states during different intervals to pre-charge current in the one or more inductive elements prior to flowing current through the fire path to pulse the diode.

Pulsed laser diode driver

An optical emitter package is disclosed. The optical emitter package can include a carrier, a switching die, and an optical emitter die mounted to the carrier. The optical emitter die can be directly electrically and mechanically connected to the carrier with a conductive adhesive. An energy storage device can be mounted to the carrier. The energy storage device can be directly electrically and mechanically connected to the carrier with a second conductive adhesive. The carrier can provide electrical communication between the switching die, the optical emitter die, and the energy storage device.

Optical emitter packages

Methods, apparatuses, and systems can be provided to implement active feedback to electrically sense or monitor the illumination and shutter pulses and adjust them actively to maintain the desired phase relationship/difference between the pulses. By maintaining the desired phase difference, the distance calculation can be made more accurate, even when conditions of the time-of-flight camera varies (e.g., temperature, aging, etc.). Advantageously, active compensation can correct for errors 'on-the-fly', eliminating detailed characterization and manual adjustment during operation.

Active compensation for phase alignment errors in time-of-flight cameras

Image capturing systems with interline CCD structures designed to reduce the delay between captures of subsequent image frames are disclosed. Proposed interline CCD structures include two or more sets of storage units associated with a given set of photodetecting elements, where each photodetecting element is associated with one storage unit of each set of storage units in that the charge generated by the photodetecting element during the acquisition of a particular image frame (i.e. during a particular exposure period) may be stored any one of these storage units prior to read-out. Providing multiple sets of storage units allows read-out of charge corresponding to one image frame and stored in one set of storage units while accumulating charge corresponding to another image frame in another set of storage units, thus reducing the delay between captures of different image frames. Consequently, errors and artifacts of the image capturing system can be minimized.

Growing community of inventors

Cambridge, MA, United States of America

Erik D Barnes