Meta Platforms Technologies, LLC

Facebook Technologies, LLC

Augusto Ronchini Ximenes

Michael Anthony Hall

Zhaoming Zhu

Ali Mesgarani

Shuochen Su

Umanath Ramachandra Kamath

Charles Patrick Saunders

This disclosure describes a method of operating an image sensor and a plurality of memory cells associated with the image sensor, each memory cell comprising: one or more input lines, a stop exposure output line; a storage capacitor; and a stop exposure circuit. The method may comprise, by each of the memory cells, sensing a voltage representing an exposure event in response to the input lines being enabled, and by a first one of the memory cells, enabling the stop exposure output line in response to a charge on the storage capacitor satisfying a charge threshold; and stopping further exposure of the image sensor in response to the stop exposure output line being enabled for the first one of the memory cells.

Automatic termination of image sensor for analog histogram depth sensing

A depth camera assembly (DCA) for multimode time-of-flight based depth sensing is presented herein. The DCA includes a projector, a detector, and a controller. The projector illuminates a target area with outgoing light comprising a plurality of light pulses. The detector includes an array of unit cells. Each unit cell includes a macropixel with a plurality of pixels that captures portions of the outgoing light reflected from the target area, and an array of memory cells coupled to the macropixel. At least one of the memory cells stores information about the captured portions of the reflected outgoing light received from the macropixel. The controller determines depth information for the target area based in part on data read from the at least one memory cell.

Multimode detector for different time-of-flight based depth sensing modalities

A depth camera assembly (DCA) includes a direct time of flight system for determining depth information for a local area. The DCA includes an illumination source, a camera, and a controller. The illumination source projects light (e.g., pulse of light) into the local area. The camera detects reflections of the projected light from objects in the local area. Using an internal gating selection procedure, the controller selects a gate window that is likely to be associated with reflection of a pulse of light from an object. The selected gate may be used for depth determination. The internal gating selection procedures may be achieved through external target location and selection or through internal self-selection.

Autonomous gating selection to reduce noise in direct time-of-flight depth sensing

Each pixel of a plurality of pixels captures a portion of outgoing light illuminating a local area reflected from the one or more objects in the local area. A flag is generated via a flag determination logic circuit coupled to each pixel of the plurality of pixels. The flag indicates whether the reflected light was captured within a threshold amount of time from a current time. A time to digital converter is enabled via a flag determination logic circuit. The time to digital converter is associated with each pixel of the plurality of pixels to generate a digital representation of time when each pixel of the plurality of pixels captured the reflected light. Depth information is determined for the one or more objects in the local area based in part on the generated flag and the digital representation of time.

Detector with synchronous event driven readout of pixels for direct time-of-flight depth sensing

A depth camera assembly is used to obtain depth information describing a local area. The depth camera assembly includes a sensor having a plurality of pixels. Some or all of the pixels are divided into groups that are coupled to respective multi-purpose time-to-digital converters. Each multi-purpose time-to-digital converter comprises an oscillator and a counter. Each pixel in a group is associated with a multiplexer that is configured to select between inputs coupled to the pixel, the oscillator, or a counter associated with a different pixel. The multiplexer outputs the signal to the counter for the time-to-digital converter associated with the pixel. A time-of-flight measurement is taken during a first portion of an image frame. During a second portion of the image frame, the sensor may be used as an intensity counter. During a third portion of the image frame, the depth sensor may be calibrated.

Time-to-digital converter for depth sensing

A depth camera assembly (DCA) includes a direct time of flight system for determining depth information for a local area. The DCA includes an illumination source, a camera, and a controller. In some embodiments, the controller uses previous image frames to determine confidence measurements, and selectively adjusts a number of pulses from the illuminator in a subsequent frame based on the determined confidence values. In some embodiments, the sensor uses autonomous gating, and the depth system includes a depth recovery pipeline which provide depth map estimates from the autonomous gated measurements.

A depth camera assembly (DCA) includes a direct time of flight system for determining depth information for a local area. The DCA includes an illumination source, a camera, and a controller. The illumination source projects light (e.g., pulse of light) into the local area. The camera detects reflections of the projected light from objects in the local area. The camera includes a detector where pixels are grouped into multiple macropixels that are coupled to an output bus. Specific macropixels from which information describing light detected by pixels in the specific macropixels is obtained. In come configurations, each macropixel includes a counter that is incremented based on detection of light by pixels in the macropixels. The counter may be used to select macropixels from which data is obtained.

Synchronous event driven readout of pixels in a detector for direct time-of-flight depth sensing

A direct time of flight depth system includes an addressable illumination source, an active depth sensor, and a controller. The addressable illumination source includes an array of emitters and an optical assembly that is used to generate an array of dots emitted into a local area. Each emitter is independently addressable, allowing selective illumination of different portions of the local area. The addressable illumination source is aligned with the active depth sensor so each dot maps to a corresponding macropixel (e.g., 4&#xd7;4 array of SPADs) on the active depth sensor. Data from the active depth sensor is readout and used to determine depth information.

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Seattle, WA, United States of America

Augusto Ronchini Ximenes