US 2021/0333402 A1 · TIME-TO-DIGITAL CONVERTER FOR DEPTH SENSING

Abstract

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.

Claims20

Dependent claims

A depth camera assembly (DCA) comprising:

a sensor comprising a plurality of pixels configured to capture images of a local area, the plurality of pixels comprising a group of pixels;
a plurality of counters that are coupled to each other, wherein each of the plurality of counters is coupled to a corresponding pixel of the group of pixels;
and
a controller configured to:
estimate, during a first portion of an image frame, raw depth values associated with light collected by each pixel of the group of pixels;
and
perform, during a second portion of the image frame, an intensity measurement for a first pixel in the group of pixels, wherein the intensity measurement is based in part on information received from the plurality of counters during the second portion of the image frame.

4 more elements

A depth camera assembly (DCA) comprising:

a first pixel;
a first time-to-digital converter coupled to the first pixel, the first time-to-digital converter comprising a first oscillator and a first counter;
a first multiplexer comprising:
a multiplexer input coupled to the first pixel;
a multiplexer input coupled to the first oscillator;
and
a multiplexer output coupled to the first counter;
a second pixel;
a second time-to-digital converter coupled to the second pixel, the second time-to-digital converter comprising a second oscillator and a second counter;
and
a second multiplexer comprising:
a multiplexer input coupled to the second pixel;
a multiplexer input coupled to the second oscillator;
a multiplexer input coupled to the first counter;
and
a multiplexer output coupled to the second counter.

13 more elements

Dependencies are inferred from the claim text.

Time-to-digital converter for depth sensing

Life of this patent

Time-to-digital converter for depth sensing

Life of this patent

Abstract

Claims20