Projector with spatial light modulation

Patent metadata

Field	Value
Publication number	US-2023213620-A1
Application number	US-202318120903-A
Country	US
Kind code	A1
Filing date	Mar 13, 2023
Priority date	Sep 30, 2016
Publication date	Jul 6, 2023
Grant date	—

Abstract

A time of flight based depth detection system is disclosed that includes a projector configured to sequentially emit multiple complementary illumination patterns. A sensor of the depth detection system is configured to capture the light from the illumination patterns reflecting off objects within the sensor's field of view. The data captured by the sensor can be used to filter out erroneous readings caused by light reflecting off multiple surfaces prior to returning to the sensor.

First claim

What is claimed is:

1 . A depth detection system, comprising:
a projection system, comprising:
a projector housing having a rigid substrate,
a first light source configured to emit light through a first plurality of light shaping components and produce a first illumination pattern, the first light source being mounted to the rigid substrate, and
a second light source configured to emit light through a second plurality of light shaping components and produce a second illumination pattern complementary to the first illumination pattern, the second light source being mounted to the rigid substrate adjacent to the first light source;
an imaging sensor proximate the projection system and configured to receive light emitted by the first and second light sources after being reflected off objects within a field of view of the imaging sensor; and a processor configured to calculate a distance between the depth detection system and the objects within the field of view of the imaging sensor by measuring an amount of time for light emitted by the first and second light sources to reflect off the objects within the field of view of the imaging sensor and return to the imaging sensor and by filtering out sensor readings associated with light reflected off surfaces outside the field of view of the imaging sensor.

2 . The depth detection system as recited in claim 1 , wherein the processor filters sensor readings associated with light reflected off surfaces outside of the field of view of the imaging sensor by identifying the light emitted by the first light source that reflects off areas within the field of view of the imaging sensor corresponding to the second illumination pattern.

3 . The depth detection system as recited in claim 1 , wherein the first and second illumination patterns comprise a series of parallel bars.

4 . The depth detection system as recited in claim 1 , wherein the first plurality of light shaping components comprises a collimating optical element, a refractive optical element, a diffractive optical element, and a micro-lens array.

5 . A method of operating a depth detection system, the method comprising:
emitting, by a first light source of a projection system of the depth detection system, light through a first plurality of light shaping components to produce a first illumination pattern, the first light source being mounted to a rigid substrate of the projection system; emitting, by a second light source of the projection system, light through a second plurality of light shaping components to produce a second illumination pattern complementary to the first illumination pattern, the second light source being mounted to the rigid substrate adjacent to the first light source; receiving, by an imaging sensor proximate the projection system, light emitted by the first and second light sources after being reflected off objects within a field of view of the imaging sensor; and calculating, by a processor of the depth detection system, a distance between the depth detection system and the objects within the field of view of the imaging sensor by measuring an amount of time for light emitted by the first and second light sources to reflect off the objects within the field of view of the imaging sensor and return to the imaging sensor and by filtering out sensor readings associated with light reflected off surfaces outside the field of view of the imaging sensor.

6 . The method of operating the depth detection system as recited in claim 5 , further comprising:
filtering, by the processor of the depth detection system, sensor readings associated with light reflected off surfaces outside of the field of view of the imaging sensor by identifying the light emitted by the first light source that reflects off areas within the field of view of the imaging sensor corresponding to the second illumination pattern.

7 . The method of operating the depth detection system as recited in claim 5 , wherein the first and second illumination patterns comprise a series of parallel bars.

8 . The method of operating the depth detection system as recited in claim 5 , wherein the first plurality of light shaping components comprises a collimating optical element, a refractive optical element, a diffractive optical element, and a micro-lens array.

Assignees

• Magic Leap Inc

Inventors

• Cohen David
• Pellman Assaf
• Tekolste Robert D
• Felzenshtein Shlomo
• Yahav Giora

Classifications

• G01S17/894

  Three-dimensional [3D] imaging with simultaneous measurement of time-of-flight at a two-dimensional [2D] array of receiver pixels, e.g. time-of-flight cameras or flash lidar · CPC title

• H04N23/56

  provided with illuminating means · CPC title

• G06T7/521

  from laser ranging, e.g. using interferometry; from the projection of structured light · CPC title

• G01S7/484

  Transmitters · CPC title

• G01S7/4815 Primary

  using multiple transmitters · CPC title