Method and system for generating light pattern using polygons

Patent metadata

Field	Value
Publication number	US-9842407-B2
Application number	US-201715455050-A
Country	US
Kind code	B2
Filing date	Mar 9, 2017
Priority date	May 20, 2015
Publication date	Dec 12, 2017
Grant date	Dec 12, 2017

Abstract

A method and system for generating light pattern using reflective polygons are provided herein. The method may include: rotating at least one polygon having a plurality of reflective facets along a rotation axis parallel to the facets; transmitting a light beam on the facets of the polygon; tilting the light beam relative to the polygon in parallel to the rotation axis so that the light beam hits each of the facets at a different tilt angle, thereby producing a light pattern comprising a plurality of lines; and controlling at least one of: the light intensity, the rotating, and the tilting, so as to produce an adjustable light pattern transmitted at a scene.

First claim

The invention claimed is:

1. A system comprising:
at least one reflective column with a polygonal cross section having a plurality of facets and at least one rotation axis;
a light source configured to transmit a light beam on the facets of the at least one reflective column;
at least one driver configured to rotate the at least one reflective column along the at least one rotation axis;
a controller configured to control at least one of the light source and the at least one driver to produce structured light transmitted at a scene; and
a sensor configured to sense reflections of the structured light reflected from the scene.

2. The system of claim 1 , wherein the light beam comprises multiple beams.

3. The system of claim 2 , further comprising a diffractive optical element, wherein the multiple beams are generated using the diffractive optical element.

4. The system of claim 3 , wherein the diffractive optical element is part of a facet of the plurality of facets.

5. The system of claim 1 , wherein:
one or more facets of the plurality of facets have optical properties different from other facets of the plurality of facets; and
a pattern of the structured light produced via the one or more facets is optically distinguishable from patterns of the structured light produced via the other facets.

6. The system of claim 1 , wherein each of the facets has different optical properties.

7. The system of claim 1 , wherein the controller controls the light source by adjusting an intensity of the light beam.

8. The system of claim 1 , wherein:
the controller is further configured to adjust a pattern of the structured light based on a predefined region of interest (ROI) of the scene; and
a part of the pattern associated with the ROI exhibits a different light intensity than other parts of the pattern.

9. The system of claim 1 , further comprising:
a computer processor configured to receive data related to the transmitted structured light and to the reflections of the structured light; wherein
the computer processor is further configured to generate a depth map of the scene based on the received data.

10. The system of claim 1 , wherein the sensor is further configured to sense the reflections of the structured light reflected from the scene and then transmitted back to the sensor by the at least one reflective column.

11. The system of claim 1 , wherein the sensor is a line sensor positioned in parallel to the at least one rotation axis of the at least one reflective column.

12. The system of claim 1 , wherein the at least one reflective column comprises a first reflective column positioned to receive the light beam from the light source, and a second reflective column having a same rotation axis as the first reflective column and further positioned to transmit the reflections of the structured light coming from the scene to the sensor.

13. The system of claim 1 , further comprising:
a plurality of optics positioned between the sensor and the at least one reflective column; and
the plurality of optics is configured to transmit the reflections coming from the scene and the at least one facet to the sensor.

14. A method comprising:
rotating at least one reflective column with a polygonal cross section having a plurality of facets along at least one rotation axis;
transmitting a light beam on the facets of the at least one reflective column;
controlling at least one of a light intensity of the light beam and the rotating of the at least one reflective column to produce structured light transmitted at a scene; and
sensing reflections of the structured light reflected from the scene.

15. The method of claim 14 , wherein the light beam comprises multiple beams generated using a diffractive optical element.

16. The method of claim 15 , wherein the diffractive optical element is part of a facet of the plurality of facets.

17. The method of claim 14 , wherein:
one or more facets of the plurality of facets have optical properties different from other facets of the plurality of facets; and
a pattern of the structured light produced via the one or more facets is optically distinguishable from patterns of the structured light produced via the other facets.

18. The method of claim 14 , wherein each of the facets has different optical properties.

19. The method of claim 14 , wherein controlling the light intensity of the light beam comprises:
adjusting a pattern of the structured light based on a predefined region of interest (ROI) of the scene; and
a part of the pattern associated with the ROI exhibits a different light intensity than other parts of the pattern.

20. The method of claim 14 , wherein sensing reflections of the structured light reflected from the scene further comprises:
sensing the reflections of the structured light reflected from the scene and then transmitted by the at least one reflective column.

Assignees

• Facebook Inc

Inventors

• Raz Guy
• Alpern Yair
• Grossinger Nadav

Classifications

• H04N9/00

  Details of colour television systems · CPC title

• G02B26/0816

  by means of one or more reflecting elements · CPC title

• G02B26/0808 Primary

  by means of one or more diffracting elements · CPC title

• G01B11/2513 Primary

  with several lines being projected in more than one direction, e.g. grids, patterns · CPC title

• G06T7/521 Primary

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