Depth scanning with multiple emitters

Patent metadata

Field	Value
Publication number	US-9267787-B2
Application number	US-201414207701-A
Country	US
Kind code	B2
Filing date	Mar 13, 2014
Priority date	Mar 15, 2013
Publication date	Feb 23, 2016
Grant date	Feb 23, 2016

Abstract

Mapping apparatus includes a transmitter, which is configured to emit, in alternation, at least two beams comprising pulses of light along respective beam axes that are mutually offset transversely relative to a scan line direction of a raster pattern. A scanner is configured to scan the two or more beams in the raster pattern over a scene. A receiver is configured to receive the light reflected from the scene and to generate an output indicative of a time of flight of the pulses to and from points in the scene. A processor is coupled to process the output of the receiver so as to generate a 3D map of the scene.

First claim

The invention claimed is:

1. Mapping apparatus, comprising:
a transmitter, which is configured to emit, in alternation, at least two beams comprising pulses of light along respective beam axes that are mutually offset transversely relative to a scan line direction of a raster pattern;
a scanner, comprising at least one rotating mirror, which is configured to rotate while the transmitter directs the at least two beams to reflect from the at least one rotating mirror so as to scan the two or more beams in the raster pattern over a scene;
a receiver, comprising a detector which is configured to receive, via reflection from the at least one mirror, the light reflected from the scene as the at least one mirror rotates, and to generate an output indicative of a time of flight of the pulses to and from points in the scene; and
a processor, which is coupled to process the output of the receiver so as to generate a 3D map of the scene.

2. The apparatus according to claim 1 , wherein the detector has a detection area, which is scanned over the scene by the rotation of the at least one mirror, and wherein the at least two beams have respective emission areas that are scanned over the scene by the rotation of the at least one mirror and, at any given location along the raster pattern, fall within the detection area.

3. The apparatus according to claim 1 , and comprising a beamsplitter, which is positioned so as to direct the beams emitted by the transmitter toward the at least one mirror, while permitting the reflected light to reach the detector, wherein the beam axes and an optical axis of the reflected light are parallel between the beamsplitter and the micromirror.

4. The apparatus according to claim 1 , wherein the receiver has a detection area, which is scanned over the scene in synchronization with the at least two beams, and wherein the at least two beams have respective emission areas that at any given location along the raster pattern fall within the detection area.

5. The apparatus according to claim 1 , wherein the transmitter comprises at least two emitters, which are respectively configured to emit the at least two beams and are mounted on a substrate in respective positions that are offset transversely relative to a projection of the scan line direction onto the substrate.

6. The apparatus according to claim 5 , wherein the transmitter comprises an edge-emitting laser die containing an array of two or more parallel laser stripes, which serve as the at least two emitters.

7. The apparatus according to claim 5 , wherein the transmitter comprises a vertically-emitting laser die containing an array of two or more vertical-cavity surface-emitting lasers (VCSELs), which serve as the at least two emitters.

8. The apparatus according to claim 5 , wherein the transmitter comprises optics, comprising an array of at least two microlenses, which are respectively aligned with the at least two emitters so that the optics reduce an angular separation between the beam axes.

9. The apparatus according to claim 5 , wherein the respective positions of the at least two emitters are diagonally offset relative to the projection of the scan line direction onto the substrate.

10. A method for mapping, comprising:
emitting, in alternation, at least two beams comprising pulses of light along respective beam axes that are mutually offset transversely relative to a scan line direction of a raster pattern;
scanning the two or more beams in the raster pattern over a scene by directing the beams to reflect from at least one mirror that rotates so as to generate the raster pattern;
receiving the light reflected from the scene by detecting, via reflection from the at least one mirror, the light that is reflected from the scene as the mirror rotates and generating, responsively to the received light, an output indicative of a time of flight of the pulses to and from points in the scene; and
processing the output so as to generate a 3D map of the scene.

11. The method according to claim 10 , wherein detecting the light comprises collecting the light within a detection area, which is scanned over the scene by rotation of the at least one mirror, and wherein the at least two beams have respective emission areas that are scanned over the scene by the rotation of the at least one mirror and, at any given location along the raster pattern, fall within the detection area.

12. The method according to claim 10 , wherein receiving the light comprises collecting the light within a detection area, which is scanned over the scene in synchronization with the at least two beams, and wherein the at least two beams have respective emission areas that at any given location along the raster pattern fall within the detection area.

13. The method according to claim 10 , wherein emitting the at least two beams comprises pulsing at least two emitters to emit the at least two beams, wherein the at least two emitters are mounted on a substrate in respective positions that are offset transversely relative to a projection of the scan line direction onto the substrate.

14. The method according to claim 13 , wherein the transmitter comprises an edge-emitting laser die containing an array of two or more parallel laser stripes, which serve as the at least two emitters.

15. The method according to claim 13 , wherein the transmitter comprises a vertically-emitting laser die containing an array of two or more vertical-cavity surface-emitting lasers (VCSELs), which serve as the at least two emitters.

16. The method according to claim 13 , wherein emitting the at least two beams comprises aligning optics, including an array of at least two microlenses, with the at least two emitters so that the optics reduce an angular separation between the beam axes.

17. The method according to claim 13 , wherein emitting the at least two beams comprises positioning the at least two emitters at a diagonal offset relative to the projection of the scan line direction onto the substrate.

Assignees

• Apple Inc

Inventors

• Shpunt Alexander
• Einat Ronen
• Mor Zafrir

Classifications

• G01J1/0477

  Prisms, wedges · CPC title

• G01S17/89

  for mapping or imaging · CPC title

• G01S7/4815

  using multiple transmitters · CPC title

• G01S7/4817

  relating to scanning · CPC title

• G01B11/24 Primary

  for measuring contours or curvatures · CPC title