Actuated optical element for light beam scanning device

Patent metadata

Field	Value
Publication number	US-10107914-B2
Application number	US-201514628054-A
Country	US
Kind code	B2
Filing date	Feb 20, 2015
Priority date	Feb 20, 2015
Publication date	Oct 23, 2018
Grant date	Oct 23, 2018

Abstract

A light beam scanning device includes a lens element assembly which dynamically adjusts a divergence of the beam. The lens element assembly can include multiple lens elements, one or more of which translates parallel to the light beam to adjust beam divergence. Divergence adjustment can include adjusting the beam divergence along one or more cross sectional axes of the beam. Beam divergence can be adjusted between consecutive scans, during a scan, etc. Beam divergence can be adjusted based on the field of view and scan rate. Beam divergence adjustment can enable dynamic adjustment of the spot size of the beam, which can enable the apparatus to adjust between scanning a wide divergence beam to detect objects in a scene and scanning a narrow divergence beam to generate detailed point clouds of the detected objects. Beam divergence adjustment can enable adjustment of reflection point intensity, enabling detection of low-reflectivity objects.

First claim

What is claimed is:

1. An apparatus, comprising:
a light beam scanning device configured to scan a light beam, within a scan range, over a scene that is within a field of view of the scan range and generate an image map of at least a portion of the scene, based at least in part upon a time of flight of the light beam to and from one or more points within the scene, wherein the light beam scanning device comprises:
a lens element assembly comprising a plurality of lens elements and configured to dynamically adjust a divergence and diameter of the light beam, such that a spot size of the light beam is adjusted, wherein at least one lens element of the plurality of lens elements is configured to be adjustable, in a direction parallel to a direction of the light beam, relative to at least one other lens element of the plurality of lens elements to dynamically adjust a diameter of the light beam along at least one axis of the light beam, relative to a diameter of the light beam along at least one other axis of the beam.

2. The apparatus of claim 1 , wherein:
to dynamically adjust a divergence of the light beam, the at least one lens element is configured to be translated relative to the at least one other lens element in a direction parallel to a direction of the light beam.

3. The apparatus of claim 1 , wherein:
the at least one lens element is configured to be translated, in a direction parallel to a direction of the light beam, to dynamically adjust a diameter of the light beam along the at least one other axis of the light beam, relative to a diameter of the light beam along at least one axis of the light beam.

4. The apparatus of claim 1 , comprising:
a scanner configured to scan the light beam, received from the lens element assembly, over a selected field of view of the scan range at one or more scan rates; and
a controller device configured to control at least the lens element assembly to dynamically adjust the divergence of the light beam as the light beam is scanned over at least a portion of the selected field of view;
wherein, to dynamically adjust the divergence of the light beam, such that the spot size of the light beam is adjusted, as the light beam is scanned over at least a portion of the selected field of view, the controller device is configured to control a position of at least a portion of the lens element assembly via at least one of:
an open loop control process; or
a closed loop control process.

5. The apparatus of claim 1 , wherein the lens element assembly comprises:
an actuated optical element configured to condition the light beam, such that the spot size of the light beam is adjusted.

6. The apparatus of claim 5 , wherein the actuated optical element comprises an actuated beam expander lens assembly.

7. The apparatus of claim 1 , wherein:
the light beam scanning device comprises:
a scanner configured to scan the light beam, received from the lens element assembly, over the field of view of the scan range; and
a detector which is configured to receive the light reflected from at least a point within the field of view; and

to generate the image map of at least a portion of the scene, the light beam scanning device is configured to determine at least a depth, azimuth, and elevation of the portion of the scene, relative to at least a portion of the light beam scanning device, based at least in part upon the time of flight of the light beam to and from the point, and an orientation of the scanner.

8. The apparatus of claim 1 , wherein:
the lens element assembly is configured to dynamically adjust a divergence of the light beam, such that a spot size of the light beam is adjusted to a particular beam spot size, based at least in part upon at least one of:
a selected beam spot size, of a set of predetermined beam spot sizes, or
a particular beam spot size specified by a received beam spot size command.

9. The apparatus of claim 1 , wherein the light beam scanning device comprises a light detection and ranging (LIDAR) device.

10. A method, comprising:
dynamically adjusting a divergence of a light beam scanned, by a scanner, over a scene that is within a field of view of a scan range, such that a spot size of a beam spot of the light beam is dynamically adjusted, the dynamically adjusting comprising:
adjusting at least one lens element, included in a lens element assembly located in a light beam pathway, relative to at least one other lens element of the lens element assembly, such that the lens element assembly adjusts the divergence of at least one axis of the emitted light beam, relative to a divergence of at least one other axis of the emitted light beam.

11. The method of claim 10 , wherein adjusting at least one lens element included in a lens element assembly comprises:
translating the at least one lens element in a direction parallel to a direction of the light beam and relative to the at least one other lens element in the lens element assembly directing the beam of light to be scanned, by the scanner, over a first field of view at a first scan rate and at a first divergence; and
based at least in part upon a time of flight of the light beam to and from a particular portion of the scene within the first field of view, directing the beam of light to be scanned, by the scanner, over a second field of view at a second scan rate and at a second divergence, wherein the second field of view encompasses a limited region of the first field of view which includes the particular portion of the scene.

12. The method of claim 11 , wherein directing the beam of light to be scanned, by the scanner, over a second field of view at a second scan rate and at a second divergence comprises:
selecting the second scan rate and the second divergence based at least in part upon the time of flight of the light beam to and from the particular portion of the scene within the first field of view.

13. The method of claim 10 , wherein adjusting the divergence of the light beam comprises adjusting the divergence of the at least one axis of the light beam to equal the divergence of the at least one other axis of the light beam.

14. A method, comprising:
configuring a light beam scanning device to scan a light beam having a dynamically-adjustable divergence, within a scan range, over a scene that is within a field of view of the scan range and generate a map of at least a portion of the scene, based at least in part upon a time of flight of the light beam to and from one or more points within the scene, wherein the configuring comprises:
coupling a lens element assembly to at least a portion of the light beam scanning device, wherein:
at least one lens element of the lens element assembly is configured to be adjustable relative to at least one other lens element of the lens element assembly; and
the lens element assembly is configured to adjust the divergence of at least one axis of the emitted light beam, relative to a divergence of at least one other axis of the light beam.

15. The method of claim 14 , wherein coupling the lens element assembly to at least a portion of the light beam scanning device comprises:
coupling the lens element assembly to a location along a pathway of the light beam between a transmitter configured to emit the light beam and a scanner configured to scan the light beam over the field of view of the scan range.

16. The method of claim 14 , wherein:
the at least one lens element is configured to be adjusted along a directional axis which is parallel to a pathway of the light beam and relative to the at least one other lens element to adju

Assignees

• Apple Inc

Inventors

• Kalscheur Micah P
• Nawasra Jawad

Classifications

• G01S17/10

  using transmission of interrupted, pulse-modulated waves (determination of distance by phase measurements G01S17/32) · CPC title

• G01S17/42

  Simultaneous measurement of distance and other co-ordinates (indirect measurement G01S17/46) · CPC title

• G01S7/4814

  of transmitters alone · CPC title

• G01S7/4817

  relating to scanning · CPC title

• G01S7/51

  Display arrangements · CPC title