Light detection and ranging sensor

• US 20170176579A1
• Filed: 12/08/2016
• Published: 06/22/2017
• Est. Priority Date: 12/20/2015
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Niclass, Cristiano L., Agranov, Gennadiy A., Waldon, Matthew C., Rezk, Mina A., Oggier, Thierry, Shpunt, Alexander
• Granted Patent: US 10,324,171 B2
• Time in Patent Office: Days
• CPC Class Codes: G01S 17/10 using transmission of interrupted, pulse-modulated waves determination of distance by phase measurements G01S17/32
• CPC Class Codes: G01S 17/42 Simultaneous measurement of distance and other co-ordinates indirect measurement G01S17/46
• CPC Class Codes: G01S 7/4817 relating to scanning
• CPC Class Codes: G01S 7/4863 Detector arrays, e.g. charge-transfer gates

Abstract

An electro-optical device includes a laser light source, which emits at least one beam of light pulses, a beam steering device, which transmits and scans the at least one beam across a target scene, and an array of sensing elements. Each sensing element outputs a signal indicative of a time of incidence of a single photon on the sensing element. Light collection optics image the target scene scanned by the transmitted beam onto the array. Circuitry is coupled to actuate the sensing elements only in a selected region of the array and to sweep the selected region over the array in synchronization with scanning of the at least one beam.

Claims

1. An electro-optical device, comprising:

a laser light source, which is configured to emit at least one beam of light pulses;

a beam steering device configured to transmit and scan the at least one beam across a target scene;

an array of sensing elements, each sensing element configured to output a signal indicative of a time of incidence of a single photon on the sensing element;

light collection optics configured to image the target scene scanned by the transmitted beam onto the array; and

circuitry coupled to actuate the sensing elements only in a selected region of the array and to sweep the selected region over the array in synchronization with scanning of the at least one beam.

2. The device according to claim 1, wherein the circuitry is configured to select the region such that at any instant during the scan, the selected region contains a part of the array onto which the light collection optics image an area of the target scene that is illuminated by the at least one beam.

3. The device according to claim 2, wherein the selected region comprises one sensing element.

4. The device according to claim 2, wherein the selected region comprises multiple sensing elements.

5. The device according to claim 1, wherein the circuitry is configured to process signals output by the sensing elements in order to determine respective distances to points in the target scene.

6. The device according to claim 1, wherein the sensing elements comprise single-photon detectors.

7. The device according to claim 6, wherein the single-photon detectors are single-photon avalanche diodes (SPADs).

8. The device according to claim 1, wherein the laser light source is configured to emit at least two beams along different, respective beam axes, such that at any instant during the scan, the light collection optics image respective areas of the target scene that are illuminated by the at least two beams onto different, respective ones of the sensing elements.

9. The device according to claim 8, wherein the beam steering device is configured to scan the at least two beams across the target scene in a two-dimensional scan, and the circuitry is configured to sweep the selected region over the array in a two-dimensional pattern corresponding to the two-dimensional scan.

10. The device according to claim 9, wherein the two-dimensional scan forms a raster pattern, and wherein the respective beam axes of the at least two beams are mutually offset transversely relative to a scan line direction of the raster pattern.

11. The device according to claim 8, wherein the beam steering device is configured to scan the at least two beams across the target scene in a linear scan in a first direction, and wherein the at least two beams comprise multiple beams arranged along a column axis in a second direction, perpendicular to the first direction.

12. The device according to claim 11, wherein the multiple beams are arranged in at least two columns, having respective column axes that are orthogonal to the first direction of the scan and are mutually offset.

13. A method for sensing, comprising:

emitting at least one beam of light pulses;

transmitting and scanning the at least one beam across a target scene;

providing an array of sensing elements, each sensing element configured to output a signal indicative of a time of incidence of a single photon on the sensing element;

imaging the target scene scanned by the transmitted beam onto the array; and

actuating the sensing elements only in a selected region of the array and sweeping the selected region over the array in synchronization with scanning of the at least one beam.

14. The method according to claim 13, wherein actuating the sensing elements comprises selecting the region such that at any instant during the scan, the selected region contains a part of the array onto which the light collection optics image an area of the target scene that is illuminated by the at least one beam.

15. The method according to claim 13, and comprising processing signals output by the sensing elements in order to determine respective distances to points in the target scene.

16. The method according to claim 13, wherein the sensing elements comprise single-photon detectors.

17. The method according to claim 13, wherein emitting at least one beam comprises emitting at least two beams along different, respective beam axes, such that at any instant during the scan, the light collection optics image respective areas of the target scene that are illuminated by the at least two beams onto different, respective ones of the sensing elements.

18. The method according to claim 17, wherein scanning the at least one beam comprises scanning the at least two beams across the target scene in a two-dimensional scan, and actuating the sensing elements comprises sweeping the selected region over the array in a two-dimensional pattern corresponding to the two-dimensional scan.

19. The method according to claim 18, wherein the two-dimensional scan forms a raster pattern, and wherein the respective beam axes of the at least two beams are mutually offset transversely relative to a scan line direction of the raster pattern.

20. The method according to claim 17, wherein scanning the at least one beam comprises scanning the at least two beams across the target scene in a linear scan in a first direction, and wherein the at least two beams comprise multiple beams arranged along a column axis in a second direction, perpendicular to the first direction.