Optical systems for remote sensing receivers

Patent metadata

Field	Value
Publication number	US-10634770-B2
Application number	US-201715636566-A
Country	US
Kind code	B2
Filing date	Jun 28, 2017
Priority date	Jun 29, 2016
Publication date	Apr 28, 2020
Grant date	Apr 28, 2020

Abstract

Optical systems that may, for example, be used in remote sensing systems, for example in systems that implement combining laser pulse transmission in LiDAR and that include dual transmit and receive systems. A dual receiver system may include a receiver including an optical system with a relatively small aperture and wide field of view for capturing reflected light from short-range (e.g., <20 meters) objects, and a receiver that includes an optical system with a relatively large aperture and small field of view for capturing reflected light from long-range (e.g., >20 meters) objects. The optical systems may refract the reflected light to photodetectors (e.g., single photo-avalanche detectors (SPADs)) that capture the light. Light captured at the photodetectors may, for example, be used to determine range information for objects or surfaces in the environment.

First claim

What is claimed is:

1. A remote sensing system, comprising:
two transmitters that transmit light through a common optical path to an object field; and
two receivers that detect reflections of the transmitted light received at the system through the common optical path, wherein the two receivers include:
a short-range optical system including a plurality of refractive lens elements that refract a portion of the light reflected from a range of 20 meters or less to a first sensor that captures the light, wherein field of view of the short-range optical system is between 45 and 65 degrees, and wherein F-number of the short-range optical system is 2.0 or less; and
a long-range optical system including a plurality of refractive lens elements that refract a portion of the light reflected from a range of 20 meters or more to a second sensor that captures the light, wherein field of view of the long-range optical system is 15 degrees or less, and wherein F-number of the long-range optical system is 1.2 or less.

2. The remote sensing system as recited in claim 1 , wherein the long-range optical system includes five refractive lens elements, and wherein surfaces of the lens elements in the long-range optical system include one or more of spherical, even-aspheric, or flat/plano surfaces.

3. The remote sensing system as recited in claim 1 , wherein the short-range optical system includes six refractive lens elements, wherein surfaces of the lens elements in the short-range optical system include one or more of spherical, even-aspheric, or flat/plano surfaces.

4. The remote sensing system as recited in claim 1 , wherein the short-range optical system includes seven refractive lens elements, wherein surfaces of the lens elements in the short-range optical system include one or more of spherical, even-aspheric, or flat/plano surfaces.

5. The remote sensing system as recited in claim 1 , wherein one or both of the short-range optical system and the long-range optical system are image-space telecentric lenses.

6. The remote sensing system as recited in claim 1 , wherein one or both of the short-range optical system and the long-range optical system include an optical bandpass filter.

7. The remote sensing system as recited in claim 1 , wherein the sensors each include one or more single photo-avalanche detectors.

8. A long-range optical system for receiving reflected light from an object field, comprising:
five refractive lens elements that refract light reflected from a range of 20 meters or more to a photodetector, wherein surfaces of the refractive lens elements are spherical, even-aspheric, or flat/plano surfaces;
wherein field of view of the optical system is 15 degrees or less, and wherein F-number of the optical system is 1.2 or less.

9. The long-range optical system as recited in claim 8 , wherein the five refractive lens elements include, in order from an object side of the optical system to an image side of the optical system:
a first lens element, wherein the first lens element is a biconvex lens with positive refractive power;
a second lens element, wherein the second lens element is a plano-concave lens with negative refractive power;
a third lens element, wherein the third lens element is a meniscus lens with positive refractive power;
a fourth lens element, wherein the fourth lens element is a meniscus lens with positive refractive power; and
a fifth lens element, wherein the fifth lens element is a biconcave lens with negative refractive power.

10. The long-range optical system as recited in claim 9 , wherein the optical system further comprises:
a stop located between the second lens element and the third lens element; and
an optical bandpass filter located at the image side surface of the second lens element.

11. The long-range optical system as recited in claim 8 , wherein the five refractive lens elements include, in order from an object side of the optical system to an image side of the optical system:
a first lens element, wherein the first lens element is a plano-convex lens with positive refractive power;
a second lens element, wherein the second lens element is a meniscus lens with positive refractive power;
a third lens element, wherein the third lens element is a biconcave lens with negative refractive power;
a fourth lens element, wherein the fourth lens element is a biconvex lens with positive refractive power; and
a fifth lens element, wherein the fifth lens element is a meniscus lens with positive refractive power.

12. The long-range optical system as recited in claim 11 , wherein the optical system further comprises:
a stop located between the first lens element and the second lens element; and
an optical bandpass filter located at the image side surface of the first lens element.

13. The long-range optical system as recited in claim 8 , wherein the long-range optical system is an image-space telecentric lens.

14. A short-range optical system for receiving reflected light from an object field, comprising:
a plurality of refractive lens elements that refract light reflected from a range of 20 meters or less to a photodetector, wherein surfaces of the refractive lens elements are spherical, even-aspheric, or flat/plano surfaces;
wherein field of view of the short-range optical system is between 45 and 65 degrees, and wherein F-number of the short-range optical system is 2.0 or less.

15. The short-range optical system as recited in claim 14 , wherein the plurality of refractive lens elements includes, in order from an object side of the optical system to an image side of the optical system:
a first lens element, wherein the first lens element is a meniscus lens with negative refractive power;
a second lens element, wherein the second lens element is a biconvex lens with positive refractive power;
a third lens element, wherein the third lens element is a meniscus lens with positive refractive power;
a fourth lens element, wherein the fourth lens element is a plano-convex lens with positive refractive power;
a fifth lens element, wherein the fifth lens element is a meniscus lens with negative refractive power; and
a sixth lens element, wherein the sixth lens element is a biconvex lens with positive refractive power.

16. The short-range optical system as recited in claim 15 , wherein the optical system further comprises:
a stop located between the second lens element and the third lens element; and
an optical bandpass filter located at the object side surface of the fourth lens element.

17. The short-range optical system as recited in claim 14 , wherein the plurality of refractive lens elements includes, in order from an object side of the optical system to an image side of the optical system:
a first lens element, wherein the first lens element is a meniscus lens with negative refractive power;
a second lens element, wherein the second lens element is a meniscus lens with positive refractive power;
a third lens element, wherein the third lens element is a plano-convex lens with positive refractive power;
a fourth lens element, wherein the fourth lens element is a plano-convex lens with positive refractive power;
a fifth lens element, wherein the fifth lens element is a biconvex lens with positive refractive power; and
a sixth lens element, wherein the sixth lens element is a biconcave lens with negative refractive power; and
a seventh lens element, wherein the seventh lens element is a meniscus lens with positive refractive power.

18. The short-range optical system as recited in claim 15 , wher

Assignees

• Apple Inc

Inventors

• Kakani Chandra S
• Shpunt Alexander
• Rezk Mina A
• Upton Robert S
• Gerson Yuval

Classifications

• G02B13/0045

  having five or more lenses · CPC title

• G02B9/60

  having five components only · CPC title

• G02B9/62

  having six components only · CPC title

• G02B13/22

  Telecentric objectives or lens systems · CPC title

• G01S17/87

  Combinations of systems using electromagnetic waves other than radio waves · CPC title