Optical position encoder

Patent metadata

Field	Value
Publication number	US-9726524-B2
Application number	US-201414510180-A
Country	US
Kind code	B2
Filing date	Oct 9, 2014
Priority date	Oct 9, 2014
Publication date	Aug 8, 2017
Grant date	Aug 8, 2017

Abstract

Optical position encoding mechanisms and methods for use in reimaged optical imaging systems. In one example, a reimaged optical imaging system includes an imaging detector, an optical component, and at least one light source coupled to the optical component and configured to be reimaged onto the imaging detector, wherein a position of an image of the at least one light source at the imaging detector encodes a position of the optical component relative to the imaging detector.

First claim

What is claimed is:

1. A reimaged thermal optical imaging system comprising:
a thermal imaging detector;
an optical component; and
at least one reflector positioned on the optical component, the at least one reflector being configured to reimage a reflection of the thermal imaging detector back onto the thermal imaging detector, wherein a position of the reimaged reflection on the thermal imaging detector encodes a position of the optical component relative to the thermal imaging detector.

2. The reimaged thermal optical imaging system of claim 1 , wherein the optical component is located at an intermediate image plane of the reimaged optical imaging system.

3. The reimaged thermal optical imaging system of claim 2 , wherein the optical component is a movable component configured to be selectively moved into and out of an optical path between the intermediate image plane and the imaging detector.

4. The reimaged thermal optical imaging system of claim 3 , wherein the optical component is a filter.

5. The reimaged thermal optical imaging system of claim 1 , wherein the thermal imaging detector is a microbolometer or solid-state photovoltaic detector array.

6. The reimaged thermal optical imaging system of claim 1 , further comprising a cold chamber, and wherein the thermal imaging detector is located within the cold chamber.

7. The reimaged thermal optical imaging system of claim 1 , wherein the reflector is one of a V-groove and a corner cube.

8. The reimaged thermal optical imaging system of claim 1 , wherein the optical component is positioned between the thermal imaging detector and an intermediate image plane of the reimaged optical imaging system along an optical path that extends between the thermal imaging detector and the intermediate image plane, the optical component being located closer to the intermediate image plane than to thermal imaging detector.

9. The reimaged thermal optical imaging system of claim 8 further comprising:
a first optical sub-system configured to receive electromagnetic radiation from a scene and focus the electromagnetic radiation onto the intermediate image plane; and
a second optical sub-system positioned between the optical component and the thermal imaging detector, the second optical sub-system being configured to relay and focus the electromagnetic radiation from the intermediate image plane onto the thermal imaging detector.

10. A thermal reimaged optical imaging system comprising:
a cold chamber;
a thermal imaging detector disposed within the cold chamber;
a first optical sub-system configured to receive and focus infrared electromagnetic radiation from a scene onto an intermediate image plane;
a second optical sub-system configured to reimage the infrared electromagnetic radiation from the intermediate image plane onto the thermal imaging detector;
a movable optical component configured to be movable into and out of an optical path of the thermal imaging detector, the movable optical component being located at the intermediate image plane when in the optical path; and
a reflector located on the movable optical component and configured to reimage the thermal imaging detector onto itself to thereby encode a position of the optical component relative to the thermal imaging detector.

11. The thermal reimaged optical imaging system of claim 10 , wherein the cold chamber is configured to cool or temperature stabilize the thermal imaging detector.

12. The thermal reimaged optical imaging system of claim 10 , wherein the reflector is one of a V-groove and a corner cube.

13. The thermal reimaged optical imaging system of claim 10 , wherein the movable optical component is a filter.

14. The thermal reimaged optical imaging system of claim 10 , wherein the thermal imaging detector is a microbolometer or solid-state photovoltaic detector array.

15. A method of determining a position of an optical component in a reimaged optical imaging system, the method comprising:
receiving and focusing electromagnetic radiation from a scene onto an intermediate image plane;
reimaging the electromagnetic radiation from the intermediate image plane onto an imaging detector configured to produce an image of the scene from the electromagnetic radiation;
moving an optical component into an optical path of the imaging detector and proximate the intermediate image plane, the optical component having a light source attached thereto; and
reimaging the light source onto the imaging detector, wherein a position of an image of the light source at the imaging detector encodes the position of the optical component relative to the imaging detector.

16. The method of claim 15 , wherein the light source is a reflector and the imaging detector is a thermal imaging detector, and wherein reimaging the light source onto the imaging detector includes reimaging a reflection of the thermal imaging detector, reflected by the reflector, onto the thermal imaging detector.

Assignees

• Raytheon Co

Inventors

• Fest Eric C
• King Page E
• Forsyth Justan

Classifications

• G01D5/341 Primary

  controlling the movement of a following part · CPC title

• H04N5/33

  Transforming infrared radiation (cameras or camera modules for generating image signals from infrared radiation H04N23/20; circuitry of SSIS for transforming infrared radiation into image signals H04N25/20) · CPC title

• G01D5/30 Primary

  the beams of light being detected by photocells · CPC title

• H04N23/23

  from thermal infrared radiation · CPC title