Vision system and method having improved performance and solar mitigation

• US 9,674,413 B1
• Filed: 04/17/2013
• Issued: 06/06/2017
• Est. Priority Date: 04/17/2013
• Status: Active Grant

• Current Assignee: Rockwell Collins, Inc. (Raytheon Technologies Corporation d/b/a RTX)
• Original Assignee: Rockwell Collins, Inc. (Raytheon Technologies Corporation d/b/a RTX)
• Inventors: Tiana, Carlo L., Wood, Robert B., Brown, Robert D.
• Primary Examiner(s): Tissire, Abdelaaziz
• Application Number:
  US13/864,991
• Time in Patent Office: 1,511 Days
• Field of Search: 34820799
• CPC Class Codes: B60K 2360/20 Optical features of instruments
• CPC Class Codes: B60K 2360/21 using cameras
• CPC Class Codes: B60K 2360/25 using filters
• CPC Class Codes: B60K 2360/693 Cover plate features
• CPC Class Codes: B60K 35/00 Instruments specially adapted for vehicles; Arrangement of instruments in or on vehicles
• CPC Class Codes: G02B 2027/0118 comprising devices for improving the contrast of the display / brillance control visibility
• CPC Class Codes: G02B 27/01 Head-up displays
• CPC Class Codes: G02B 27/0101 characterised by optical features G02B27/0172 takes precedence
• CPC Class Codes: G02B 5/23 Photochromic filters
• CPC Class Codes: G06T 5/20 using local operators
• CPC Class Codes: G06T 5/94 based on local image properties, e.g. for local contrast enhancement
• CPC Class Codes: H04N 23/63 by using electronic viewfinders
• CPC Class Codes: H04N 23/951 by using two or more images to influence resolution, frame rate or aspect ratio

Abstract

An enhanced vision system can be used on a vehicle such as an aircraft. The vision system includes a lens, a sensor array and a chromic layer disposed between the lens and the sensor array. A method can protect a focal plane array associated with an enhanced vision or other sensor from solar exposure. The method includes providing a focal plane sensor array and providing at least one photochromic layer in front of the focal plane array.

Claims

1. An enhanced vision system, comprising:

a lens;

a sensor array; and

a plurality of photochromic layers disposed in a sequential order, each photochromic layer disposed on a different plane between the lens and the sensor array, wherein a material of each photochromic layer of the plurality of photochromic layers is associated with a temporal response characteristic and a transmittance response characteristic;

wherein, for each photochromic layer of the plurality of photochromic layers, the transmittance response characteristic is inversely proportional to an intensity of light received by the photochromic layer and proportional to a temperature of the photochromic layer; and

wherein the temporal response characteristic corresponds to a type of light received by the plurality of photochromic layers.

2. The system of claim 1, wherein a first photochromic layer of the plurality of photochromic layers is a passive layer, and wherein the plurality of photochromic layers are arranged such that the first photochromic layer receives a ray of light before a second photochromic layer receives the ray of light, and wherein the first photochromic layer is disposed closer to the lens than the second photochromic layer.

3. The system of claim 2, wherein the first photochromic layer is configured to uniformly darken when exposed to an ambient light, and wherein a gain associated with the sensor array is higher due to the first photochromic layer being uniformly darkened.

4. The system of claim 1, wherein the system is operated in a high gain mode and a normal mode.

5. The system of claim 1, wherein a first photochromic layer of the plurality of photochromic layers has a first response sensor.

6. The system of claim 1, wherein the sensor array is a focal plane array.

7. The system of claim 1, wherein the transmittance response characteristic is associated with a thermal response of a photochromic material.

8. The system of claim 1, wherein the plurality of photochromic layers includes a first photochromic layer and a second photochromic layer, wherein the first photochromic layer has a first temporal response characteristic and a first transmittance response characteristic, wherein the second photochromic layer has a second temporal response characteristic and a second transmittance response characteristic, wherein the first temporal response characteristic and the first transmittance response characteristic are responsive to sunlight, and wherein the second temporal response characteristic and the second transmittance response characteristic are responsive to runway landing lights.

9. The system of claim 1, wherein the array is an infrared, or visible light array.

10. A method of protecting a focal plane sensor array from solar exposure, the method comprising:

providing the focal plane sensor array; and

providing a plurality of photochromic layers in front of the focal plane array, wherein the plurality of photochromic layers are disposed in a sequential order, each photochromic layer disposed on a different plane, wherein a material of each of the at least one photochromic layer is associated with a first temporal response characteristic and a first transmittance response characteristic;

wherein the first transmittance response characteristic is inversely proportional to an intensity of light received by the at least one photochromic layer and proportional to a temperature of the at least one photochromic layer; and

wherein the first temporal response characteristic is based on the type of light received by the at least one photochromic layer.

11. The method of claim 10, wherein the at least one photochromic layer is a passive layer.

12. The method of claim 10, further comprising:

providing at least one other photochromic layer associated with a second temporal response characteristic and a second transmittance response characteristic.

13. The method of claim 10, wherein the focal plane array is part of a camera.

14. The method of claim 10, wherein the temporal response characteristic responds and recovers from solar disc exposure in the range of a microsecond or faster.

15. The method of claim 10, wherein at least one response characteristic corresponds to a response and recovery constant optimized for a given application.

16. The method of claim 10, wherein the focal plane sensor array operates at a higher gain due to the use of the at least one photochromic layer.

17. A camera, comprising:

a sensor array;

a first photochromic layer having a first material associated with a first temporal response characteristic and a first transmittance response characteristic in response to receiving a first type of light; and

a second photochromic layer having a second material associated with a second temporal response characteristic and a second transmittance response characteristic in response to receiving a second type of light;

wherein the first photochromic layer and the second photochromic layer are disposed in front of the sensor array in a sequential order with each photochromic layer disposed on a different plane.

18. The camera of claim 17, wherein the first photochromic layer is a passive polymer film or glass layer.

19. The camera of claim 17, wherein the first photochromic layer includes silverhalides.

20. The camera of claim 17, wherein the first photochromic layer has a response recovery time in the order of microseconds.