Imaging system and method for use in monitoring a field of regard

• US 8,937,651 B2
• Filed: 04/27/2008
• Issued: 01/20/2015
• Est. Priority Date: 04/19/2007
• Status: Expired due to Fees

• Current Assignee: Eshel Aviv, Ltd.
• Original Assignee: DVP Technologies Ltd.
• Inventors: Guissin, Rami, Lavi, Eitan
• Primary Examiner(s): Ustaris, Joseph
• Assistant Examiner(s): Barazesh, Ellyar Y
• Application Number:
  US12/596,241
• Publication Number:
  US 20100283842A1
• Time in Patent Office: 2,459 Days
• Field of Search: None
• US Class Current: 348/68
• CPC Class Codes: G02B 13/06 Panoramic objectives; So-called "sky lenses" including panoramic objectives having reflecting surfaces
• CPC Class Codes: G02B 26/0816 by means of one or more reflecting elements
• CPC Class Codes: G02B 27/1066 for enhancing image performance, like resolution, pixel numbers, dual magnifications or dynamic range, by tiling, slicing or overlapping fields of view
• CPC Class Codes: G02B 27/144 using partially transparent surfaces without spectral selectivity G02B27/147 takes precedence
• CPC Class Codes: G02B 27/145 having sequential partially reflecting surfaces
• CPC Class Codes: H04N 23/55 Optical parts specially adapted for electronic image sensors; Mounting thereof
• CPC Class Codes: H04N 23/58 Means for changing the camera field of view without moving the camera body, e.g. nutating or panning of optics or image sensors
• CPC Class Codes: H04N 23/60 Control of cameras or camera modules
• CPC Class Codes: H04N 23/698 for achieving an enlarged field of view, e.g. panoramic image capture

Abstract

A method and system are presented for monitoring a field of regard. At least a part of a field of regard is imaged by concurrently collecting a plurality of light components propagating from a plurality of zones, respectively, located within the field of regard, a combined collected light beam is produced, and corresponding data is generated being indicative of a combined image of the at least part of the field of regard formed by the collected light components. This image data indicative of the combined image data is processed and analyzed, and if existence of a certain condition or event is identified in the image data, a corresponding control signal is generated.

Claims

1. A method for monitoring a field of regard, the method comprising:

imaging at least a part of the field of regard by concurrently collecting a plurality of light components propagating along different optical paths from a plurality of different zones, respectively, located within the field of regard, said plurality of light components being concurrently collected by a corresponding plurality of light collecting units having a first numerical aperture of light collection being the same for each of the plurality of light collecting units;

superimposing a plurality of images of the plurality of said different zones of the field of regard, respectively, by concurrently projecting the plurality of light components collected from said plurality of different zones in an additive manner onto a common light sensitive surface of a same light detector to form a combined image that is made up of the plurality of the superimposed images of different zones, thereby obtaining flux averaging of said plurality of light components;

generating image data indicative of said combined image; and

processing and analyzing the image data indicative of the combined image, and upon identifying existence of a certain condition or event in the image data, generating a corresponding control signal indicative of the existence of said condition or event in at least one of said plurality of different zones, thereby enabling to further scan at least some of the zones based on analysis of the image data of the combined image with said first numerical aperture or a different second numerical aperture.

2. A monitoring system comprising:

an optical system comprising;

a light collection arrangement comprising a plurality of light collecting units having a first numerical aperture of light collection being the same for all the light collecting units, the light collecting units being configured for collecting a plurality of light components propagating along different optical paths from a plurality of different zones, respectively, of a field of regard;

a light combiner arrangement configured to receive the light components collected along the different optical paths from said plurality of light collecting units for combining the collected light components of said plurality of different zones of the field of regard and producing a combined light, and directing said combined light along a combined optical path;

a light detection unit comprising a light sensitive surface accommodated in said combined optical path for receiving the combined light and generating image data indicative of the received combined light, said image data being therefore indicative of a plurality of superimposed images of the plurality of said different zones of the field of regard, respectively, concurrently projected onto the light sensitive surface in an additive manner, thereby obtaining flux averaging of said plurality of light components; and

a control unit connectable to the optical system, and configured and operable for receiving the image data indicative of the combined image, and processing and analyzing the image data so as to, upon detecting that the image data is indicative of existence of a certain condition or event in the at least part of the field of regard, generating a control signal, thereby enabling to selectively operate the optical system to scan at least some of the zones based on analysis of the image data of the combined image with said first numerical aperture or a different second numerical aperture.

3. The system according to claim 2, comprising a single light detector.

4. The system according to claim 3, wherein the control unit is configured and operable for using the control signal for operating the optical system to produce data indicative of one or more separate images of one or more of the zones, thereby enabling to identify one or more zones of the field of regard with which the condition or event is associated.

5. The system according to claim 4, comprising a display for visual representation of the one or more separate images.

6. The system according to claim 4, configured and operable for either concurrently producing the data indicative of the separate images of the zones, or sequentially producing the data indicative of the separate images of the zones until identifying the one or more of the zones with which the condition or event is associated.

7. The system according to claim 4, configured and operable for directing the collected light components onto a plurality of the light sensing regions of the light detector, thereby concurrently producing the data indicative of the separate images of the zones.

8. The system according to claim 4, comprising a light directing arrangement configured and operable for selectively allowing projection of at least one of the light components onto the light detector, while preventing detection of the other light components, thereby sequentially producing the data indicative of the separate images of the zones until identifying the one or more zones with which the condition or event is associated.

9. The system according to claim 2, wherein the optical system is configured and operable for imaging at least a part of at least one of the zones with a second numerical aperture of light collection different from a first numerical aperture of collection used for producing the combined light beam.

10. The system according to claim 9, wherein the optical system comprises at least one scanning mechanism for scanning at least one of the zones to collect light from successive parts of the field of regard with the second numerical aperture.

11. The system according to claim 9, wherein the control unit is configured and operable to selectively actuate the optical system for carrying out the imaging with the second numerical aperture of the light collection, upon identifying the certain condition or event in the image data indicative of the combined image.

12. The system according to claim 11, wherein the control unit is configured and operable to actuate the optical system for carrying out the imaging with the second numerical aperture of the at least one zone, that has been identified as that with which the condition or event is associated.

13. The system according to claim 9, wherein the light combining arrangement is configured and operable for selectively projecting the combined light beam corresponding to the first numerical aperture of light collection, and one or more light components collected with the second numerical aperture, onto the same light sensing surface.

14. The system according to claim 2, wherein the optical system is configured and operable for separately collecting and focusing each of the light components towards a common beam combiner of the light combining arrangement, and projecting the combined light beam onto the light detector.

15. The system according to claim 14, wherein the optical system is configured and operable for performing the separate collection and focusing concurrently for the plurality of light components.

16. The system according to claim 14, wherein the optical system is configured and operable for selectively performing the separate collection and focusing of the light component.

17. The system according to claim 2, wherein the light collection arrangement has one of the following configurations:

(i) a curved light deflecting surface for deflecting the light components from multiple regions thereof, respectively, towards different optical paths, and multiple focusing lenses accommodated in the optical paths, respectively;

(ii) a curved light deflecting surface for deflecting the light components from multiple regions thereof, respectively, towards different optical paths;

(iii) is configured and operable for collecting the light components from different zones with overlapping solid angles of collection;

(iv) is configured and operable for collecting light from the entire field of regard with a third numerical aperture of light collection higher than a first numerical aperture of light collection used for producing the combined light beam; and

(v) is configured for collecting the plurality of light components with a first numerical aperture from different directions of light propagation associated with the zones of different angular segments of a 360°

space of the field of regard.

18. The system according to claim 2, wherein the optical system is configured to provide the combined light beam containing the same relative flux for each of the light components being combined.

19. The system according to claim 2, wherein the light combining arrangement is configured for separately combining at least two groups of the light components, thereby producing at least two combined light portions, and combining the at least two light portions into the combined light beam.

20. The system according to claim 2, wherein the light collection arrangement is configured and operable for collecting light from the entire field of regard with a third numerical aperture of light collection higher than a first numerical aperture of light collection used for producing the combined light beam, the light detection unit-comprising two light sensitive surfaces, the control unit operating to actuate the optical system for imaging the multiple zones of the field of regard with the combined light beam and the imaging of the entire field of regard with higher numerical aperture onto the two different light sensitive surfaces, respectively.

21. The system according to claim 20, wherein the control unit is configured and operable to use the control signal indicative of the certain condition or event in the combined image to actuate image processing of the image of the entire field of regard to search for a zone therein with which the condition is associated.

22. The system according to claim 9, wherein the optical system has one of the following configurations:

is configured and operable for sequentially acquiring first and second images with the first and second numerical apertures of light collection, the first image being the image of the zone and the second image being the image of a selected part of the zone;

comprising a scanning mechanism operable for scanning the field of regard, each scan including a plurality of zones forming a part of the field of regard.

23. The system according to claim 9, wherein the optical system is configured and operable for sequentially acquiring first and second images with the first and second numerical apertures of light collection, the first image being the image of the zone and the second image being the image of a selected part of the zone, the control unit being configured and operable for displaying on the same display the first image of the zone and the second image of the part of the zone acquired with the respectively higher and lower numerical apertures of light collection and the same image resolution.

24. The system according to claim 23, wherein the control unit is configured and operable for concurrently displaying the first and second images being concurrently acquired by two different light detectors of the light detection unit.

25. The system according to claim 24, wherein the control unit is configured and operable for sequentially displaying the first and second images being sequentially acquired using the same light detector, the optical system comprising an optical switch operable for sequentially switching between first and second light collection paths of the different numerical apertures of light collection.

26. The system according to claim 9, wherein the optical system comprises a scanning mechanism operable for scanning the field of regard, each scan including a plurality of zones forming a part of the field of regard, and an optical switch being configured and operable for selectively deflecting the collected light to thereby either allow or prevent its propagation to the detector.

27. The system according to claim 2, wherein the light collection arrangement is configured for collecting the plurality of light components with a first numerical aperture from different directions of light propagation associated with the zones of different angular segments of a 360°

space of the field of regard, the optical system comprising a scanning mechanism for scanning the field of regard, each scan including the plurality of the different angular segments.

28. The system according to claim 2, wherein the light collection arrangement is configured for collecting the plurality of light components with a first numerical aperture from different directions of light propagation associated with the zones of different angular segments of a 360°

space of the field of regard, the optical system being configured and operable for imaging, for at least some of the zones, at least a part thereof with a second lower numerical aperture.

29. The system according to claim 28, wherein the optical system is configured and operable for selectively carrying out the imaging with the second numerical aperture, being actuated by the control unit upon identifying the certain condition or event in the first combined image data.

30. The system according to claim 2, mounted on an imaging capsule.

31. The system according to claim 2, carried by a housing configured to be mountable onto a distal end of an imaging endoscope.

32. The system according to claim 9, wherein said control unit is configured and operable for, upon identifying the existence of the condition or event in the image data indicative of the combined image, performing an additional processing and analyzing step on image data corresponding to the second numerical aperture for determining a precise location of said event in the field of regard.

33. An imaging capsule comprising an optical system-comprising:

a light collection arrangement comprising a plurality of light collecting units configured and operable for concurrently collecting a plurality of light components propagating along different optical paths from a plurality of different zones, respectively, of a field of regard, said light collection units having a first numerical aperture of light collection, being the same for the light collecting units;

a light combiner arrangement configured to receive the light components collected along the different optical paths from said plurality of light collecting units for combining the collected light components of said plurality of different zones of the field of regard and producing a combined light beam, and directing the combined light beam along a combined optical path;

a light detection unit comprising a light sensitive surface accommodated in the combined optical path for receiving the combined light beam and generating image data indicative of the combined light, the image data being indicative of a plurality of superimposed images of the plurality of said different zones of the field of regard, respectively, corresponding to the plurality of light components concurrently projected in an additive manner onto the light sensitive surface such that flux averaging of the plurality of light components is obtained, thereby enabling detection of an existence of a certain condition in one or more of the zones from analysis of the combined image.

34. The imaging capsule according to claim 33, wherein the light collection arrangement is configured for collecting the plurality of light components with a first numerical aperture from different directions of light propagation associated with the zones of different angular segments of a 360°

space of the field of regard.

35. An endoscope comprising:

a flexible member comprising a working channel and an optical system secured to the working channel, the optical system comprising;

a front optical arrangement at a distal end of the flexible member for collecting light propagating from a front zone of a field of regard;

a peripheral optical arrangement comprising light collection arrangement for concurrently collecting a plurality of light components coming from a plurality of different peripheral zones, respectively, of a field of regard, said peripheral optical arrangement being configured for collecting said plurality of light components from the plurality of different peripheral zones with a plurality of light collecting units, respectively, having a first numerical aperture of light collection, being the same for the plurality of light collecting units;

a light detection unit comprising a first imaging detector associated with the front optical arrangement, and a second imaging detector associated with the peripheral optics; and

a switching arrangement for selectively allowing light components from a selected one of the zones or a combined light from a predetermined number of the selected zones, to propagate to the detection unit, wherein the plurality of light components that are collected by the peripheral optical arrangement are projected in an additive manner onto a common region of the second detector to form a combined image in which the flux of said light components is substantially averaged, and wherein the combined image is made up of a plurality of superimposed images, and wherein each of the superimposed images corresponds to each one of the plurality of the different peripheral zones, respectively; and

the endoscope thereby having a frontal viewing capability using the front end optical arrangement and the first imaging detector, and enabling switched peripheral observation using the peripheral optics and the second imaging detector.