Security camera system and method of steering beams to alter a field of view

• US 8,614,743 B2
• Filed: 09/24/2007
• Issued: 12/24/2013
• Est. Priority Date: 09/24/2007
• Status: Active Grant

• Current Assignee: Harris Corporation (L3Harris Technologies, Inc.)
• Original Assignee: Exelis Incorporated (L3Harris Technologies, Inc.)
• Inventors: Winsor, Robert Scott
• Primary Examiner(s): BAYARD, DJENANE M
• Application Number:
  US11/860,037
• Publication Number:
  US 20090079824A1
• Time in Patent Office: 2,283 Days
• Field of Search: None
• US Class Current: 348/143
• CPC Class Codes: G01S 3/7864 T.V. type tracking systems
• CPC Class Codes: G02B 26/0891 forming an optical wedge
• CPC Class Codes: G02B 26/108 having one or more prisms as scanning elements
• 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 23/667 Camera operation mode switching, e.g. between still and video, sport and normal or high- and low-resolution modes
• CPC Class Codes: H04N 23/69 Control of means for changing angle of the field of view, e.g. optical zoom objectives or electronic zooming

Abstract

A security camera system according to present invention embodiments includes a telephoto type lens with one or more factors of optical zoom. A set of prisms that steer incoming beams from the surrounding environment (to adjust the field of view) is disposed in front of the lens. The security camera system preferably includes a wide angle staring mode that encompasses a large field of view, where the prisms are oriented to provide no steering effect. The security camera system further includes a high-resolution zoom mode, where the telephoto lens focuses on a region of interest and the prisms perform beam steering to adjust the field of view and enable the region of interest or an object to remain at the center of the security camera system view. Image processing techniques may be employed that consider the beam steering angle and the field of view to compensate for distortion effects.

Claims

1. A security camera system comprising:

a lens assembly to provide at least one of a zoom view and a wide angle view;

a beam manipulating assembly disposed distally of said lens assembly and including a plurality of beam manipulating devices positioned coincident each other to successively receive an incoming beam with each beam manipulating device mounted on a corresponding rotation assembly to rotate that beam manipulating device relative to other beam manipulating devices to steer said incoming beam from a surrounding environment and control a field of view of said security camera system, wherein each rotation assembly rotates said corresponding beam manipulating device about a common transverse axis of rotation extending through said coincident beam manipulating devices and to angular positions relative to an optical axis of that beam manipulating device, and wherein said plurality of beam manipulating devices comprises prisms;

an image capture device to capture images through said lens assembly and beam manipulating devices; and

a controller to control said lens and rotation assemblies to provide a desired field of view, wherein said controller controls said rotation assemblies to rotate said beam manipulating devices to positions at angular offsets from each other relative to said common transverse axis of rotation to steer said incoming beam for said desired field of view and includes;

a track module to identify an object within said field of view and control said beam manipulating assembly to orient said beam manipulating devices relative to each other to adjust said field of view to encompass said object in response to object motion.

2. The system of claim 1, wherein said prisms include planar surfaces.

3. The system of claim 2, wherein said prisms include gratings to compensate for dispersion effects from said steering of said incoming beam.

4. The system of claim 1, wherein said controller controls said beam manipulating assembly to orient said beam manipulating devices relative to each other to inhibit steering of said incoming beam in response to said lens assembly providing said wide angle view.

5. The system of claim 1, wherein said controller controls said beam manipulating assembly to orient said beam manipulating devices relative to each other to enable steering of said incoming beam in response to said lens assembly providing said zoom view.

6. The system of claim 1, wherein said controller further includes:

an image processing module to process said captured images to compensate for distortion effects from said steering of said incoming beam.

7. The system of claim 6, wherein said beam manipulating assembly includes at least one sensor to monitor orientation of said beam manipulating devices relative to each other, and said image processing module processes said captured images in accordance with said orientation of said beam manipulating devices.

8. The system of claim 1, wherein said security camera system includes a planar aperture.

9. The system of claim 1, wherein said controller further includes:

a scan module to control said beam manipulating assembly to continuously adjust orientation of said beam manipulating devices relative to each other to alter said field of view to scan a desired area.

10. The system of claim 1, wherein said controller further includes:

an image processing module to identify a location of said object within said captured images for adjusting said field of view to encompass said object in response to object motion.

11. A method of adjusting a field of view of a camera system including a lens assembly, a beam manipulating assembly disposed distally of said lens assembly and including a plurality of beam manipulating devices positioned coincident each other to successively receive an incoming beam with each beam manipulating device mounted on a corresponding rotation assembly to rotate that beam manipulating device relative to other beam manipulating devices, a controller and an image capture device, wherein each rotation assembly rotates said corresponding beam manipulating device about a common transverse axis of rotation extending through said coincident beam manipulating devices and to angular positions relative to an optical axis of that beam manipulating device, said method comprising:

(a) providing at least one of a zoom view and a wide angle view;

(b) controlling said lens and rotation assemblies to provide a desired field of view, wherein said rotation assemblies are controlled to rotate said beam manipulating devices to positions at angular offsets from each other relative to said common transverse axis of rotation to steer said incoming beam from a surrounding environment to control said field of view, and wherein said plurality of beam manipulating devices comprises prisms;

(c) capturing images through said lens assembly and beam manipulating devices; and

(d) identifying an object within said field of view and controlling said beam manipulating assembly to orient said beam manipulating devices relative to each other to adjust said field of view to encompass said object in response to object motion.

12. The method of claim 11, wherein said prisms include planar surfaces.

13. The method of claim 12, wherein said prisms include gratings to compensate for dispersion effects from said steering of said incoming beam.

14. The method of claim 11, wherein step (b) further includes:

(b.1) controlling said beam manipulating assembly to orient said beam manipulating devices relative to each other to inhibit steering of said incoming beam in response to providing said wide angle view.

15. The method of claim 11, wherein step (b) further includes:

(b.1) controlling said beam manipulating assembly to orient said beam manipulating devices relative to each other to enable steering of said incoming beam in response to providing said zoom view.

16. The method of claim 11, wherein step (c) further includes:

(c.1) processing said captured images to compensate for distortion effects from said steering of said incoming beam.

17. The method of claim 16, wherein said beam manipulating assembly includes at least one sensor to monitor orientation of said beam manipulating devices relative to each other, and step (c.1) further includes:

(c.1.1) processing said captured images in accordance with said orientation of said beam manipulating devices.

18. The method of claim 11, wherein said camera system includes a planar aperture.

19. The method of claim 11, wherein step (b) further includes:

(b.1) controlling said beam manipulating assembly to continuously adjust orientation of said beam manipulating devices relative to each other to alter said field of view to scan a desired area.

20. The method of claim 11, wherein step (d) further includes:

(d.1) identifying a location of said object within said captured images for adjusting said field of view to encompass said object in response to object motion.