OPTICAL IMAGING WITH FOVEATION

• US 20130016178A1
• Filed: 07/06/2012
• Published: 01/17/2013
• Est. Priority Date: 07/17/2011
• Status: Active Grant

• Current Assignee: Ziva Corporation
• Original Assignee: Ziva Corporation
• Inventors: Husain, Anis, Ranalli, Eliseo, Birkbeck, Aaron L.
• Granted Patent: US 9,071,742 B2
• Time in Patent Office: Days
• US Class Current: 348/36
• CPC Class Codes: G02B 13/06 Panoramic objectives; So-called "sky lenses" including panoramic objectives having reflecting surfaces
• CPC Class Codes: G02B 17/086 wherein the system is made of a single block of optical material, e.g. solid catadioptric systems
• CPC Class Codes: G02B 17/0896 with variable magnification or multiple imaging planes, including multispectral systems systems with only refractive elements G02B15/14
• CPC Class Codes: G02B 26/0825 the reflecting element being a flexible sheet or membrane, e.g. for varying the focus flexible mirrors for cosmetic use A45D42/24
• CPC Class Codes: G02B 26/0833 the reflecting element being a micromechanical device, e.g. a MEMS mirror, DMD G02B26/0825 takes precedence; micromechanical devices in general B81B
• CPC Class Codes: G02B 26/127 Adaptive control of the scanning light beam, e.g. using the feedback from one or more detectors G02B27/0031 takes precedence
• CPC Class Codes: G03B 37/02 with scanning movement of lens or cameras
• CPC Class Codes: H04N 23/45 for generating image signals from two or more image sensors being of different type or operating in different modes, e.g. with a CMOS sensor for moving images in combination with a charge-coupled device [CCD] for still images
• 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

Abstract

Selected described embodiments include an imager providing concurrent wide field of view (WFOV) and foveated images. The imager includes a frontend optic configured to receive light from a scene. Corrective optics reduces distortions, and transmits the light to a beam splitter. One portion of the light exiting the beam splitter is focused on a WFOV image detector. A second portion of the light falls on a scanning mirror that can be configured to target a selected field position in the field of view. From the scanning mirror, the light passes through a magnifier and is corrected by an adaptive wavefront corrector. The corrector may be configured to correct aberrations corresponding to the particular field of view selected by the scanning mirror. The light from the wavefront corrector is focused on a foveated image detector. The images captured by the image detectors may be stored, processed, and transmitted to other systems.

Claims

1. An imaging systems, comprising:

a frontend optic configured to receive light from a scene in a wide field of view (WFOV);

a beam splitter configured to receive light exiting from the frontend optic and divide the light exiting from the frontend optic into at least two beams, the at least two beams comprising a first beam and a second beam;

a wide field of view (WFOV) image detector configured to receive the first beam;

a scanning component controllable by one or more scan position signals;

an adaptive wavefront corrector controllable by one or more wavefront correction signals;

an optical magnifier; and

a foveated image detector;

wherein;

the scanning component is configured to receive all or part of the second beam and reflect a portion of the second beam towards the adaptive wavefront corrector, the portion of the second beam reflected towards the adaptive wavefront corrector corresponds to a part of the WFOV received by the frontend optic, the portion of the second beam reflected towards the adaptive wavefront corrector is determined by position of the scanning component, the position of the scanning component is determined by the one or more scan position signals;

the adaptive wavefront corrector is configured (1) to correct the portion of the second beam reflected by the scanning component based on the one or more wavefront correction signals to obtain a corrected portion of the second beam, and (2) to reflect the corrected portion of the second beam towards the foveated image detector; and

the optical magnifier is interposed in light path between the scanning component and the foveated image detector;

so that a WFOV images of the scene are formed on the WFOV image detector and foveated images of selected portions of the scene are formed on the foveated image detector.

2. An imaging system according to claim 1, further comprising a corrective optics block interposed in light path between the frontend optic and the beam splitter.

3. An imaging system according to claim 2, wherein the scanning component comprises a tip-tilt mirror.

4. An imaging system according to claim 3, further comprising a wide field of view optical block interposed in light path between the beam splitter and the WFOV image detector, the wide field of view optical block being configured to focus the first beam on the WFOV image detector.

5. An imaging system according to claim 3, wherein the adaptive wavefront corrector comprises a deformable mirror.

6. An imaging system according to claim 3, wherein the adaptive wavefront corrector comprises a liquid crystal spatial light modulator.

7. An imaging system according to claim 3, further comprising a folding mirror interposed between the scanning component and the foveated image detector, so that the second beam passes through folded optics.

8. An imaging system according to claim 3, wherein the frontend optic comprises a catadioptric lens.

9. An imaging system according to claim 3, wherein the frontend optic comprises a Boule lens.

10. An imaging system according to claim 3, wherein the frontend optic comprises a fisheye lens.

11. An imaging system according to claim 3, wherein the frontend optic is a panoramic optic and the WFOV images formed on the WFOV image detector are panoramic images.

12. An imaging system according to claim 3, wherein the frontend optic is a panoramic optic and the WFOV images formed on the WFOV image detector are 360 degree images.

13. An imaging system according to claim 3, wherein solid angle ratio of the foveated images to the WFOV images is less than one.

14. An imaging system according to claim 3, wherein solid angle ratio of the foveated images to the WFOV images is no greater than 0.5.

15. An imaging system according to claim 3, wherein solid angle ratio of the foveated images to the WFOV images is no greater than 0.1.

16. An imaging system according to claim 3, wherein the beam splitter is configured so that more light energy goes into the second beam than into the first beam.

17. An imaging system according to claim 3, wherein the beam splitter comprises a partially reflective mirror, the first beam passes through the partially reflective mirror, and the second beam is reflected by the partially reflective mirror.

18. An imaging system according to claim 3, wherein the beam splitter comprises a partially reflective mirror, the second beam passes through the partially reflective mirror, and the first beam is reflected by the partially reflective mirror.

19. An imaging system according to claim 3, further comprising a processor system configured (1) to provide the one or more scan position signals and the one or more wavefront correction signals so that the foveated images are corrected based on positions of the scanning component. (2) read the WFOV images captured by the WFOV image detector, and (3) read the foveated images captured by the foveated image detector.

20. An imaging system according to claim 19, wherein the processor system stores a table relating the positions of the scanning component to settings of the adaptive wavefront corrector.

21. An imaging method, comprising:

receiving through a frontend optic light from a scene in a wide field of view (WFOV);

dividing light that exits from frontend optic into at least two beams, the at least two beams comprising a first beam and a second beam;

projecting the first beam onto a wide field of view (WFOV) image detector;

selecting a portion of the second beam with a scanning component controllable by one or more scan position signals;

correcting the second beam by configuring an adaptive wavefront corrector controllable by one or more wavefront correction signals;

magnifying the second beam; and

projecting the second beam onto a foveated image detector.

22. An imaging method according to claim 21, further comprising:

capturing wide field of view images formed on the WFOV image detector; and

capturing foveated images formed on the foveated image detector.

23. An imaging method according to claim 22, further comprising:

determining the one or more scan position signals;

determining the one or more wavefront correction signals;

providing the one or more scan position signals to the scanning component; and

providing the one or more wavefront correction signals to the adaptive wavefront corrector;

wherein the foveated image is corrected based on position of the scanning component.