Hemispherical Star Camera

• US 20160381267A1
• Filed: 06/23/2015
• Published: 12/29/2016
• Est. Priority Date: 06/23/2015
• Status: Active Grant

• Current Assignee: Charles Stark Draper Laboratory Incorporated
• Original Assignee: Charles Stark Draper Laboratory Incorporated
• Inventors: Harrison, Samuel, Boyle, John James, Waldron, Erik L., Blasche, Gregory P., Bohn, Paul, Dawson, Robin Mark Adrian, Foley, Walter, Jamula, Matthew T., Laine, Juha-Pekka J., Lane, Benjamin F., McClain, Sean, Rogomentich, Francis J., Smith, Stephen P.
• Granted Patent: US 10,901,190 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01C 21/025 with the use of startrackers
• CPC Class Codes: G02B 13/005 having spherical lenses only
• CPC Class Codes: G02B 13/06 Panoramic objectives; So-called "sky lenses" including panoramic objectives having reflecting surfaces
• CPC Class Codes: G02B 23/16 Housings; Caps; Mountings; Supports, e.g. with counterweight
• CPC Class Codes: H04N 23/11 for generating image signals from visible and infrared light wavelengths
• 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 23/55 Optical parts specially adapted for electronic image sensors; Mounting thereof
• CPC Class Codes: H04N 23/695 Control of camera direction for changing a field of view, e.g. pan, tilt or based on tracking of objects
• CPC Class Codes: H04N 25/702 SSIS architectures characterised by non-identical, non-equidistant or non-planar pixel layout

Abstract

A digital camera optically couples a monocentric lens to image sensor arrays, without optical fibers, yet shields the image sensor arrays from stray light. In some digital cameras, baffles are disposed between an outer surface of a monocentric lens and each image sensor array to shield the image sensor arrays from stray light. In other such digital cameras, an opaque mask defines a set of apertures, one aperture per image sensor array, to limit the amount of stray light. Some digital cameras include both masks and baffles.

Claims

1. A digital camera, comprising:

a monocentric lens having a focal length, an outer surface and a center;

a plurality of pixelated optical sensor arrays, each pixelated optical sensor array being oriented toward the center of the monocentric lens and spaced apart from the outer surface of the monocentric lens, such that the pixelated optical sensor array is disposed about the focal length of the monocentric lens from the center of the monocentric lens; and

for each pixelated optical sensor array of the plurality of pixelated optical sensor arrays, at least one baffle disposed between the outer surface of the monocentric lens and the pixelated optical sensor array, the baffle corresponding to the pixelated optical sensor array and having a longitudinal axis normal to the baffle'"'"'s corresponding pixelated optical sensor array and extending through the center of the monocentric lens.

2. A digital camera according to claim 1, wherein a portion, less than all, of the outer surface of the monocentric lens comprises a mask that defines a plurality of transparent apertures therethrough and is otherwise opaque at a predetermined wavelength, such that each aperture of the plurality of apertures is aligned with the respective baffle of the at least one baffle and limits an amount of light that can pass from the monocentric lens to the corresponding pixelated optical sensor array.

3. A digital camera according to claim 1, wherein the monocentric lens has no central aperture.

4. A digital camera according to claim 1, wherein at least one of the at least one baffle comprises a tube.

5. A digital camera according to claim 1, wherein at least one of the at least one baffle is frustoconical.

6. A digital camera according to claim 1, wherein a wall of at least one baffle is opaque at a predetermined wavelength.

7. A digital camera according to claim 1, wherein a wall of at least one baffle has a total hemispherical reflectivity of less than about 25% at predetermined wavelength.

8. A digital camera according to claim 1, wherein at least one baffle is spaced apart from the outer surface of the monocentric lens by at least about 1 mm.

9. A digital camera according to claim 1, wherein one end of at least one baffle is in contact with the outer surface of the monocentric lens.

10. A digital camera according to claim 1, wherein at least one baffle is spaced apart from the baffle'"'"'s corresponding pixelated optical sensor array by at least about 1 mm.

11. A digital camera according to claim 1, wherein one end of at least one baffle is in contact with the baffle'"'"'s corresponding pixelated optical sensor array.

12. A digital camera according to claim 1, wherein at least one pixelated optical sensor array of the plurality of pixelated optical sensor arrays is planar.

13. A digital camera according to claim 1, wherein at least one pixelated optical sensor array of the plurality of pixelated optical sensor arrays is curved.

14. A digital camera according to claim 1, wherein at least one pixelated optical sensor array of the plurality of pixelated optical sensor arrays is substantially parallel to the outer surface of the monocentric lens.

15. A digital camera according to claim 1, further comprising:

an object catalog storing information about objects expected to be viewed by the digital camera; and

a navigation controller communicatively coupled to the object catalog and to the plurality of pixelated optical sensor arrays, wherein the navigation controller uses at least some of the information stored in the object catalog and image data from at least one pixelated optical sensor array of the plurality of pixelated optical sensor arrays to automatically determine at least one of;

a location of the digital camera and an orientation of the digital camera.

16. A digital camera according to claim 1, further comprising:

an object catalog storing information about objects expected to be viewed by the digital camera; and

a navigation controller communicatively coupled to the object catalog and to the plurality of pixelated optical sensor arrays, wherein the navigation controller uses at least some of the information stored in the object catalog and image data from at least one pixelated optical sensor array of the plurality of pixelated optical sensor arrays to automatically generate course correction information.

17. A digital camera, comprising:

a monocentric lens having a focal length, an outer surface and a center;

a plurality of pixelated optical sensor arrays, each pixelated optical sensor array being oriented toward the center of the monocentric lens and spaced apart from the outer surface of the monocentric lens, such that the pixelated optical sensor array is disposed about the focal length of the monocentric lens from the center of the monocentric lens; and

a mask disposed between the monocentric lens and the plurality of pixelated optical sensor arrays, the mask defining a separate aperture corresponding to each pixelated optical sensor array of the plurality of pixelated optical sensor arrays and being otherwise opaque at a predetermined wavelength, each aperture being centered on a respective line normal to the aperture'"'"'s corresponding pixelated optical sensor array and extending through the center of the monocentric lens, each aperture limiting an amount of light that can pass from the monocentric lens to the aperture'"'"'s corresponding pixelated optical sensor array.

18. A digital camera according to claim 17, wherein the mask is disposed on the outer surface of the lens.

19. A digital camera according to claim 17, further comprising, for each pixelated optical sensor array of the plurality of pixelated optical sensor arrays, a baffle disposed between the outer surface of the monocentric lens and the pixelated optical sensor array, the baffle corresponding to the pixelated optical sensor array and having a longitudinal axis normal to the baffle'"'"'s corresponding pixelated optical sensor array and extending through the center of the monocentric lens.

20. A digital camera according to claim 17, further comprising:

an object catalog storing information about objects expected to be viewed by the digital camera; and

a navigation controller communicatively coupled to the object catalog and to the plurality of pixelated optical sensor arrays, wherein the navigation controller uses at least some of the information stored in the object catalog and image data from at least one pixelated optical sensor array of the plurality of pixelated optical sensor arrays to automatically determine at least one of;

a location of the digital camera and an orientation of the digital camera.

21. A digital camera according to claim 17, further comprising:

an object catalog storing information about objects expected to be viewed by the digital camera; and

a navigation controller communicatively coupled to the object catalog and to the plurality of pixelated optical sensor arrays, wherein the navigation controller uses at least some of the information stored in the object catalog and image data from at least one pixelated optical sensor array of the plurality of pixelated optical sensor arrays to automatically generate course correction information.