SINGLE LENS SPLITTER CAMERA

• US 20080075441A1
• Filed: 03/02/2007
• Published: 03/27/2008
• Est. Priority Date: 03/03/2006
• Status: Active Grant

• Current Assignee: Gentex Corporation
• Original Assignee: Honeywell International Inc.
• Inventors: Phinney, Thomas, Jelinek, Jan
• Granted Patent: US 7,933,507 B2
• Time in Patent Office: Days
• US Class Current: 396/18
• CPC Class Codes: G06V 40/19 Sensors therefor

Abstract

A camera system may be used to capture iris images of targeted people who may be unaware of being targeted and hence their movement may not be constrained in any way. Iris images may be used for identification and/or tracking of people. In one illustrative embodiment, a camera system may include a focus camera and an iris camera, where the focus camera is sensitive to ambient light or some spectrum thereof, and the iris camera is sensitive to infrared or some other wavelength light. The focus camera and the iris camera may share an optical lens, and the focus camera may be used to auto-focus the lens on a focus target. A beam splitter or other optical element may be used to direct light of some wavelengths to the focus camera for auto-focusing the lens, and other wavelengths to the iris camera for image capture of the iris images.

Claims

1. A camera system comprising:

an iris camera having an optical axis;

a focus camera having an optical axis, wherein the optical axis of the focus camera is angularly offset from the optical axis of the iris camera;

a lens; and

a beam splitter arranged downstream of the lens, the beam splitter directing a first wavelength or range of wavelengths of incoming light to the focus camera and a second wavelength or range of wavelengths of incoming light to the iris camera.

2. The camera system of claim 1, wherein the optical axis of the focus camera is arranged at least substantially perpendicular to the optical axis of the iris camera.

3. The camera system of claim 1, wherein the beam splitter is configured to permit the second wavelength or range of wavelengths of incoming light to pass straight through the beam splitter.

4. The camera system of claim 1, wherein the first wavelength or range of wavelengths of light includes ambient light.

5. The camera system of claim 1, wherein the first wavelength or range of wavelengths of light includes visible light.

6. The camera system of claim 1, wherein the second wavelength or range of wavelengths of light includes flash illumination light.

7. The camera system of claim 1, wherein the second wavelength or range of wavelengths of light includes infrared light.

8. The camera system of claim 1, wherein the focus camera is sensitive to visible light or some sub spectra thereof.

9. The camera system of claim 1, wherein the iris camera is sensitive to infrared light.

10. The camera system of claim 1, wherein an output of the focus camera is used to locate a given focus target.

11. The camera system of claim 10, wherein an output of the focus camera is used to auto-focus the lens on the focus target.

12. The camera system of claim 1, further comprising a near infrared flash that is used in conjunction with the iris camera.

13. An camera system comprising:

a first camera that is sensitive to ambient light;

a second camera that is sensitive to light from a flash discharge;

a lens; and

a beam splitter disposed downstream of the lens, the beam splitter splitting the light passing through the lens into an ambient light image that is directed to the first camera, and a flash light image that is directed to the second camera.

14. The camera system of claim 13, wherein an output of the first camera is used to auto-focus the lens.

15. The camera system of claim 13, wherein the second camera is configured to capture an infrared image of an iris of a target subject.

16. A method of capturing an iris image using a camera system comprising a focus camera, an iris camera and a lens disposed upstream of and shared by the focus camera and the iris camera, the method comprising the steps of:

finding a focus target in a focus camera image;

focusing the lens on the focus target using the focus camera; and

capturing the iris image using the iris camera.

17. The method of claim 16, wherein the focus camera focuses the lens using ambient light or some spectra thereof.

18. The method of claim 16, further comprising a step of correcting the lens focus after the lens is focused by the focus camera, but prior to capturing the iris image.

19. The method of claim 16, further comprising a step of finding a focus target within an image seen or sensed by the focus camera.

20. The method of claim 19, further comprising a step of extracting image data and using the image data to precisely auto focus the focus camera.

21. The method of claim 16, further comprising the step of splitting the light that passes through the shared lens into an ambient light based image and an infrared light based image, wherein the ambient light based image is directed to the focus camera and the infrared light based image is directed to the iris camera.