System and method for efficiently delivering rays from a light source to create an image

• US 8,905,547 B2
• Filed: 12/29/2010
• Issued: 12/09/2014
• Est. Priority Date: 01/04/2010
• Status: Active Grant

• Current Assignee: Elbit Systems of America LLC (Elbit Systems Limited)
• Original Assignee: Elbit Systems of America LLC (Elbit Systems Limited)
• Inventors: Tilleman, Michael M., Wolfe, Richard S.
• Primary Examiner(s): Luu, Thanh
• Assistant Examiner(s): Owens, Danell L
• Application Number:
  US12/981,137
• Publication Number:
  US 20110164221A1
• Time in Patent Office: 1,441 Days
• Field of Search: 353/20, 353/81, 353/94, 359/485.06, 359/489.09, 359/489.11, 359/630, 359/618, 359/619, 359/629, 359/634, 362/19, 362/551
• US Class Current: 353/20
• CPC Class Codes: G02B 27/283 used for beam splitting or combining
• CPC Class Codes: H04N 9/3167 for polarizing the light beam polarizing optical systems per se G02B27/28

Abstract

In accordance with one embodiment of the present disclosure, a system may include a polarizing beamsplitter for splitting one or more unpolarized rays received from an illumination source into a first polarized component and a second polarized component, the first polarized component and the second polarized component having orthogonal polarizations to each other. The system may also include a half-wave plate for rotating the second polarized component to the same polarization as the first polarized component. The system may further include a lens group for passing the first polarized component to a target plane as a first polarized ray, and further for separately passing the second polarized component to the target plane as a second polarized ray.

Claims

1. A system, comprising:

a polarizing beamsplitter to combine a first polarized ray received from a first illumination system with a second polarized ray received from a second illumination system to form a combined polarized ray;

a second polarizing beamsplitter to split the combined polarized ray into a first polarized component and a second polarized component, the first polarized component and the second polarized component having orthogonal polarizations to each other;

a half-wave plate to rotate the second polarized component to the same polarization as the first polarized component; and

a lens group to pass the first polarized component to a single image generator as a first polarized ray, and further to separately pass the second polarized component to the single image generator as a second polarized ray;

wherein both the first and second illumination systems comprise;

an illumination source to emit a first unpolarized ray;

a beam homogenizer to redistribute an illumination spatial distribution of the one or more unpolarized rays to a plurality of different spatial distribution profiles;

an illumination system polarizing beamsplitter to split the first unpolarized ray into a first polarized illumination system component and a second polarized illumination system component, the first polarized illumination system component and the second polarized illumination system component having orthogonal polarizations to each other;

an illumination system half-wave plate to rotate the second polarized illumination system component to the same polarization as the first polarized illumination system component; and

an illumination system lens group to pass the first polarized illumination system component to the polarizing beam splitter as a first polarized illumination system ray, and further to separately pass the second polarized illumination system component to the polarizing beamsplitter as a second polarized illumination system ray; and

wherein the first polarized ray received at the polarizing beamsplitter from the first illumination system comprises at least one of the first and second polarized illumination system rays of the first illumination system, and wherein the second polarized ray received at the polarizing beamsplitter from the second illumination system comprises at least one of the first and second polarized illumination system rays of the second illumination system.

2. The system of claim 1, wherein the beam homogenizer converts the illumination spatial distribution of the one or more unpolarized rays to a substantially homogenous spatial distribution.

3. The system of claim 1, wherein the beam homogenizer converts the illumination spatial distribution of the one or more unpolarized rays to a profile selected from the group consisting of:

a saddle function distribution, a substantially flat-top distribution, a super-Gaussian distribution, a flattened Gaussian distribution, a super Lorentzian distribution, a Fermi-Dirac profile distribution, and a step function distribution.

4. The system of claim 3 wherein the beam homogenizer first converts the illumination spatial distribution of the one or more unpolarized rays to a profile selected from the group and then converts the illumination spatial distribution of the one or more unpolarized rays to a different profile selected from the group.

5. The system of claim 1, wherein the lens group tailors a contour of the first and second polarized rays to match a pattern of a target plane.

6. The system of claim 1, wherein the single image generator reflects the first and second polarized rays as reflected rays, wherein the reflected rays remain substantially polarized, and wherein the system further comprises:

an imaging lens to refract the reflected rays as refracted rays; and

a component to reflect the refracted rays to a target in order to form an image.

7. The system of claim 6, wherein the component further transmits illumination from outer scenery to the target so as to form an overlapping image that includes the image and the outer scenery.

8. The system of claim 6, wherein the component includes a preferential polarization reflection to reflect the refracted rays having a particular polarization.

9. The system of claim 6, wherein the component includes a preferential spectral coating to reflect the refracted rays having a particular chromatic content.

10. The system of claim 6, further comprising a quarter-wave-plate to convert the first and second polarized rays from a primary linear polarization to a circular polarization, and further to convert the reflected rays from the circular polarization to a secondary linear polarization orthogonal to the primary linear polarization.

11. The system of claim 1, wherein the system comprises a Head-Up Display (HUD) projection system.

12. The system of claim 1, wherein the lens group further reshapes a beam cross section of the first and second polarized rays.

13. A system, comprising:

a polarizing beamsplitter to combine a first polarized ray received from a first illumination system with a second polarized ray received from a second illumination system and further with a third polarized ray received from a third illumination system to form a combined polarized ray;

a second polarizing beamsplitter to split the combined polarized ray into a first polarized component and a second polarized component, the first polarized component and the second polarized component having orthogonal polarizations to each other;

a half-wave plate to rotate the second polarized component to the same polarization as the first polarized component; and

a lens group to pass the first polarized component to a single image generator as a first polarized imaging ray, and further to separately pass the second polarized component to the single image generator as a second polarized imaging ray;

wherein both the first and second illumination systems comprise;

an illumination source to emit a first unpolarized ray; and

a beam homogenizer to redistribute an illumination spatial distribution of the one or more unpolarized rays to a plurality of different spatial distribution profiles.

14. The system of claim 13, wherein the lens group further tailors a contour of the first and second polarized imaging rays to match a pattern of the single image generator.

15. The system of claim 13, wherein the single image generator is operable to reflect the first and second polarized imaging rays as reflected rays, wherein the reflected rays remain substantially polarized and further comprising:

an imaging lens to refract the reflected rays as refracted rays; and

a component to reflect the refracted rays to a target in order to form an image.

16. The system of claim 15, wherein the component further transmits illumination from outer scenery to the target so as to form an overlapping image that includes the image and the outer scenery.

17. The system of claim 13, wherein both the first and second illumination systems comprise:

an illumination system polarizing beamsplitter to split the first unpolarized ray into a first polarized illumination system component and a second polarized illumination system component, the first polarized illumination system component and the second polarized illumination system component having orthogonal polarizations to each other;

an illumination system half-wave plate to rotate the second polarized illumination system component to the same polarization as the first polarized illumination system component; and

an illumination system lens group to pass the first polarized illumination system component to the polarizing beam splitter as a first polarized illumination system ray, and further to separately pass the second polarized illumination system component to the polarizing beamsplitter as a second polarized illumination system ray; and

wherein the first polarized ray received at the polarizing beamsplitter from the first illumination system comprises at least one of the first and second polarized illumination system rays of the first illumination system, and wherein the second polarized ray received at the polarizing beamsplitter from the second illumination system comprises at least one of the first and second polarized illumination system rays of the second illumination system.

18. The system of claim 17, wherein the polarizing beamsplitter further combines a fourth polarized ray received from a fourth illumination system with the first, second, and third polarized rays to form the combined polarized ray.

19. The system of claim 13, wherein the polarizing beamsplitter further cascades a combination of polarized rays to form the combined polarized ray.

20. The system of claim 13, wherein the first polarized ray has a wavelength for a first color;

and wherein the second polarized ray has a wavelength for a second color.

21. A method, comprising:

combining a first polarized ray received from a first illumination system with a second polarized ray received from a second illumination system to form a combined polarized ray;

splitting the combined polarized ray into a first polarized component and a second polarized component, the first polarized component and the second polarized component having orthogonal polarizations to each other;

rotating the second polarized component to the same polarization as the first polarized component;

passing the first polarized component to a single image generator as a first polarized ray, and separately passing the second polarized component to the single image generator as a second polarized ray; and

at both of the first and second illumination systems;

emitting a first unpolarized ray;

redistributing an illumination spatial distribution of the one or more unpolarized rays to a plurality of different spatial distribution profiles;

splitting the first unpolarized ray into a first polarized illumination system component and a second polarized illumination system component, the first polarized illumination system component and the second polarized illumination system component having orthogonal polarizations to each other;

rotating the second polarized illumination system component to the same polarization as the first polarized illumination system component; and

passing the first polarized illumination system component to the polarizing beamsplitter as a first polarized illumination system ray, and separately passing the second polarized illumination system component to the polarizing beamsplitter as a second polarized illumination system ray; and

wherein the first polarized ray received at the polarizing beamsplitter from the first illumination system comprises at least one of the first and second polarized illumination system rays of the first illumination system, and wherein the second polarized ray received at the polarizing beamsplitter from the second illumination system comprises at least one of the first and second polarized illumination system rays of the second illumination system.

22. The method of claim 21, wherein redistributing the illumination spatial distribution of the one or more unpolarized rays comprises converting the illumination spatial distribution of the one or more unpolarized rays to a substantially homogenous spatial distribution.

23. The method of claim 21, further comprising tailoring a contour of the first and second polarized rays to match a pattern of a target plane.

24. The method of claim 21, further comprising:

reflecting, at the single image generator, the first and second polarized rays as reflected rays, wherein the reflected rays remain substantially polarized;

refracting the reflected rays as refracted rays; and

reflecting, at a component, the refracted rays to a target in order to form an image.

25. The method of claim 24, further comprising transmitting, at the component, illumination from outer scenery to the target so as to form an overlapping image that includes the image and the outer scenery.

26. The method of claim 24, further comprising converting the first and second polarized rays from a primary linear polarization to a circular polarization, and further converting the reflected rays from the circular polarization to a secondary linear polarization orthogonal to the primary linear polarization.

27. A method, comprising:

combining a first polarized ray received from a first illumination system with a second polarized ray received from a second illumination system and further with a third polarized ray received from a third illumination system to form a combined polarized ray;

splitting the combined polarized ray into a first polarized component and a second polarized component, the first polarized component and the second polarized component having orthogonal polarizations to each other;

rotating the second polarized component to the same polarization as the first polarized component; and

passing the first polarized component to a single image generator as a first polarized imaging ray, and separately passing the second polarized component to the single image generator as a second polarized imaging ray; and

at both of the first and second illumination systems;

emitting a first unpolarized ray; and

redistributing an illumination spatial distribution of the one or more unpolarized rays to a plurality of different spatial distribution profiles.

28. The method of claim 27, further comprising tailoring a contour of the first and second polarized imaging rays to match a pattern of the image generator.

29. The method of claim 27, further comprising:

reflecting, at the single image generator, the first and second polarized imaging rays as reflected rays, wherein the reflected rays remain substantially polarized;

refracting the reflected rays as refracted rays; and

reflecting, at a component, the refracted rays to a target in order to form an image.

30. The method of claim 29, further comprising, transmitting, at the component, illumination from outer scenery to the target so as to form an overlapping image that includes the image and the outer scenery.

31. The method of claim 27, further comprising:

at both of first and second illumination systems;

splitting the first unpolarized ray into a first polarized illumination system component and a second polarized illumination system component, the first polarized illumination system component and the second polarized illumination system component having orthogonal polarizations to each other;

rotating the second polarized illumination system component to the same polarization as the first polarized illumination system component; and

passing the first polarized illumination system component to the polarizing beamsplitter as a first polarized illumination system ray, and separately passing the second polarized illumination system component to the polarizing beamsplitter as a second polarized illumination system ray; and

wherein the first polarized ray received at the polarizing beamsplitter from the first illumination system comprises at least one of the first and second polarized illumination system rays of the first illumination system, and wherein the second polarized ray received at the polarizing beamsplitter from the second illumination system comprises at least one of the first and second polarized illumination system rays of the second illumination system.

32. The method of claim 27, wherein the first polarized ray has a wavelength for a first color;

and wherein the second polarized ray has a wavelength for a second color.