System and Method for Efficiently Delivering Rays from a Light Source to Create an Image

• US 20110164221A1
• Filed: 12/29/2010
• Published: 07/07/2011
• 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.
• Granted Patent: US 8,905,547 B2
• Time in Patent Office: Days
• 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 operable to split 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;

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

a lens group operable to pass the first polarized component to a target plane as a first polarized ray, and further operable to separately pass the second polarized component to the target plane as a second polarized ray.

2. The system of claim 1, further comprising a beam homogenizer operable to redistribute an illumination spatial distribution of the one or more unpolarized rays.

3. The system of claim 2, wherein the beam homogenizer operable to redistribute the illumination spatial distribution of the one or more unpolarized rays comprises the beam homogenizer operable to convert the illumination spatial distribution of the one or more unpolarized rays to a substantially homogenous spatial distribution.

4. The system of claim 2, wherein the beam homogenizer operable to redistribute the illumination spatial distribution of the one or more unpolarized rays comprises the beam homogenizer operable to convert the illumination spatial distribution of the one or more unpolarized rays to an arbitrary spatial distribution.

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

6. The system of claim 1, wherein the target plane comprises an image generator operable to reflect 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 operable to refract the reflected rays as refracted rays; and

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

7. The system of claim 6, wherein the component is further operable to transmit 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 for reflecting the refracted rays having a particular polarization.

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

10. The system of claim 6, further comprising a quarter-wave-plate operable to convert the first and second polarized rays from a primary linear polarization to a circular polarization, and further operable 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, further comprising the illumination source, wherein the illumination source is selected from one of:

a light emitting diode;

an incandescent lamp;

an electric discharge lamp; and

a laser.

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

13. The system of claim 1, wherein the lens group is further operable to reshape a beam cross section of the first and second polarized rays.

14. A system, comprising:

a polarizing beamsplitter operable 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 operable 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 operable to rotate the second polarized component to the same polarization as the first polarized component; and

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

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

16. The system of claim 14, further comprising:

the single image generator, 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;

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

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

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

18. The system of claim 14, wherein both the first and second illumination systems comprise:

an illumination source operable to emit a first unpolarized ray;

a beam homogenizer operable to convert an illumination spatial distribution of the first unpolarized ray to a substantially homogenous radiance spatial distribution;

an illumination system polarizing beamsplitter operable 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 operable 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 operable to pass the first polarized illumination system component to the polarizing beam splitter as a first polarized illumination system ray, and further operable 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.

19. The system of claim 14, wherein the polarizing beamsplitter is further operable to combine a third polarized ray received from a third illumination system with the first and second polarized rays to form the combined polarized ray.

20. The system of claim 14, wherein the polarizing beamsplitter is further operable to combine a fourth polarized ray received from a fourth illumination system with the first, second, and third polarized rays to form the combined polarized ray.

21. The system of claim 14, wherein the polarizing beamsplitter is further operable to cascade a combination of polarized rays to form the combined polarized ray.

22. The system of claim 14, 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

23. A method, comprising:

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;

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

passing the first polarized component to a target plane as a first polarized ray, and separately passing the second polarized component to the target plane as a second polarized ray.

24. The method of claim 23, further comprising redistributing an illumination spatial distribution of the one or more unpolarized rays.

25. The method of claim 24, 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.

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

27. The method of claim 23, wherein the target plane comprises an image generator, and wherein the method further comprises:

reflecting, at the 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.

28. The method of claim 27, 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.

29. The method of claim 27, 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.

30. 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; 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.

31. The method of claim 30, further comprising tailoring a contour of the first and second polarized imaging rays to match a pattern of the image generator.

32. The method of claim 30, 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.

33. The method of claim 32, 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.

34. The method of claim 30, further comprising:

at both of first and second illumination systems;

emitting a first unpolarized ray;

converting an illumination spatial distribution of the first unpolarized ray to a substantially homogenous radiance spatial distribution;

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.

35. The method of claim 30, further comprising combining, at the polarizing beamsplitter, a third polarized ray received from a third illumination system with the first and second polarized rays to form the combined polarized ray.

36. The method of claim 30, 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.