Filter for enhancing vision and/or protecting the eyes and method of making a filter

• US 20040114242A1
• Filed: 09/05/2003
• Published: 06/17/2004
• Est. Priority Date: 09/06/2002
• Status: Active Grant

• Current Assignee: RealD Incorporated
• Original Assignee: ColorLink, Incorporated (RealD Incorporated)
• Inventors: Sharp, Gary D.
• Granted Patent: US 7,106,509 B2
• Time in Patent Office: Days
• US Class Current: 359/498
• CPC Class Codes: G02B 27/288 Filters employing polarising elements, e.g. Lyot or Solc filters G02B5/3016 takes precedence
• CPC Class Codes: G02B 5/3041 comprising multiple thin layers, e.g. multilayer stacks

Abstract

The selective filtering of light by polarization interference may be used to enhance vision and/or protect eyes from harmful light rays. For example, such filtering may be used in sunglasses, color corrective eyewear or protective eyewear. The selective filtering of incident light may provide any desired spectral transmission (including visible light and light not visible to the eye) and is performed by a pair of polarizing elements that sandwich a retarder stack. The filtering structure may be formed by multi-layer polarizing structures and may be formed by fabricating sheet laminates that are die cut to form inexpensive laminates. The laminates may be flat or curved in one (e.g., wrap-around) or more dimensions.

Claims

1. An optical filter for vision comprising:

an input polarizing element;

an output polarizing element; and

a retarder stack between the input polarizing element and the output polarizing element;

wherein the input polarizing element, the output polarizing element, and the retarder stack, at least partially positioned in a field of view, substantially filter at least one band of light.

2. An optical filter according to claim 1, wherein

the optical filter is configured for human vision;

and

the input polarizing element, the output polarizing element, and the retarder stack, are adapted to be positioned at least partially in a human'"'"'s field of view.

3. An optical filter according to claim 1, wherein

the optical filter is configured for animal vision;

and

the input polarizing element, the output polarizing element, and the retarder stack, are adapted to be positioned at least partially in an animal'"'"'s field of view.

4. An optical filter according to claim 1, wherein the at least one band of light is an inter-primary band of light.

5. An optical filter according to claim 1, wherein the at least one band of light has a wavelength that is smaller than or equal to about 400 nm.

6. An optical filter according to claim 1, wherein the at least one band of light has a wavelength that is greater than or equal to about 700 nm.

7. An optical filter according to claim 1, wherein the at least one band of light has a wavelength of about 500 nm.

8. An optical filter according to claim 1, wherein the at least one band of light has a wavelength of about 580 nm.

9. An optical filter according to claim 1, wherein at least two inter-primary bands of light are filtered.

10. An optical filter according to claim 1, wherein the input polarizing element, the output polarizing element, and the retarder stack, filter light so as to maintain a color neutral appearance.

11. An optical filter according to claim 1, wherein the optical filter is one of a pair of sunglasses, a canopy for a helmet, or a visor.

12. An optical filter for vision comprising:

an input polarizing element;

an output polarizing element; and

a retarder stack between the input polarizing element and the output polarizing element;

wherein the input polarizing element, the output polarizing element, and the retarder stack, at least partially positioned in a field of view, substantially filter light to improve color deficient vision.

13. An optical filter according to claim 12, wherein

the optical filter is configured for human vision;

and

the input polarizing element, the output polarizing element, and the retarder stack, are adapted to be positioned at least partially in a human'"'"'s field of view.

14. An optical filter according to claim 12, wherein

the optical filter is configured for animal vision;

and

the input polarizing element, the output polarizing element, and the retarder stack, are adapted to be positioned at least partially in an animal'"'"'s field of view.

15. An optical filter according to claim 12, wherein the light is substantially filtered at wavelengths of about 500 nm and about 580 nm.

16. An optical filter for vision comprising:

an input polarizing element;

an output polarizing element; and

a retarder stack between the input polarizing element and the output polarizing element;

wherein the input polarizing element, the output polarizing element, and the retarder stack, at least partially positioned in a field of view, substantially filter harmful light rays.

17. An optical filter according to claim 16, wherein

the optical filter is configured for human vision;

and

the input polarizing element, the output polarizing element, and the retarder stack, are adapted to be positioned at least partially in a human'"'"'s field of view.

18. An optical filter according to claim 16, wherein

the optical filter is configured for animal vision;

and

the input polarizing element, the output polarizing element, and the retarder stack, are adapted to be positioned at least partially in an animal'"'"'s field of view.

19. An optical filter according to claim 16, wherein the harmful light rays are laser light rays.

20. An optical filter for vision comprising:

an input polarizing element;

an output polarizing element; and

a retarder stack between the input polarizing element and the output polarizing element;

wherein the input polarizing element, the output polarizing element, and the retarder stack, at least partially positioned in a field of view, substantially filter light such that at least two bands of light are substantially attenuated.

21. An optical filter according to claim 20, wherein

the optical filter is configured for human vision;

and

the input polarizing element, the output polarizing element, and the retarder stack, are adapted to be positioned at least partially in a human'"'"'s field of view.

22. An optical filter according to claim 20, wherein

the optical filter is configured for animal vision;

and

the input polarizing element, the output polarizing element, and the retarder stack, are adapted to be positioned at least partially in an animal'"'"'s field of view.

23. An optical filter according to claim 20, wherein a power spectrum of the input polarizing element, the output polarizing element, and the retarder stack is selected such that color saturation is increased.

24. An optical filter according to claim 20, where the power spectrum is color neutral.

25. An optical filter according to claim 20, wherein the power spectrum is selected to improve color deficient vision.

26. An optical filter according to claim 25, wherein the color deficient vision is color blindness.

27. An optical filter according to claim 23, wherein the optical filter is a lens.

28. An optical filter for enhancing vision and/or protecting eyes from harmful light rays comprising a pair of polarizing elements that sandwich a retarder stack,

wherein the optical filter has a spectral transmission providing at least one of:

color vision enhancement,

color vision deficiency compensation, or

attenuation of harmful light rays.

29. An optical filter according to claim 28, wherein

the optical filter is configured for human vision;

and

the pair of polarizing elements that sandwich the retarder stack, is at least partially positioned in a human'"'"'s field of view.

30. An optical filter according to claim 28, wherein

the optical filter is configured for animal vision;

and

the pair of polarizing elements that sandwich the retarder stack, is at least partially positioned in an animal'"'"'s field of view.

31. An optical filter according to claim 28, wherein the optical filter is a double-notch filter that blocks inter-primary light.

32. An optical filter according to claim 28, wherein the optical filter is color neutral.

33. An optical filter according to claim 28, wherein the optical filter increases color saturation.

34. An optical filter according to claim 28, wherein the optical filter is one of a lens, a pair of sunglasses, corrective eyewear, protective eyewear, or a visor.

35. A method of filtering light for color vision enhancement, color vision deficiency compensation, or attenuation of harmful light rays comprising;

polarizing input light to form polarized light;

wavelength selectively rotating the polarization of the polarized light to form rotated light; and

analyzing the rotated light.

36. A method according to claim 35, where the rotation of light is determined in accordance with one or both of:

predetermined lighting conditions of an environment; and

a person'"'"'s vision.

37. An optical filter for vision comprising:

an input polarizing element;

an output polarizing element; and

a retarder stack between the input polarizing element and the output polarizing element;

wherein the input polarizing element, the output polarizing element, and the retarder stack, at least partially positioned in a field of view, filter light to substantially reduce at least one near zero chromaticity response band of light.

38. An optical filter according to claim 37, wherein

the optical filter is configured for human vision;

and

the input polarizing element, the output polarizing element, and the retarder stack, are adapted to be positioned at least partially in a human'"'"'s field of view.

39. An optical filter according to claim 37, wherein

the optical filter is configured for animal vision;

and

the input polarizing element, the output polarizing element, and the retarder stack, are adapted to be positioned at least partially in an animal'"'"'s field of view.

40. An optical filter according to claim 37, wherein the input polarizing element, the output polarizing element, and the retarder stack, filter light to substantially reduce at least two near zero chromaticity response bands of light.

41. An optical filter according to claim 37, wherein the input polarizing element, the output polarizing element, and the retarder stack, filter light to substantially reduce at least three near zero chromaticity response bands of light.

42. An optical filter for vision comprising:

an input polarizing element;

an output polarizing element; and

a retarder stack between the input polarizing element and the output polarizing element;

wherein the retarder stack, the input polarizing element, and the output polarizing element, at least partially positioned in a field of view, have a light transmittancy at 450 nm, 540 nm and 610 nm that is greater than a light transmittancy at 500 nm or 580 nm.

43. An optical filter according to claim 42, wherein

the optical filter is configured for human vision;

and

the input polarizing element, the output polarizing element, and the retarder stack, are adapted to be positioned at least partially in a human'"'"'s field of view.

44. An optical filter according to claim 42, wherein

the optical filter is configured for animal vision;

and

the input polarizing element, the output polarizing element, and the retarder stack, are adapted to be positioned at least partially in an animal'"'"'s field of view.

45. A method for improving a person'"'"'s or animal'"'"'s vision comprising:

determining an initial spectral profile of the person'"'"'s or animal'"'"'s vision;

determining a desired spectral profile for the person'"'"'s or animal'"'"'s vision; and

providing eyewear for the person or the animal, wherein the eyewear comprises an input polarizing element, an output polarizing element, and a retarder stack, configured to substantially filter at least one band of light to compensate for the difference between the desired spectral profile and the initial spectral profile.

46. A method according to claim 45, wherein the input polarizing element, the output polarizing element, and the retarder stack, substantially filter at least one inter-primary band of light.

47. A method according to claim 45, wherein the eyewear has a light transmittancy at 450 nm, 540 nm and 610 nm that is greater than a light transmittancy at 500 nm or 580 nm.

48. A method according to claim 45, wherein the eyewear is a wavelength selective polarizing filter.

49. A method according to claim 45, further comprising:

selecting a power spectrum of the input polarizing element, the output polarizing element, and the retarder stack, such that color saturation is increased.

50. A method according to claim 49, wherein the power spectrum is color neutral.

51. A method according to claim 49, where the power spectrum is selected to improve color deficient vision of the person or the animal.

52. A method according to claim 45, wherein the input polarizing element, the output polarizing element, and the retarder stack, substantially filter light so as to protect the person'"'"'s or the animal'"'"'s vision from harmful light rays.

53. A method according to claim 45, wherein the input polarizing element, the output polarizing element, and the retarder stack, filter light to substantially reduce at least one near zero chromaticity response band of light.