Placement of a computer generated display with focal plane at finite distance using optical devices and a see-through head-mounted display incorporating the same
Fixed position optical devices for displaying augmented reality images are provided herein. In one embodiment an optical device includes a AIIE having a waveguide that reflects a computer generated image along a central viewing axis, the computer generated image being received from an image generator optically coupled to the waveguide, and a fixed lens assembly for coupling a background image with the computer generated image to create the augmented reality display, the fixed lens assembly including a proximal lens disposed on one side of the waveguide, the proximal lens being fixedly spaced apart from the waveguide at a first distance, and a distal lens disposed on an opposing side of the AIIE from the one side, the distal lens being fixedly spaced apart from the waveguide at a second distance.
1. An optical device providing an augmented reality display, comprising:
an augmented image insertion element (AIIE) that reflects a computer generated image (CGI) along a central viewing axis, the CGI being receivable from an image generator optically coupled to the AIIE; and
a fixed optics lens assembly for coupling a background image with the CGI to create the augmented reality display, the fixed lens assembly comprising:
a proximal static fixed lens disposed on one side of the AIIE, the proximal fixed lens being fixedly spaced apart from the AIIE at a first distance so that a first air gap is created therebetween;
a distal static fixed lens disposed on an opposing side of the AIIE from the one side, the distal fixed lens being fixedly spaced apart from the AIIE at a second distance so that a second air gap is created therebetween; and wherein the proximal fixed lens is pre-configured to shift an apparent focal plane of the CGI, and further wherein the distal fixed lens and proximal fixed lens each have a shape and position pre-configured, and wherein a combination of a focusing power of the distal fixed lens, a focusing power of the proximal fixed lens, and a total finite distance between the distal fixed lens and the proximal fixed lens provides zero overall focusing power of the optical device such that a focal plane of the background image is substantially unchanged.
2. The optical device according to claim 1 , wherein the proximal lens is pre-configured to shift an apparent focus of the CGI from infinity to a finite distance.
3. The optical device according to claim 1 , wherein the proximal lens is further pre-configured to shift a focal power of the background image to account for a prescription of a wearer.
4. The optical device according to claim 1 , wherein at least one of the proximal lens and the distal lens comprise diffractive elements.
5. The optical device according to claim 1 , further comprising a variable opacity layer disposed between the distal lens and the AIIE to control a relative intensity of the background image.
6. The optical device according to claim 5 , wherein the variable opacity layer is segmented into pixels, wherein the pixels can be selectively utilized to transmit or occlude objects within the central viewing axis.
7. The optical device according to claim 1 , wherein the distal lens comprises a photochromic or polarized coating that controls a relative intensity of the background image.
8. The optical device according to claim 1 , wherein the AIIE comprises an optical waveguide with two parallel surfaces.
9. The optical device according to claim 1 , wherein the proximal lens and the distal lens are each plano-spherical.
10. The optical device according to claim 1 , wherein the proximal lens comprises a concave surface that faces the AIIE and a concave surface that faces away from the AIIE; and wherein the distal lens comprises a convex surface that faces the AIIE and a second convex surface that faces away from the AIIE.
11. The optical device according to claim 1 , wherein the proximal lens and the distal lens are spherical lenses, each one of the spherical lenses comprising two surfaces having different radii of curvature.
12. The optical device according to claim 11 , wherein the proximal lens comprises a meniscus lens; and wherein the distal lens comprises a meniscus lens.
13. The optical device according to claim 1 , wherein the proximal lens and the distal lens are each plano-aspherical.
14. A device, comprising:
a frame that is configured to be worn on a head of an individual; and
an image generator optically coupled to at least one of two optical devices;
each of the two optical devices disposed on the frame, one of the two optical devices for each eye of the individual, wherein each of the optical devices comprises:
an augmented image insertion element (AIIE) comprising a waveguide that reflects a computer generated image (CGI) along a central viewing axis, the CGI being receivable from the image generator optically coupled to the waveguide; and
a fixed optics lens assembly for coupling a background image with the CGI to create the augmented reality display, the fixed lens assembly comprising:
a proximal static fixed lens disposed on one side of the waveguide, the proximal lens being fixedly spaced apart from the waveguide at a first distance; and
a distal static fixed lens disposed on an opposing side of the AIIE from the one side, the distal lens being fixedly spaced apart from the waveguide at a second distance;
and wherein the proximal fixed lens is pre-configured to shift an apparent focal plane of the CGI, and further wherein the distal fixed lens and proximal fixed lens each have a shape and position pre-configured, and wherein a combination of a focusing power of the distal fixed lens, a focusing power of the proximal fixed lens, and a total finite distance between the distal fixed lens and the proximal fixed lens provides zero overall focusing power of the optical device such that a focal plane of the background image is substantially unchanged.
15. The device according to claim 14 , wherein each of the two optical devices is disposed at a face form angle θ relative to a reference axis X that is orthogonal to the central viewing axis.
16. The device according to claim 15 , wherein each of the two optical modules is pivoted relative to the central viewing axis according to a pantoscopic tilt angle ϕ.
17. The device according to claim 16 , wherein the pantoscopic tilt angle ϕ is set such that the central viewing axis is aligned with a central gaze angle of the eye.
18. The device according to claim 15 , wherein the distal lens is plano-convex and the proximal lens is plano-concave.
19. The device according to claim 15 , wherein the distal lens has spherical surfaces and the proximal lens is a meniscus lens.
20. An optical device providing an augmented reality display, comprising:
an augmented image insertion element (AIIE) for reflecting a computer generated image (CGI) along a central viewing axis, the CGI being receivable from an image generator optically coupled to the AIIE; and
a fixed optics lens assembly for coupling a background image with the CGI to create the augmented reality display, the fixed lens assembly comprising:
a proximal static fixed lens disposed on one side of the AIIE, the proximal fixed lens being fixedly spaced apart from the AIIE at a first distance so that a first air gap is created therebetween;
a distal static fixed lens disposed on an opposing side of the AIIE from the one side, the distal fixed lens being fixedly spaced apart from the AIIE at a second distance so that a second air gap is created therebetween; and wherein the proximal fixed lens is pre-configured to shift an apparent focal plane of the CGI, further wherein the distal fixed lens and proximal fixed lens each have a shape and position pre-configured, and wherein a combination of a focusing power of the distal fixed lens, a focusing power of the proximal fixed lens, and a total finite distance between the distal fixed lens and the proximal fixed lens provides zero overall focusing power of the optical device such that a focal plane of the background image is substantially unchanged.
21. The optical device according to claim 20 , wherein at least one surface of each of the distal fixed lens and proximal fixed lens is a non-planar surface; and wherein the radii of curvature of each of the non-planar surfaces is pre-configured to correct optical performance at various gaze angles.
22. The optical device according to claim 21 , wherein said radii of curvature of each of the each of the non-planar surfaces is optimized to minimize spherical focusing power variation and cylinder focusing power as a function of gaze angle.
23. The optical device according to claim 21 , wherein the proximal lens and the distal lens are each plano-spherical.
24. The optical device according to claim 21 , wherein the proximal lens comprises a concave surface that faces the AIIE and a concave surface that faces away from the AIIE; and wherein the distal lens comprises a convex surface that faces the AIIE and a second convex surface that faces away from the AIIE.
25. The optical device according to claim 21 , wherein the proximal lens and the distal lens are each spherical lenses and wherein each spherical lens comprises two surfaces have different radii of curvature.
26. The optical device according to claim 21 , wherein the proximal lens comprises a meniscus lens; and wherein the distal lens comprises a meniscus lens.
27. The optical device according to claim 21 , wherein at least one of said non-planar surfaces is a freeform surface.
28. The optical device according to claim 27 , wherein said freeform surface is pre-configured according to a non-axisymmetric freeform function.