Optical display apparatus, method, and applications

• US 10,088,681 B2
• Filed: 05/09/2014
• Issued: 10/02/2018
• Est. Priority Date: 05/24/2013
• Status: Active Grant

• Current Assignee: University of Rochester
• Original Assignee: University of Rochester
• Inventors: Rolland, Jannick P., Bauer, Aaron
• Primary Examiner(s): Allen, Stephone B
• Assistant Examiner(s): Fissel, Travis
• Application Number:
  US14/891,208
• Publication Number:
  US 20160091723A1
• Time in Patent Office: 1,607 Days
• Field of Search: 359 13, 359 14, 359629-633, 345 9, 348115, 349 11
• CPC Class Codes: G02B 17/0816 off-axis or unobscured systems in which not all of the mirrors share a common axis of rotational symmetry, e.g. at least one of the mirrors is warped, tilted or decentered with respect to the other elements
• CPC Class Codes: G02B 2027/011 comprising device for correcting geometrical aberrations, distortion
• CPC Class Codes: G02B 2027/013 comprising a combiner of particular shape, e.g. curvature
• CPC Class Codes: G02B 2027/015 involving arrangement aiming to get less bulky devices
• CPC Class Codes: G02B 2027/0178 Eyeglass type eyeglass details G02C
• CPC Class Codes: G02B 27/0012 Optical design, e.g. procedures, algorithms, optimisation routines
• CPC Class Codes: G02B 27/0172 characterised by optical features
• CPC Class Codes: G02B 27/0176 characterised by mechanical features
• CPC Class Codes: G02B 5/23 Photochromic filters

Abstract

A see-through optical display apparatus includes an image generating component, a tilted primary mirror having a non-flat, freeform, front optical surface, and a tilted secondary mirror having a non-flat, freeform, front optical surface, wherein the apparatus has an external pupil. A method for designing/making a see-through optical display apparatus for displaying an image generated by or on an image generating component of the apparatus.

Claims

1. A see-through optical head-worn display (HWD) apparatus, comprising:

an image generating component;

a tilted primary mirror having a non-flat, freeform, front optical surface; and

a tilted secondary mirror having a non-flat, freeform, front optical surface,

wherein the apparatus has an external pupil, and wherein the non-flat, freeform, front optical surfaces of the tilted primary mirror and the tilted secondary mirror have concave curvatures.

2. The apparatus of claim 1, wherein the external pupil is an aperture stop located at the entrance pupil of an observer viewing the image.

3. The apparatus of claim 1, wherein the image generating component is an OLED microdisplay.

4. The apparatus of claim 1, wherein at least one of the mirrors'"'"' surfaces has a photochromic or an electrochromic coating.

5. The apparatus of claim 1, wherein the primary mirror and the secondary mirror form a two-mirror optical system, and

wherein the primary mirror is a semi-transparent/semi-reflective optical component, and the secondary mirror has a 100% reflective freeform front optical surface.

6. The apparatus of claim 5, wherein at least one of the mirrors'"'"' surfaces has a photochromic or an electrochromic coating.

7. The apparatus of claim 5, wherein the primary mirror has a non-flat, freeform, rear optical surface.

8. The apparatus of claim 1, further comprising a flat surface, semi-transparent/semi-reflective optical component.

9. The apparatus of claim 5, wherein the image generating component, primary mirror, and secondary mirror are fitted within a spherical volume having a radius that is equal to or less than 14 millimeters (mm).

10. The apparatus of claim 1, characterized by a field of view (FOV) between 20-30 degrees.

11. The apparatus of claim 1, further comprising an eyeglass frame to which the image generating component, the primary mirror, and the secondary mirror are coupled.

12. The apparatus of claim 1, further comprising a head-wearable structure to which the image generating component, the primary mirror, and the secondary mirror are coupled.

13. A method for designing and making a see-through optical head-worn display (HWD) apparatus of claim 1 for displaying an image generated by or on an image generating component of the apparatus, comprising:

a) determining an apparatus specification;

b) selecting a field of view and an aperture stop size for the apparatus;

c) positioning the aperture stop at an entrance pupil of an observing optical system;

d) designing a rotationally symmetric, spherical optical system;

e) determining an aberration content of the apparatus over the full field of view;

f) identifying a dominant aberration comprising one of coma and astigmatism, and

i) if coma;

determining whether the coma is more field constant or more field dependent, and

if more field constant;

adding a coma term to the optical surface nearest to the aperture stop, or

if more field dependent;

adding a spherical aberration term to the optical surface furthest from the aperture stop;

or

ii) if astigmatism;

determining whether the astigmatism is more field constant or more field dependent, and

if more field constant;

adding an astigmatism term to the optical surface nearest to the aperture stop, or

if more field dependent;

adding a coma term to the optical surface furthest from the aperture stop;

g) optimizing the optical system design;

h) determining whether the aberration content of the optimized design decreased, and

iii) if no;

determining whether the apparatus meets the determined specification, and

if yes;

design is complete, or

if no;

determining whether the limiting aberration is more field constant or more field dependent, and

if more field constant;

adding the next higher-order aberration term to the surface nearest to the aperture stop, or

if more field dependent;

adding the next higher-order aberration term to the surface furthest from the aperture stop;

i) repeating steps (g) through (h);

or

iv) if yes;

repeating steps (e) through (h).

14. A see-through optical head-worn display (HWD) apparatus, comprising:

an image generating component;

a tilted tertiary mirror having a non-flat, freeform, front optical surface;

a tilted secondary mirror having a non-flat, freeform, front optical surface;

a primary mirror comprising a flat surface, semi-transparent/semi-reflective optical component; and

an external pupil;

wherein the primary mirror, the secondary mirror, and the tertiary mirror form a three-mirror optical system;

wherein the non-flat, freeform, front optical surfaces of the tertiary mirror and the secondary mirror have concave curvatures and

wherein the secondary mirror and the tertiary mirror have 100% reflective freeform front optical surfaces.

15. The apparatus of claim 14, wherein at least one of surfaces of the primary mirror, the secondary mirror, or the tertiary mirror has a photochromic or an electrochromic coating.

16. The apparatus of claim 14, wherein the image generating component, primary mirror, secondary mirror and tertiary mirror are fitted within a spherical volume having a diameter that is equal to or less than 32.5 millimeters (mm).