See-through eyepiece for head wearable display

Patent metadata

Field	Value
Publication number	US-9459455-B2
Application number	US-201314135284-A
Country	US
Kind code	B2
Filing date	Dec 19, 2013
Priority date	Dec 19, 2013
Publication date	Oct 4, 2016
Grant date	Oct 4, 2016

Abstract

An eyepiece for a head wearable display includes a light guide component for guiding display light received at a peripheral location offset from a viewing region and emitting the display light along an eye-ward direction in the viewing region. The light guide component includes an input surface oriented to receive the display light into the light guide component, an eye-ward facing surface having a reflection portion and a viewing portion, a folding surface oriented to reflect the display light received through the input surface to the reflection portion of the eye-ward facing surface, and a first interface surface oriented to receive the display light reflected from the reflection portion of the eye-ward facing surface. A partially reflective layer is disposed on the first interface surface in the viewing region to reflect the display light along the eye-ward direction through viewing portion of the eye-ward facing surface.

First claim

What is claimed is:

1. An eyepiece for a head wearable display, the eyepiece comprising:
a light guide component for guiding display light received at a peripheral location offset from a viewing region and emitting the display light along an eye-ward direction in the viewing region, the light guide component including:
an input surface oriented to receive the display light into the light guide component at the peripheral location;
an eye-ward facing surface having a reflection portion and a viewing portion, wherein the input surface is a distinct and separate surface from the eye-ward facing surface;
a folding surface disposed adjacent to the input surface and opposing the eye-ward facing surface, the folding surface oriented to reflect the display light received through the input surface to the reflection portion of the eye-ward facing surface; and
a first interface surface disposed opposing the eye-ward facing surface in the viewing region and oriented to receive the display light reflected from the reflection portion of the eye-ward facing surface, wherein the first interface surface and the folding surface are discontinuous surfaces with different curvatures; and

a partially reflective layer disposed on the first interface surface in the viewing region, the partially reflective layer to reflect the display light along the eye-ward direction through the viewing portion of the eye-ward facing surface.

2. The eyepiece of claim 1 , wherein the partially reflective layer comprises a beam splitter or polarizing beam splitter that partially reflects the display light along the eye-ward direction.

3. The eyepiece of claim 1 , further comprising:
a see-through add-on component mounted to the light guide component along the first interface surface in the viewing region,
wherein the partially reflective layer is disposed in the viewing region at an interface between the first interface surface of the light guide component and the see-through add-on component,
wherein the see-through add-on component and the viewing region of the light guide component are at least partially transparent to external scene light travelling along the eye-ward direction.

4. The eyepiece of claim 3 , wherein the see-through add-on component is formed of a material having an index of refraction substantially equivalent to that of the light guide component.

5. The eyepiece of claim 3 , wherein the see-through add-on component comprises:
a second interface surface having a size and curvature that mates to the first interface surface of the light guide component; and
an external scene facing surface having a first curvature that is complementary to a second curvature of the eye-ward facing surface in the viewing region to substantially offset optical power of the eye-ward facing surface in the viewing region.

6. The eyepiece of claim 5 , wherein the first curvature of the external scene facing surface of the see-through add-on component forms a continuous surface with the folding surface of the light guide component.

7. The eyepiece of claim 1 , wherein the reflection portion of the eye-ward facing surface and the folding surface are clear surfaces that are oriented to reflect the display light via total internal reflection.

8. The eyepiece of claim 1 , wherein the input surface is curved to impart optical power to the display light received into the light guide component to reduce distortion.

9. The eyepiece of claim 1 , wherein the folding surface, the eye-ward facing surface, and the first interface surface are all curved surfaces shaped to impart optical power in reflection on the display light and wherein the light guide component has a rectangular cross-sectional shape.

10. The eyepiece of claim 9 , wherein the light guide component magnifies the display light emitted along the eye-ward direction relative to the display light received at the input surface.

11. The eyepiece of claim 1 , wherein the folding surface and at least the reflection portion of the eye-ward facing surface are coated with an anti-fingerprint coating.

12. The eyepiece of claim 1 , wherein the light guide component displays an image plane that is flatter than 0.1 diopters.

13. A head wearable display for displaying an image to a user, the head wearable display comprising:
a display source to generate display light;
a see-through eyepiece including:
a light guide component for guiding the display light received at a peripheral location offset from a viewing region and emitting the display light along an eye-ward direction in the viewing region, the light guide component including an input surface to receive the display light, an eye-ward facing surface having a reflection portion and a viewing portion, a folding surface oriented to reflect the display light to the reflection portion of the eye-ward facing surface, and a first interface surface disposed in the viewing region, wherein the input surface is a distinct and separate surface from the eye-ward facing surface, wherein the first interface surface and the folding surface are discontinuous surfaces with different curvatures;
a see-through add-on component mounted to the light guide component along the first interface surface in the viewing region; and
a partially reflective layer disposed at the first interface surface in the viewing region, the partially reflective layer to reflect the display light along the eye-ward direction through the viewing portion of the eye-ward facing surface; and

a frame assembly to support the see-through eyepiece and the display source for wearing on a head of the user with the viewing region positioned in front of the eye of the user.

14. The head wearable display of claim 13 , wherein the partially reflective layer comprises a beam splitter or polarizing beam splitter that partially reflects the display light along the eye-ward direction.

15. The head wearable display of claim 13 , wherein the see-through add-on component is formed of a material having an index of refraction substantially equivalent to that of the light guide component.

16. The head wearable display of claim 13 , wherein the see-through add-on component comprises:
a second interface surface having a size and curvature that mates to the first interface surface of the light guide component; and
an external scene facing surface having a first curvature that is complementary to a second curvature of the eye-ward facing surface in the viewing region to substantially offset optical power of the eye-ward facing surface in the viewing region.

17. The head wearable display of claim 13 , wherein the reflection portion of the eye-ward facing surface and the folding surface are clear surfaces that are oriented to reflect the display light via total internal reflection.

18. The head wearable display of claim 13 , wherein the folding surface, the eye-ward facing surface, and the first interface surface are all curved surfaces shaped to impart optical power in reflection on the display light.

19. The head wearable display of claim 13 , wherein the light guide component and the see-through add-on component both have a rectangular cross-sectional shape.

20. The head wearable display of claim 13 , wherein the folding surface and at least the reflection portion of the eye-ward facing surface are coated with an anti-fingerprint coating.

Assignees

• Google Inc

Inventors

• Cakmakci Ozan
• Gupta Anurag
• Martinez Oscar A

Classifications

• G02B5/30

  Polarising elements (light-modulating devices with active elements G02F1/00) · CPC title

• G02B1/18

  Coatings for keeping optical surfaces clean, e.g. hydrophobic or photo-catalytic films (G02B1/16 takes precedence) · CPC title

• G02B27/144

  using partially transparent surfaces without spectral selectivity (G02B27/147 takes precedence) · CPC title

• G02B27/283

  used for beam splitting or combining · CPC title

• G02B2027/0118

  comprising devices for improving the contrast of the display / brillance control visibility · CPC title