System for providing illumination of the eye
A thin transparent layer can be integrated in a head mounted display device and disposed in front of the eye of a wearer. The thin transparent layer may be configured to output light such that light is directed onto the eye to create reflections therefrom that can be used, for example, for glint based tracking. The thin transparent layer can be configured to reduced obstructions in the field of the view of the user.
1 . A head-mounted display system configured to project light to an eye of a user to display augmented reality image content in a vision field of said user, said head-mounted display system comprising:
a frame configured to be supported on a head of the user;
an image projector configured to project images into the user's eye to display image content in the vision field of the user;
a transparent layer supported on said frame and disposed at a location in front of the user's eye when the user wears said head-mounted display such that said transparent layer transmits light from an environment in front of the user to the user's eye to provide a view of the environment in front of the user;
at least one elongate light guide having a first end and a second end, said first end disposed within said transparent layer, said first end of said at least one elongate light guide having an output for emitting light such that said light is directed to said eye; and
at least one camera disposed to receive at least a portion of the light reflected from the eye to capture images using light reflected from the user's eye.
2 . The head-mounted display system of claim 1 , wherein said at least one elongate light guide comprises a plurality of elongate light guides.
3 . The head-mounted display system of claim 2 , wherein said plurality of elongate light guides each have outputs that create point sources illuminating said eye of the user.
4 . The head-mounted display system of claim 1 , wherein said transparent layer has first and second sides and said at least one elongate light guide comprises a first elongate light guide embedded in said first side of said transparent layer and a second elongate light guides embedded in said second side of said transparent layer.
5 . The head-mounted display system of claim 4 , wherein first and second sides are nasal and temporal sides of said transparent layer.
6 . The head-mounted display system of claim 4 , wherein first and second sides are superior and inferior sides of said transparent layer.
7 . The head-mounted display system of claim 1 , wherein said transparent layer has first and second sides and said at least one elongate light guide comprises a first pair of elongate light guides embedded in said first side of said transparent layer and a second pair of elongate light guides embedded in said second side of said transparent layer.
8 . The head-mounted display system of claim 7 , wherein said first and second pairs of elongate light guides each have outputs that create point sources illuminating said eye of the user.
9 . The head-mounted display system of claim 1 , wherein said output of said at least one elongate light guide creates a point source illuminating said eye of the user.
10 . The head-mounted display system of claim 1 , further comprising at least one light source, said at least one light source optically coupled to said at least one elongate light guide to inject light therein such that light is output from said first end of said at least one elongate light guide.
11 . The head-mounted display system of claim 10 , wherein said at least one light source comprises one or more infrared light sources.
12 . The head-mounted display system of claim 10 , wherein said at least one light source comprises one or more light emitting diodes (LEDs) or lasers.
13 . The head-mounted display system of claim 1 , further comprising an eyepiece disposed on the frame, said eyepiece configured to direct light into said user's eye to display augmented reality image content to the user's vision field, at least a portion of said eyepiece being transparent and disposed at a location in front of the user's eye when the user wears said head-mounted display such that said transparent portion transmits light from an environment in front of the user to the user's eye to provide a view of the environment in front of the user.
14 . The head-mounted display system of claim 13 , wherein said eyepiece is configured to receive light from said image projector and to direct said light into said user's eye to display augmented reality image content to the user's vision field.
15 . The head-mounted display system of claim 13 , wherein said eyepiece comprises at least one waveguide.
16 . The head-mounted display system of claim 15 , wherein said image projector is configured to direct light into said at least one waveguide.
17 . The head-mounted display system of claim 15 , wherein said at least one waveguide comprises a stack of waveguides.
18 . The head-mounted display system of claim 17 , wherein different waveguides of the stack of waveguides are configured to output light with different wavefront divergence as if projected from different distances from the user's eye.
19 . The head-mounted display system of claim 17 , wherein different waveguides of the stack of waveguides are configured to output light with different colors.
20 . The head-mounted display system of claim 13 , wherein said transparent layer comprises a protective layer for said eyepiece.