Eyewear with pinhole and slit cameras
A head mounted display system can include a camera, at least one waveguide, at least one coupling optical element that is configured such that light is coupled into the waveguide(s) and guided therein, and at least one out-coupling element. The at least one out-coupling element can be configured to couple light that is guided within the waveguide(s) out of the waveguide(s) and direct the light to the camera. The at least one coupling element may include a diffractive optical element having optical power. Additionally or alternatively, the at least one coupling optical element may have a coupling area, for coupling light into the waveguide(s), the coupling area having an average thickness in a range from 0.1 to 3 millimeters across and/or may have a pinhole sized and/or slit shaped coupling area.
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 the user, the head-mounted display system comprising:
a frame configured to be supported on a head of the user;
an image projector configured to project images comprising image content;
at least one camera; and
an eyepiece supported by the frame, the eyepiece configured to direct the images into the eye of the user to display the image content in the vision field of the user, at least a portion of the eyepiece being transparent to enable the user to view an environment in front of the user while viewing the displayed image content, the eyepiece comprising:
a waveguide;
at least one in-coupling optical element configured such that light incident thereon is coupled into the waveguide and guided therein, wherein the incident light includes light reflected off a surface of the eye, wherein the at least one in-coupling optical element comprises a diffractive optical element having a coupling area for coupling the incident light into the waveguide, wherein the coupling area is a pinhole size coupling area having an average thickness in a range from 0.1 to 3 millimeters across; and
at least one out-coupling optical element configured to couple at least a portion of the light guided within the waveguide out of the waveguide to be captured by the at least one camera, wherein the at least one camera generates at least one image of the eye based on the captured light.
2. The system of claim 1 , wherein the average thickness of the coupling area is in a range from 0.5 to 2 millimeters.
3. The system of claim 1 , wherein the average thickness of the coupling area is in a range from 1 to 2 millimeters.
4. The system of claim 1 , wherein the coupling area has a rectangular shape.
5. The system of claim 1 , wherein the coupling area has an arcuate shape.
6. The system of claim 1 , wherein the coupling area has a non-arcuate shape.
7. The system of claim 1 , wherein the coupling area has a slit shape.
8. The system of claim 1 , wherein the coupling area has a length and a width, wherein the length is longer than the width, and wherein the coupling area is straight along the length.
9. The system of claim 1 , wherein the coupling area has an aspect ratio in a range from 5 to 100.
10. The system of claim 1 , wherein the coupling area has an aspect ratio in a range from 10 to 100.
11. The system of claim 1 , wherein the at least one out-coupling optical element comprises a diffractive optical element.
12. The system of claim 1 , wherein a coupling area of the at least one out-coupling optical element has an aspect ratio in a range from 1 to 2.
13. The system of claim 1 , wherein the at least one out-coupling optical element has a coupling area for coupling light out of the waveguide having a thickness from 0.5 mm to 3.0 millimeters across.
14. The system of claim 1 , further comprising at least one light source arranged to illuminate at least a portion of the eye of the user with infrared light.
15. The system of claim 14 , wherein the at least one light source comprises one or more infrared light emitting diodes.
16. The system of claim 14 , wherein the at least one light source is pulsed.
17. The system of claim 14 , further comprising an off-axis reflector arranged to receive the infrared light from the at least one light source and direct the received infrared light toward the eye.