Eye imaging in head worn computing
Aspects of the present invention relate to methods and systems for imaging, recognizing, and tracking of a user's eye that is wearing a HWC. Aspects further relate to the processing of images reflected from the user's eye and controlling displayed content in accordance therewith.
1. A method comprising:
receiving, via a first side of a partially reflective and partially transmissive surface disposed in-line with transfer optics, image light produced by a display of a wearable head device;
transmitting, via a second side of the partially reflective and partially transmissive surface, the image light to an eye of a user of the wearable head device, wherein the second side of the partially reflective and partially transmissive surface is different from the first side of the partially reflective and partially transmissive surface;
receiving eye-image light from the eye via the second side of the partially reflective and partially transmissive surface, the eye-image light comprising image light reflected in the eye;
reflecting, via the partially reflective and partially transmissive surface, the eye-image light toward a camera; and
capturing, via the camera, the eye-image light.
2. The method of claim 1 , wherein the camera is disposed within a dark light trap of the wearable head device.
3. The method of claim 2 , further comprising capturing, via the dark light trap, off-pixel light.
4. The method of claim 1 , wherein the display comprises a front-lit reflective display.
5. The method of claim 1 , wherein the display comprises an emissive display.
6. The method of claim 1 , wherein:
the display is positioned to face the first side of the partially reflective and partially transmissive surface, and
the partially reflective and partially transmissive surface is positioned such that the second side of the partially reflective and partially transmissive surface faces the eye.
7. The method of claim 6 , wherein the camera is positioned to face the second side of the partially reflective and partially transmissive surface.
8. The method of claim 7 , wherein the camera is further positioned such that an optical path from the eye to the camera does not intersect the display.
9. The method of claim 6 , wherein the camera is positioned to face the first side of the partially reflective and partially transmissive surface.
10. The method of claim 1 , wherein the camera is positioned such that an optical path from the eye to the camera comprises a portion of an optical path for the image light in the transfer optics.
11. The method of claim 1 , wherein the image light presented to the eye has a first polarization and the eye-image light captured by the camera has a second polarization, different from the first polarization.
12. The method of claim 1 , further comprising a polarizer disposed between the camera and the partially reflective and partially transmissive surface.
13. The method of claim 1 , wherein the display is disposed in-line with the partially reflective and partially transmissive surface.
14. The method of claim 1 , wherein the partially reflective and partially transmissive surface is a substantially planar surface.