Eye glint imaging in see-through computer display systems
Disclosure herein concerns a method that includes illuminating a user's eye with an illumination source in a head-worn display, capturing an image of the user's eye with an eye camera in the head-worn display, wherein the image includes an eye glint produced by light from the illumination source that is reflected from a surface of the user's eye, determining a size of an eye glint in the captured image, and identifying a change in focus distance for the user's eye in correspondence with a change in the size of the eye glint.
1. A method, comprising:
illuminating a user's eye with an illumination source of a wearable head device including a display to produce an eye glint;
capturing an image of the user's eye with a camera of the wearable head device, wherein the image includes the eye glint;
determining a sharpness of the eye glint in the captured image;
determining, based on the sharpness of the eye glint, a focus distance for the user's eye;
adjusting a display image based on the determined focus distance; and
presenting the display image on the display.
2. The method of claim 1 , wherein the illumination source comprises an LED.
3. The method of claim 1 , wherein the display comprises the illumination source.
4. The method of claim 1 , further comprising determining, based on the determined focus distance, a view target of the user.
5. The method of claim 1 , further comprising selecting, based on the determined focus distance, a display mode for the display.
6. The method of claim 5 , wherein the display mode comprises a brightness.
7. The method of claim 1 , wherein the eye glint is positioned a non-zero distance from an iris of the user's eye in the captured image.
8. The method of claim 1 , wherein capturing the image of the user's eye comprises capturing the image of the user's eye using a camera lens having an f-number greater than five.
9. The method of claim 8 , further comprising adjusting a brightness of a dedicated light source directed at the user's eye.
10. The method of claim 9 , further comprising:
modulating the brightness of the dedicated light source by adjusting a duty cycle of the dedicated light source; and
synchronizing the camera with the duty cycle.
11. The method of claim 1 , wherein the camera comprises an infrared camera.
12. A wearable head device comprising:
a display;
an illumination source configured to illuminate an eye of a user of the wearable head device, wherein illuminating the eye produces an eye glint;
a camera configured to capture an image of the eye, the captured image including the eye glint; and
one or more processors configured to:
determine a sharpness of the eye glint in the captured image;
determine, based on the sharpness of the eye glint, a focus distance of the eye;
adjust a display image based on the determined focus distance; and
present the display image on the display.
13. The wearable head device of claim 12 , wherein the illumination source comprises an LED.
14. The wearable head device of claim 12 , wherein the display comprises the illumination source.
15. The wearable head device of claim 12 , wherein the one or more processors are further configured to determine, based on the determined focus distance, a view target of the user.
16. The wearable head device of claim 12 , wherein the one or more processors are further configured to select, based on the determined focus distance, a display mode for the display.
17. The wearable head device of claim 16 , wherein the display mode comprises a brightness setting.
18. The wearable head device of claim 12 , wherein the eye glint is positioned a non-zero distance from an iris of the eye in the captured image.
19. The wearable head device of claim 12 , further comprising a camera lens having an f-number greater than five, wherein capturing the image of the eye comprises capturing the image of the eye using the camera lens.
20. The wearable head device of claim 19 , further comprising a dedicated light source directed at the eye, wherein the one or more processors are further configured to adjust a brightness of the dedicated light source.
21. The wearable head device of claim 20 , wherein the one or more processors are further configured to:
modulate the brightness of the dedicated light source by adjusting a duty cycle of the dedicated light source; and
synchronize the camera with the duty cycle.
22. The wearable head device of claim 12 , wherein the camera comprises an infrared camera.