Apparatus for a near-eye display
An apparatus for providing gaze tracking in a near-eye display. Certain examples provide an apparatus including a light modulator configured to receive light of a first range of wavelengths and generate an image beam therefrom. The light modulator is further configured to receive light of a second range of wavelengths and generate a probe beam therefrom. The apparatus also includes one or more light guides including one or more in-coupling element areas, and one or more out-coupling element areas. The one or more in-coupling diffractive element areas are configured to receive and in-couple the image beam and the probe beam into the one or more light guides. The one or more out-coupling element areas are configured to out-couple, from the one or more light guides: the image beam to a user's eye for user viewing, and the probe beam to the user's eye for detection of reflection therefrom.
1. A method comprising:
generating, with a light source, light having first and second ranges of wavelengths;
receiving, with a light modulator, the light of a first range of wavelengths;
generating, with the light modulator, an image beam from the light of a first range of wavelengths;
receiving, with the light modulator, the light of a second range of wavelengths;
generating, with the light modulator, simultaneously with generation of the image beam by the light modulator, a probe beam from the light of a second range of wavelengths;
receiving and in-coupling, by the one or more in-coupling element areas of a first light guide of first and second light guides, the image beam and the probe beam into the first light guide;
receiving and in-coupling, by the one or more in-coupling element areas of a second light guide, the image beam into the second light guide;
out-coupling, with the one or more out-coupling element areas of the first light guide, from the first light guide the image beam to an eye of a user for user viewing;
expanding, with the one or more out-coupling element areas of the first light guide, the probe beam;
out-coupling, with the one or more out-coupling element areas of the first light guide, the probe beam to the eye for detection of reflection therefrom; and
out-coupling, with the one or more out-coupling element areas of the second light guide, from the second light guide the image beam to the eye for user viewing.
2. A method as claimed in claim 1 , further comprising:
controlling, with the light modulator, a pattern, shape and/or size of the probe beam; and/or
dynamically vary a pattern of the probe beam.
3. A method as claimed in claim 1 , further comprising detecting, with a detector, reflections of the probe beam.
4. A method as claimed of claim 3 , further comprising modifying, with a controller, the probe beam dependent upon the detection of the reflected probe beam.
5. A method as claimed in claim 3 , further comprising reflecting, with a reflector, the reflected probe beam to the detector.
6. A method as claimed in claim 3 , further comprising determining, with a controller, a user's gaze based on the detected reflected probe beam.
7. A method as claimed in claim 1 , wherein the light of the first range of wavelengths comprises visible light and the light of the second range of wavelengths comprises Infrared light.
8. A method as claimed in claim 1 , wherein the light source is simultaneously generates the light of the first range of wavelengths, and the light of the second range of wavelengths.
9. A method as claimed in claim 1 , further comprising selectively filtering, with a selectively controllable filter, one of: the light of the first range of wavelengths and the light of the second range of wavelengths.
10. A method as claimed in claim 1 , further comprising generating, with a light source, sequentially the light of the first range of wavelengths and the light of the second range of wavelengths.
11. A method as claimed in claim 1 , wherein the one or more in-coupling element areas and one or more out-coupling element areas are comprised in a single light guide.
12. A method as claimed in claim 1 , wherein the one or more light guides is configured as an exit pupil expander.
13. A method as claimed in claim 1 , wherein the apparatus is configured for use as a near eye display and a gaze tracker.
14. A module operable with the method of claim 1 .
15. A device operable with the method of claim 1 , wherein the device is configured for at least one at least one of:
portable use, wearable use, head mountable use, wireless communications.
16. A method as claimed in claim 1 where the one or more in-coupling element areas comprise at least one in-coupling diffractive element area.
17. A method as claimed in claim 1 where the one or more out-coupling element areas comprise at least one out-coupling diffractive element area.
18. A method as claimed in claim 1 wherein the first and second light guides are first and second overlapping light guides.