Eyepieces for use in wearable display systems
An example a head-mounted display device includes a light projector and an eyepiece. The eyepiece is arranged to receive light from the light projector and direct the light to a user during use of the wearable display system. The eyepiece includes a waveguide having an edge positioned to receive light from the display light source module and couple the light into the waveguide. The waveguide includes a first surface and a second surface opposite the first surface. The waveguide includes several different regions, each having different grating structures configured to diffract light according to different sets of grating vectors.
1. A method comprising:
obtaining a waveguide comprising a first surface and a second surface opposite the first surface,
wherein in a first region of the waveguide, the second surface defines a plurality of first grating structures configured to diffract light according to a first diffraction pattern,
wherein in a second region of the waveguide different from the first region, the second surface defines a plurality of second grating structures configured to diffract light according to a second diffraction pattern different from the first diffraction pattern,
wherein in a third region of the waveguide different from the first and second regions, the second surface defines a plurality of third grating structures configured to diffract light according to a third diffraction pattern different from the first and second diffraction patterns; and
wherein the second region of the waveguide at least partially encloses the third region of the waveguide;
directing light into the first region of the waveguide;
transmitting at least some of the light from the first region to the second region of the waveguide;
transmitting at least some of the light from the second region to the third region of the waveguide; and
outputting at least some of the light from the third region of the waveguide.
2. The method of claim 1 , wherein directing light into the first region of the waveguide comprises directing the light from a light projector into the first region of the waveguide.
3. The method of claim 1 , wherein the light represents one or more images.
4. The method of claim 1 , wherein further comprising outputting at least some of the light from the third region of the waveguide towards an eye of a user.
5. The method of claim 4 , wherein the user is wearing a head-mounted display device comprising the waveguide.
6. The method of claim 1 , further comprising:
propagating at least some of the light within the second region of the waveguide.
7. The method of claim 6 , wherein propagating at least some of the light within the second region of the waveguide comprises expanding, in a first direction, a spatial distribution of at least some of the light within the second region of the waveguide.
8. The method of claim 7 , further comprising:
propagating at least some of the light within the third region of the waveguide.
9. The method of claim 8 , wherein propagating at least some of the light within the third region of the waveguide comprises expanding, in a second direction, the spatial distribution of at least some of the light within the third region of the waveguide.
10. The method of claim 9 , wherein the first direction is orthogonal to the second direction.