US 12,216,283 B2
Optical structure for augmented reality display
Mohmed Salim Valera, Sutton Coldfield (GB)
Assigned to Snap Inc., Santa Monica, CA (US)
Filed by Snap Inc., Santa Monica, CA (US)
Filed on Jun. 29, 2023, as Appl. No. 18/344,696.
Application 18/344,696 is a continuation of application No. 17/053,725, granted, now 11,782,275, previously published as PCT/GB2019/050958, filed on Apr. 3, 2019.
Claims priority of application No. 1808055 (GB), filed on May 17, 2018.
Prior Publication US 2023/0341696 A1, Oct. 26, 2023
This patent is subject to a terminal disclaimer.
Int. Cl. G02B 27/01 (2006.01); F21V 8/00 (2006.01); G02B 5/18 (2006.01); G02B 27/42 (2006.01)
CPC G02B 27/0172 (2013.01) [G02B 5/18 (2013.01); G02B 6/0023 (2013.01); G02B 6/005 (2013.01); G02B 6/0076 (2013.01); G02B 27/4205 (2013.01); G02B 2005/1804 (2013.01); G02B 2027/0112 (2013.01)] 20 Claims
OG exemplary drawing
 
1. An optical structure for use in an augmented reality display, the optical structure comprising a first waveguide and a second waveguide, wherein:
the first waveguide comprises:
a first input diffractive optical element configured to receive light and diffract the received light so that diffracted wavelengths of the light in a first one or more colours are coupled into the first waveguide, to be totally internally reflected within the first waveguide, and so that diffracted wavelengths of the light in a second one or more colours are coupled out of the first waveguide in a direction towards the second waveguide; and
a first output diffractive optical element configured to receive and diffract totally internally reflected light within the first waveguide in order to couple the totally internally reflected light out of the first waveguide towards a viewer;
the second waveguide comprises:
a second input diffractive optical element configured to receive diffracted light that is coupled out of the first waveguide by the first input diffractive optical element, and to diffract the received light so that diffracted wavelengths of the light in the second one or more colours are coupled into the second waveguide, to be totally internally reflected within the second waveguide; and
a second output diffractive optical element configured to receive and diffract totally internally reflected light within the second waveguide in order to couple the totally internally reflected light out of the second waveguide towards the viewer; and
the diffractive optical elements have a period which is a separation of diffractive optical features, and wherein an inverse of the period of the second output diffractive optical element is equal to the inverse of the period of the first input diffractive optical element plus the inverse of the period of the second input diffractive optical element.