US 12,442,967 B2
Optical systems having gradient index optical structures
Vikrant Bhakta, Santa Clara, CA (US); Scott M. DeLapp, San Diego, CA (US); Jonathan B. Pfeiffer, Lafayette, CO (US); Hyungryul Choi, San Jose, CA (US); and Guolin Peng, Sunnyvale, CA (US)
Filed by Apple Inc., Cupertino, CA (US)
Filed on Sep. 22, 2021, as Appl. No. 17/482,149.
Application 17/482,149 is a continuation of application No. PCT/US2021/013504, filed on Jan. 14, 2021.
Claims priority of provisional application 62/961,972, filed on Jan. 16, 2020.
Prior Publication US 2022/0011496 A1, Jan. 13, 2022
Int. Cl. G02B 3/00 (2006.01); F21V 8/00 (2006.01); G02B 6/34 (2006.01); G02B 27/01 (2006.01)
CPC G02B 6/0023 (2013.01) [G02B 3/0087 (2013.01); G02B 6/34 (2013.01); G02B 27/0172 (2013.01); G02B 2027/0178 (2013.01)] 25 Claims
OG exemplary drawing
 
13. A display system comprising:
a display module that produces image light;
a waveguide having first and second opposing surfaces;
an input coupler configured to couple the image light into the waveguide, wherein the input coupler comprises an input coupling prism or a first diffractive grating;
a second diffractive grating configured to diffract the image light out of the waveguide;
a gradient index (GRIN) lens separate from the second diffractive grating and the waveguide, wherein the second diffractive grating is interposed between the GRIN lens and the waveguide along an axis perpendicular to the first surface, wherein the GRIN lens has a gradient refractive index, wherein world light passes through the GRIN lens, and wherein the GRIN lens has a negative optical power with a first magnitude; and
an additional lens overlapping the second diffractive grating along the axis and through which the world light passes, wherein the waveguide is interposed between the GRIN lens and the additional lens and wherein the additional lens has a positive optical power with a second magnitude that is less than the first magnitude.