US 12,449,583 B2
Low distortion imaging through a C-shape flat optical architecture
Valter Drazic, Betton (FR); and Oksana Shramkova, Liffré (FR)
Assigned to InterDigital CE Patent Holdings, SAS, Paris (FR)
Appl. No. 18/020,770
Filed by InterDigital CE Patent Holdings, SAS, Paris (FR)
PCT Filed Aug. 10, 2021, PCT No. PCT/EP2021/072246
§ 371(c)(1), (2) Date Feb. 10, 2023,
PCT Pub. No. WO2022/034060, PCT Pub. Date Feb. 17, 2022.
Claims priority of application No. 20305928 (EP), filed on Aug. 13, 2020.
Prior Publication US 2023/0324595 A1, Oct. 12, 2023
Int. Cl. F21V 8/00 (2006.01); G02B 27/01 (2006.01)
CPC G02B 6/0036 (2013.01) [G02B 6/0016 (2013.01); G02B 6/0076 (2013.01); G02B 27/0172 (2013.01); G02B 2027/0123 (2013.01); G02B 2027/0132 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A waveguide apparatus comprising:
an in-coupler grating configured to use diffraction order M1, the in-coupler grating having a first grating pitch Λ1 and a first grating vector G1 substantially perpendicular to a first axis, x;
a first eye pupil expander grating configured to use diffraction order M2, the first eye pupil expander having a second grating pitch Λ2 and second a grating vector G2 having a first angle ΦG with respect to the first axis;
a second eye pupil expander grating configured to use diffraction order M3, the second eye pupil expander having a third grating pitch Λ3 and a third grating vector G3 having a second angle of between 80°+ΦG and 100°+ΦG with respect to the first axis; and
an out-coupler grating configured to use diffraction order M4, the out-coupler grating having a fourth grating pitch Λ4 and a fourth grating vector G4 substantially perpendicular to the first axis;
wherein the out-coupler grating is configured to use a first diffractive order, and at least one of the in-coupler grating and the eye pupil expander gratings is configured to use a second diffractive order; and
wherein the third grating pitch Λ3 of the second eye pupil expander substantially satisfies:

OG Complex Work Unit Math