US 12,222,503 B2
Optical arrangement for a display
Rory Thomas Alexander Mills, Rochester (GB); and Ian Thomas Macken, Rochester (GB)
Assigned to SNAP INC., Santa Monica, CA (US)
Appl. No. 17/594,426
Filed by Snap Inc., Santa Monica, CA (US)
PCT Filed Mar. 17, 2020, PCT No. PCT/GB2020/050678
§ 371(c)(1), (2) Date Oct. 15, 2021,
PCT Pub. No. WO2020/212682, PCT Pub. Date Oct. 22, 2020.
Claims priority of application No. 19275056 (EP), filed on Apr. 18, 2019; and application No. 1905529 (GB), filed on Apr. 18, 2019.
Prior Publication US 2022/0187605 A1, Jun. 16, 2022
Int. Cl. G02B 27/01 (2006.01); G02B 17/08 (2006.01); G02B 27/09 (2006.01)
CPC G02B 27/0172 (2013.01) [G02B 17/086 (2013.01); G02B 27/0944 (2013.01); G02B 2027/013 (2013.01); G02B 2027/0178 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A folded optical arrangement for use in a display, the display to transmit an image from an image plane to a user's eye, the arrangement providing a folded optical transmission path and comprising:
a collimating element having a first optical element and a second optical element, the first optical element comprising a first plurality of optically powered surfaces, and the second optical element comprising at least one optically powered surface, the collimating element configured to receive light forming the image from an image source, and to collimate and output the light,
wherein the first optical element comprising the first optically powered surface is arranged to receive the light forming the image, and the second optically powered surface is reflective and arranged to receive light from the first optically powered surface,
wherein the first plurality of optically powered surfaces and the at least one optically powered surface are arranged to define a plurality of interfaces along the folded optical path and wherein a refractive index change at each interface is predetermined to control a direction of light passing through each interface, and
wherein one surface of the first optical element and one surface of the second optical element are adjacent to one another and the adjacent surfaces have a different shape and each define an angle with another surface of the respective optical element at an opposing end of the adjacent surfaces so as to provide opposing angles, and wherein the opposing angles are not equal.