US 12,169,267 B2
Folded optical systems
Takeyoshi Saiga, Tokyo (JP)
Assigned to Apple Inc., Cupertino, CA (US)
Filed by Apple Inc., Cupertino, CA (US)
Filed on Jun. 21, 2023, as Appl. No. 18/338,658.
Application 18/338,658 is a continuation of application No. 17/329,009, filed on May 24, 2021, granted, now 11,726,304.
Claims priority of provisional application 63/030,224, filed on May 26, 2020.
Prior Publication US 2024/0036293 A1, Feb. 1, 2024
This patent is subject to a terminal disclaimer.
Int. Cl. G02B 13/10 (2006.01); G02B 13/00 (2006.01); G03B 17/17 (2021.01)
CPC G02B 13/007 (2013.01) [G02B 13/003 (2013.01); G03B 17/17 (2013.01)] 20 Claims
OG exemplary drawing
 
1. An optical system, comprising:
in order from an object side of the optical system to an image side of the optical system:
a first lens group comprising a power prism that includes a first surface, a second surface, and a third surface on an optical axis of the optical system, wherein the first surface is a transmissive aspherical surface that provides positive refractive power for the prism, wherein the second surface is a reflective surface that folds the optical axis of the optical system, and wherein the third surface is a transmissive surface; and
a second lens group comprising in order from the object side to the image side:
a first lens with positive refractive power,
a second lens with negative refractive power;
a third lens with negative refractive power; and
a fourth lens with positive refractive power; and
wherein the optical system satisfies the conditional expression:
0.6<B/A<2.3,
where A is power of the optical system, and B is power of the first lens group.