Patent ID: 11914121
Assignee: CANON KABUSHIKI KAISHA
Field: Optics (Instruments)
Classification: CPC G | IPC G

Claim 6:
7. An image pickup apparatus comprising:
a reduction optical system disposed on an image side of a main optical system, a composite focal length of the main optical system and the reduction optical system being shorter than a focal length of the main optical system; and
an image pickup element configured to pick up an image formed via the reduction optical system,
wherein the reduction optical system comprises:
a first lens element disposed closest to an object side and having a positive refractive power;
a second lens element disposed closest to an image side and having a positive refractive power; and
a positive lens and a negative lens disposed between the first lens element and the second lens element, and
wherein following conditional expressions are satisfied:

0.440≤fp1/f<1.500, and

0.600<fp1/fp2<2.500,

where fp1 is a focal length of the first lens element, f is a focal length of the reduction optical system, and fp2 is a focal length of the second lens element.