Patent ID: 11931004
Assignee: OLYMPUS CORPORATION
Field: Optics (Instruments)
Classification: CPC A  G | IPC A  G

Claim 0:
1. An objective optical system comprising:
a first spherical lens and a second spherical lens that are arrayed in this order from an object; and
at least one of a first optical medium and a second optical medium,
wherein the first optical medium is a solid or liquid disposed at an object side of the first spherical lens and is in close contact with a surface on the object side of the first spherical lens, over an entire optical path; and
the second optical medium is a solid or liquid disposed at an opposite side of the second spherical lens from the object and is in close contact with a surface on the opposite side of the second spherical lens from the object, over the entire optical path; and
wherein a back focal point is located at the opposite side, from the object, of a surface on the object side of the second spherical lens; and
an image transmission system that is disposed at the opposite side of the second spherical lens from the object,
wherein the back focal point is located inside the second spherical lens.