Patent ID: 11892708
Assignee: CANON KABUSHIKI KAISHA
Field: Audio-visual technology (Electrical engineering)
Classification: CPC G  H | IPC G  H

Claim 0:
1. A stereoscopic optical system comprising two optical systems arranged in parallel,
wherein each of the two optical systems includes, in order from an object side to an image side, a front unit having a negative refractive power, an intermediate unit having two reflective surfaces, and a rear unit,
wherein a distance between optical axes of rear units is smaller than a distance between optical axes of front units in the two optical systems due to bending of an optical path by the two reflective surfaces,
wherein at least one of the intermediate unit and the rear unit has a positive refractive power,
wherein the front unit includes, in order from the object side to the image side, a first subunit consisting of one or more negative lenses disposed on the object side of a positive lens closest to an object in the front unit, and a second subunit having a positive power, and
wherein the following inequalities are satisfied:

0.20≤f1a/f1≤0.42; and

0.61≤|f3/f2|≤0.90;, where f1, f2, f3, and f1A are focal lengths of the front unit, the intermediate unit, the rear unit, and the first subunit for d-line, respectively.