Stereoscopic-vision endoscope offering a large angle of introversion and a necessary and sufficient sense of three-dimensionality

A stereoscopic-vision endoscope, comprising:

• a tubular elongated insertional part;
• an objective optical system situated in the distal portion of said insertional part;
• a relay optical system situated in said insertional part for transmitting an object image formed by said objective optical system;
• a pupil dividing means for dividing a light beam emanating from an object image formed by said relay optical system into a plurality of portions;
• image formation optical systems for receiving light beams from said pupil dividing means so as to form a plurality of object images having parallax;
• and
• imaging means for picking up object images formed by said image formation optical system;
• said relay optical system including a system of relay lenses that satisfies the following condition (A3):
• condition (A3):
• .phi./L>0.078
• where .phi. denotes an outer diameter of said system of relay lenses and L denotes a relay length of said system of relay lenses.

A stereoscopic-vision endoscope, comprising:

• a tubular elongated insertional part;
• an objective optical system situated in the distal portion of said insertional part;
• a relay optical system situated in said insertional part for transmitting an object image formed by said objective optical system;
• an illumination light transmitting means situated in said insertional part;
• a pupil dividing means for dividing a light beam emanating from an object image formed by said relay optical system into a plurality of portions;
• image formation optical systems for receiving light beams from said pupil dividing means so as to form a plurality of object images having parallax;
• and
• imaging means for picking up object images formed by said image formation optical system;
• said relay optical system including a system of relay lenses that satisfies at least one of the following conditions (A1) to (A4):
• condition (A1):
• .phi..sup.2 /L>0.573
• condition (A2):
• .phi./.PHI.>0.71
• condition (A3):
• .phi./.PHI..gtoreq.0.72
• condition (A4):
• .phi./L>0.078
• where .phi. denotes an outer diameter of said system of relay lenses, L denotes a relay length of said system of relay lenses, and .PHI. denotes an outer diameter of said insertional part.