Patent ID: 8130454
Filing Date: 2012-03-06
Classification: G02B

Abstract:
1. An endoscope objective optical system used in an endoscope, comprising: an objective optical system including a first lens group having a positive refractive power, an aperture stop, a second lens group having a negative refractive power and a third lens group having a positive refractive power, the first lens group, the aperture stop and the second and third lens group being successively disposed from the object side, wherein the second lens group is made movable along an optical axis to change the focal length of the objective optical system, the lens surface at the object-side outermost position in the first lens group is formed so as to be convex on the object side; the first lens group is the most object side lens group of the endoscope objective optical system; and wherein if the focal length of the first lens disposed at the object-side outermost position in the first lens group is f