Nikon Corporation

Hiroyuki Ishigami

Akihiko Obama

Takuji Hamasaki

Kunihiko Shimizu

An optical system comprises a first lens group Gdisposed in a most object side and having positive refractive power, a stop member ST disposed at an image side of the first lens group G, and a second lens group Gdisposed at an image side of the stop member ST. A predetermined conditional expression is satisfied, whereby light beyond the maximum angle of view collected on the focal point position of a most object side lens group having positive refractive power is reduced, so that heat generated by a member in the vicinity of the focal point position is reduced.

Optical system and optical device provided therewith

An optical device comprises: a first holding frame holding an optical system; a second holding frame holding the first holding frame and having a groove provided on a face opposing the first holding frame; an elastic member provided between the first holding frame and the second holding frame; a position determining portion capable of determining a position of the first holding frame towards the elastic member, and provided to sandwich, with the elastic member, the first holding frame; a fixing portion is capable of fixing the first holding frame towards the position determining portion so that the first holding frame is fixed, and which is provided to sandwich, with the position determining portion, the first holding frame; and a protruding portion which has a first end fixed to the first holding frame, and another end which differs from the first end and which is inserted into the groove.

Growing community of inventors

Yokohami, Japan

Hiroyuki Ishigami