OPTICAL SYSTEM AND OPTICAL DEVICE PROVIDED THEREWITH

Title:

OPTICAL SYSTEM AND OPTICAL DEVICE PROVIDED THEREWITH

Document Type and Number:

WIPO Patent Application WO/2014/065267

Kind Code:

A1

Abstract:

Provided is an optical system whereby the amount of non-effective light (i.e. light beyond the maximum field of view) converging on the focal point of an object-side-most lens group having positive optical power is reduced, making it possible to reduce heating of a member near said focal point, prevent deformation and degradation of said member, and reduce the impact on imaging performance. Said optical system has the following: an object-side-most first lens group (G1), which has positive optical power; a diaphragm member (ST) disposed on the image side of the first lens group (G1); and a second lens group (G2) disposed on the image side of the diaphragm member (ST). This optical system satisfies the relations 0.20 < ds/f1 < 0.60 and 1.00×φ2 <φs < 0.8×φ1 (in mm), with ds representing the distance along the optical axis between the surface of the image-side-most lens of the first lens group (G1) and the diaphragm member (ST), f1 representing the focal length of the first lens group (G1), φ2 representing the outer diameter of the object-side-most lens of the second lens group (G2), and φs representing the aperture diameter of the diaphragm member (ST).

Inventors:

ISHIGAMI HIROYUKI (JP)
SHIMIZU KUNIHIKO (JP)
OBAMA AKIHIKO (JP)
HAMASAKI TAKUJI (JP)

Application Number:

PCT/JP2013/078549

Publication Date:

May 01, 2014

Filing Date:

October 22, 2013

Export Citation:

Click for automatic bibliography generation Help

Assignee:

NIKON CORP (JP)

International Classes:

G02B15/20; G02B13/18

Foreign References:

JP2009128607A	2009-06-11
JP2005250285A	2005-09-15
JPH063626A	1994-01-14
JPH03213814A	1991-09-19
JPH04362909A	1992-12-15
JPH02148011A	1990-06-06
JP2009216920A	2009-09-24
JPH06186478A	1994-07-08
JPH0954248A	1997-02-25
JP2001296465A	2001-10-26

Other References: