OPTICAL SYSTEM - OLYMPUS CORP

Title:

OPTICAL SYSTEM

Document Type and Number:

WIPO Patent Application WO/2010/084915

Kind Code:

A1

Abstract:

An optical system for viewing a front object and a generally side object comprises, sequentially from the front object side, a first lens group having a negative refractive index, a second lens group including a reflective-refractive lens, an aperture stop, and a third lens group having a positive refractive index. The reflective-refractive lens is provided with a first surface formed on the front object side, a second surface formed on an image side, and a third surface formed circumferentially to surround an optical axis between the first surface and the second surface. The first surface is provided with a first transmission surface formed around the optical axis, and a first reflection surface that faces the image side and is formed around the first transmission surface. The first surface is defined by an aspherical surface consisting of a concave surface in the vicinity of the optical axis and a convex surface in the vicinity of the first reflection surface. The second surface is provided with a second transmission surface formed around the optical axis and a second reflection surface that faces the front object side and that is formed around the second transmission surface. The third surface is defined by a transmission surface.

Inventors:

MIZUSAWA MASAYUKI (JP)

Application Number:

PCT/JP2010/050714

Publication Date:

July 29, 2010

Filing Date:

January 21, 2010

Export Citation:

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Assignee:

OLYMPUS CORP (JP)
MIZUSAWA MASAYUKI (JP)

International Classes:

G02B17/08

Domestic Patent References:

WO2008153114A1	2008-12-18
WO2003042743A1	2003-05-22

Other References: