Zoom lens and image pickup apparatus using the same

Patent metadata

Field	Value
Publication number	US-8928993-B2
Application number	US-201313755198-A
Country	US
Kind code	B2
Filing date	Jan 31, 2013
Priority date	Mar 12, 2012
Publication date	Jan 6, 2015
Grant date	Jan 6, 2015

Abstract

A zoom lens comprises in order from an object side a first lens unit having a positive refractive power. The first lens unit consist one positive lens. The zoom lens satisfies the following conditional expressions (1) and (2).

Fno (W) <2.7  (1)

3.1< f t /f w

where,
Fno (W) denotes an F-number of the zoom lens at a wide angle end, f t denotes a focal length at a telephoto end of the overall zoom lens system, and f w denotes a focal length at the wide angle end of the overall zoom lens system.

First claim

What is claimed is:

1. A zoom lens comprising in order from an object side:
a first lens unit having a positive refractive power;
a second lens unit having a negative refractive power;
a third lens unit having a positive refractive power; and
a fourth lens unit having a positive refractive power,

wherein
the zoom lens satisfies the following conditional expressions (3), (4), (5), and (6)
Σ d 1G /f t <0.13  (3)

Σ d 1G /Σd 3G <0.5  (4)

2.1 <…

Assignees

• Olympus Imaging Corp

Inventors

• Yanai Tetsuya
• Miki Mayu
• Ueda Minoru
• Nakagawa Koji
• Kon Toyoki

Classifications

• G02B15/173

  Physics · mapped topic

• G02B15/14 Primary

  Physics · mapped topic

• G02B13/009

  Physics · mapped topic

• G02B15/144113 Primary

  Physics · mapped topic