The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 11, 2008
Filed:
Oct. 06, 2005
Keiji Matsusaka, Osaka, JP;
Keiji Matsusaka, Osaka, JP;
Konica Monolta Opto, Inc., Hachioji-Shi, JP;
Abstract
A zoom optical system has lens groups, and performs zooming by varying distances between the respective lens groups in an optical axis direction thereof. The zoom optical system has two or more lens groups having a negative optical power and a positive optical power in this order from an object side. The first lens group (Gr) and the second lens group (Gr) each have three or less lens elements. The second lens group (Gr) includes a positive lens element having a refractive index of 1.7 or more. The positive lens element has at least one aspherical surface. With this arrangement, provided are a compact and superfine zoom optical system with a zoom ratio of about two to three times, an imaging lens device incorporated with the zoom optical system, and a digital apparatus loaded with the imaging lens device.