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Patent Searching and Data


Title:
OBJECTIVE LENSES HAVING MULTIPLE FOCAL LENGTHS AND A SMALL FOCAL-LENGTH RATIO
Document Type and Number:
WIPO Patent Application WO/2019/157289
Kind Code:
A3
Abstract:
The objective lens has multiple focal lengths within a focal length interval and a relatively small focal-length ratio in a range from 1.05 to 2.75, and a travel-to-focal-length ratio in a range from 0.5 to 0.4. The objective lens has three main lens groups that define a negative-positive- positive optical system configuration. The first lens group has a rearward lens sub-group that is axially movable for focusing so that the lens length stays the same during focusing. The objective lenses use optical compensation rather than mechanical compensation to move between the design focal lengths each having an in-focus image. This simplifies operation while increasing reliability and reducing cost. A small set of one or more of the objective lenses can be used to replace a large set of prime lenses each having a single focal length, so that fewer lenses are needed to cover the same focal length span.

Inventors:
NEIL, Iain, A. (Via Corba 8B, 6952 Canobbio, Canobbio(IT), CH)
Application Number:
US2019/017224
Publication Date:
September 19, 2019
Filing Date:
February 08, 2019
Export Citation:
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Assignee:
NEIL, Iain, A. (Via Corba 8B, 6952 Canobbio, Canobbio(IT), CH)
International Classes:
G02B15/177; G02B15/04
Foreign References:
US20110304921A12011-12-15
Attorney, Agent or Firm:
HELLER II, Morgan, S. (Downs Rachlin Martin PLLC, 199 Main StreetP.O. Box 19, Burlington VT, 05402-0190, US)
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