GB943180A - Variable focal length lens system - Google Patents

Variable focal length lens system

Info

Publication number
GB943180A
GB943180A GB19823/62A GB1982362A GB943180A GB 943180 A GB943180 A GB 943180A GB 19823/62 A GB19823/62 A GB 19823/62A GB 1982362 A GB1982362 A GB 1982362A GB 943180 A GB943180 A GB 943180A
Authority
GB
United Kingdom
Prior art keywords
focal length
lens element
convergent
divergent
rear face
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
GB19823/62A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Pierre Angenieux SA
Original Assignee
Pierre Angenieux SA
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Pierre Angenieux SA filed Critical Pierre Angenieux SA
Publication of GB943180A publication Critical patent/GB943180A/en
Expired legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B15/00—Optical objectives with means for varying the magnification
    • G02B15/14—Optical objectives with means for varying the magnification by axial movement of one or more lenses or groups of lenses relative to the image plane for continuously varying the equivalent focal length of the objective
    • G02B15/144—Optical objectives with means for varying the magnification by axial movement of one or more lenses or groups of lenses relative to the image plane for continuously varying the equivalent focal length of the objective having four groups only
    • G02B15/1441—Optical objectives with means for varying the magnification by axial movement of one or more lenses or groups of lenses relative to the image plane for continuously varying the equivalent focal length of the objective having four groups only the first group being positive

Abstract

943,180. Variable focal length lens systems. P. ANGENIEUX. May 23,1962 [May 31, 1961], No. 19823/62. Drawings to Specification.. Heading G2J. A variable focal length lens system comprising a first frontal convergent member which is fixed for focusing on an object at any given distance, a second axially movable divergent member, and a third axially movable convergent member, all these members being aligned on the same optical axis in front of a fixed correcting member also aligned on the same optical axis, is characterized in that said second member produces a magnification lower than 0. 5 (and preferably greater than 0.15) when it has completed its forward stroke while simultaneously the third member, which has then completed its backward stroke, produces a magnification also lower than 0. 5 (and preferably greater than 0. 15), said third member consisting of at least three lens elements among which are a divergent lens element having a concave rear face and a convergent lens element located behind the rear face of said divergent lens element at a distance which at minimum is zero and at maximum is 5% of the focal length of the third member, the front face of said convergent lens element being convex and having a radius of curvature at least equal to that of the rear face of said divergent lens element, this last-named radius being greater than half the focal length of said third member (and preferably less than twice this focal length). Preferably the ratio of the focal length of said third member to that of said second member ranges from 1 to 1. 6. Numerical data for three examples of embodiment are given.
GB19823/62A 1961-05-31 1962-05-23 Variable focal length lens system Expired GB943180A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR863423A FR1315029A (en) 1961-05-31 1961-05-31 Variable focal length lens

Publications (1)

Publication Number Publication Date
GB943180A true GB943180A (en) 1963-12-04

Family

ID=8756233

Family Applications (1)

Application Number Title Priority Date Filing Date
GB19823/62A Expired GB943180A (en) 1961-05-31 1962-05-23 Variable focal length lens system

Country Status (2)

Country Link
FR (1) FR1315029A (en)
GB (1) GB943180A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3415592A (en) * 1965-03-01 1968-12-10 Eastman Kodak Co Linear motion zoom objective
US3512872A (en) * 1968-07-16 1970-05-19 Wollensak Inc Variable magnification lens system
US3549242A (en) * 1966-10-27 1970-12-22 Nippon Kogaku Kk Zooming lens of extremely high zooming ratio
US4270848A (en) * 1975-11-21 1981-06-02 Pierre Angenieux Image enlarging optical variator

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1299903B (en) * 1963-08-27 1969-07-24 Nippon Kogaku Kk Pancratic lens
CN103033912B (en) * 2011-09-30 2016-10-05 奥林巴斯株式会社 Zoom lens, use the camera head of this camera lens, image transfer apparatus and system

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3415592A (en) * 1965-03-01 1968-12-10 Eastman Kodak Co Linear motion zoom objective
US3549242A (en) * 1966-10-27 1970-12-22 Nippon Kogaku Kk Zooming lens of extremely high zooming ratio
US3512872A (en) * 1968-07-16 1970-05-19 Wollensak Inc Variable magnification lens system
US4270848A (en) * 1975-11-21 1981-06-02 Pierre Angenieux Image enlarging optical variator

Also Published As

Publication number Publication date
FR1315029A (en) 1963-01-18

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