US3883228A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Variable magnification zoom lens
Assignee: 3M Co
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Filing: 1973-07-09
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Granted: 1975-05-13
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Expires: 1993-07-09
Abstract
Abstract A zoom lens providing variable magnification in a short fixed object plane to image plane distance in which a lens barrel contains a prime lens and a low power, air-spaced doublet coaxial with and at one end of the prime lens, the doublet combining with the prime lens to provide a plurality of magnifications at the image plane of objects at the object plane upon synchronized movement of the lens barrel and one element of the doublet with respect to the lens barrel and the other elements to a plurality of predetermined correlated positions.
Inventors
- 👤 Ellis I Betensky
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 05:41
CPC Classifications
G; G02; G02B; G02B13/00; G02B13/24; G02B15/00; G02B15/14; G02B15/142; G02B15/16; G03; G03B; G03B27/00; G03B27/32; G03B27/52; G03B27/522
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
115 words
An asymmetrical zoom lens providing variable magnification in a short, fixed object plane to image plane distance, comprising: a lens barrel, a prime lens within said lens barrel, and a lower power, air spaced doublet within said lens barrel coaxial with and at one end of said prime lens, one of the elements of said doublet being supported for axial movement with respect to said lens barrel and the other elements, said doublet combining with said prime lens to provide a plurality of magnifications at the image plane of objects at the object plane upon synchronized movement of said lens barrel and said movable element of said doublet to a plurality of predetermined correlated positions.
Claim 2
Dependent Claim
115 words
An asymmetrical zoom lens providing variable magnification in a short, fixed object plane to image plane distance, comprising: a lens barrel, a prime lens within said lens barrel, and a lower power, air spaced doublet within said lens barrel coaxial with and at one end of said prime lens, one of the elements of said doublet being supported for axial movement with respect to said lens barrel and the other elements, said doublet combining with said prime lens to provide a plurality of magnifications at the image plane of objects at the object plane upon synchronized movement of said lens barrel and said movable element of said doublet to a plurality of predetermined correlated positions.
Claim 3
Dependent Claim
54 words
The zoom lens of claim 1 including means for moving said lens barrel to said plurality of predetermined positions, and means for moving said one element of said doublet axially with respect to said lens barrel and the other elements to said plurality of predetermined positions in correlation with movement of said lens barrel.
Claim 4
Dependent Claim
27 words
The zoom lens of claim 1 wherein said doublet is behind said prime lens with respect to light progressing from the object plane to the image plane.
Claim 5
Dependent Claim
25 words
The zoom lens of claim 3 wherein said doublet comprises a positive meniscus lens element adjacent said prime lens and a negative meniscus lens element.
Claim 6
Dependent Claim
53 words
The zoom lens of claim 4 wherein said prime lens is a six element lens comprising from front to rear a double positive lens element, a double negative lens element, a positive meniscus lens element, a second positive meniscus lens element, a negative meniscus lens element and a third positive meniscus lens element.
Claim 7
Dependent Claim
23 words
The zoom lens of claim 1 wherein the element of said doublet closest to said prime lens is supported for said axial movement.
Claim 8
Dependent Claim
119 words
The zoom lens of claim 1 wherein said doublet is behind said prime lens with respect to light progressing from the object plane to the image plane, the element of said doublet closest to said prime lens is supported for said axial movement, and wherein the lens elements have substantially the following characteristics and spatial relations in which the lens elements are numbered from the front, N is the index of refraction for the D line, V is the Abbe number, and R, T and S refer, respectively, to the radii of curvature of the lens surfaces, the axial thickness of the lens elements, and the axial spacing between the lens elements, numbered by subscript from front to rear:
Claim 9
Dependent Claim
120 words
The zoom lens of claim 1 wherein said doublet is behind said prime lens with respect to light progressing from the object plane to the image plane, the element of said doublet farthest removed from said prime lens is supported for said axial movement and wherein the lens elements have substantially the following characteristics and spatial relations in which the lens elements are numbered from the front, N is the index of refraction for the D line, V is the Abbe number, and R, T and S refer, respectively, to the radii of curvature of the lens surfaces, the axial thickness of the lens elements, and the axial spacing between the lens elements, numbered by subscript from front to rear:
References Cited (Backward Citations)
US3436145A
Cited
US3728010A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-05-12 | 1978-11-11 | 1979-05-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-12 | 1982-11-11 | 1983-05-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-12 | 1986-11-11 | 1987-05-13 | $7700.00 | Window Closed / Lapsed |