US3771853A
Expired / Lapsed
US
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Four component zoom lens
Assignee: Nikon Corp
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Filing: 1971-12-09
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Granted: 1973-11-13
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Expires: 1991-12-09
Abstract
Abstract A zoom lens of the type in which a first lens group is divergent and all lens groups are movable and which is suitable for use with still cameras. The zoom lens comprises a first lens group of divergence, a second lens group of convergence, a third lens group of divergence and a fourth lens group of convergence, these lens groups being arranged in the named order in the direction from an object. The second to fourth lens groups are displaceable along a common optical axis in the same direction while they are maintained in predetermined conditions. At the same time, the first lens group is displaceable in the opposite direction so as to contribute to the magnification variance and maintain a predetermined focal point.
Inventors
- 👤 S Nakamura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 22:46
CPC Classifications
G; G02; G02B; G02B15/00; G02B15/14; G02B15/16; G02B15/177
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
144 words
A zoom lens of the type in which a first lens group is divergent and all lens groups are movable, comprising a first lens group of divergence, a second lens group of convergence, a third lens group of divergence and a fourth lens group of convergence, said lens groups being disposed away from an object in the named order and having focal lengths of f1, f2, f3 and f4, respectively, said first to third lens groups having interprincipal-plane spacings S1, S2 and S3 at their respective minimum focal length sides, said fourth lens group having a spacing S4 between its principal plane and the image plane, wherein elements of the zoom lens are determined so as to satisfy the following conditions: S4 > f4 S3 + f3 <f4S4/S4 - f4 f3 > S3 > 0 f4 - f3 - S3 > OR = 0
Claim 2
Dependent Claim
144 words
A zoom lens of the type in which a first lens group is divergent and all lens groups are movable, comprising a first lens group of divergence, a second lens group of convergence, a third lens group of divergence and a fourth lens group of convergence, said lens groups being disposed away from an object in the named order and having focal lengths of f1, f2, f3 and f4, respectively, said first to third lens groups having interprincipal-plane spacings S1, S2 and S3 at their respective minimum focal length sides, said fourth lens group having a spacing S4 between its principal plane and the image plane, wherein elements of the zoom lens are determined so as to satisfy the following conditions: S4 > f4 S3 + f3 <f4S4/S4 - f4 f3 > S3 > 0 f4 - f3 - S3 > OR = 0
Claim 3
Dependent Claim
41 words
A zoom lens according to claim 1, wherein a stop is interposed between the third and fourth lens groups, the fourth lens group being a doublet comprising two concave and convex lenses cemented together, and the lens satisfies the following conditions:
Claim 4
Dependent Claim
47 words
A zoom lens according to claim 1, wherein a stop is interposed between the second and third lens groups, the fourth lens group is a doublet comprisiNg two concave and convex lenses cemented together, and an additional convex meniscus lens, and the lens satisfies the following conditions:
Claim 5
Dependent Claim
12 words
A zoom lens according to claim 1, which satisfies the following conditions:
Claim 6
Dependent Claim
142 words
A variable focal length objective lens system consisting in seriation of a first lens group of divergence, a second lens group of convergence, a third lens group of divergence and a fourth lens group of convergence, all of said groups being movable for zooming, said second, third and fourth lens groups being displacable toward an object, satisfying the following condition: psi (x) > or = x > phi (x) where psi (x), x and phi (x) represent the amounts of displacement of the second, third and fourth lens groups, respectively, and psi (x) and phi (x) are functions which increase with any variation of x; and further the first lens groups is displaceable toward an image, while satisfying the following condition: y S1 + f1 - psi (x) - P where y represents the amount of displacement of the first lens groups;
Claim 7
Dependent Claim
142 words
A variable focal length objective lens system consisting in seriation of a first lens group of divergence, a second lens group of convergence, a third lens group of divergence and a fourth lens group of convergence, all of said groups being movable for zooming, said second, third and fourth lens groups being displacable toward an object, satisfying the following condition: psi (x) > or = x > phi (x) where psi (x), x and phi (x) represent the amounts of displacement of the second, third and fourth lens groups, respectively, and psi (x) and phi (x) are functions which increase with any variation of x; and further the first lens groups is displaceable toward an image, while satisfying the following condition: y S1 + f1 - psi (x) - P where y represents the amount of displacement of the first lens groups;
Claim 8
Dependent Claim
109 words
A variable focal length objective lens system according to claim 5, wherein the first lens group includes a negative meniscus single lens element convex toward the object and a biconcave doublet of which the cemented surface is concave toward the object, the second lens group including a biconvex doublet of which the cemented surface is concave toward the object and a positive meniscus single lens element convex toward the object, the third lens group including a biconcave doublet of which the cemented surface is concave toward the object, and the fourth lens group including at least a biconvex doublet of which the cemented surface is convex toward the object.
Claim 9
Dependent Claim
28 words
A variable focal length objective lens system according to claim 6, wherein the second, third and fourth lens groups move by different displacement amount respectively to each other.
Claim 10
Dependent Claim
23 words
A variable focal length objective lens system according to claim 6, the third lens group moves in unison with the second lens group.
Claim 11
Dependent Claim
25 words
A variable focal length objective lens system according to claim 6, wherein the fourth lens group further includes a positive meniscus concave toward the object.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-11-12 | 1977-05-14 | 1977-11-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-12 | 1981-05-14 | 1981-11-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-12 | 1985-05-14 | 1985-11-13 | $7700.00 | Window Closed / Lapsed |