US4687302A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Zoom lens
Assignee: Canon Inc
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Filing: 1986-09-04
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Granted: 1987-08-18
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Expires: 2006-09-04
Abstract
Abstract A zoom lens comprising, from front to rear, a negative first component, a positive second component, a positive or negative third component and a positive fourth component. To effect zooming, the first, second and third components are made to axially move in differential relation to each other. This makes it possible to achieve a minimization of the bulk and size of the entire system and a valuable increase in the angle of view field for the wide angle setting.
Inventors
- 👤 Keiji Ikemori
- 👤 Tsunefumi Tanaka
- 👤 Masatake Kato
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 20:53
CPC Classifications
G; G02; G02B; G02B15/00; G02B15/14; G02B15/16; G02B15/177; G02B15/144; G02B15/1445; G02B15/144511; G02B15/144515
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
125 words
A zoom lens comprising: from front to rear, a negative first component, a positive second component, a negative third component and a positive fourth component, said first, said second and said third components being moved axially independent of each other when zooming, and said fourth component remaining stationary during zooming and wherein said first and said second components are closest to each other when in the telephoto positions, and said third and said fourth components are closest to each other when in the wide angle positions and also satisfying the following conditions: 1<f4/fT<8 0.5<|f1|/fT<1.2 f2<|f1|<|f3| wherein f1, f2, f3 and f4 are the focal lengths of said first, second, third and fourth components respectively, and fT is the longest focal length of the entire system.
Claim 2
Dependent Claim
125 words
A zoom lens comprising: from front to rear, a negative first component, a positive second component, a negative third component and a positive fourth component, said first, said second and said third components being moved axially independent of each other when zooming, and said fourth component remaining stationary during zooming and wherein said first and said second components are closest to each other when in the telephoto positions, and said third and said fourth components are closest to each other when in the wide angle positions and also satisfying the following conditions: 1<f4/fT<8 0.5<|f1|/fT<1.2 f2<|f1|<|f3| wherein f1, f2, f3 and f4 are the focal lengths of said first, second, third and fourth components respectively, and fT is the longest focal length of the entire system.
Claim 3
Dependent Claim
50 words
A zoom lens comprising: from front to rear, a negative first component, a positive second component, a positive third component and a positive fourth component, said first, said second and said third components being moved axially independent of each other when zooming, and said fourth component remaining stationary during zooming.
Claim 4
Dependent Claim
50 words
A zoom lens comprising: from front to rear, a negative first component, a positive second component, a positive third component and a positive fourth component, said first, said second and said third components being moved axially independent of each other when zooming, and said fourth component remaining stationary during zooming.
Claim 5
Dependent Claim
42 words
A zoom lens according to claim 2, wherein said first and said second components are closest to each other when in the telephoto positions, and said third and said fourth components are closest to each other when in the wide angle positions.
Claim 6
Dependent Claim
44 words
A zoom lens according to claim 3, satisfying the following conditions: 1<f4/fT<8 0.5<|f1|/fT<1.2 f2<|f1|<f3 wherein f1, f2, f3 and f4 are the focal lengths of said first, second, third and fourth components respectively, and fT is the longest focal length of the entire system.
Claim 7
Dependent Claim
85 words
A zoom lens comprising: from front to rear, a negative first component, a positive second component, a third component and a fourth component, and said first, second and third components being moved axially independent of each other when zooming, and said fourth component remaining stationary during zooming and satisfying the following conditions: 1<f4/fT<8 0.5<f1/fT<1.2 f2<|f1|<|f3| wherein f1, f2, f3 and f4 are the focal lengths of said first, second, third and fourth components respectively, and fT is the longest focal length of the entire system.
Claim 8
Dependent Claim
85 words
A zoom lens comprising: from front to rear, a negative first component, a positive second component, a third component and a fourth component, and said first, second and third components being moved axially independent of each other when zooming, and said fourth component remaining stationary during zooming and satisfying the following conditions: 1<f4/fT<8 0.5<f1/fT<1.2 f2<|f1|<|f3| wherein f1, f2, f3 and f4 are the focal lengths of said first, second, third and fourth components respectively, and fT is the longest focal length of the entire system.
Claim 9
Dependent Claim
81 words
A zoom lens comprising: from front to rear, a negative first component, a positive second component, a third component and a fourth component, said first, second and third components being moved axially independent of each other when zooming, and said fourth component remaining stationary during zooming and satisfying the following conditions: 0.5<f1/fT<1.2 f2<|f1|<|f3 wherein f1, f2 and f3 are the focal lengths of said first, second, and third components respectively, and fT is the longest focal length of the entire system.
Claim 10
Dependent Claim
81 words
A zoom lens comprising: from front to rear, a negative first component, a positive second component, a third component and a fourth component, said first, second and third components being moved axially independent of each other when zooming, and said fourth component remaining stationary during zooming and satisfying the following conditions: 0.5<f1/fT<1.2 f2<|f1|<|f3 wherein f1, f2 and f3 are the focal lengths of said first, second, and third components respectively, and fT is the longest focal length of the entire system.
Claim 11
Dependent Claim
19 words
A zoom lens according to claim 6, wherein said third component includes a positive lens and a negative lens.
Claim 12
Dependent Claim
15 words
A zoom lens according to claim 6, wherein said third component includes a doublet lens.
Claim 13
Dependent Claim
15 words
A zoom lens according to claim 6, wherein said fourth component is a positive lens.
Claim 14
Dependent Claim
19 words
A zoom lens according to claim 6, wherein said fourth component includes a positive lens and a negative lens.
Claim 15
Dependent Claim
24 words
A zoom lens according to claim 6, wherein said second component includes a plurality of positive lenses, a negative lens and a positive lens.
References Cited (Backward Citations)
US3975089A
Cited
US4306776A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-08-17 | 1991-02-16 | 1991-08-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-08-17 | 1995-02-16 | 1995-08-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-08-17 | 1999-02-16 | 1999-08-18 | $7700.00 | Window Closed / Lapsed |