US3922072A
Expired / Lapsed
US
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Biocular magnifying lenses
Assignee: Qioptiq Ltd
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Filing: 1974-08-15
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Granted: 1975-11-25
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Expires: 1994-08-15
Abstract
Abstract A biocular magnifying lens comprises from front to back a first positive bi-convex element, a second positive bi-convex element and a positive meniscus element convex towards the front, a negative meniscus element concave towards the front being interposed between the first positive bi-convex element and the second positive bi-convex element and/or between the second positive bi-convex element and the positive meniscus element such that the lens may be used as an eyepiece in a night vision device.
Inventors
- 👤 Philip John Rogers
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 15:38
CPC Classifications
G; G02; G02B; G02B25/00; G02B25/002; G02B25/004
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
153 words
A biocular magnifying lens faster than f/1.0 having a front part, a middle part, and a back part, the front part being convergent and having a focal length between +3F and +12F, where F is the focal length of the complete lens, the middle part being convergent and having a focal length between +1.6F and +2F, there being a divergent element included in at least one of the front and middle parts, and the back part being convergent and having a focal length between +1F and +1.75F, the back part comprising a component convex towards the front, and in which lens spherical aberration introduced by convergent elements is corrected by at least one front surface of at least one divergent element included in at least one of the front and middle parts, astigmatism is controlled by the spacing between the middle and back parts, and the parts are arranged to effect coma correction.
Claim 2
Dependent Claim
153 words
A biocular magnifying lens faster than f/1.0 having a front part, a middle part, and a back part, the front part being convergent and having a focal length between +3F and +12F, where F is the focal length of the complete lens, the middle part being convergent and having a focal length between +1.6F and +2F, there being a divergent element included in at least one of the front and middle parts, and the back part being convergent and having a focal length between +1F and +1.75F, the back part comprising a component convex towards the front, and in which lens spherical aberration introduced by convergent elements is corrected by at least one front surface of at least one divergent element included in at least one of the front and middle parts, astigmatism is controlled by the spacing between the middle and back parts, and the parts are arranged to effect coma correction.
Claim 3
Dependent Claim
47 words
A lens according to claim 1 wherein the back part comprises a meniscus component convex towards the front, the ratio of the radius of curvature of the front surface of the meniscus component to the radius of curvature of its back surface being between +0.5 and zero.
Claim 4
Dependent Claim
38 words
A lens according to claim 2 wherein the back part comprises a component convex towards the front and having a back face with a radius of curvature of or approaching infinity such that the component is effectively convex-plano.
Claim 5
Dependent Claim
14 words
A lens according to claim 1 wherein the back part comprises a bi-convex component.
Claim 6
Dependent Claim
36 words
A lens according to claim 4 wherein the ratio of the radius of curvature of the front surface of the bi-convex component to the radius of curvature of its back surface is between zero and -1.5.
Claim 7
Dependent Claim
18 words
A lens according to claim 1 having a prism interposed between the middle part and the back part.
Claim 8
Dependent Claim
38 words
A lens according to claim 6 in which the prism is cemented to the back surface of the middle part, said back surface having a radius of curvature of or approaching infinity such that it is effectively planar.
Claim 9
Dependent Claim
15 words
A lens according to claim 7 wherein the prism is a 45*, 45*, 90* prism.
Claim 10
Dependent Claim
18 words
A lens according to claim 1 wherein the front part comprises a convergent element and a divergent element.
Claim 11
Dependent Claim
18 words
A lens according to claim 9 wherein said convergent element has a focal length between +1.75F and +4.75F.
Claim 12
Dependent Claim
18 words
A lens according to claim 10 wherein said divergent element has a focal length between -2.5F and infinity.
Claim 13
Dependent Claim
18 words
A lens according to claim 1 wherein the middle part comprises a convergent element and a divergent element.
Claim 14
Dependent Claim
21 words
A lens according to claim 12 wherein said convergent element and said divergent element are cemented together to form a doublet.
Claim 15
Dependent Claim
22 words
A lens according to claim 13 wherein said convergent element is of crown glass and said divergent element is of flint glass.
Claim 16
Dependent Claim
18 words
A lens according to claim 12 wherein the convergent element has a focal length between +1F and +2F.
Claim 17
Dependent Claim
18 words
A lens according to claim 15 wherein the divergent element has a focal length between -1.5F and infinity.
Claim 18
Dependent Claim
38 words
A lens according to claim 1 comprising from front to back, a first positive bi-convex element, a negative meniscus element concave towards the front, a second positive bi-convex element, and a positive meniscus element convex towards the front.
Claim 19
Dependent Claim
38 words
A lens according to claim 1 comprising from front to back, a first positive bi-convex element, a second positive bi-convex element, a negativE meniscus element concave towards the front, and a positive meniscus element convex towards the front.
Claim 20
Dependent Claim
48 words
A lens according to claim 1 comprising from front to back, a first positive bi-convex element, a first negative meniscus element concave towards the front, a second positive bi-convex element, a second negative meniscus element concave towards the front, and a positive meniscus element convex towards the front.
References Cited (Backward Citations)
US3614209A
Cited
US3658412A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-11-24 | 1979-05-26 | 1979-11-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-24 | 1983-05-26 | 1983-11-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-24 | 1987-05-26 | 1987-11-25 | $7700.00 | Window Closed / Lapsed |