Patent FR2292153A1 successfully refreshed from Google Patents.
US3909115A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Lens with high resolving power but relatively small reduction ratio
Assignee: Canon Inc
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Filing: 1973-12-20
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Granted: 1975-09-30
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Expires: 1993-12-20
Abstract
Abstract The lens consists of the first, the second . . . and the eighth lens group seen from the object. The first lens group comprises a negative meniscus lens with a convex face facing the object and works as a positive lens as a whole. The second lens group comprises a positive meniscus lens with a convex face facing the object. The third lens group comprises a negative meniscus lens with a convex face facing the object. The fourth lens group comprises a lens with a concave face facing the object and works as a negative lens as a whole. The fifth lens group comprises a negative meniscus lens with a concave face facing the object. The sixth lens group comprises a positive meniscus lens with a concave face facing the object. The seventh lens group comprises a lens with convex faces. The eighth lens group comprises a positive meniscus lens with the convex face facing the object. Each of the principal rays from the lens system is converted to be parallel to the optical axis by means of the sixth, the seventh and the eighth lens.
Inventors
- 👤 Ichiro Kano
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 21:34
CPC Classifications
G; G02; G02B; G02B13/00; G02B13/24
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
230 words
A non-symmetric telecentric lens system consisting of eight lens groups, said eight lens groups being in order from the object side first, second, third, fourth, fifth, sixth seventh and eighth groups, said first lens group comprising a negative meniscus lens having a convex surface facing the object side, said first lens group performing as a positive lens as a whole, said second lens group comprising a positive meniscus lens having a convex surface facing the object side, said third lens group comprising a convex lens and a concave lens cemented together, said lens having the surface closest to the object side being convex and performing as a negative meniscus as a whole, said fourth lens group comprising a lens including a concave surface closest to the object side and performing as a negative lens as a whole, said fifth lens group comprising a convex lens and a and a concave lens cemented together, a surface of the convex lens facing the object side, said fifth lens group performing as a negative meniscus lens, asaid sixth lens group comprising a positive meniscus lens having a concave surface facing the object side, said seventh lens group comprising a lens having convex surfaces and said eighth group comprising a positive meniscus lens composed of a concave lens and a convex lens cemented together, said eighth group having a convex surface nearest the object.
Claim 2
Dependent Claim
230 words
A non-symmetric telecentric lens system consisting of eight lens groups, said eight lens groups being in order from the object side first, second, third, fourth, fifth, sixth seventh and eighth groups, said first lens group comprising a negative meniscus lens having a convex surface facing the object side, said first lens group performing as a positive lens as a whole, said second lens group comprising a positive meniscus lens having a convex surface facing the object side, said third lens group comprising a convex lens and a concave lens cemented together, said lens having the surface closest to the object side being convex and performing as a negative meniscus as a whole, said fourth lens group comprising a lens including a concave surface closest to the object side and performing as a negative lens as a whole, said fifth lens group comprising a convex lens and a and a concave lens cemented together, a surface of the convex lens facing the object side, said fifth lens group performing as a negative meniscus lens, asaid sixth lens group comprising a positive meniscus lens having a concave surface facing the object side, said seventh lens group comprising a lens having convex surfaces and said eighth group comprising a positive meniscus lens composed of a concave lens and a convex lens cemented together, said eighth group having a convex surface nearest the object.
Claim 3
Dependent Claim
26 words
A lens system according to claim 1 in which the first lens group consists of a negative meniscus lens and a lens with opposite convex surfaces.
Claim 4
Dependent Claim
25 words
A lens system according to claim 2 in which the negative meniscus lens and the lens with opposite convex surfaces are cemented to each other.
Claim 5
Dependent Claim
27 words
A lens system according to claim 1 in which the third lens group comprises a convex lens and a concave lens respectively arranged from the object side.
Claim 6
Dependent Claim
47 words
A lens system according to claim 1 in which the fourth lens group is composed of a concave lens having two concave surfaces with a concave surface closest to the object side, and the concave surface farthest from the object and a convex lens being cemented together.
Claim 7
Dependent Claim
26 words
A lens system according to claim 1 in which the fifth lens comprises a concave lens and a convex lens arranged respectively from the object side.
Claim 8
Dependent Claim
36 words
A lens system according to claim 1 in which the eight lens group comprises a lens having opposite convex surfaces and a lens having opposite concave surfaces, said convex lens being closer to the object side.
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) | 1978-09-29 | 1979-03-31 | 1979-09-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-29 | 1983-03-31 | 1983-09-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-29 | 1987-03-31 | 1987-09-30 | $7700.00 | Window Closed / Lapsed |