US3576360A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Wide angle photographic objective of large aperture ratio
Assignee: Nikon Corp
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Filing: 1968-11-19
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Granted: 1971-04-27
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Expires: 1988-11-19
Abstract
Abstract The present invention provides a compact wide angle camera lens system of large aperture ratio having long back focus comprising eight lens groups, by which the aperture ratio of F/1.4, angle of field 62* and longer back focus than the focal length of the whole system is obtained.
Inventors
- 👤 Yoshiyuki Shimizu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 21:57
CPC Classifications
G; G02; G02B; G02B13/00; G02B13/04
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
194 words
A wide angle photographic objective of large aperture ratio having long back focus consisting of, as observed from the direction in which light is projected, a first negative meniscus single lens (L1), a second negative meniscus single lens (L2), said first and second negative meniscus lenses being separated by an air space and having their convex surfaces toward an object, a third biconvex lens (L3) separated from said second lens by an air space, a fourth biconcave lens (L4) cemented to said third lens, the composite power of said third and fourth lenses being positive, a fifth biconcave lens component (L5) separated from said fourth lens by an air space, a sixth positive meniscus lens (L6) separated from said fifth lens component and having an outer surface which is concave toward the object, said fifth lens component being a doublet which includes a biconcave lens element cemented to a positive meniscus, a seventh positive single lens (L7) separated from said sixth lens by an air space, and an eighth positive single lens (L8) slightly separated from said seventh lens, the respective rear surfaces of said seventh and eighth lenses being concave toward the object.
Claim 2
Dependent Claim
194 words
A wide angle photographic objective of large aperture ratio having long back focus consisting of, as observed from the direction in which light is projected, a first negative meniscus single lens (L1), a second negative meniscus single lens (L2), said first and second negative meniscus lenses being separated by an air space and having their convex surfaces toward an object, a third biconvex lens (L3) separated from said second lens by an air space, a fourth biconcave lens (L4) cemented to said third lens, the composite power of said third and fourth lenses being positive, a fifth biconcave lens component (L5) separated from said fourth lens by an air space, a sixth positive meniscus lens (L6) separated from said fifth lens component and having an outer surface which is concave toward the object, said fifth lens component being a doublet which includes a biconcave lens element cemented to a positive meniscus, a seventh positive single lens (L7) separated from said sixth lens by an air space, and an eighth positive single lens (L8) slightly separated from said seventh lens, the respective rear surfaces of said seventh and eighth lenses being concave toward the object.
Claim 3
Dependent Claim
31 words
A wide photographic objective according to claim 1, of which the detailed data is as follows: Aperture ratio F:1.4 Angle of field 62* Focal length f 100.00 Back focus s'' 106.44
Claim 4
Dependent Claim
32 words
A wide angle photographic objective according to claim 1, of which the detailed data is as follows: Aperture ratio F:1.4 Angle of field 62* Focal Length f 100.00 Back focus s'' 106.67
Claim 5
Dependent Claim
192 words
A wide angle photographic objective of large aperture ratio having long back focus consisting of, as observed from the direction in which light is projected, a first negative meniscus single lens(L1), a second negative meniscus single lens (L2), said first and second negative meniscus lenses being separated by an air space and having their convex surfaces toward an object, a third biconvex lens (L3) separated from said second lens by an air space, a fourth biconcave lens (L4) cemented to said third lens, the composite power of said third and fourth lenses being positive, a fifth biconcave lens (L5separated from said fourth lens by an air space, a sixth positive meniscus lens cOmponent (L6) separated from said fifth lens and having an outer surface which is concave toward the object, said sixth lens component being a doublet which includes a biconcave lens element cemented to a biconvex lens element, a seventh positive single lens (L7) separated from said sixth lens by an air space, and an eighth positive single lens (L8) slightly separated from said seventh lens, the respective rear surfaces of said seventh and eighth lenses being concave toward the object.
Claim 6
Dependent Claim
192 words
A wide angle photographic objective of large aperture ratio having long back focus consisting of, as observed from the direction in which light is projected, a first negative meniscus single lens(L1), a second negative meniscus single lens (L2), said first and second negative meniscus lenses being separated by an air space and having their convex surfaces toward an object, a third biconvex lens (L3) separated from said second lens by an air space, a fourth biconcave lens (L4) cemented to said third lens, the composite power of said third and fourth lenses being positive, a fifth biconcave lens (L5separated from said fourth lens by an air space, a sixth positive meniscus lens cOmponent (L6) separated from said fifth lens and having an outer surface which is concave toward the object, said sixth lens component being a doublet which includes a biconcave lens element cemented to a biconvex lens element, a seventh positive single lens (L7) separated from said sixth lens by an air space, and an eighth positive single lens (L8) slightly separated from said seventh lens, the respective rear surfaces of said seventh and eighth lenses being concave toward the object.
Claim 7
Dependent Claim
32 words
A wide angle photographic objective according to claim 1, of which the detailed data is as follows: Aperture ratio f:1.4 Angle of field 62* Focal length f 100.00 Back focus s'' 107.77
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) | 1974-04-26 | 1974-10-26 | 1975-04-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-04-26 | 1978-10-26 | 1979-04-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-04-26 | 1982-10-26 | 1983-04-27 | $7700.00 | Window Closed / Lapsed |