Patent US3877796A successfully refreshed from Google Patents.
US3877796A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rear converter lens
Assignee: YABE OPTICAL INST Manufacturing CO Ltd
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Filing: 1973-10-25
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Granted: 1975-04-15
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Expires: 1993-10-25
Abstract
Abstract Rear converter lens to be attached behind a master lens. The rear converter lens consists of six groups of lens component, wherein the first lens component is of negative refractive power; the second lens component, positive refractive power; the third lens component, negative refractive power; the fourth lens component, positive refractive power; the fifth lens component, negative refractive power; and the six lens component, positive refractive power.
Inventors
- 👤 Shinji Yabe
- 👤 Kaoru Seiyama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 19:45
CPC Classifications
G; G02; G02B; G02B13/00; G02B13/02; G02B15/00
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
336 words
A rear converter lens, of which the total focal length of lens components of the whole system is of negative refractive power, characterized in that the rear converter lens consists of six groups of lens components, wherein the first lens component from a master lens has a slightly convex surface towards the side of the master lens and is of negative refractive power; the second lens component being of positive refractive power; the third lens component having a slightly convex surface towards the side of the second lens component and being of negative refractive power; the fourth and the fifth lens components being of positive refractive power and being of negative refractive power respectively, which are confronting each other with sharp concavities at a distance of axial air space; and the sixth lens component being of positive refractive power, and that when F represents the total focal length of the whole system; F1.2.3.4, the total focal length of lenses from the first to the fourth lens components inclusive; F5.6, the total focal length of lenses of the fifth and the sixth lens components; L, the total axial length of the axial thickness added to the axial space of each lens component; F1, F2, . . . , the focal length of each lens component in order from the side of the object; R1, R2, . . . , the radius of curvature of refractive surfaces of each lens component in order from the side of the object; D1, D2, . . . , the axial thickness of each lens component in order from the side of the object; S1, S2, . . . , the axial space of each lens component in order from the side of the object; N1, N2, . . . , the refractive index of each lens component in order from the side of the object; V1, V2, . . . , the Abee number of each lens component in order from the side of the object; following conditions will be satisfied:
Claim 2
Dependent Claim
336 words
A rear converter lens, of which the total focal length of lens components of the whole system is of negative refractive power, characterized in that the rear converter lens consists of six groups of lens components, wherein the first lens component from a master lens has a slightly convex surface towards the side of the master lens and is of negative refractive power; the second lens component being of positive refractive power; the third lens component having a slightly convex surface towards the side of the second lens component and being of negative refractive power; the fourth and the fifth lens components being of positive refractive power and being of negative refractive power respectively, which are confronting each other with sharp concavities at a distance of axial air space; and the sixth lens component being of positive refractive power, and that when F represents the total focal length of the whole system; F1.2.3.4, the total focal length of lenses from the first to the fourth lens components inclusive; F5.6, the total focal length of lenses of the fifth and the sixth lens components; L, the total axial length of the axial thickness added to the axial space of each lens component; F1, F2, . . . , the focal length of each lens component in order from the side of the object; R1, R2, . . . , the radius of curvature of refractive surfaces of each lens component in order from the side of the object; D1, D2, . . . , the axial thickness of each lens component in order from the side of the object; S1, S2, . . . , the axial space of each lens component in order from the side of the object; N1, N2, . . . , the refractive index of each lens component in order from the side of the object; V1, V2, . . . , the Abee number of each lens component in order from the side of the object; following conditions will be satisfied:
Claim 3
Dependent Claim
336 words
A rear converter lens, of which the total focal length of lens components of the whole system is of negative refractive power, characterized in that the rear converter lens consists of six groups of lens components, wherein the first lens component from a master lens has a slightly convex surface towards the side of the master lens and is of negative refractive power; the second lens component being of positive refractive power; the third lens component having a slightly convex surface towards the side of the second lens component and being of negative refractive power; the fourth and the fifth lens components being of positive refractive power and being of negative refractive power respectively, which are confronting each other with sharp concavities at a distance of axial air space; and the sixth lens component being of positive refractive power, and that when F represents the total focal length of the whole system; F1.2.3.4, the total focal length of lenses from the first to the fourth lens components inclusive; F5.6, the total focal length of lenses of the fifth and the sixth lens components; L, the total axial length of the axial thickness added to the axial space of each lens component; F1, F2, . . . , the focal length of each lens component in order from the side of the object; R1, R2, . . . , the radius of curvature of refractive surface of each lens component in order from the side of the object; D1, D2, . . . , the axial thickness of each lens component in order from the side of the object; S1, S2, . . . , the axial space of each lens component in order from the side of the object; N1, N2, . . . , the refractive index of each lens component in order from the side of the object; V1, V2, . . . , the Abbe number of each lens component in order from the side of the object; following conditions will be satisfied;
Claim 4
Dependent Claim
336 words
A rear converter lens, of which the total focal length of lens components of the whole system is of negative refractive power, characterized in that the rear converter lens consists of six groups of lens components, wherein the first lens component from a master lens has a slightly convex surface towards the side of the master lens and is of negative refractive power; the second lens component being of positive refractive power; the third lens component having a slightly convex surface towards the side of the second lens component and being of negative refractive power; the fourth and the fifth lens components being of positive refractive power and being of negative refractive power respectively, which are confronting each other with sharp concavities at a distance of axial air space; and the sixth lens component being of positive refractive power, and that when F represents the total focal length of the whole system; F1.2.3.4, the total focal length of lenses from the first to the fourth lens components inclusive; F5.6, the total focal length of lenses of the fifth and the sixth lens components; L, the total axial length of the axial thickness added to the axial space of each lens component; F1, F2, . . . , the focal length of each lens component in order from the side of the object; R1, R2, . . . , the radius of curvature of refractive surface of each lens component in order from the side of the object; D1, D2, . . . , the axial thickness of each lens component in order from the side of the object; S1, S2, . . . , the axial space of each lens component in order from the side of the object; N1, N2, . . . , the refractive index of each lens component in order from the side of the object; V1, V2, . . . , the Abbe number of each lens component in order from the side of the object; following conditions will be satisfied;
References Cited (Backward Citations)
GB190718121A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-04-14 | 1978-10-14 | 1979-04-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-14 | 1982-10-14 | 1983-04-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-14 | 1986-10-14 | 1987-04-15 | $7700.00 | Window Closed / Lapsed |