US3597048A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Varifocal objective with movable lens component of positive refractivity
Assignee: Individual
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Filing: 1969-02-07
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Granted: 1971-08-03
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Expires: 1989-02-07
Abstract
Abstract A variable focal length objective of simple physical construction affording a relative aperture of 1:1.4 or greater and an image forming power that meets high requirements. The objective comprises at least 6 lens members, the second lens member being displaceably mounted so as to change the focal length. With respect to the side of the longer conjugate, the first lens member of theobjective has a dispersing or negative power, the second and third lens members have a positive or collective power, the lens surface of the fourth lens member is convexly formed to such a degree that its radius of curvature is shorter than the radius of curvature of the preceding glass-air surfaces. The first lens member is further shaped in such a fashion that the stronger curved surface thereof exhibits a dispersing or negative power and is curved towards the second lens member. Regardless of the position of the displaceable second lens member the focal length of the first two lens members taken together is always positive.
Inventors
- 👤 Ludwig Bertele
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 08:26
CPC Classifications
G; G02; G02B; G02B15/00; G02B15/14; G02B15/146; G02B15/1461
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
187 words
An objective of variable focal length comprising six lens members, at least one of said lens members being a compound lens member, wherein, considering the lens members from the side of the longer conjugate: a. the first lens member is a dispersing meniscus which is curved toward the second lens member; b. the second lens member is a displaceable bi-convex lens member of positive power; c. the first and second lens members together have a positive power; d. the third lens member has a positive power and the convex surface facing the second lens member is more strongly curved than the lens surface facing away therefrom; e. the fourth lens member has positive power with a convex curved surface facing the third lens member; f. said convex curved surface of said fourth lens member has a radius of curvature which is shorter than that of each of the air-glass surfaces of the first three lens members; g. the fifth lens member has a negative power, with the more strongly curved surface facing the image; and, h. the sixth lens member is bi-convex and has a positive power.
Claim 2
Dependent Claim
187 words
An objective of variable focal length comprising six lens members, at least one of said lens members being a compound lens member, wherein, considering the lens members from the side of the longer conjugate: a. the first lens member is a dispersing meniscus which is curved toward the second lens member; b. the second lens member is a displaceable bi-convex lens member of positive power; c. the first and second lens members together have a positive power; d. the third lens member has a positive power and the convex surface facing the second lens member is more strongly curved than the lens surface facing away therefrom; e. the fourth lens member has positive power with a convex curved surface facing the third lens member; f. said convex curved surface of said fourth lens member has a radius of curvature which is shorter than that of each of the air-glass surfaces of the first three lens members; g. the fifth lens member has a negative power, with the more strongly curved surface facing the image; and, h. the sixth lens member is bi-convex and has a positive power.
Claim 3
Dependent Claim
19 words
An Objective according to claim 1, wherein at least one of said lens members is a cemented lens member.
Claim 4
Dependent Claim
16 words
An objective according to claim 2, wherein said fourth lens member is a cemented lens member.
Claim 5
Dependent Claim
185 words
An objective according to claim 3 wherein: the focal length F of the entire systems ranges from 15.8 mm. when said second lens member is in its rearmost position to 28.4 mm. when said second lens member is in its forward position and is 21.15 mm. when said second lens member is in its middle position; the focal length of the lens group consisting of said third, fourth, fifth and sixth lens members is 27.13 mm; the focal length of said first lens member is -100.73 mm. and the free diameter thereof is about 23 mm.; the focal length of said second lens member is -60.17 mm. and the free diameter thereof is about 24 mm.; said fourth lens member consists of two lens elements cemented together; said first through third lens members, said two lens elements and said fifth and sixth lens members, designated L1-L7, respectively, have radii of curvature r1-r13, thicknesses d1-d7 and separations l1-l5, respectively, said radii of curvature thickness and separations, as well as the refractive indices nd and Abbe numbers gamma d are substantially as given in the following table:
Claim 6
Dependent Claim
16 words
An objective according to claim 2, wherein said second lens member is a cemented lens member.
Claim 7
Dependent Claim
169 words
An objective according to claim 5, wherein: the focal length F of the entire system ranges from 15.5 mm. when said second lens member is in its rearmost position to 24.5 mm. when said second lens member is in its middle position; the focal length of the lens group consisting of said third, fourth, fifth and sixth lens members is 23 mm.; the focal length of said first lens member is -12.17 mm. and the free lens diameter is about 23 mm; the focal length of said second lens member is +68.4 mm. and the free lens diameter is about 23 mm.; said second lens member consists of two lens elements cemented together; said first lens member, said two lens elements, and said third through sixth lens members, designated L1-L7, respectively, have radii of curvature r1-r13, thicknesses d1-d7 and separations l1-l5, respectively, said radii of curvature, thicknesses and separations, as well as the refractive indices nd and Abbe numbers gamma d are substantially as given in the following table;
Claim 8
Dependent Claim
16 words
An objective according to claim 2, wherein said third lens member is a cemented lens member.
Claim 9
Dependent Claim
184 words
An objective according to claim 7, wherein: the focal length F of the entire system ranges from 15.5 mm. when said second lens member is in its rearmost position to 24.5 mm. when said second lens member is in its forward position and is 19.5 mm. when said second lens member is in its middle position; the focal length of the lens group consisting of said third, fourth, fifth and sixth lens members is 22.8 mm.; the focal length of said first lens member is -121.5 mm. and the free diameter thereof is about 23 mm.; the focal length of said second lens member is +68,2 and the free diameter thereof is about 23 mm; said third lens member consists of two lens elements cemented together; said first and second lens members, said two lens elements, and said fourth through sixth lens members, designated L1-L7, respectively, have radii of curvature r1-r13, thicknesses d1-d7 and separations l1-l5, respectively, said radii of curvature, thicknesses and separations as well as the refractive indices nd and Abbe numbers gamma d are substantially as given in the following table:
Claim 10
Dependent Claim
23 words
An objective according to claim 2, wherein each of said fourth lens member and said fifth lens member is a cemented lens member.
Claim 11
Dependent Claim
188 words
An objective according to claim 9, wherein: the focal length F, of the entire system ranges from 15.8 mm. when said second lens member is in its rearmost position to 28.4 mm. when said second lens member is in its forward position and is 21.1 mm. when said second lens member is in its middle position; the focal length of the lens group consisting of said third, fourth, fifth and sixth lens members is +27.1 mm.; the focal length of said second lens member is +100.7 mm. and the free lens diameter thereof is about 23 mm.; the focal length of said second lens member is +60.2 mm. and the free lens diameter thereof is about 24 mm.; said fourth and fifth lens members each consist of two lens elements cemented together; said first through third lens members, and said lens elements and said sixth lens members, designated L1-L8, respectively, have radii of curvature r1-r14, thicknesses d1-d8 and separations l1-l15, respectively, said radii of curvature, thicknesses and separations, as well as the refractive indices nd and Abbe numbers gamma d are substantially as given in the following table:
References Cited (Backward Citations)
US3227042A
Cited
US3466113A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-08-02 | 1975-02-01 | 1975-08-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-08-02 | 1979-02-01 | 1979-08-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-08-02 | 1983-02-01 | 1983-08-03 | $7700.00 | Window Closed / Lapsed |