GB1109912A - Improvements in or relating to optical objectives of variable equivalent focal length - Google Patents
Improvements in or relating to optical objectives of variable equivalent focal lengthInfo
- Publication number
- GB1109912A GB1109912A GB27526/65A GB2752666A GB1109912A GB 1109912 A GB1109912 A GB 1109912A GB 27526/65 A GB27526/65 A GB 27526/65A GB 2752666 A GB2752666 A GB 2752666A GB 1109912 A GB1109912 A GB 1109912A
- Authority
- GB
- United Kingdom
- Prior art keywords
- focal length
- divergent
- numerically
- members
- component
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B15/00—Optical objectives with means for varying the magnification
- G02B15/14—Optical objectives with means for varying the magnification by axial movement of one or more lenses or groups of lenses relative to the image plane for continuously varying the equivalent focal length of the objective
- G02B15/144—Optical objectives with means for varying the magnification by axial movement of one or more lenses or groups of lenses relative to the image plane for continuously varying the equivalent focal length of the objective having four groups only
- G02B15/1441—Optical objectives with means for varying the magnification by axial movement of one or more lenses or groups of lenses relative to the image plane for continuously varying the equivalent focal length of the objective having four groups only the first group being positive
- G02B15/144109—Optical objectives with means for varying the magnification by axial movement of one or more lenses or groups of lenses relative to the image plane for continuously varying the equivalent focal length of the objective having four groups only the first group being positive arranged +--+
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Lenses (AREA)
Abstract
1,109,912. Zoom lenses. RANK ORGANISATION Ltd. June 29, 1966 [June 29, 1965], No. 27526/65. Heading G2J. A zoom lens has a first stationary positive member, second and third negative movable members and a fourth stationary positive member, the minimum separation between the second and third members occurring when the focal length of the objective lies between half and three quarters of its maximum value in the range of variation, and the focal lengths is and f c respectively of the second and third members each lie numerically between 3 and 6 times the minimum value of the ratio of the focal length of the objective to the f-number. The movable divergent second member consists of a divergent meniscus compound component with its air-exposed surfaces convex to the front having a focal length between 4f B and 8f B followed by a divergent simple component having a focal length between 0-75f B and 2f B , the total axial movement (i. e. the axial distance between the positions occupied at the two ends of the focal length range) lying numerically between 1À5f B and 2-5f B . The movable divergent third member consists of a divergent compound component having a focal length between 1À5f c and 3f c followed by a divergent simple meniscus component with its surfaces concave to the front having a focal length between 1À5f c and 3f c and performing a total axial movement which lies numerically between 0-5f c and 0À75f c . Focusing for different object distances is effected by movement of the rear portion only of the front member i. e. S 1 is variable. Optical data are provided for the example shown which has a zoom ratio of 16.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB27526/65A GB1109912A (en) | 1965-06-29 | 1966-06-29 | Improvements in or relating to optical objectives of variable equivalent focal length |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB2752665 | 1965-06-29 | ||
GB27526/65A GB1109912A (en) | 1965-06-29 | 1966-06-29 | Improvements in or relating to optical objectives of variable equivalent focal length |
Publications (1)
Publication Number | Publication Date |
---|---|
GB1109912A true GB1109912A (en) | 1968-04-18 |
Family
ID=31948068
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB27526/65A Expired GB1109912A (en) | 1965-06-29 | 1966-06-29 | Improvements in or relating to optical objectives of variable equivalent focal length |
Country Status (1)
Country | Link |
---|---|
GB (1) | GB1109912A (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2250104A (en) * | 1990-10-12 | 1992-05-27 | Asahi Optical Co Ltd | Four group zoom lens |
GB2316499A (en) * | 1996-08-12 | 1998-02-25 | Asahi Optical Co Ltd | Fast aspherical four group zoom lens system |
-
1966
- 1966-06-29 GB GB27526/65A patent/GB1109912A/en not_active Expired
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2250104A (en) * | 1990-10-12 | 1992-05-27 | Asahi Optical Co Ltd | Four group zoom lens |
US5223979A (en) * | 1990-10-12 | 1993-06-29 | Asahi Kogaku Kogyo K.K. | Zoom lens system |
GB2316499A (en) * | 1996-08-12 | 1998-02-25 | Asahi Optical Co Ltd | Fast aspherical four group zoom lens system |
US5815323A (en) * | 1996-08-12 | 1998-09-29 | Asahi Kogaku Kogyo Kabushiki Kaisha | Fast aspherical zoom lens system |
GB2316499B (en) * | 1996-08-12 | 2001-01-03 | Asahi Optical Co Ltd | Fast aspherical four group zoom lens system |
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