JPS5639510A - Behind the lens iris - Google Patents
Behind the lens irisInfo
- Publication number
- JPS5639510A JPS5639510A JP11414179A JP11414179A JPS5639510A JP S5639510 A JPS5639510 A JP S5639510A JP 11414179 A JP11414179 A JP 11414179A JP 11414179 A JP11414179 A JP 11414179A JP S5639510 A JPS5639510 A JP S5639510A
- Authority
- JP
- Japan
- Prior art keywords
- lens
- lenses
- iris
- positive
- behind
- 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.)
- Granted
Links
Landscapes
- Lenses (AREA)
Abstract
PURPOSE: To reduce size and improve the quantity of peripheral light in a bright behind photographic lens iris for wide angle by incorporating modified Tessar for lens type and giving numerical limitations to the optical specifications of the lens system.
CONSTITUTION: The lens system consists of both the positive meniscus 1st and 2nd lenses, the biconcave negative 3rd lenses of which the face of larger lens curvature is directed to the image side and the positive 4th lens of a cemented lens of a biconvex positive lens and a negative meniscus lens, from the front side. When the overall length is difined as Σd, the combined focal length from the 1st up to the 3rd lens as f1.2.3, the spacing between the 3rd and 4th lenses as d6, the radius of curvature of the 1st face of the 1st lens as R1, the refractive index of the 3rd lens as n3 and the Abbe number of the 4th lens as ν4, ν5, the numerical limitations 0.31f<Σd<0.34f, 1.7f<|f1,2,3|<3.5f, 0.025f<d6<0.05f, 0.31f<R1<0.33f, 1.69<n3<1.78, 12<ν5- ν4<22 are given and the iris is disposed behind. Thereby, the drawbacks are overcome and the photographic lens of 62° angle of view and F2.8 is consituted.
COPYRIGHT: (C)1981,JPO&Japio
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP11414179A JPS5639510A (en) | 1979-09-07 | 1979-09-07 | Behind the lens iris |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP11414179A JPS5639510A (en) | 1979-09-07 | 1979-09-07 | Behind the lens iris |
Publications (2)
Publication Number | Publication Date |
---|---|
JPS5639510A true JPS5639510A (en) | 1981-04-15 |
JPH0118402B2 JPH0118402B2 (en) | 1989-04-05 |
Family
ID=14630161
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP11414179A Granted JPS5639510A (en) | 1979-09-07 | 1979-09-07 | Behind the lens iris |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS5639510A (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5860716A (en) * | 1981-10-07 | 1983-04-11 | Nippon Kogaku Kk <Nikon> | Behind stop lens |
JPS6081777A (en) * | 1983-10-12 | 1985-05-09 | Sanyo Electric Co Ltd | Nickel-zinc battery |
US11709346B2 (en) | 2017-02-08 | 2023-07-25 | Largan Precision Co., Ltd. | Optical imaging system, imaging apparatus and electronic device |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5430027A (en) * | 1977-08-11 | 1979-03-06 | Olympus Optical Co Ltd | Photographic lens of shortened type |
JPS5461920A (en) * | 1977-10-27 | 1979-05-18 | Canon Inc | Rear aperture large aperture photographic lens |
-
1979
- 1979-09-07 JP JP11414179A patent/JPS5639510A/en active Granted
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5430027A (en) * | 1977-08-11 | 1979-03-06 | Olympus Optical Co Ltd | Photographic lens of shortened type |
JPS5461920A (en) * | 1977-10-27 | 1979-05-18 | Canon Inc | Rear aperture large aperture photographic lens |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5860716A (en) * | 1981-10-07 | 1983-04-11 | Nippon Kogaku Kk <Nikon> | Behind stop lens |
JPS6081777A (en) * | 1983-10-12 | 1985-05-09 | Sanyo Electric Co Ltd | Nickel-zinc battery |
US11709346B2 (en) | 2017-02-08 | 2023-07-25 | Largan Precision Co., Ltd. | Optical imaging system, imaging apparatus and electronic device |
US11988817B2 (en) | 2017-02-08 | 2024-05-21 | Largan Precision Co., Ltd. | Optical imaging system, imaging apparatus and electronic device |
Also Published As
Publication number | Publication date |
---|---|
JPH0118402B2 (en) | 1989-04-05 |
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