CN103823293A - Focal length increasing lens - Google Patents
Focal length increasing lens Download PDFInfo
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- CN103823293A CN103823293A CN201310608321.5A CN201310608321A CN103823293A CN 103823293 A CN103823293 A CN 103823293A CN 201310608321 A CN201310608321 A CN 201310608321A CN 103823293 A CN103823293 A CN 103823293A
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- focal length
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- length lens
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Abstract
The invention discloses a focal length increasing lens. From an object side to an image plane side, the focal length increasing lens comprises two parts of a first lens group G1 with positive diopter and a second lens group G2 with negative diopter. The first lens group G1 comprises a number of lenses orderly from the object side to the face of the most image space side of the second positive lens. The second lens group comprises all lenses on the image space side of the first lens group. According to the invention, after the focal length increasing lens and a focal length increased lens are combined, when the focal length increasing lens is located at a telescoping end, the distance from the last face of the image space side to an image plane is FBT; when the focal length increasing lens is located at the telescoping end, the magnification of the focal length increasing lens is At; and when the focal length of the second lens group G2 is EF2, the focal length increasing lens provided by the invention meets the condition that 3.0</=(FBT*At)/(-EF2)</=6.0. The focal length increasing lens provided by the invention has the advantages of small volume, low cost, good performance and strong versatility, can be connected with the image space side of a large picture digital single lens reflex lens, and has a stepless zoom focal length increasing function.
Description
Technical field
The present invention relates to optical technical field, be specially a kind of focal length lens that increases.
Background technology
At present, known increasing focal length lens has the two schemes that is connected on camera lens object one side and be connected on camera lens image planes one side, be connected on object one side increasing focal length lens have a known TOHKEMY 2008-70433 patent, because camera lens has a variety of specification sizes, the versatility of increasing focal length lens that is connected on the front of camera lens is poor, and effective aperture and volume are all larger, be difficult to realize the small and exquisite scheme easily of low-cost and high-performance.In addition, be connected on camera lens image space one side increasing focal length lens and have No. 2011-112725, known TOHKEMY, although realized very easily the effect that increases focal length, versatility is also fine, but the rear lens focus that can see and double from embodiment after focal length lens combination is apart from very short, cannot realize the function of zoom increasing focal length, in addition, the length of whole optical system is also long, realize small size, and low cost is more difficult.
Summary of the invention
Technical matters solved by the invention is to provide a kind of focal length lens that increases, thereby solves the problem in above-mentioned background technology.
Technical matters solved by the invention realizes by the following technical solutions:
A kind of focal length lens that increases, from object side, comprise successively the first lens group G1 of positive diopter to image planes side, two part compositions of negative dioptric the second lens combination G2, foregoing first lens group G1 is by, several pieces of lens compositions by the face of image side that plays second positive lens from object side successively number.Aforesaid the second lens combination is made up of all lens of image space one side of first lens group, increasing focal length lens of the present invention and quilt increase focal length lens in the time of telescope end after increasing focal length lens combination, be FBT from the last one side of image side to the distance of image planes, the enlargement ratio that increases the increasing focal length lens of focal length lens in the time of telescope end is At, when the focal length of the second lens combination G2 is EF2, the present invention's formula that will meet the following conditions.
3.0≤(FBT×At)／(-EF2)≤6.0 (1)
As a kind of technical scheme of optimization, the described increasing focal length lens formula (2) that satisfies condition;
0.85≤FBT／(-EF)≤1.5 (2)
Wherein,
FBT: increase focal length lens and increased after focal length lens combination, increasing focal length lens in the time of telescope end, the face of image side is to the distance of image planes.
EF: the focal length that increases the whole optical system of focal length lens.
As a kind of technical scheme of optimization, the described increasing focal length lens formula (3) that satisfies condition;
0.15≤(FBT-FBW)／(-EF)≤0.8 (3)
FBT: increase focal length lens and increased after focal length lens combination, increasing focal length lens in the time of telescope end, the face of image side is to the distance of image planes.
FBW: increase focal length lens and increased after focal length lens combination, increasing focal length lens in the time of wide-angle side, the face of image side is to the distance of image planes.
EF: the focal length that increases the whole optical system of focal length lens.
Inventor is through a large amount of experiments repeatedly, find: if exceed the upper limit of conditional (1), increase focal length lens and long by the back focal length length FBT of the telescope end after the combination of multiplication focal length lens, or the enlargement ratio of telescope end is too large, or the diopter of the second lens combination is too strong, will cause so various aberrations well to make corrections, and do not reach desirable imaging effect, if exceed the lower limit of conditional (1), the back focal length length FBT of the telescope end that increases focal length and combined by multiplication focal length lens will be too short, or the enlargement ratio of telescope end is too little, or the diopter of the second lens combination too a little less than, will cause so the needed back focal length insufficient space of zoom and cannot realize zoom and increase the function of focal length.
If exceed the upper limit of conditional (2), increase focal length lens and oversize by the back focal length of the telescope end after the combination of increasing focal length lens, or the diopter that increases focal length is too strong, increase focal length function although can realize easily zoom, but will cause aberration to be difficult to be maked corrections, cannot reach desirable imaging effect, if exceed the lower limit of conditional (2), although various aberrations are easy to be maked corrections, but increase focal length lens and too short by the back focal length FBT of the telescope end after the combination of increasing focal length lens, or increase focal length lens light curvature too a little less than, to cause realizing large zoom and increase focal length function.
If exceed the upper limit of conditional (3), increase focal length lens and too large by the back focal length difference (FBT-FBW) of telescope end and wide-angle side after the combination of increasing focal length, although be easy to realize the increasing focal length function of large zoom, but because the displacement of increasing focal length lens is oversize, physical construction is difficult to realize, and unsuitable miniaturization, cost degradation.If exceed the lower limit of conditional (3), the amount of movement that increases focal length lens will be very little, although be all easy in physical construction and performance realize, be difficult to realize the increasing focal length function of large zoom.
Owing to having adopted above structure, the present invention has following beneficial effect:
The invention has the beneficial effects as follows, provide one to be connected to slr camera camera lens image space one side, volume is little, and cost is low, and performance is good, and the electrodeless zoom of highly versatile increases the camera lens of focal length function.
Accompanying drawing explanation
Fig. 1 is that the zoom of the first embodiment increases focal length lens;
Fig. 2 is the telescope end of the first embodiment and the spherical aberration of wide-angle side, curvature of field aberration, distortion aberration and ratio chromatism, schematic diagram;
Fig. 3 is that the zoom of the second embodiment increases focal length lens;
Fig. 4 is the telescope end of the second embodiment and the spherical aberration of wide-angle side, curvature of field aberration, distortion aberration and ratio chromatism, schematic diagram;
Fig. 5 is that the zoom of the 3rd embodiment increases focal length lens;
Fig. 6 is the 3rd telescope end of embodiment and the spherical aberration of wide-angle side, curvature of field aberration, distortion aberration and ratio chromatism, schematic diagram.
embodiment
For technological means, creation characteristic that the present invention is realized, reach object and effect is easy to understand, below in conjunction with specific embodiment, further set forth the present invention.
The first embodiment
As shown in Figure 1, the zoom of the first embodiment increases focal length lens and comprises successively from object side, the first lens group G1 of positive diopter, and there is negative dioptric the second lens combination G2.
The telescope end of the first embodiment and the spherical aberration of wide-angle side, curvature of field aberration, distortion aberration and ratio chromatism, are as shown in Figure 2.
The data of the first embodiment are as follows.
R (mm): the radius-of-curvature of each face
D (mm): each eyeglass price and lens thickness
The refractive index of each glass of Nd:d line
Vd: the Abbe number of glass
Focal length :-71.9036
FNO： 4.8～5.7
Partly draw angle (degree): 7.83～6.25
Enlargement ratio: 1.549～1.958
Be 100mm by increasing focal length lens focal length
The second embodiment
As shown in Figure 3, the zoom of the second embodiment increases focal length lens and comprises successively from object side, the first lens group G1 of positive diopter, and there is negative dioptric the second lens combination G2.
The telescope end of the second embodiment and the spherical aberration of wide-angle side, curvature of field aberration, distortion aberration and ratio chromatism, are as shown in Figure 4.
The data of the second embodiment are as follows.
R (mm): the radius-of-curvature of each face
D (mm): each eyeglass price and lens thickness
The refractive index of each glass of Nd:d line
Vd: the Abbe number of glass
Focal length :-63.714
FNO： 5.0～5.7
Partly draw angle (degree): 7.07～6.21
Enlargement ratio: 1.719～1.968
Be 100mm by increasing focal length lens focal length
The 3rd embodiment
As shown in Figure 5, the zoom of the 3rd embodiment increases focal length lens and comprises successively from object side, the first lens group G1 of positive diopter, and there is negative dioptric the second lens combination G2.
The 3rd telescope end of embodiment and the spherical aberration of wide-angle side, curvature of field aberration, distortion aberration and ratio chromatism, are as shown in Figure 6.
The data of the 3rd embodiment are as follows.
R (mm): the radius-of-curvature of each face
D (mm): each eyeglass price and lens thickness
The refractive index of each glass of Nd:d line
Vd: the Abbe number of glass
Focal length :-48.427
FNO： 5.6～6.9
Partly draw angle (degree): 5.98～4.9
Enlargement ratio: 2.03～2.49
Be 100mm by increasing focal length lens focal length
Conditional conclusive table
More than show and described ultimate principle of the present invention and principal character and advantage of the present invention.The technician of the industry should understand; the present invention is not restricted to the described embodiments; that in above-described embodiment and instructions, describes just illustrates principle of the present invention; without departing from the spirit and scope of the present invention; the present invention also has various changes and modifications, and these changes and improvements all fall in the claimed scope of the invention.The claimed scope of the present invention is defined by appending claims and equivalent thereof.
Claims (3)
1. one kind increases focal length lens, it is characterized in that: the first lens group G1 that comprises successively positive diopter from object side to image planes side, two part compositions of negative dioptric the second lens combination G2, foregoing first lens group G1 is by, several pieces of lens compositions by the face of image side that plays second positive lens from object side successively number.Aforesaid the second lens combination is to increase focal length lens in the time of telescope end after being become increasing focal length lens of the present invention and increased focal length lens combination by all lens combination of image space one side of first lens group, be FBT from the last one side of image side to the distance of image planes, the enlargement ratio that increases the increasing focal length lens of focal length lens in the time of telescope end is At, when the focal length of the second lens combination G2 is EF2, the present invention's formula that will meet the following conditions
3.0≤(FBT×At)／(-EF2)≤6.0 (1)。
2. a kind of focal length lens that increases according to claim 1, is characterized in that: the described increasing focal length lens formula (2) that satisfies condition,
0.85≤FBT／(-EF)≤1.5 (2)
Wherein,
FBT: increase focal length lens and increased after focal length lens combination, increasing focal length lens in the time of telescope end, the face of image side is to the distance of image planes.
EF: the focal length that increases the whole optical system of focal length lens.
3. a kind of focal length lens that increases according to claim 2, is characterized in that: the described increasing focal length lens formula (3) that satisfies condition,
0.15≤(FBT-FBW）／(-EF)≤0.8 (3)
FBT: increase focal length lens and increased after focal length lens combination, increasing focal length lens in the time of telescope end, the face of image side is to the distance of image planes.
FBW: increase focal length lens and increased after focal length lens combination, increasing focal length lens in the time of wide-angle side, the face of image side is to the distance of image planes.
EF: the focal length that increases the whole optical system of focal length lens.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310608321.5A CN103823293A (en) | 2013-11-19 | 2013-11-19 | Focal length increasing lens |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310608321.5A CN103823293A (en) | 2013-11-19 | 2013-11-19 | Focal length increasing lens |
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| CN103823293A true CN103823293A (en) | 2014-05-28 |
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| CN201310608321.5A Pending CN103823293A (en) | 2013-11-19 | 2013-11-19 | Focal length increasing lens |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106168708A (en) * | 2016-08-12 | 2016-11-30 | 安徽长庚光学科技有限公司 | A kind of shifting axle teleconverter lens |
| CN109507790A (en) * | 2017-09-15 | 2019-03-22 | 富士胶片株式会社 | Postposition teleconverter and photographic device |
-
2013
- 2013-11-19 CN CN201310608321.5A patent/CN103823293A/en active Pending
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106168708A (en) * | 2016-08-12 | 2016-11-30 | 安徽长庚光学科技有限公司 | A kind of shifting axle teleconverter lens |
| CN106168708B (en) * | 2016-08-12 | 2019-03-08 | 安徽长庚光学科技有限公司 | A kind of shifting axis teleconverter lens |
| CN109507790A (en) * | 2017-09-15 | 2019-03-22 | 富士胶片株式会社 | Postposition teleconverter and photographic device |
| CN109507790B (en) * | 2017-09-15 | 2022-04-05 | 富士胶片株式会社 | Rear-mounted range-increasing lens and camera device |
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Application publication date: 20140528 |