CN1204062A - Afocal zoom lens system - Google Patents
Afocal zoom lens system Download PDFInfo
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- CN1204062A CN1204062A CN 98114962 CN98114962A CN1204062A CN 1204062 A CN1204062 A CN 1204062A CN 98114962 CN98114962 CN 98114962 CN 98114962 A CN98114962 A CN 98114962A CN 1204062 A CN1204062 A CN 1204062A
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Abstract
An afocal zoom lens system comprises an object, an objective lens group of a positive refractive power, an erecting optical group, and an eyepiece lens group of a positive refractive power. The objective lens group includes a first lens unit o f positive refractive power, a second lens unit of a negative refractive power and a third lens unit of a positive refractive power. The first lens unit and the second lens unit are mo vable when zooming.
Description
The present invention relates to the afocal lens system, particularly relate to Afocal zoom lens system.
The afocal lens system is generally used in the finder system of binocular telescope, telescope and camera.Tradition afocal lens system is divided into real image type and virtual image type.The Galileo type is the example of typical virtual image type lens system.The real image type is divided into several different groups again according to employed erecting system.
There is a problem in Galileo type lens combination in increasing field angle.Zone around the visual field should be dark, so that watch the thing in the visual field, but this zone is bright in Galileo type system, therefore, the function of Galileo type system is poor, because it can not clearly observe thing.
Traditional real image type afocal lens system comprises the object lens of positive light coke, the eyepiece and the positive image optical system of positive light coke, and the inverted image that is used for object lens are become is just come.Yet,, be used for the enlarging objective imaging, so the eyepiece field of view angle that is produced is very big usually because real image type afocal lens system comprises eyepiece.Thereby the number of its restriction lens makes balance aberration difficulty, the especially variation of aberration in the zoom process.And positive image optical system uses prism to make systems bulky and use bother.Especially, traditional real image type burnt zoom system, pancreatic system far away can zoom, comprises that at least two mobile lens groups are used for zoom.Therefore, except that the structure of lens combination, it is complicated more that lens barrel also becomes.
Traditional real image type Afocal zoom lens system is disclosed in the following files:
(1) the flat 5-5840 of Japanese Laid-Open Patent Application
(2) U.S. Patent No. 5,311, and 355
(3) U.S. Patent No. 5,491, and 588
In file (1)-(3), objective lens comprises three lens combination that have positive focal power respectively in the above, and a part and the eyepiece group of objective lens can move when changing enlargement ratio.Therefore, in the zoom process, except that the focus of eyepiece group moved, the focus of objective lens also moved.Therefore, also move so that obtain field image clearly in an aperture.To make the design complexity of zoom lens barrel like this, and increase the size of system.
In addition, the Afocal zoom lens system in above-mentioned file (1)-(3) has high enlargement ratio, so the focal length of eyepiece group is short.Therefore, the interpupillary distance of system is shorter than 13mm, and the people with glasses can not use this system.System also has a shortcoming, and for example the aperture of eyepiece is little.
The purpose of this invention is to provide a kind of Afocal zoom lens system, this system bulk is little, belongs to the real image type, eliminates the one or more limitations and the deficiency of described existing structure basically.
Another object of the present invention provides a kind of Afocal zoom lens system, and the interpupillary distance of this system is long, is approximately 19mm, so that the user who is suitable for wearing glasses.Another purpose of the present invention provides a kind of Afocal zoom lens system with big emergent pupil, and emergent pupil is approximately 6.3mm.
Other features and advantages of the present invention will propose in the following description, and local clearer by following description meeting, perhaps can learn by practice of the present invention.Purpose of the present invention and other advantages can realize and reach by the special device that proposes in instructions and claims and the accompanying drawing.
In order to reach described these advantages, and according to purpose of the present invention, as embodiment and general description, the present invention includes the Afocal zoom lens system that is used to observe thing, this system comprises the objective lens of a positive light coke, and this objective lens has first lens unit of positive light coke, second lens unit of negative power and the 3rd lens unit of positive light coke; An erect image light group is used for objective lens imaging erect image; With eyepiece group with positive light coke, be used to observe erect image light group positive picture.First lens unit of objective lens and second lens unit can move when zoom.
Should be appreciated that the describe, in general terms of front and following detailed all are illustrative and indicative, is in order further to explain claims of the present invention.
Accompanying drawing is included in this instructions, combines with instructions, and an ingredient of book as an illustration, so that understand the present invention better.Accompanying drawing shows several embodiments of the present invention, explains principle of the present invention with instructions.
In the accompanying drawings:
Figure 1A is the schematic sectional view according to the Afocal zoom lens system of most preferred embodiment of the present invention, the light path the when system of showing is positioned at wide-angle position;
Figure 1B is the schematic sectional view according to the Afocal zoom lens system of most preferred embodiment of the present invention, and the system of showing is positioned at the light path of the position of dolly-out,ing dolly-back;
Fig. 2 A is the actual cut-open view according to the Afocal zoom lens system of most preferred embodiment of the present invention, and the system of showing is positioned at the light path of wide-angle position;
Fig. 2 B is the actual cut-open view according to the Afocal zoom lens system of most preferred embodiment of the present invention, and the system of showing is positioned at the light path of the position of dolly-out,ing dolly-back;
Fig. 3 A is according to the Afocal zoom lens system of most preferred embodiment of the present invention spherical aberration curve map at wide-angle position;
Fig. 3 B is according to the Afocal zoom lens system of most preferred embodiment of the present invention astigmatism curve map at wide-angle position;
Fig. 3 C is according to the Afocal zoom lens system of most preferred embodiment of the present invention distortion curve figure at wide-angle position;
Fig. 4 A is according to the Afocal zoom lens system of most preferred embodiment of the present invention spherical aberration curve map in the position of dolly-out,ing dolly-back;
Fig. 4 B is according to the Afocal zoom lens system of most preferred embodiment of the present invention astigmatism curve map in the position of dolly-out,ing dolly-back;
Fig. 4 C is according to the Afocal zoom lens system of most preferred embodiment of the present invention distortion curve figure in the position of dolly-out,ing dolly-back.
To describe most preferred embodiment of the present invention in detail below, the example of described most preferred embodiment be shown in the accompanying drawing.
Referring to Figure 1A-1B, comprise the objective lens 1 of a positive light coke according to the Afocal zoom lens system of most preferred embodiment of the present invention; An erect image light group 2 is used for objective lens 1 imaging is carried out erect image; Eyepiece group 3 with a positive light coke.Thing is placed on the front of objective lens 1, and final picture becomes the rear in eyepiece group 3.
Objective lens 1 comprises, first lens unit 11 has single positive lenticular lens element, and this lenticular lens element is aspheric surface away from thing towards the one side of final imaging; Second lens unit 12 has single negative lens element, and this negative lens element is a concave surface towards the one side of picture, and is aspheric surface towards the one side of thing; With the 3rd lens unit 13, have single positive element, this positive element is a convex surface towards the one side of thing.First lens unit 11 of objective lens 1 and second lens unit 12 can move when zoom.First, second of objective lens 1 and the 3rd lens unit 11,12 and 13 are made of plastics separately.
Erect image light group 2 comprises prism 22 and first and second catoptron 21 and 23 respectively.First catoptron 21 is between second lens unit 12 and the 3rd lens unit 13 of objective lens 1.The prism 22 and second catoptron 23 are between the 3rd lens unit 13 and eyepiece group 3 of objective lens 1, and prism 22 is near thing one side, and second catoptron 23 is near picture one side.
Eyepiece group 3 has single lenticular lens element, is aspheric surface towards a side of thing.The lens element of eyepiece group 3 also is made of plastics.
In a preferred embodiment of the invention, objective lens 1 comprises first lens unit 11 with positive focal power, the 3rd lens unit 13 that has second lens unit 12 of negative focal power and have positive focal power.When changing enlargement ratio, move first lens unit 11 and second lens unit 12, so that according to a preferred embodiment of the invention Afocal zoom lens system is classified into the type of dolly-out,ing dolly-back.Principal point is formed on the front of first lens unit 11 in optical system, the compactness so objective lens 1 becomes.Therefore, the entire length of system is shorter.
When from the wide-angle position zoom when dolly-out,ing dolly-back the position, the 3rd lens unit 13 of objective lens 1 is fixing, and first lens unit 11 of objective lens 1 and second lens unit 12 are mobile to a side of thing.Therefore, the distance between first lens unit 11 and second lens unit 12 shortens, and first catoptron 21 of erect image light group 2 and the variable in distance between second lens unit 12.When first lens unit 11 moved, enlargement ratio changed.Simultaneously, second lens unit 12 moves, so that the variation of the focal plane of balance objective lens 1, this variation is moved by first lens unit 11 and caused.
Shown in Fig. 2 A-2B, in far away burnt zoom system, pancreatic system according to a preferred embodiment of the invention, light beam is respectively by after first lens unit 11 and second lens unit 12 of objective lens 1, by 21 reflections of first catoptron.First catoptron 21 is 45 to be placed, so that the picture of vertical direction is become the picture of horizontal direction.Then, light beam is by the 3rd lens unit 13 and prism 22 transmission and reflection, and vertically, the along continuous straight runs upset looks like then.At last, the catoptron of placing with the 45 direction 23 makes 90 ° of angles of beam reflection light beam incide eyepiece group 3, and picture is turned on its initial vertical direction.
In the present invention, the dispersion values V2 of second lens unit 12 of objective lens 1 satisfies following condition:
-21＜V2＜42
It is expensive that lens material becomes in limited time when the value of dispersion values V2 is lower than above-mentioned condition following, and be higher than going up in limited time of above-mentioned condition as dispersion values V2, and it is big that aberration becomes.
Among the present invention, the zone of reasonableness of second lens unit 12 of objective lens 1 is 21＜V2＜42.
Eyepiece group 3 has aspheric surface, so that the curvature of field and the distortion of balance eyepiece group 3.
Because first, second and third lens unit 11,12 of objective lens 1 and 13 and eyepiece group 3 make by plastics, so the general assembly (TW) of burnt zoom system, pancreatic system far away has lightened.
During the asphericity coefficient of listing in the following table is used in down and establishes an equation:
Wherein:
Z is the surperficial camber apart from systematic optical axis y place;
C is the basic point curvature on surface, optical axis place;
K is the quadric surface coefficient; And
A
4, A
6, A
8, A
10It is the aspheric surface coefficient.
Numerical value is according to a preferred embodiment of the invention listed among the table 1-6.In table, r represents radius-of-curvature, and d represents distance or the lens thickness between lens, and nd represents the refractive index of d light, and v represents the Abbe number of lens.The unit of all length calculates with mm.
Numerical value according to a first advantageous embodiment of the invention is shown in Table 1.According to a first advantageous embodiment of the invention, the field angle scope is 8.12 ° to 4.24 °, and the zoom ratio scope is 2.25 to 4.44.
Table 1
| The surface sequence number | Radius-of-curvature (r) | Distance (d) | Refractive index (nd) | Abbe number (v) |
| ????1 | ???19．447 | ???3．96 | ???1．49176 | ???57．4 |
| ??? *2 ? | ??-44．079?? | ??????A | ||
| ??? *3 | ??-86．257???? | ???2．70 | ???1．58700 | ???31．0 |
| ????4 | ???13．633 | ??????B | ||
| ????5 | ?????∞ | ??13．17??? | ||
| ????6 | ??16．000 | ???3．87 | ???1．49176 | ???57．4 |
| ????7 | ?????∞ | ???4．?80 | ||
| ????8 | ?????∞ | ??14．80 | ???1．49176 | ???57．4 |
| ????9 | ?????∞ | ???4．60 | ||
| ????10 | ?????∞ | ???6．43???? | ||
| ??? *11 | ???22．000 | ???2．70 | ???1．49176 | ???57．4 |
| ????12 | ??-31．610??? | ??19．00??? |
Asterisk (
*) the expression aspheric surface, A and B represent the variation distance between lens.Wide-angle position and change distance A when dolly-out,ing dolly-back the position and B is shown in Table 2.
Table 2
| Focal length | Wide-angle position | The position of dolly-out,ing dolly-back |
| ??A | ??13．405 | ???9．794 |
| ??B | ???9．163 | ??54．547 |
The asphericity coefficient A of second, third and the tenth one side r2, r3 and r11
4, A
6, A
8And A
10Be shown in Table 3 respectively.
Table 3
| ????????r2 | ?????????r3 | ????????r11 | |
| ??K | ??0．11268725E+02 | ??0．17049603E+0 ??3 | ?-0．13000000E+01 |
| ??A 4 | ??0．38737119E-04 | ??0．12738439E-04 | ??0．0 |
| ??A 6 | ??0．37048305E-06 | ??0．55184575E-05 | ??0．0 |
| ??A 8 | ?-0．51923184E-08 | ?-0．19507904E-06 | ??0．0 |
| ??A 10 | ??0．29478065E-10 | ??0．28421268E-08 | ??0．0 |
Fig. 3 A-3C shows spherical aberration, astigmatism and the distortion that according to a preferred embodiment of the invention far away burnt zoom system, pancreatic system is positioned at wide-angle position respectively.Fig. 4 A-4C shows spherical aberration, astigmatism and the distortion that according to a preferred embodiment of the invention far away burnt zoom system, pancreatic system is positioned at the position of dolly-out,ing dolly-back respectively.
Numerical value according to a second, preferred embodiment of the present invention is listed in the table 4.According to second preferred embodiment of the present invention, the field angle scope is 8.12 ° to 4.24 °, and the zoom ratio scope is 2.25 to 4.44.
Table 4
| The surface sequence number | Radius-of-curvature (r) | Distance (d) | Refractive index (nd) | Abbe number (v) |
| ????1 | ????22．563 | ???4．50 | ??1．49176?? | ???57．4 |
| ??? *2 | ???-62．027 | ????A | ||
| ??? *3 | ???394．273 | ???2．55 | ??1．58700?? | ???31．0 |
| ????4 | ????16．504 | ????B |
| ????5 | ????∞ | ????15．24 | ||
| ????6 | ????16．000 | ????4?20 | ????1．49176 | ????57．4 |
| ????7 | ????∞ | ????4．80 | ||
| ????8 | ????∞ | ????14．80 | ????1．49176 | ????57．4 |
| ????9 | ????∞ | ????4?60 | ||
| ????10 | ????∞ | ????6．43 | ||
| ??? *11 | ????22．000 | ????2．70 | ????1．49176 | ????57．4 |
| ????12 | ????-31．610 | ????19．00 |
Asterisk (
*) the expression aspheric surface, A and B represent the variation distance between lens.Variation distance A and B in the wide-angle position and the position of dolly-out,ing dolly-back list in the table 5.
Table 5
| Focal length | Wide-angle position | The position of dolly-out,ing dolly-back |
| ????A | ????16．162 | ??8．915 |
| ????B | ????8．766 | ?61．986 |
The asphericity coefficient A of second and third and ten one side r2, r3 and r11
4, A
6, A
8And A
10List in the table 6.
Table 6
As mentioned above, Afocal zoom lens system according to a preferred embodiment of the invention is simple in structure, volume is little, because objective lens 1 has first lens of positive light coke, second lens of negative power and the 3rd lens of positive light coke, and when zoom, first lens unit 11 and second lens unit 12 can move.
| ????r2 | ????r3 | ????r11 | |
| ?K | ?0．76999510 | -0．90000000E+02 | -0．13000000E+01 |
| ?A 4 | ?0．15720021E-04 | -0．47608866E-05 | ?0．0 |
| ?A 6 | ?0．15264627E-06 | ?0．16248882E-05 | ?0．0 |
| ?A 8 | -0．37296182E-08 | -0．58236213E-07 | ?0．0 |
| ?A 10 | ?0．23787898E-10 | ?0．64076923E-09 | ?0．0 |
And it is easier to use Afocal zoom lens system of the present invention to observe picture, because the interpupillary distance of eyepiece group is elongated, is approximately 19mm.In addition, this Afocal zoom lens system is in light weight, cost is low, because the lens of object lens and eyepiece group are made of plastics.
Though this paper illustrates and described the present invention in conjunction with the preferred embodiments of the present invention, obviously, those skilled in the art is easy to make various modification and improvement, and the scope and spirit of the present invention that do not break away from appended claims and limited.
Claims (11)
1. far away burnt zoom system, pancreatic system of observing thing comprises:
The objective lens of a positive light coke has first lens unit of positive light coke, second lens unit of negative power and the 3rd lens unit of positive light coke;
An erect image light group is used for described objective lens imaging is carried out erect image; And
The eyepiece group of a positive light coke is used to observe the picture of just having crossed;
Wherein, first lens unit of described objective lens and second lens unit can move when zoom.
2. Afocal zoom lens system as claimed in claim 1, first, second of wherein said objective lens and the 3rd lens unit and described eyepiece group have single lens element.
3. Afocal zoom lens system as claimed in claim 1, wherein:
First lens unit has single positive lenticular lens element, and element is an aspheric surface away from the one side of object space;
Second lens unit has single negative lens element, and the one side of element towards picture side is concave surface, is aspheric surface towards the one side of object space;
The 3rd lens unit has the element of single positive lens, and element is a convex surface towards the one side of object space.
4. Afocal zoom lens system as claimed in claim 1, first, second of wherein said objective lens and the 3rd lens unit and described eyepiece group are made of plastics.
5. Afocal zoom lens system as claimed in claim 1, first and second lens units of wherein said objective lens all have an aspheric surface at least.
6. Afocal zoom lens system as claimed in claim 1, wherein first lens unit can move so that change the enlargement ratio of system, second lens unit can move so that the focal plane of balance objective lens changes, and this variation is moved by first lens unit and caused.
7. Afocal zoom lens system as claimed in claim 6, wherein erect image light group comprises: first catoptron, between second lens unit and the 3rd lens unit of objective lens; Second catoptron is between the 3rd lens unit and eyepiece group of objective lens; And a prism, also between the 3rd lens unit and eyepiece group of objective lens.
8. Afocal zoom lens system as claimed in claim 1, wherein the eyepiece group has single biconvex lens unit, is aspheric surface towards the one side of object space.
9. Afocal zoom lens system as claimed in claim 1, wherein first lens unit of objective lens and the variable in distance between second lens unit when changing enlargement ratio.
10. Afocal zoom lens system as claimed in claim 1, wherein the interpupillary distance of eyepiece group is greater than 10mm.
11. Afocal zoom lens system as claimed in claim 1, wherein the dispersion values of second lens unit of objective lens satisfies following condition:
-21＜V2＜42
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 98114962 CN1204062A (en) | 1997-05-21 | 1998-05-21 | Afocal zoom lens system |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR19775/97 | 1997-05-21 | ||
| CN 98114962 CN1204062A (en) | 1997-05-21 | 1998-05-21 | Afocal zoom lens system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN1204062A true CN1204062A (en) | 1999-01-06 |
Family
ID=5224378
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 98114962 Pending CN1204062A (en) | 1997-05-21 | 1998-05-21 | Afocal zoom lens system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN1204062A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100451717C (en) * | 2005-11-16 | 2009-01-14 | 索尼株式会社 | Image capture apparatus and zoom lens |
| CN102243373A (en) * | 2011-06-24 | 2011-11-16 | 南京英田光学工程有限公司 | Optical system of remote lens-type detector with super-large exit pupil diameter |
-
1998
- 1998-05-21 CN CN 98114962 patent/CN1204062A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100451717C (en) * | 2005-11-16 | 2009-01-14 | 索尼株式会社 | Image capture apparatus and zoom lens |
| CN102243373A (en) * | 2011-06-24 | 2011-11-16 | 南京英田光学工程有限公司 | Optical system of remote lens-type detector with super-large exit pupil diameter |
| CN102243373B (en) * | 2011-06-24 | 2014-06-25 | 南京英田光学工程有限公司 | Optical system of remote lens-type detector with super-large exit pupil diameter |
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