CN112346227A - Zoom lens - Google Patents
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- CN112346227A CN112346227A CN202011224242.0A CN202011224242A CN112346227A CN 112346227 A CN112346227 A CN 112346227A CN 202011224242 A CN202011224242 A CN 202011224242A CN 112346227 A CN112346227 A CN 112346227A
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- 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
- G02B15/144113—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 +-++
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- 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
- G02B15/16—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 with interdependent non-linearly related movements between one lens or lens group, and another lens or lens group
- G02B15/20—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 with interdependent non-linearly related movements between one lens or lens group, and another lens or lens group having an additional movable lens or lens group for varying the objective focal length
Abstract
The present invention relates to a zoom lens, including: the zoom lens comprises a first lens group with positive focal power, a second lens group with negative focal power, a diaphragm, a third lens group with positive focal power and a fourth lens group with positive focal power which are arranged in sequence from an object side to an image side; the first lens group and the third lens group are fixed groups, the second lens group is a zooming group capable of moving along the optical axis, and the fourth lens group is a focusing group capable of moving along the optical axis; the second lens group and the third lens group satisfy: less than or equal to 9.5 (d)1‑d2)/(fT/fW) | < 13, wherein d1The distance from the image side surface of the last lens of the second lens group to the object side surface of the first lens of the third lens group is from the wide-angle end of the zoom lens; d2The distance from the image side surface of the last lens of the second lens group to the object side surface of the first lens of the third lens group is the distance from the image side surface of the last lens of the second lens group to the object side surface of the first lens of the third lens group when the distance from the telephoto end of the zoom lens is larger than the distance from the image side surface; f. ofTIs the focal length value of the telescopic end, fWIs focal length at wide angle end. The invention has high imaging quality.
Description
Technical Field
The invention relates to the field of optical imaging, in particular to a zoom lens.
Background
The zoom lens is more and more popular in the security monitoring market because the focal length of the zoom lens is variable, so that the zoom lens is applicable to various monitoring scenes.
The existing constant-aperture zoom lens in the market still has some performance defects to limit the use scene. If the angle at the wide angle end is not large enough, the monitoring range is limited; the aperture is small, and the monitoring requirement of a low-illumination environment cannot be met; the resolving power is insufficient, the resolution ratio is low, the zooming range is small, the monitoring range is limited, and the like.
Disclosure of Invention
The present invention is directed to solve the above problems, and an object of the present invention is to provide a zoom lens that solves the problem of poor imaging performance of the zoom lens.
To achieve the above object, the present invention provides a zoom lens including: the zoom lens comprises a first lens group with positive focal power, a second lens group with negative focal power, a diaphragm, a third lens group with positive focal power and a fourth lens group with positive focal power which are arranged in sequence from an object side to an image side;
the first lens group and the third lens group are fixed groups, the second lens group is a zooming group capable of moving along an optical axis, and the fourth lens group is a focusing group capable of moving along the optical axis;
the second lens group and the third lens group satisfy:
9.5≤|(d1-d2)/(fT/fW)|≤13
wherein d is1Representing the distance from the image side surface of the last lens of the second lens group to the object side surface of the first lens of the third lens group at the wide-angle end of the zoom lens; d2The distance from the image side surface of the last lens of the second lens group to the object side surface of the first lens of the third lens group when the distance from the telephoto end of the zoom lens is represented; f. ofTIs the focal length value of the telescopic end, fWIs a focal length value at the wide-angle end.
According to an aspect of the present invention, the first lens group includes: one lens with negative focal power and two lenses with positive focal power; in the direction from the object side to the image side, the focal powers of the first lens and the third lens are positive, and the focal power of the second lens is negative;
according to an aspect of the present invention, the second lens group includes: three lenses with negative focal power and one lens with positive focal power; wherein, in the direction from the object side to the image side, the focal power of the fourth lens and the seventh lens is negative;
according to an aspect of the present invention, the third lens group includes: two lenses with negative focal power and six lenses with positive focal power; wherein, the optical power of the ninth lens and the fifteenth lens is positive from the object side to the image side.
According to an aspect of the present invention, the eighth lens in the third lens group is an aspherical lens having positive power in a direction from the object side to the image side.
According to one aspect of the invention, two lenses are adopted in the first lens group to form a first cemented lens group;
in the second lens group, a fifth lens and a sixth lens form a second cemented lens group;
in the third lens group, from the object side to the image side, a tenth lens, an eleventh lens and a twelfth lens form a third cemented lens group, and a thirteenth lens and a fourteenth lens form a fourth cemented lens group.
According to an aspect of the present invention, the fourth lens group includes: one lens with negative focal power and two lenses with positive focal power; in the direction from the object side to the image side, the focal power of the sixteenth lens and the eighteenth lens is positive, and the focal power of the seventeenth lens is negative; alternatively, the first and second electrodes may be,
the fourth lens group includes: two lenses with negative focal power and two lenses with positive focal power; wherein, from the object side to the image side, the optical power of the sixteenth lens and the eighteenth lens is positive, and the optical power of the seventeenth lens and the nineteenth lens is negative.
According to an aspect of the invention, said first lens group focal length f1Focal length f of the third lens group3The following relation is satisfied: f is more than or equal to 1.41/f3|≤3.5。
According to an aspect of the present invention, the zoom lens has a wide-angle end focal length fWThe optical total length L of the zoom lens satisfies the following relational expression: f is more than or equal to 0.1W/L|≤0.15。
According to one aspect of the invention, the refractive index Nd of at least one lens with positive focal power in the first lens group1And Abbe number Vd1The following relation is satisfied: nd of not less than 1.41≤1.6，60≤Vd1≤95。
According to one aspect of the invention, the refractive index Nd of at least two negative-power lenses in the second lens group2And Abbe number Vd2The following relation is satisfied: nd of not less than 1.42≤1.6，40≤Vd2≤70。
According to an aspect of the invention, the refractive index Nd of at least two lenses with positive optical power in the third lens group3And Abbe number Vd3The following relation is satisfied: nd of not less than 1.43≤1.6，60≤Vd3≤95。
According to one scheme of the invention, the zoom lens disclosed by the invention can realize high-quality imaging under different multiplying powers by reasonably matching the four lens groups.
According to one scheme of the invention, the zoom lens achieves a high-quality imaging effect by reasonably distributing glass with different refractive indexes.
According to an aspect of the present invention, the zoom lens of the present invention has excellent resolving power, and the image quality is close to the diffraction limit.
According to one scheme of the invention, the zoom lens has a large and constant aperture, and the illumination is uniform under different multiplying powers.
According to one scheme of the invention, the zoom lens can realize infrared confocal, and high-quality imaging under both visible light wavelength and infrared light wavelength is ensured.
According to one scheme of the invention, the zoom lens has the advantages of small distortion, high imaging quality, uniform image quality, fine image quality, rich colors and high contrast.
According to an aspect of the present invention, the zoom lens of the present invention has a high transmittance as a whole and uniform image brightness.
According to one scheme of the invention, the zoom lens can solve the problem of temperature drift, and clear imaging can be realized in the temperature range of-40 ℃ to 80 ℃ without refocusing.
According to one aspect of the present invention, the zoom lens of the present invention has a good single-piece structure and assembly tolerance, and good manufacturability.
According to one scheme of the invention, the first lens group is used as a fixed group and mainly plays a role in light collection, so that light can smoothly enter an imaging system, the tolerance sensitivity of the system is further reduced, and in addition, the chromatic aberration of the system and the temperature drift of the system can be corrected, thereby ensuring good color reproducibility and high-quality optical performance.
According to one scheme of the invention, the second lens group is used as a zooming group, mainly has a zooming function, ensures the optical imaging quality of the system under different multiplying powers, secondly ensures the temperature drift correction and chromatic aberration correction of the athermalization system through lens focal power matching, and shares the pressure of tolerance sensitivity of the system.
According to one aspect of the present invention, the third lens group acts as a fixed group, and is beneficial for reducing tolerance sensitivity of the system, correcting chromatic aberration of the system, and correcting temperature drift of the system by effectively matching lens power.
According to one scheme of the invention, the fourth lens group is used as a focusing group, and mainly has the functions of reasonably focusing in the zooming process, ensuring high optical performance under different multiplying powers, and ensuring that light rays smoothly enter an image plane through the matching of lens focal power to maintain a smaller CRA.
Drawings
FIG. 1 is a view schematically showing a configuration of a zoom lens according to an embodiment at three ends of a wide angle end, a middle end, and a telephoto end;
FIG. 2 is a diagram schematically showing distortion, chromatic aberration of magnification, and chromatic aberration of position of a zoom lens at the wide-angle end, the middle end, and the telephoto end according to an embodiment;
FIG. 3 is a diagram schematically showing performance at the wide-angle end, defocus curves of visible light and infrared light, and defocus curves of high and low temperatures of a zoom lens according to an embodiment;
FIG. 4 is a structural view schematically showing a zoom lens in the second embodiment at three ends of a wide angle end, a middle end and a telephoto end;
FIG. 5 is a diagram schematically showing distortion, chromatic aberration of magnification, and chromatic aberration of position of a zoom lens in the second embodiment at the wide-angle end, the middle end, and the telephoto end;
FIG. 6 is a diagram schematically showing performance at the wide-angle end, defocus curves of visible light and infrared light, and defocus curves at high and low temperatures in the second zoom lens according to the embodiment;
FIG. 7 is a structural view schematically showing a zoom lens in the third embodiment at the wide-angle end, the middle end, and the telephoto end;
FIG. 8 is a diagram schematically showing distortion, chromatic aberration of magnification, and chromatic aberration of position of a zoom lens in the third embodiment at the wide-angle end, the middle end, and the telephoto end;
fig. 9 is a diagram schematically showing performance at the wide-angle end, a defocus curve of visible light and infrared light, and a defocus curve at high and low temperatures of the zoom lens according to the third embodiment;
fig. 10 is a structural view schematically showing a zoom lens in the fourth embodiment at three ends of a wide angle end, a middle end, and a telephoto end;
fig. 11 is a diagram schematically showing distortion, chromatic aberration of magnification, chromatic aberration of position of the zoom lens in the fourth embodiment at the wide-angle end, the middle end, and the telephoto end;
FIG. 12 is a diagram schematically showing performance at the wide-angle end, defocus curves of visible light and infrared light, and defocus curves at high and low temperatures in a four-zoom lens according to the embodiment;
fig. 13 is a structural view schematically showing a penta zoom lens of the embodiment at three ends of a wide angle end, a middle end and a telephoto end;
fig. 14 is a diagram schematically showing distortion, chromatic aberration of magnification, and chromatic aberration of position of the quinta zoom lens of the embodiment at the wide-angle end, the middle end, and the telephoto end.
Fig. 15 is a diagram schematically showing performance at the wide-angle end, a defocus curve of visible light and infrared light, and a defocus graph at high and low temperatures in the penta zoom lens according to the embodiment.
Detailed Description
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments will be briefly described below. It is obvious that the drawings in the following description are only some embodiments of the invention, and that for a person skilled in the art, other drawings can be derived from them without inventive effort.
In describing embodiments of the present invention, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like are used in an orientation or positional relationship that is based on the orientation or positional relationship shown in the associated drawings, which is for convenience and simplicity of description only, and does not indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and thus, the above-described terms should not be construed as limiting the present invention.
The present invention is described in detail below with reference to the drawings and the specific embodiments, which are not repeated herein, but the embodiments of the present invention are not limited to the following embodiments.
As shown in fig. 1, according to an embodiment of the present invention, a zoom lens of the present invention includes: the zoom lens includes, in order from the object side to the image side along the optical axis, a first lens group G1 having positive power, a second lens group G2 having negative power, a stop, a third lens group G3 having positive power, and a fourth lens group G4 having positive power.
In this embodiment, the first lens group G1 and the third lens group G3 are fixed groups, the second lens group G2 is a zoom group movable along the optical axis, and the fourth lens group G4 is a focus group movable along the optical axis. In the present embodiment, the interval between the second lens group G2 and the third lens group G3 gradually decreases from the wide-angle end to the telephoto end, and the second lens group G2 and the third lens group G3 satisfy:
9.5≤|(d1-d2)/(fT/fW)|≤13
wherein d is1At the wide angle end of the zoom lensThe distance from the image side of the last lens of the second lens group G2 to the object side of the first lens of the third lens group G3; d2Showing the distance from the image side surface of the last lens of the second lens group G2 to the object side surface of the first lens of the third lens group G3 at the telephoto end of the zoom lens; f. ofTIs the focal length value of the telescopic end, fWIs a focal length value at the wide-angle end.
With the above arrangement, the second lens group G2 can be moved horizontally in the optical axis direction to achieve a zooming effect of the entire zoom lens. In addition, by setting the variation in the distance between the second lens group G2 and the third lens group G3 and the zoom lens focal length value to the above relationship, it is advantageous to improve the imaging quality of the zoom lens at different magnifications.
As shown in fig. 1, according to one embodiment of the present invention, the first lens group G1 includes: one lens with negative focal power and two lenses with positive focal power; in the direction from the object side to the image side, the power of the first lens L1 is positive, the power of the second lens L2 is negative, and the power of the third lens L3 is positive. In the present embodiment, the first cemented lens group B1 (e.g., the second lens L2 and the third lens L3) is formed of two lenses in the first lens group G1.
Through the arrangement, in the first lens group G1, by matching the positive and negative focal powers of the lenses, light rays can smoothly enter the zoom lens, so that the tolerance sensitivity of the whole zoom lens is favorably reduced.
As shown in fig. 1, according to one embodiment of the present invention, the second lens group G2 includes: three lenses with negative focal power and one lens with positive focal power; wherein, in the direction from the object side to the image side, a fourth lens L4, a fifth lens L5, a sixth lens L6 and a seventh lens L7 are sequentially arranged; the optical powers of the fourth lens L4 and the seventh lens L7 are negative; the fifth lens L5 and the sixth lens L6 constitute a second cemented lens group B2.
Through the arrangement, in the second lens group G2, the positive and negative focal powers of the lenses are matched, so that the temperature drift and chromatic aberration of a athermalized imaging system can be corrected, the advantages of fineness, uniformity and high contrast of imaging image quality under the conditions of high temperature and low temperature are ensured, and meanwhile, the pressure of tolerance sensitivity of the zoom lens system is effectively shared and reduced through the arrangement of the second lens group G2.
As shown in fig. 1, according to one embodiment of the present invention, the third lens group G3 includes: two lenses with negative focal power and six lenses with positive focal power; in the image-side direction, an eighth lens L8, a ninth lens L9, a tenth lens L10, an eleventh lens L11, a twelfth lens L12, a thirteenth lens L13, a fourteenth lens L14, and a fifteenth lens L15 are disposed in this order. In the present embodiment, the eighth lens L8 in the third lens group G3 is an aspherical lens having positive power, and the powers of the ninth lens L9 and the fifteenth lens L15 are positive. In the present embodiment, in the third lens group G3, the tenth lens L10, the eleventh lens L11, and the twelfth lens L12 constitute a third cemented lens group B3, and the thirteenth lens L13 and the fourteenth lens L14 constitute a fourth cemented lens group B4 from the object side to the image side.
Through the arrangement, in the third lens group G3, the positive and negative focal powers among the lenses are reasonably matched, so that the tolerance sensitivity of the system is effectively reduced, the imaging quality of the whole zoom lens system is improved, and the advantages of correcting chromatic aberration and temperature drift of the zoom lens system are realized.
As shown in fig. 1, according to one embodiment of the present invention, the fourth lens group G4 includes: one lens with negative focal power and two lenses with positive focal power; wherein, in the direction from the object side to the image side, a sixteenth lens L16, a seventeenth lens L17 and an eighteenth lens L18 are sequentially arranged; the powers of the sixteenth lens L16 and the eighteenth lens L18 are positive, and the power of the seventeenth lens L17 is negative.
Through the arrangement, in the fourth lens group G4, by reasonably matching positive and negative focal powers among lenses, sufficient back focus and a larger imaging picture are favorably ensured, a smaller chief ray incident angle is favorably achieved, and the zoom lens provided by the invention has higher picture color reducibility.
According to another embodiment of the present invention, the fourth lens group G4 includes: two lenses with negative focal power and two lenses with positive focal power; wherein, in the direction from the object side to the image side, a sixteenth lens L16, a seventeenth lens L17, an eighteenth lens L18 and a nineteenth lens L19 are sequentially disposed; the powers of the sixteenth lens L16 and the eighteenth lens L18 are positive, and the powers of the seventeenth lens L17 and the nineteenth lens L19 are negative.
Through the arrangement, in the fourth lens group G4, by reasonably matching positive and negative focal powers among lenses, sufficient back focus and a larger imaging picture are favorably ensured, a smaller chief ray incident angle is favorably achieved, and the zoom lens provided by the invention has higher picture color reducibility.
As shown in FIG. 1, according to one embodiment of the present invention, the first lens group G1 has a focal length f1Focal length f of the third lens group G33The following relation is satisfied: f is more than or equal to 1.41/f3|≤3.5。
Through the arrangement, the focal length of the first lens group G1 and the focal length of the third lens group G3 satisfy the relational expression, so that reasonable collocation of focal powers of the two lens groups is realized, chromatic aberration of a system is favorably corrected, tolerance sensitivity of the system is favorably reduced, and imaging quality is favorably improved.
According to one embodiment of the present invention, as shown in FIG. 1, the wide-angle end focal length f of the zoom lensWThe optical total length L of the zoom lens satisfies the following relation: f is more than or equal to 0.1W/L|≤0.15。
Through the arrangement, the relationship between the focal length of the wide-angle end of the zoom lens and the optical total length of the zoom lens is set in the range, so that the imaging quality of the optical system is improved, the image quality is fine and smooth, the image quality is uniform, the contrast is high, the control of the volume of the system is facilitated, and the production cost is controlled.
As shown in FIG. 1, according to one embodiment of the present invention, the refractive index Nd of at least one lens with positive power in the first lens group G11And Abbe number Vd1The following relation is satisfied: nd of not less than 1.41≤1.6，60≤Vd1≤95。
Through the arrangement, the chromatic aberration and high-low temperature performance of the zoom lens can be corrected, and the imaging quality of the whole zoom lens is further improved.
As shown in FIG. 1, according to one embodiment of the present invention, in the second lens group G2, at least two lenses with negative refractive power have refractive index Nd2And Abbe number Vd2The following relation is satisfied: nd of not less than 1.42≤1.6，40≤Vd2≤70。
Through the arrangement, the chromatic aberration and high-low temperature performance of the zoom lens can be corrected, and the imaging quality of the whole zoom lens is further improved.
As shown in FIG. 1, according to one embodiment of the present invention, the third lens group G3 has at least two lenses with positive refractive power and refractive index Nd3And Abbe number Vd3The following relation is satisfied: nd of not less than 1.43≤1.6，60≤Vd3≤95。
Through the arrangement, the chromatic aberration and high-low temperature performance of the zoom lens can be corrected, and the imaging quality of the whole zoom lens is further improved.
According to the invention, the first lens group G1 is used as a fixed group, which mainly plays a role of light collection, so that light can smoothly enter the imaging system, thereby reducing tolerance sensitivity of the system, and in addition, chromatic aberration of the system and temperature drift of the system can be corrected, thereby ensuring good color rendition and high-quality optical performance.
According to the invention, the second lens group G2 is used as a zoom group, mainly has a zoom function, ensures the optical imaging quality of the system under different magnifications, secondly ensures the temperature drift correction and chromatic aberration correction of a athermalization system through the lens focal power matching, and shares the pressure of the tolerance sensitivity of the system.
According to the present invention, the third lens group G3 acts as a fixed group and is beneficial for reducing tolerance sensitivity, correcting chromatic aberration of the system and correcting temperature drift of the system by effectively matching lens powers.
According to the invention, the fourth lens group G4 is used as a focusing group, and mainly has the main functions of reasonably focusing in the zooming process, ensuring high optical performance under different magnifications, and ensuring that light rays smoothly enter an image plane through the matching of lens focal power, so as to maintain a smaller CRA.
Five sets of embodiments according to the above-described arrangement of the present invention are given below to specifically explain the zoom lens according to the present invention.
The values of the examples that specifically satisfy the above conditional expressions are summarized as shown in table 1 below:
TABLE 1
Further, in the following embodiments, the surface types of all the aspherical lenses satisfy the aspherical equation:
Z＝cy2/{1+[1-(1+k)c2y2]1/2}+A4y4+A6y6+A8y8+A10y10+A12y12+A14y14+A16y16
wherein, the parameter c is the curvature corresponding to the radius of the aspheric lens, y is the radial coordinate of the aspheric lens, the unit is the same as the unit of the lens length, k is the conic coefficient of the aspheric surface, a4, a6 … a16 are the corresponding order coefficients of the aspheric surface, respectively.
The first implementation mode comprises the following steps:
the zoom lens according to the present invention has eighteen lenses, and has a plurality of cemented lens groups, plus Stop surface Stop, for a total of 32 surfaces. The 32 faces are arranged in sequence according to the structural sequence of the invention, and for convenience of description, the 32 faces are numbered as sur1 to sur32, wherein Stop faces replace sur13, cemented faces in the cemented lens group are represented by one number, and an imaging face is represented as Image.
As described above, in the present embodiment, specific parameters of the zoom lens of the present invention are shown by table 2.
Table 2 is a parameter table of the first embodiment:
TABLE 2
In the present embodiment, the parameters of the zoom lens of the present embodiment are as shown in table 3 below:
| wide angle end | Intermediate (II) | Telescope end | |
| Focal length | 19.4 | 38.8 | 77.2 |
| FNO. | 1.2 | 1.2 | 1.2 |
| Half field angle | 19.8 | 9.6 | 4.7 |
| Total length of | 160 | 160 | 160 |
TABLE 3
In the present embodiment, the aspherical surface data is as shown in table 4 below:
TABLE 4
Referring to fig. 1, 2, and 3, by optimizing the above parameter values, the zoom lens according to the present embodiment achieves a constant large aperture performance with FNO of 1.2, and ensures an optimal effect of a maximum field angle at the wide-angle end and the telephoto end, while satisfying confocal of visible light and infrared light. In addition, the zoom lens also has the advantage of temperature compensation, and the lens can ensure the resolution power same as the normal temperature without refocusing in a larger temperature difference range.
The second embodiment:
the zoom lens according to the present invention has eighteen lenses, and has a plurality of cemented lens groups, plus Stop surface Stop, for a total of 32 surfaces. The 32 faces are arranged in sequence according to the structural sequence of the invention, and for convenience of description, the 32 faces are numbered as sur1 to sur32, wherein Stop faces replace sur13, cemented faces in the cemented lens group are represented by one number, and an imaging face is represented as Image.
As described above, in the present embodiment, specific parameters of the zoom lens of the present invention are shown by table 5.
Table 5 is a parameter table of embodiment two:
TABLE 5
In the present embodiment, the parameters of the zoom lens of the present embodiment are as shown in table 6 below:
| wide angle end | Intermediate (II) | Telescope end | |
| Focal length | 19.35 | 38.7 | 77.0 |
| FNO. | 1.2 | 1.2 | 1.2 |
| Half field angle | 19.5 | 9.6 | 4.7 |
| Total length of | 162 | 162 | 162 |
TABLE 6
In the present embodiment, the aspherical surface data is as shown in table 7 below:
| numbering | k | A4 | A6 | A8 |
| surf14 | -0.285 | -4.882E-06 | -3.103E-08 | 1.304E-10 |
| surf15 | 8.826 | -9.348E-06 | -3.936E-08 | -1.281E-10 |
| Numbering | A10 | A12 | A14 | A16 |
| surf14 | -1.793E-12 | 7.143E-15 | -1.786E-17 | 1.211E-20 |
| surf15 | 6.870E-12 | -9.722E-15 | 3.885E-17 | -6.699E-20 |
TABLE 7
Referring to fig. 4, 5, and 6, by optimizing the above parameter values, the zoom lens according to the present embodiment achieves a constant large aperture performance with FNO of 1.2, and ensures an optimal effect of a maximum field angle at the wide-angle end and the telephoto end, while satisfying confocal of visible light and infrared light. In addition, the zoom lens also has the advantage of temperature compensation, and the lens can ensure the resolution power same as the normal temperature without refocusing in a larger temperature difference range.
The third embodiment is as follows:
the zoom lens according to the present invention has eighteen lenses, and has a plurality of cemented lens groups, plus Stop surface Stop, for a total of 31 surfaces. The 31 planes are arranged in sequence according to the structural sequence of the invention, and for convenience of description, the 31 planes are numbered as sur1 to sur31, wherein Stop planes replace sur13 by Stop, cemented planes in the cemented lens group are represented by one number, and an imaging plane is represented by Image.
As described above, in the present embodiment, specific parameters of the zoom lens of the present invention are shown in table 8 (in the table, standard represents a spherical surface, and aspheric represents an aspherical surface).
Table 8 is a parameter table of the third embodiment:
TABLE 8
In the present embodiment, the parameters of the zoom lens of the present embodiment are as shown in table 9 below:
| wide angle end | Intermediate (II) | Telescope end | |
| Focal length | 19 | 37.8 | 76.5 |
| FNO. | 1.2 | 1.2 | 1.2 |
| Half visionField angle | 20.4 | 10.1 | 4.9 |
| Total length of | 158 | 158 | 158 |
TABLE 9
In the present embodiment, the aspherical surface data is as shown in table 10 below:
| numbering | k | A4 | A6 | A8 |
| surf14 | -0.217 | -4.326E-06 | -2.983E-08 | 1.363E-10 |
| surf15 | 8.337 | -8.015E-06 | -3.768E-08 | -1.253E-10 |
| Numbering | A10 | A12 | A14 | A16 |
| surf14 | -1.79E-12 | 7.134E-15 | -1.785E-17 | 1.262E-20 |
| surf15 | 7.009E-13 | -9.844E-15 | 3.905E-17 | -6.689E-20 |
Referring to fig. 7, 8, and 9, by optimizing the above parameter values, the zoom lens according to the present embodiment achieves a constant large aperture performance with FNO of 1.2, and ensures an optimal effect of a maximum field angle at the wide-angle end and the telephoto end, while satisfying confocal of visible light and infrared light. In addition, the zoom lens also has the advantage of temperature compensation, and the lens can ensure the resolution power same as the normal temperature without refocusing in a larger temperature difference range.
The fourth embodiment:
the zoom lens according to the present invention has nineteen lenses, and has a plurality of cemented lens groups, plus Stop surface Stop, for a total of 33 surfaces. The 33 faces are arranged in sequence according to the structural sequence of the invention, and for convenience of description, 32 faces are numbered as sur1 to sur33, wherein Stop faces replace sur13, cemented faces in the cemented lens group are represented by one number, and an imaging face is represented by Image.
As described above, in the present embodiment, specific parameters of the zoom lens of the present invention are shown by table 5.
Table 11 is an embodiment four parameter table:
TABLE 11
In the present embodiment, the parameters of the zoom lens of the present embodiment are as shown in table 12 below:
TABLE 12
In the present embodiment, the aspherical surface data is as shown in table 13 below:
| numbering | k | A4 | A6 | A8 |
| surf14 | -0.885 | 2.35E-07 | -1.969E-08 | 9.383E-11 |
| surf15 | 10.724 | -3.493E-06 | 9.471E-09 | -4.777E-10 |
| Numbering | A10 | A12 | A14 | A16 |
| surf14 | -2.105E-12 | 1.307E-14 | -4.468E-17 | 5.689E-20 |
| surf15 | 2.528E-13 | -9.781E-15 | 1.55E-17 | -6.471E-21 |
Watch 13
Referring to fig. 10, 11, and 12, by optimizing the above parameter values, the zoom lens according to the present embodiment achieves a constant large aperture performance with FNO of 1.2, and ensures an optimal effect of a maximum field angle at the wide-angle end and the telephoto end, while satisfying confocal of visible light and infrared light. In addition, the zoom lens also has the advantage of temperature compensation, and the lens can ensure the resolution power same as the normal temperature without refocusing in a larger temperature difference range.
The fifth embodiment:
the zoom lens according to the present invention has eighteen lenses, and has a plurality of cemented lens groups, plus Stop surface Stop, for a total of 33 surfaces. The 33 faces are arranged in sequence according to the structural sequence of the invention, and for convenience of description, the 33 faces are numbered sur1 to sur31, wherein Stop faces replace sur13, cemented faces in the cemented lens group are represented by one number, and an imaging face is represented by Image.
As described above, in the present embodiment, specific parameters of the zoom lens of the present invention are shown by table 14.
Table 14 is a parameter table of the fifth embodiment:
TABLE 14
In the present embodiment, the parameters of the zoom lens of the present embodiment are as shown in table 15 below:
| wide angle end | Intermediate (II) | Telescope end | |
| Focal length | 19.4 | 42.1 | 76.2 |
| FNO. | 1.2 | 1.2 | 1.2 |
| Half field angle | 18.2 | 8.6 | 4.5 |
| Total length of | 163 | 163 | 163 |
In the present embodiment, the aspherical surface data is shown in table 16 below:
| numbering | k | A4 | A6 | A8 |
| surf14 | -0.18 | -2.16E-06 | -2.219E-08 | 7.792E-11 |
| surf15 | 11.18 | -2.685E-06 | -4.942E-09 | -3.582E-10 |
| Numbering | A10 | A12 | A14 | A16 |
| surf14 | -1.704E-12 | 9.317E-15 | -2.919E-17 | 3.17E-20 |
| surf15 | 2.006E-12 | -9.198E-15 | 1.812E-17 | -1.438E-20 |
TABLE 16
Referring to fig. 13, 14, and 15, by optimizing the above parameter values, the zoom lens according to the present embodiment achieves a constant large aperture performance with FNO of 1.2, and ensures an optimal effect of a maximum field angle at the wide-angle end and the telephoto end, while satisfying confocal of visible light and infrared light. In addition, the zoom lens also has the advantage of temperature compensation, and the lens can ensure the resolution power same as the normal temperature without refocusing in a larger temperature difference range.
As can be seen from the above description, the zoom lens of the invention realizes that the maximum aperture is less than or equal to 1.2, and can realize confocal of visible light and infrared light. And temperature compensation is considered in the design of the lens, and the lens can ensure the resolution power same as the normal temperature without refocusing in the temperature range of-40 ℃ to 80 ℃.
The above description is only one embodiment of the present invention, and is not intended to limit the present invention, and it is apparent to those skilled in the art that various modifications and variations can be made in the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (12)
1. A zoom lens, comprising: a first lens group (G1) having positive power, a second lens group (G2) having negative power, a stop, a third lens group (G3) having positive power, and a fourth lens group (G4) having positive power, which are disposed in this order from the object side to the image side;
the first lens group (G1) and the third lens group (G3) are fixed groups, the second lens group (G2) is a zoom group movable along an optical axis, and the fourth lens group (G4) is a focus group movable along the optical axis;
the second lens group (G2) and the third lens group (G3) satisfy:
9.5≤|(d1-d2)/(fT/fW)|≤13
wherein d is1Representing a distance from an image side surface of a last lens of the second lens group (G2) to an object side surface of a first lens of the third lens group (G3) at a wide-angle end of the zoom lens; d2Represents the image side surface of the last lens of the second lens group (G2) to the third lens at the telephoto end of the zoom lensThe distance between the object side surfaces of the first lens of the three lens groups (G3); f. ofTIs the focal length value of the telescopic end, fWIs a focal length value at the wide-angle end.
2. A zoom lens according to claim 1, wherein the first lens group (G1) includes: one lens with negative focal power and two lenses with positive focal power; wherein, in the direction from the object side to the image side, the optical power of the first lens (L1) and the third lens (L3) is positive, and the optical power of the second lens (L2) is negative;
3. a zoom lens according to claim 1, wherein the second lens group (G2) includes: three lenses with negative focal power and one lens with positive focal power; wherein, in the object-side to image-side direction, the powers of the fourth lens (L4) and the seventh lens (L7) are negative;
4. a zoom lens according to claim 1, wherein the third lens group (G3) includes: two lenses with negative focal power and six lenses with positive focal power; wherein, in the direction from the object side to the image side, the powers of the ninth lens (L9) and the fifteenth lens (L15) are positive.
5. The zoom lens according to claim 4, wherein an eighth lens (L8) in the third lens group (G3) is an aspherical lens having positive optical power in a direction from the object side to the image side.
6. A zoom lens according to any one of claims 2 to 5, wherein the first cemented lens group (B1) is constituted by two lenses in the first lens group (G1);
in the second lens group (G2), a fifth lens (L5) and a sixth lens (L6) constitute a second cemented lens group (B2);
in the third lens group (G3), in a direction from the object side to the image side, a tenth lens (L10), an eleventh lens (L11), and a twelfth lens (L12) constitute a third cemented lens group (B3), and a thirteenth lens (L13) and a fourteenth lens (L14) constitute a fourth cemented lens group (B4).
7. A zoom lens according to any one of claims 1 to 5, wherein the fourth lens group (G4) comprises: one lens with negative focal power and two lenses with positive focal power; wherein, in the direction from the object side to the image side, the optical power of the sixteenth lens (L16) and the eighteenth lens (L18) is positive, and the optical power of the seventeenth lens (L17) is negative; alternatively, the first and second electrodes may be,
the fourth lens group (G4) includes: two lenses with negative focal power and two lenses with positive focal power; wherein, in the direction from the object side to the image side, the powers of the sixteenth lens (L16) and the eighteenth lens (L18) are positive, and the powers of the seventeenth lens (L17) and the nineteenth lens (L19) are negative.
8. A zoom lens according to any one of claims 1 to 5, wherein the first lens group (G1) has a focal length f1A focal length f from the third lens group (G3)3The following relation is satisfied: f is more than or equal to 1.41/f3|≤3.5。
9. The zoom lens according to any one of claims 1 to 5, wherein the zoom lens has a wide-angle end focal length fWThe optical total length L of the zoom lens satisfies the following relational expression: f is more than or equal to 0.1W/L|≤0.15。
10. A zoom lens according to any one of claims 2 to 5, wherein the refractive index Nd of at least one lens of the first lens group (G1) having positive optical power1And Abbe number Vd1The following relation is satisfied: nd of not less than 1.41≤1.6，60≤Vd1≤95。
11. A zoom lens according to any one of claims 1 to 5, wherein in the second lens group (G2), at least two lenses having negative optical power have refractive indexes Nd2And Abbe number Vd2The following relation is satisfied: nd of not less than 1.42≤1.6，40≤Vd2≤70。
12. A zoom lens according to any one of claims 1 to 5, wherein in the third lens group (G3), there are at least two lenses having positive optical power and having refractive index Nd3And Abbe number Vd3The following relation is satisfied: nd of not less than 1.43≤1.6，60≤Vd3≤95。
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|---|---|---|---|
| CN202011224242.0A CN112346227A (en) | 2020-11-05 | 2020-11-05 | Zoom lens |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011224242.0A CN112346227A (en) | 2020-11-05 | 2020-11-05 | Zoom lens |
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| Publication Number | Publication Date |
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| CN112346227A true CN112346227A (en) | 2021-02-09 |
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|---|---|---|---|
| CN202011224242.0A Pending CN112346227A (en) | 2020-11-05 | 2020-11-05 | Zoom lens |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116149034A (en) * | 2022-12-31 | 2023-05-23 | 福建福光股份有限公司 | Continuous zooming camera lens |
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2020
- 2020-11-05 CN CN202011224242.0A patent/CN112346227A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116149034A (en) * | 2022-12-31 | 2023-05-23 | 福建福光股份有限公司 | Continuous zooming camera lens |
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