CN220855315U

CN220855315U - Lens

Info

Publication number: CN220855315U
Application number: CN202322251114.0U
Authority: CN
Inventors: 邝健; 叶波; 欧阳霞
Original assignee: Shenzhen Dongzheng Optical Technology Co Ltd
Current assignee: Shenzhen Dongzheng Optical Technology Co Ltd
Priority date: 2023-08-18
Filing date: 2023-08-18
Publication date: 2024-04-26
Anticipated expiration: 2033-08-18

Abstract

The embodiment of the utility model relates to the technical field of optical imaging, and discloses a lens, which comprises a first lens group with negative focal power, a second lens group with positive focal power, a diaphragm and a third lens group with positive focal power, wherein the first lens group with negative focal power, the second lens group with positive focal power, the diaphragm and the third lens group with positive focal power are sequentially arranged from an object side to an image side along an optical axis. The lens is characterized in that a first lens group with negative focal power, a second lens group with positive focal power, a diaphragm and a third lens group with positive focal power are sequentially arranged from an object side to an image side along an optical axis, the focal length f _s1 of the first lens group and the focal length f of the lens meet the condition that the f _s1/f is less than or equal to 1.6, the focal length f _s2 of the second lens group and the focal length f of the lens meet the condition that the f _s2/f is less than or equal to 1.8, and the imaging requirements of wide angle large aperture, low distortion, clear imaging and high contrast can be achieved.

Description

Lens

Technical Field

The application belongs to the technical field of optical imaging, and particularly relates to a lens.

Background

With the continuous development of the photovoltaic industry, the near infrared imaging technology is widely applied to the field of solar panel detection, and at present, the requirements of the field of solar panel detection on an imaging lens are higher and higher, and the imaging lens with small aperture, large distortion and unclear imaging in the past can not meet the application scene requirements of current mainstream manufacturers.

Disclosure of utility model

The embodiment of the application aims to provide a lens, which is used for solving the problems of small aperture, large distortion and insufficient imaging of an imaging lens in the prior art.

To achieve the above object, according to one aspect of the present application, there is provided a lens comprising:

A first lens group having negative power, a second lens group having positive power, a stop, and a third lens group having positive power, which are disposed in order from an object side to an image side along an optical axis;

The focal length f _s1 of the first lens group and the focal length f of the lens satisfy: 1.2 is less than or equal to |f _s1/f is less than or equal to 1.6;

The focal length f _s2 of the second lens group and the focal length f of the lens satisfy: and f _s2/f is less than or equal to 1.4 and less than or equal to 1.8.

Optionally, the first lens group includes a first lens having positive focal power and a meniscus structure, a second lens having negative focal power and a meniscus structure, a third lens having negative focal power and a meniscus structure, a fourth lens having negative focal power and a biconcave structure, and a fifth lens having positive focal power and a biconvex structure, which are sequentially arranged from an object side to an image side along an optical axis.

Optionally, the fourth lens and the fifth lens are glued to form a first glued lens group.

Optionally, the second lens group includes at least a sixth lens having positive focal power and a biconvex structure.

Optionally, the third lens group includes an eighth lens having positive power and a meniscus structure, a ninth lens having positive power and a biconvex structure, a tenth lens having negative power and a meniscus structure, and an eleventh lens having positive power and a biconvex structure, which are sequentially disposed from the object side to the image side along the optical axis.

Optionally, the ninth lens and the tenth lens are cemented into a second cemented lens group.

Optionally, the third lens group includes a seventh lens having positive power and a biconvex structure, an eighth lens having negative power and a biconcave structure, a ninth lens having positive power and a biconcave structure, a tenth lens having negative power and a meniscus structure, and an eleventh lens having positive power and a biconcave structure, which are sequentially disposed from the object side to the image side along the optical axis.

Optionally, the seventh lens and the eighth lens are cemented into a third cemented lens group, and the ninth lens and the tenth lens are cemented into a second cemented lens group.

Optionally, the focal length f _s3i of the eleventh lens satisfies: f _s3i is more than or equal to 24.00 and less than or equal to 28.00.

Optionally, the back focal length BFL of the lens and the image plane full field height H of the lens satisfy: BFL/H is more than or equal to 0.7 and less than or equal to 0.9.

The adjusting component provided by the application has the beneficial effects that: the lens comprises a first lens group with negative focal power, a second lens group with positive focal power, a diaphragm and a third lens group with positive focal power, which are sequentially arranged from an object side to an image side along an optical axis; the focal length f _s1 of the first lens group and the focal length f of the lens satisfy: 1.2 is less than or equal to |f _s1/f is less than or equal to 1.6; the focal length f _s2 of the second lens group and the focal length f of the lens satisfy: and f _s2/f is less than or equal to 1.4 and less than or equal to 1.8. The lens sequentially comprises a first lens group with negative focal power, a second lens group with positive focal power, a diaphragm and a third lens group with positive focal power from an object side to an image side along an optical axis, wherein the focal length fs1 of the first lens group and the focal length f of the lens meet the condition of 1.2- _s1/f-1.6, the focal length fs2 of the second lens group and the focal length f of the lens meet the condition of 1.4-f _s2/f-1.8, and meanwhile, the first lens group, the second lens group, the diaphragm and the third lens group are utilized to move along the optical axis to focus, so that the imaging requirements of large aperture, low distortion, clear imaging and high contrast can be realized.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments or the description of the prior art will be briefly described below, it being obvious that the drawings in the following description are only some embodiments of the present application, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic diagram of a lens layout of a lens barrel according to an embodiment of the present application;

FIG. 2 is a schematic diagram of a lens layout of a lens barrel according to another embodiment of the present application;

FIG. 3 is a schematic view of a lens layout of a lens barrel according to another embodiment of the present application;

FIG. 4 is a MTF diagram of a lens according to an embodiment of the present application;

FIG. 5 is a graph of distortion of a lens barrel according to an embodiment of the present application;

FIG. 6 is an axial aberration diagram of a lens according to an embodiment of the present application;

fig. 7 is a graph of relative illuminance of a lens according to an embodiment of the application.

Wherein, each reference sign in the figure:

100. A first lens group; 110. a first lens; 120. a second lens; 130. a third lens; 140. a first cemented lens group; 141. a fourth lens; 142. a fifth lens;

200. a second lens group; 210. a sixth lens;

300. a diaphragm;

400. A third lens group; 410. a third cemented lens group; 411. a seventh lens; 412. an eighth lens; 420. a second cemented lens group; 421. a ninth lens; 422. a tenth lens; 430. and an eleventh lens.

Detailed Description

In order to make the technical problems, technical schemes and beneficial effects to be solved more clear, the application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the application.

It will be understood that when an element is referred to as being "mounted" or "disposed" on another element, it can be directly on the other element or be indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or be indirectly connected to the other element.

It is to be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like are merely for convenience in describing and simplifying the description based on the orientation or positional relationship shown in the drawings, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus are not to be construed as limiting the application.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present application, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.

According to an aspect of the present application, as shown in fig. 1 to 3, an embodiment of the present application provides a lens including a first lens group 100 having negative power, a second lens group 200 having positive power, a stop 300, and a third lens group 400 having positive power, which are disposed in order from an object side to an image side along an optical axis; wherein, the focal length f _s1 of the first lens group 100 and the focal length f of the lens satisfy: 1.2 is less than or equal to |f _s1/f is less than or equal to 1.6; the focal length f _s2 of the second lens group 200 and the focal length f of the lens satisfy: and f _s2/f is less than or equal to 1.4 and less than or equal to 1.8.

Specifically, the focal length f _s1 of the first lens group 100 and the focal length f of the lens satisfy: 1.2 < f _s1/f < 1.6, which enables large field light to pass through the subsequent lens group at a gentle angle; if the above condition (|f _s1/f|) is lower than the lower limit, the negative focal length absolute value is reduced, the off-axis aberration is increased, which is unfavorable for aberration balance, and the aperture of the rear lens is also increased, which is unfavorable for miniaturization of the lens; if the above conditional expression |f _s1/f| is higher than the upper limit, the negative focal length absolute value increases, and the overall length of the lens will be lengthened, which is also unfavorable for the realization of miniaturization of the lens. The focal length fs2 of the second lens group 200 and the focal length f of the lens satisfy: 1.4.ltoreq.f _s2/f.ltoreq.1.8, which may be that on-axis field light passes through the aperture 300 at a more gentle small angle; if the above conditional expression |f _s2/f| is lower than the lower limit, the positive focal length absolute value is reduced, the spherical aberration is increased, the tolerance sensitivity of the lens group is increased, and the assembly stability is not facilitated; if the above conditional expression |f _s2/f| is higher than the upper limit, the positive focal length absolute value increases, and the overall length of the lens will be lengthened, which is unfavorable for the realization of miniaturization of the lens.

The lens is formed by sequentially arranging a first lens group 100 with negative focal power, a second lens group 200 with positive focal power, a diaphragm 300 and a third lens group 400 with positive focal power from an object side to an image side along an optical axis, enabling a focal length fs1 of the first lens group 100 and a focal length f of the lens to meet a condition of 1.2 < f _s1/f < 1.6, enabling a focal length fs2 of the second lens group 200 and a focal length f of the lens to meet a condition of 1.4 < f _s2/f < 1.8, and enabling the whole group of the first lens group 100, the second lens group 200, the diaphragm 300 and the third lens group 400 to move in the optical axis direction for focusing, thereby realizing wide-angle large aperture, low distortion, clear imaging and high contrast imaging requirements.

In one embodiment, as shown in fig. 1 and 2, the first lens group 100 includes a first lens 110 having positive power and a meniscus structure, a second lens 120 having negative power and a meniscus structure, a third lens 130 having negative power and a meniscus structure, a fourth lens 141 having negative power and a biconcave structure, and a fifth lens 142 having positive power and a biconvex structure, which are sequentially disposed from an object side to an image side along an optical axis.

Specifically, the first lens group 100 can effectively reduce distortion and spherical aberration of the whole optical imaging system by reasonably matching lenses with positive and negative focal powers, and make incident light rays with large angles integrally diverge and then smoothly enter subsequent light paths.

In a specific embodiment, as shown in fig. 1 and 2, the fourth lens 141 and the fifth lens 142 are cemented into a first cemented lens group 140.

Specifically, the fourth lens element 141 and the fifth lens element 142 are bonded to form the first bonding lens group 140, which can correct chromatic aberration of the imaging system by reasonably matching with optical materials, effectively ensure color reproducibility of a picture, and reduce tolerance sensitivity and improve imaging effect.

In the embodiment of the application, one end face of the lens with the meniscus structure is outwards convex, and the other end face is plane or inwards concave; the two end faces of the lens with the biconcave structure are concave inwards, the two end faces of the lens with the biconvex structure are convex outwards, and the meniscus structure, the biconcave structure and the biconvex structure are in three different structural forms of the lens.

In one embodiment, as shown in fig. 1-3, the second lens group 200 includes at least a sixth lens 210 having positive optical power and a biconvex structure.

Specifically, the second lens group 200 includes at least one lens with positive power, which can further converge the light passing through the first lens group 100 and reduce aberration of the imaging system.

In one embodiment, as shown in fig. 1 and 2, the third lens group 400 includes an eighth lens 412 having positive power and a meniscus structure, a ninth lens 421 having positive power and a biconvex structure, a tenth lens 422 having negative power and a meniscus structure, and an eleventh lens 430 having positive power and a biconvex structure, which are sequentially disposed from an object side to an image side along an optical axis.

Specifically, the third lens group 400 can reduce the aberration of the system by properly matching the positive and negative power lenses.

In a specific embodiment, as shown in fig. 1 and 2, the ninth lens 421 and the tenth lens 422 are cemented into a second cemented lens group 420.

Specifically, the ninth lens 421 and the tenth lens 422 are glued to form the second gluing lens group 420, which can reasonably correct chromatic aberration, reduce the incident angle of light, reduce the tolerance sensitivity of the optical system, and effectively improve the imaging quality of the whole optical system.

In another embodiment, as shown in fig. 3, the third lens group 400 includes a seventh lens 411 having positive power and a biconvex structure, an eighth lens 412 having negative power and a biconcave structure, a ninth lens 421 having positive power and a biconcave structure, a tenth lens 422 having negative power and a meniscus structure, and an eleventh lens 430 having positive power and a biconvex structure, which are sequentially disposed from the object side to the image side along the optical axis.

Specifically, in the present embodiment, the third lens group 400 functions the same as the third lens group 400 in the above-described embodiments, and the difference is mainly that the arrangement of the respective lenses of the third lens group 400 is different, but the aberration of the system can still be reduced.

In another specific embodiment, as shown in fig. 3, the seventh lens 411 and the eighth lens 412 are cemented into a third cemented lens group 410, and the ninth lens 421 and the tenth lens 422 are cemented into a second cemented lens group 420.

Specifically, the seventh lens 411 and the eighth lens 412 are cemented to form the third cemented lens group 410, and the ninth lens 421 and the tenth lens 422 are cemented to form the second cemented lens group 420, so that chromatic aberration can be reasonably corrected, meanwhile, the incident angle of light is reduced, the tolerance sensitivity of the optical system is reduced, and the imaging quality of the whole optical system is effectively improved.

In a specific embodiment, focal length f _s3i of eleventh lens 430 satisfies: f _s3i is more than or equal to 24.00 and less than or equal to 28.00.

Specifically, the eleventh lens 430 is the lens closest to the image side in the third lens group 400, and the focal length f _s3i of the lens satisfies: and f _s3i is more than or equal to 24.00 and less than or equal to 28.00, and the residual spherical aberration generated by the front lens group can be effectively compensated, so that the resolution of the lens is effectively improved. If the focal length f _s3i of the eleventh lens 430 is higher than 28.00, the back focus will be increased, which is disadvantageous for miniaturization of the lens.

In one embodiment, the back focal length BFL of the lens and the image plane full field height H of the lens satisfy: BFL/H is more than or equal to 0.7 and less than or equal to 0.9.

Specifically, the back focal length of the lens and the full view field height of the image surface of the lens meet the above conditions, so that the incidence angle of the principal ray of the image surface can be effectively reduced, and the relative illuminance of the system is improved. If the conditional BFL/H is lower than 0.7, the back focal length is reduced, the incidence angle of the image plane of the main light is increased, and the relative illuminance is reduced; if BFL/H is higher than 0.9, the back focal length increases, and the overall length of the lens also increases, which is unfavorable for miniaturization of the lens.

In a specific embodiment, taking a lens layout diagram of the lens shown in fig. 1 as an example, parameters of each lens therein are illustrated as follows:

Wherein the mirrors of the lenses are arranged in order from the object side to the image side along the optical axis, for example: mirror 1 and mirror 2 of the first lens 110, mirror 3 and mirror 4 of the second lens 120, and so on, the diaphragm 300 can be regarded as mirror 14 (not shown in the table of the surface number 14).

In this embodiment, the total optical length ttl= 77.40mm, the aperture F1.40, the focal length f=12.35 mm, the back focal length bfl=12.81 mm, and the total image height h=16.00 mm.

As shown in fig. 4, an MTF (thermal refining transfer function) diagram of the lens provided by this embodiment is shown, with the abscissa representing the normalized field of view height, the ordinate representing the MTF value, the solid line representing the meridian direction, and the broken line representing the arc loss direction; from the graph, the maximum frequency of 1001p/mm shows that the MTF value of the central view field is larger than 0.70, the MTF value of the edge view field is larger than 0.4, the imaging performance is excellent, and the near infrared camera with 5 mu pixels can be matched.

As shown in fig. 5, a distortion graph of the lens provided by the embodiment is shown, wherein the distortion graph represents the distortion percentage of the lens along with the change of the field of view, and the abscissa represents the distortion percentage and the ordinate represents the normalized field of view height; it can be seen from the figure that at the maximum field of view, the maximum distortion is 2%.

As shown in fig. 6, an axial aberration curve of the lens provided by this embodiment is shown, where the axial aberration curve represents axial aberration of the lens along with the change of the aperture, where three curves respectively correspond to axial aberration at a wavelength of 0.750 μm, a wavelength of 1.050 μm, and a wavelength of 1.400 μm, an abscissa represents an axial aberration value, and an ordinate represents a normalized field of view height; it can be seen from the figure that the subject is less likely to be dispersed when the axial chromatic aberration is less than 0.02 mm.

As shown in fig. 7, a graph of the relative illuminance of the lens provided by this embodiment is shown, which represents the relative illuminance of the lens as a function of the field of view, wherein the abscissa represents the normalized field of view height and the ordinate represents the illuminance ratio with respect to the central field of view; it can be seen from the figure that at maximum field of view, the relative illuminance is greater than 0.52, and the edges have no apparent dark angle.

According to another aspect of the present application, an embodiment of the present application also provides an image pickup apparatus including the lens in any of the above embodiments.

It will be appreciated that the imaging apparatus, due to the inclusion of the lens described above, also has the advantages and benefits of the lens described above, with large aperture, low distortion, clear imaging, and high contrast.

In addition, the lens can be applied to not only a machine vision system, but also security monitoring equipment, a video recorder, a camera and the like.

In summary, implementing the lens and the image capturing apparatus provided in this embodiment has at least the following beneficial effects:

The technical features of the above embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The foregoing examples illustrate only a few embodiments of the utility model, which are described in detail and are not to be construed as limiting the scope of the claims. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the utility model, which are all within the scope of the utility model. Accordingly, the scope of protection of the present utility model is to be determined by the appended claims.

Claims

1. A lens, comprising:

A first lens group (100) having negative optical power, a second lens group (200) having positive optical power, a stop (300), and a third lens group (400) having positive optical power, which are disposed in order from an object side to an image side along an optical axis;

The focal length f _s1 of the first lens group (100) and the focal length f of the lens satisfy: 1.2 is less than or equal to |f _s1/f is less than or equal to 1.6;

The focal length f _s2 of the second lens group (200) and the focal length f of the lens satisfy: 1.4 is less than or equal to |f _s2/f is less than or equal to 1.8;

The third lens group (400) comprises a seventh lens (411) with positive focal power and a biconvex structure, an eighth lens (412) with negative focal power and a biconcave structure, a ninth lens (421) with positive focal power and a biconcave structure, a tenth lens (422) with negative focal power and a meniscus structure, and an eleventh lens (430) with positive focal power and a biconvex structure, which are sequentially arranged from the object side to the image side along an optical axis;

The seventh lens (411) and the eighth lens (412) are cemented into a third cemented lens group (410), and the ninth lens (421) and the tenth lens (422) are cemented into a second cemented lens group (420).

2. The lens according to claim 1, wherein the first lens group (100) includes a first lens (110) having positive power and a meniscus structure, a second lens (120) having negative power and a meniscus structure, a third lens (130) having negative power and a meniscus structure, a fourth lens (141) having negative power and a biconcave structure, and a fifth lens (142) having positive power and a biconvex structure, which are disposed in order from an object side to an image side along an optical axis.

3. The lens according to claim 2, characterized in that the fourth lens (141) and the fifth lens (142) are cemented into a first cemented lens group (140).

4. The lens according to claim 1, characterized in that the second lens group (200) comprises a sixth lens (210) having positive optical power and a biconvex structure.

5. The lens according to claim 1, wherein the third lens group (400) includes an eighth lens (412) having positive power and a meniscus structure, a ninth lens (421) having positive power and a biconvex structure, a tenth lens (422) having negative power and a meniscus structure, and an eleventh lens (430) having positive power and a biconvex structure, which are disposed in order from an object side to an image side along an optical axis.

6. The lens according to claim 5, characterized in that the ninth lens (421) and the tenth lens (422) are cemented into a second cemented lens group (420).

7. A lens according to claim 5 or 6, characterized in that the focal length f _s3i of the eleventh lens (430) satisfies: f _s3i is more than or equal to 24.00 and less than or equal to 28.00.

8. The lens of claim 1, wherein a back focal length BFL of the lens and an image plane full field height H of the lens satisfy: BFL/H is more than or equal to 0.7 and less than or equal to 0.9.