阅读说明：本技术 光学镜头 (Optical lens ) 是由 王东方 栾晓宇 姚波 于 2018-06-22 设计创作，主要内容包括：本申请公开了一种光学镜头,该光学镜头沿着光轴由物侧至像侧依序可包括：第一透镜、第二透镜、第三透镜、第四透镜、第五透镜和第六透镜。其中,第一透镜可具有负光焦度,其物侧面为凸面,像侧面为凹面；第二透镜可具有负光焦度,其物侧面为凸面,像侧面为凹面；第三透镜可具有正光焦度,其物侧面为凹面,像侧面为凸面；以及第四透镜可具有正光焦度,其物侧面和像侧面均为凸面。根据本申请的光学镜头,可实现小型化、高解像、低成本、大视场角、小畸变等中的至少一个有益效果。(The present application discloses an optical lens, which sequentially comprises, from an object side to an image side along an optical axis: the lens includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens. The first lens can have negative focal power, and the object side surface of the first lens is a convex surface, and the image side surface of the first lens is a concave surface; the second lens can have negative focal power, and the object side surface of the second lens is a convex surface, and the image side surface of the second lens is a concave surface; the third lens can have positive focal power, and the object side surface of the third lens is a concave surface, and the image side surface of the third lens is a convex surface; and the fourth lens may have a positive optical power, with both the object-side surface and the image-side surface being convex. According to the optical lens of the present application, at least one advantageous effect of miniaturization, high resolution, low cost, a large angle of view, small distortion, and the like can be achieved.)

1. The optical lens sequentially comprises from an object side to an image side along an optical axis: a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens,

it is characterized in that the preparation method is characterized in that,

the first lens has negative focal power, the object side surface of the first lens is a convex surface, and the image side surface of the first lens is a concave surface;

the second lens has negative focal power, the object side surface of the second lens is a convex surface, and the image side surface of the second lens is a concave surface;

the third lens has positive focal power, the object side surface of the third lens is a concave surface, and the image side surface of the third lens is a convex surface; and

the fourth lens has positive focal power, and both the object-side surface and the image-side surface of the fourth lens are convex surfaces.

2. An optical lens barrel according to claim 1, wherein the fifth lens element has a positive optical power, and both the object-side surface and the image-side surface thereof are convex.

3. An optical lens barrel according to claim 1, wherein the sixth lens element has a negative power, and has a concave object-side surface and a convex image-side surface.

4. An optical lens according to claim 1, wherein the fifth lens and the sixth lens are cemented to each other to constitute a cemented lens.

5. An optical lens according to claim 1, wherein the first lens to the sixth lens are all glass lenses.

6. An optical lens according to claim 1, characterized in that the optical lens has at least two aspherical lenses.

7. An optical lens according to claim 6, wherein at least two of the second lens, the third lens and the fourth lens are aspheric lenses.

8. An optical lens barrel according to any one of claims 1 to 7, wherein the second lens satisfies the conditional expression:

0.5≤R3/(R4+d3)≤3

wherein R3 is the radius of curvature of the object-side surface of the second lens;

r4 is the radius of curvature of the image-side surface of the second lens; and

d3 is the center thickness of the second lens.

9. An optical lens barrel according to any one of claims 1 to 7, wherein the third lens satisfies the conditional expression:

|R6|/(|R5|+d5)≤1.5

wherein R5 is a radius of curvature of an object-side surface of the third lens;

r6 is the radius of curvature of the image-side surface of the third lens; and

d5 is the center thickness of the third lens.

10. An optical lens according to any one of claims 1 to 7, wherein the optical lens satisfies the conditional expression:

(FOV×F)/Y≤78

wherein the FOV is the maximum field angle of the optical lens;

f is the whole group of focal length values of the optical lens; and

and Y is the image height corresponding to the maximum field angle of the optical lens.

11. An optical lens barrel according to any one of claims 1 to 7, wherein a distance TTL between a center of an object side surface of the first lens and an imaging surface of the optical lens on the optical axis and a full group focal length value F of the optical lens satisfy: TTL/F is less than or equal to 7.5.

12. The optical lens sequentially comprises from an object side to an image side along an optical axis: a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens,

it is characterized in that the preparation method is characterized in that,

the first lens, the second lens and the sixth lens each have a negative optical power;

the third lens, the fourth lens and the fifth lens each have positive optical power;

the fifth lens and the sixth lens are mutually glued to form a cemented lens; and

the radius of curvature R5 of the object side surface of the third lens, the radius of curvature R6 of the image side surface of the third lens and the center thickness d5 of the third lens satisfy: i R6I/(IR 5I + d5) is less than or equal to 1.5.

Technical Field

The present application relates to an optical lens, and more particularly, to an optical lens including six lenses.

Background

With the rapid development of science and technology, the performance requirement of an optical lens is higher and higher, and the function of a vehicle-mounted lens (especially a side-view lens or a around-view lens) needs high resolution and small aberration, and the characteristic of small distortion is required under the condition of meeting a large angle.

Resolution can be generally improved by increasing the number of lenses, and aberrations can be corrected using aspherical surfaces. The increase of the lens can increase the volume of the lens, which is not beneficial to miniaturization and is contrary to the miniaturization trend of modern optical systems; the aspheric surface is adopted, and if a plastic lens is adopted, the plastic has a large thermal expansion coefficient, so that the defocused image blurring problem caused by temperature change exists; if a glass aspheric surface is used, the cost is too high. The field angle requirement of the vehicle-mounted lens is higher and higher, and the requirement of large angle is met, and the problem of small distortion is also solved.

Disclosure of Invention

The present application provides an optical lens that is adaptable for on-board installation and that overcomes, at least in part, at least one of the above-identified deficiencies in the prior art.

An aspect of the present application provides an optical lens that may include, in order from an object side to an image side along an optical axis: the lens includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens. The first lens can have negative focal power, and the object side surface of the first lens is a convex surface, and the image side surface of the first lens is a concave surface; the second lens can have negative focal power, and the object side surface of the second lens is a convex surface, and the image side surface of the second lens is a concave surface; the third lens can have positive focal power, and the object side surface of the third lens is a concave surface, and the image side surface of the third lens is a convex surface; and the fourth lens may have a positive optical power, with both the object-side surface and the image-side surface being convex.

In one embodiment, the fifth lens can have a positive optical power, and both the object-side surface and the image-side surface can be convex.

In one embodiment, the sixth lens element can have a negative power, and the object-side surface can be concave and the image-side surface can be convex.

In one embodiment, the fifth lens and the sixth lens may be cemented with each other to constitute a cemented lens.

In one embodiment, each of the first to sixth lenses may be a glass lens.

In one embodiment, the optical lens may have at least two aspheric lenses.

In one embodiment, at least two of the second lens, the third lens and the fourth lens may be aspheric lenses.

In one embodiment, the second lens may satisfy the conditional expression: R3/(R4+ d3) is more than or equal to 0.5 and less than or equal to 3, wherein R3 is the curvature radius of the object side surface of the second lens; r4 is the radius of curvature of the image-side surface of the second lens; and d3 is the center thickness of the second lens.

In one embodiment, the third lens may satisfy the conditional expression: i R6I/(IR 5I + d5) is less than or equal to 1.5, wherein R5 is the curvature radius of the object side surface of the third lens; r6 is the radius of curvature of the image-side surface of the third lens; and d5 is the center thickness of the third lens.

In one embodiment, the optical lens may satisfy the conditional expression: (FOV xF)/Y is less than or equal to 78, wherein the FOV is the maximum field angle of the optical lens; f is the whole group of focal length values of the optical lens; and Y is the image height corresponding to the maximum field angle of the optical lens.

In one embodiment, a distance TTL between a center of an object side surface of the first lens element and an imaging surface of the optical lens on an optical axis and a full-group focal length value F of the optical lens may satisfy: TTL/F is less than or equal to 7.5.

Another aspect of the present application provides an optical lens that may include, in order from an object side to an image side along an optical axis: the lens includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens. The first lens, the second lens and the sixth lens can all have negative focal power; the third lens, the fourth lens and the fifth lens can all have positive focal power; the fifth lens and the sixth lens can be mutually glued to form a cemented lens; and the radius of curvature R5 of the object-side surface of the third lens, the radius of curvature R6 of the image-side surface of the third lens, and the center thickness d5 of the third lens may satisfy: i R6I/(IR 5I + d5) is less than or equal to 1.5.

In one embodiment, the object-side surface of the first lens element can be convex and the image-side surface can be concave.

In one embodiment, the object-side surface of the second lens element can be convex and the image-side surface can be concave.

In one embodiment, the object-side surface of the third lens element can be concave and the image-side surface can be convex.

In one embodiment, both the object-side surface and the image-side surface of the fourth lens can be convex.

In one embodiment, both the object-side surface and the image-side surface of the fifth lens can be convex.

In one embodiment, the object-side surface of the sixth lens element can be concave, and the image-side surface can be convex.

In one embodiment, each of the first to sixth lenses may be a glass lens.

In one embodiment, the optical lens may have at least two aspheric lenses.

In one embodiment, at least two of the second lens, the third lens and the fourth lens may be aspheric lenses.

In one embodiment, the second lens may satisfy the conditional expression: R3/(R4+ d3) is more than or equal to 0.5 and less than or equal to 3, wherein R3 is the curvature radius of the object side surface of the second lens; r4 is the radius of curvature of the image-side surface of the second lens; and d3 is the center thickness of the second lens.

In one embodiment, the optical lens may satisfy the conditional expression: (FOV xF)/Y is less than or equal to 78, wherein the FOV is the maximum field angle of the optical lens; f is the whole group of focal length values of the optical lens; and Y is the image height corresponding to the maximum field angle of the optical lens.

In one embodiment, a distance TTL between a center of an object side surface of the first lens element and an imaging surface of the optical lens on an optical axis and a full-group focal length value F of the optical lens may satisfy: TTL/F is less than or equal to 7.5.

The optical lens adopts six lenses, and at least one of the beneficial effects of high resolution, miniaturization, low cost, large field angle, small distortion and the like of the optical lens is realized by optimally setting the shapes of the lenses, reasonably distributing the focal power of each lens and the like.

Drawings

Other features, objects, and advantages of the present application will become more apparent from the following detailed description of non-limiting embodiments when taken in conjunction with the accompanying drawings. In the drawings:

fig. 1 is a schematic view showing a structure of an optical lens according to embodiment 1 of the present application;

fig. 2 is a schematic structural view showing an optical lens according to embodiment 2 of the present application; and

fig. 3 is a schematic view showing a structure of an optical lens according to embodiment 3 of the present application.

Detailed Description

For a better understanding of the present application, various aspects of the present application will be described in more detail with reference to the accompanying drawings. It should be understood that the detailed description is merely illustrative of exemplary embodiments of the present application and does not limit the scope of the present application in any way. Like reference numerals refer to like elements throughout the specification. The expression "and/or" includes any and all combinations of one or more of the associated listed items.

It should be noted that in this specification, the expressions first, second, third, etc. are used only to distinguish one feature from another, and do not represent any limitation on the features. Thus, the first lens discussed below may also be referred to as the second lens or the third lens, and the first cemented lens may also be referred to as the second cemented lens, without departing from the teachings of the present application.

In the drawings, the thickness, size, and shape of the lens have been slightly exaggerated for convenience of explanation. In particular, the shapes of the spherical or aspherical surfaces shown in the drawings are shown by way of example. That is, the shape of the spherical surface or the aspherical surface is not limited to the shape of the spherical surface or the aspherical surface shown in the drawings. The figures are purely diagrammatic and not drawn to scale.

Herein, the paraxial region refers to a region near the optical axis. If the lens surface is convex and the convex position is not defined, it means that the lens surface is convex at least in the paraxial region; if the lens surface is concave and the concave position is not defined, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the object is called the object side surface, and the surface of each lens closest to the image plane is called the image side surface.

It will be further understood that the terms "comprises," "comprising," "has," "having," "includes" and/or "including," when used in this specification, specify the presence of stated features, elements, and/or components, but do not preclude the presence or addition of one or more other features, elements, components, and/or groups thereof. Moreover, when a statement such as "at least one of" appears after a list of listed features, the entirety of the listed features is modified rather than modifying individual elements in the list. Furthermore, when describing embodiments of the present application, the use of "may" mean "one or more embodiments of the present application. Also, the term "exemplary" is intended to refer to an example or illustration.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present application will be described in detail below with reference to the embodiments with reference to the attached drawings.

The features, principles, and other aspects of the present application are described in detail below.

An optical lens according to an exemplary embodiment of the present application includes, for example, six lenses having optical power, i.e., a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens. The six lenses are arranged in order from the object side to the image side along the optical axis.

The optical lens according to the exemplary embodiment of the present application may further include a photosensitive element disposed on the image plane. Alternatively, the photosensitive element provided to the imaging surface may be a photosensitive coupling element (CCD) or a complementary metal oxide semiconductor element (CMOS).

The first lens element can have a negative power, and can have a convex object-side surface and a concave image-side surface. The first lens is arranged in a meniscus shape which is convex towards the object side, so that light rays with a large field of view can be collected as far as possible and enter a rear optical system. In practical application, the outdoor installation and use environment of the vehicle-mounted lens is considered, the vehicle-mounted lens can be in severe weather such as rain and snow, the design of the meniscus shape protruding towards the object side is more suitable for the environments such as rain and snow, the water drops can slide off, and the influence of the external environment on imaging is reduced. Furthermore, the first lens can adopt a high-refractive-index material, for example, the refractive index Nd1 of the material of the first lens is larger than or equal to 1.7, so as to be beneficial to reducing the front-end aperture and improving the imaging quality.

The second lens element can have a negative power, and can have a convex object-side surface and a concave image-side surface. The second lens can disperse light, so that the trend of the light is stably transited to a rear system, and meanwhile, the large-angle light enters the optical system as far as possible, and the illumination is favorably improved.

The third lens element can have a positive optical power, and can have a concave object-side surface and a convex image-side surface. The third lens can converge the light, so that the diffused light can smoothly enter the rear system. The third lens is provided with positive focal power and can compensate spherical aberration introduced by the first two groups of lenses; and the second lens and the first lens are arranged oppositely, which is beneficial to realizing the requirements of miniaturization and large field angle and meeting the characteristic of small distortion.

The fourth lens element can have a positive optical power, and can have a convex object-side surface and a convex image-side surface. The fourth lens can converge light rays, further collects the light rays and is beneficial to shortening the physical total length of the optical system.

The fifth lens element can have a positive optical power, and can have a convex object-side surface and a convex image-side surface.

The sixth lens element can have a negative power, and can have a concave object-side surface and a convex image-side surface.

As known to those skilled in the art, cemented lenses may be used to minimize or eliminate chromatic aberration. The use of the cemented lens in the optical lens can improve the image quality and reduce the reflection loss of light energy, thereby improving the imaging definition of the lens. In addition, the use of the cemented lens can also simplify the assembly process in the lens manufacturing process.

In an exemplary embodiment, the fifth lens and the sixth lens may be combined into a cemented lens by cementing the image-side surface of the fifth lens with the object-side surface of the sixth lens. By introducing the cemented lens consisting of the fifth lens and the sixth lens, the chromatic aberration influence can be eliminated, the field curvature is reduced, and the coma is corrected; meanwhile, the cemented lens may also retain a part of chromatic aberration to balance the entire chromatic aberration of the optical system. The air space between the two lenses is omitted by gluing the lenses, so that the optical system is compact as a whole, and the requirement of system miniaturization is met. In addition, the gluing of the lenses can reduce tolerance sensitivity problems of lens units due to tilt/decentration during assembly.

In the cemented lens, the fifth lens close to the object side has positive focal power, and the sixth lens close to the image side has negative focal power, so that the arrangement is favorable for further and smooth transition of light rays passing through the fourth lens to a rear optical system, and the total length of the system is favorably reduced so as to realize short TTL.

In an exemplary embodiment, a diaphragm for limiting the light beam may be disposed between, for example, the third lens and the fourth lens to further improve the imaging quality of the lens. When the diaphragm is arranged at the position, the front and the rear light rays can be effectively converged, the total length of the optical system is shortened, and the calibers of the front and the rear lens groups are reduced. It should be noted, however, that the positions of the diaphragms disclosed herein are merely examples and not limitations; in alternative embodiments, the diaphragm may be disposed at other positions according to actual needs.

In an exemplary embodiment, the optical lens according to the present application may further include a filter disposed between the sixth lens and the imaging surface to filter light rays having different wavelengths, as necessary; and may further include a protective glass disposed between the optical filter and the imaging surface to prevent internal elements (e.g., chips) of the optical lens from being damaged.

In the exemplary embodiment, the radius of curvature R3 of the object-side surface of the second lens, the radius of curvature R4 of the image-side surface of the second lens, and the center thickness d3 of the second lens may satisfy 0.5. ltoreq. R3/(R4+ d 3). ltoreq.3, and more desirably, may further satisfy 0.6. ltoreq. R3/(R4+ d 3). ltoreq.2.8.

In an exemplary embodiment, the radius of curvature R5 of the object-side surface of the third lens, the radius of curvature R6 of the image-side surface of the third lens, and the center thickness d5 of the third lens can satisfy | R6|/(| R5| + d5) ≦ 1.5, and more desirably, can further satisfy | R6|/(| R5| + d5) ≦ 1. As described above, the second lens and the third lens are provided in a specific shape and are opposed to each other, which contributes to the demand for a smaller size and a larger angle of view and satisfies the characteristic of small distortion.

In an exemplary embodiment, the conditional expression may be satisfied between the maximum field angle FOV of the optical lens, the entire group of focal length values F of the optical lens, and the image height Y corresponding to the maximum field angle of the optical lens: (FOV × F)/Y.ltoreq.78, and more desirably, (FOV × F)/Y.ltoreq.75 can be further satisfied. By satisfying the conditional expression (FOV F)/Y ≦ 78, it is helpful for the optical lens to realize a small distortion characteristic.

In an exemplary embodiment, TTL/F ≦ 7.5 is satisfied between the total optical length TTL of the optical lens and the entire set of focal length values F of the optical lens, and more desirably, TTL/F ≦ 7.4 may be further satisfied. With such an arrangement, the miniaturization characteristic is facilitated.

In an exemplary embodiment, an optical lens according to the present application may have at least 2 aspherical lenses. The aspheric lens has the characteristics that: the curvature varies continuously from the center of the lens to the periphery. Unlike a spherical lens having a constant curvature from the center to the periphery of the lens, an aspherical lens has better curvature radius characteristics, and has the advantages of improving distortion aberration and improving astigmatic aberration. After the aspheric lens is adopted, the aberration generated in imaging can be eliminated as much as possible, so that the imaging quality of the lens is improved. For example, the second lens element, the third lens element and the fourth lens element have at least two aspheric lens elements, which can be beneficial to improve the resolution and correct the aberration. Ideally, the fourth lens is an aspherical mirror. The first lens can also adopt an aspheric lens to improve the resolution quality. It is understood that the optical lens according to the present application may increase the number of aspherical lenses in order to improve the imaging quality.

In an exemplary embodiment, the lens used in the optical lens may be a plastic lens, or may be a glass lens. The lens made of plastic has a large thermal expansion coefficient, and when the ambient temperature change of the lens is large, the lens made of plastic causes a large amount of change of the optical back focus of the lens. The glass lens can reduce the influence of temperature on the optical back focus of the lens. According to the application, the first lens of the optical lens can adopt the glass lens so as to enhance the performance of the lens under the conditions of high temperature and low temperature, reduce the influence of the environment on the whole system and improve the overall performance of the optical lens. Furthermore, the first lens can adopt a glass aspheric lens, so that the resolving power is further improved, and the caliber of the front end is reduced. Desirably, glass lenses are used for the first to sixth lenses.

According to the optical lens of the embodiment of the application, the shape of the lens is optimally set, the focal power is reasonably distributed, the front end aperture can be reduced, the TTL is shortened, the miniaturization of the lens is ensured, and meanwhile, the high resolution and the large field angle are realized; in addition, the second lens and the third lens are arranged in a manner of facing each other (the second lens has a convex meniscus shape toward the object side, and the third lens has a convex meniscus shape toward the image side), which contributes to a small size and a large field angle, and satisfies a small distortion characteristic.

However, it will be appreciated by those skilled in the art that the number of lenses constituting the lens barrel may be varied to achieve the various results and advantages described in the present specification without departing from the claimed subject matter. For example, although six lenses are exemplified in the embodiment, the optical lens is not limited to including six lenses. The optical lens may also include other numbers of lenses, if desired.

Specific examples of an optical lens applicable to the above-described embodiments are further described below with reference to the drawings.