CN111983785A

CN111983785A - Optical imaging system, image capturing module and electronic device

Info

Publication number: CN111983785A
Application number: CN202010955203.1A
Authority: CN
Inventors: 谭怡翔; 刘秀; 党绪文; 李明
Original assignee: OFilm Tech Co Ltd
Current assignee: Nanchang OFilm Precision Optical Products Co Ltd; OFilm Group Co Ltd
Priority date: 2020-09-11
Filing date: 2020-09-11
Publication date: 2020-11-24

Abstract

The invention provides an optical imaging system, an image capturing module and an electronic device. The optical imaging system comprises the following components in sequence from an object side to an image side: a first lens element with negative refractive power; a second lens element and a third lens element with refractive power; a fourth lens element with positive refractive power having a convex object-side surface and a convex image-side surface; a fifth lens element with negative refractive power; a sixth lens element with positive refractive power having a convex image-side surface along an optical axis; a seventh lens element with negative refractive power having a convex object-side surface and a concave image-side surface; the optical imaging system satisfies the following conditional expression: almax is less than or equal to 30 degrees; the optical imaging system comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an optical imaging system and an optical imaging system, wherein the optical imaging system comprises an object side surface, an image side surface and an effective optical area of the first lens, the fourth lens and the seventh lens, the effective optical area of the object side surface and the effective optical area of the image side surface of the first.

Description

Optical imaging system, image capturing module and electronic device

Technical Field

The present disclosure relates to optical imaging technologies, and particularly to an optical imaging system, an image capturing module and an electronic device.

Background

With the wide application of mobile phones, tablet computers, unmanned planes, computers and other electronic products in life, various electronic products with shooting functions are continuously emerging. The improvement and innovation of the shooting effect of the camera lens in the electronic product becomes one of the focuses of people, and meanwhile, the improvement of the technology becomes an important content, and whether a micro camera element can be used for shooting pictures with high picture quality, high resolution and high definition, even pictures with clear picture quality under the dark light condition becomes a key consideration factor for selecting the electronic product by modern people. Therefore, miniaturization and performance improvement of the optical system design become key factors for improving the shooting quality of the current camera.

In the process of implementing the present application, the inventor finds that at least the following problems exist in the prior art: the existing optical imaging system is difficult to realize a larger angle of view and better image quality simultaneously under the condition of keeping miniaturization.

Disclosure of Invention

In view of the above, it is desirable to provide an optical imaging system, an image capturing module and an electronic device to solve the above problems.

Embodiments of the present application provide an optical imaging system, in order from an object side to an image side, comprising: a first lens element with negative refractive power; a second lens element with refractive power; a third lens element with refractive power; the fourth lens element with positive refractive power has a convex object-side surface and a convex image-side surface; a fifth lens element with negative refractive power; the sixth lens element with positive refractive power has a convex image-side surface along an optical axis; the seventh lens element with negative refractive power has a convex object-side surface and a concave image-side surface; the optical imaging system satisfies the following conditional expression: almax is less than or equal to 30 degrees; the optical imaging system comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an optical imaging system and an optical imaging system, wherein the optical imaging system comprises an object side surface, an image side surface and an effective optical area of the first lens, the fourth lens and the seventh lens, the effective optical area of the object side surface and the effective optical area of the image side surface of the first.

The optical imaging system meets the above formula, and through reasonable arrangement of the surface type bending degree, the surface type complexity of all lenses in the optical imaging system is low, and the increase of field curvature and distortion in the T direction is inhibited to a certain extent; meanwhile, the forming difficulty is favorably reduced, and the integral image quality is improved. The optical imaging system of the embodiment of the application has the advantages that through the reasonable configuration of the lenses, the micro-design is met, the field angle is increased, the field angle is larger than that of a conventional lens, the relative brightness is improved, the viewing area is improved, and the optical imaging system can achieve high pixels and good image quality.

In some embodiments, the optical imaging system satisfies the following conditional expression:

FOV is more than or equal to 110 degrees, and FNO is less than or equal to 2.4;

wherein, FOV is the maximum field angle of the optical imaging system, and FNO is the f-number of the optical imaging system.

Satisfy the above formula, on the one hand, optical imaging system 10 can realize getting for instance at super wide angle to promote the area of finding a view and in order to obtain more image information, on the other hand, can also guarantee good luminous flux, and then improve optical imaging quality.

SD1/ImgH<0.57；

the SD1 is the vertical distance from the edge of the optically effective area of the object-side surface of the first lens element to the optical axis, and ImgH is half of the image height corresponding to the maximum field angle of the optical imaging system.

Satisfying the above formula, can making the bore of first lens object side relatively less to realize the characteristic of little head when satisfying super wide angle, reduced the required cavity area of optical imaging system for electronic equipment effectively, reduced the cost and the processing degree of difficulty, and then improved the yield, also made electronic equipment more pleasing to the eye.

FOV/f>71°/mm；

wherein FOV is the maximum field angle of the optical imaging system, and f is the focal length of the optical imaging system.

Satisfying the above formula, the optical imaging system can provide a field angle of over 110 degrees, and the viewing area of the picture can be effectively increased. Furthermore, the field angle can reach 124 degrees, the effective focal length is reduced, and the optical imaging system has certain microspur capability while accommodating more image capturing areas; through reasonable refractive power configuration, the capturing capability of the system on low-frequency details can be improved, and the design requirement of high image quality is met.

SD1/AT12<6.1；

wherein SD1 is the vertical distance from the edge of the optically effective area of the object-side surface of the first lens element to the optical axis, and AT12 is the distance between the image-side surface of the first lens element and the object-side surface of the second lens element on the optical axis.

SD1 represents the head size of the optical imaging system 10, affecting structural arrangement, assembly yield, etc.; the SD1 is effectively compressed, the size of the head can be reduced, the width of the optical imaging system perpendicular to the optical axis direction is reduced, the integral volume is compressed to a greater extent by matching with the reduction of AT12, the compactness of the optical imaging system is improved, and the ghost risk is reduced; on the other hand, the structure arrangement difficulty is reduced, and the assembly forming yield is improved.

0.64＜(|R62|+|R72|)/f＜0.94；

wherein R62 is a radius of curvature of an image-side surface of the sixth lens element at an optical axis, R72 is a radius of curvature of an image-side surface of the seventh lens element at a paraxial region, and f is a focal length of the optical imaging system.

The combined structure of the sixth lens and the seventh lens can counteract most of the distortion and coma generated by the front lens; through reasonable curvature radius setting, larger spherical aberration and vertical axis chromatic aberration can be avoided, so that reasonable distribution of primary aberration on each lens is facilitated, and tolerance sensitivity is reduced.

1.8＜(|f6|+|f7|)/f＜2.5；

wherein f6 is the focal length of the second lens, f7 is the focal length of the third lens, and f is the focal length of the optical imaging system.

The size of the sixth lens and the size of the seventh lens and the focal length of the optical imaging system are reasonably configured, so that large spherical aberration generated by the rear lens group can be avoided, and the integral resolving power of the optical imaging system is improved; meanwhile, the surface type complexity of the fifth lens group is favorably reduced, and the yield of the optical imaging system is favorably improved.

1.3＜(|CT3|+|CT4|+|CT5|)/BF＜1.8；

wherein CT3 is a thickness of the third lens element on an optical axis, CT4 is a thickness of the fourth lens element on an optical axis, CT5 is a thickness of the fifth lens element on an optical axis, and BF is a minimum distance between the sixth lens element and an image plane in an optical axis direction.

Satisfying the above formula, it can ensure that the optical imaging system 10 and the photosensitive element have sufficient matching space, which is beneficial to the improvement of the assembly yield. Meanwhile, the reasonable arrangement of the CT3, the CT4 and the CT5 can reduce the optical length, thereby being beneficial to forming symmetry and reducing optical distortion.

0.59＜|R71|/|f7|＜1.1；

wherein R71 is a radius of curvature of an object-side surface of the seventh lens at an optical axis, and f7 is a focal length of the seventh lens.

Through reasonable arrangement of focal power and curvature radius of the seventh lens, the surface type complexity of the seventh lens is low, and increase of field curvature and distortion in the T direction is restrained to a certain extent; the forming difficulty is favorably reduced, and the integral image quality is improved.

AT45/ET45<1.3；

wherein AT45 is the distance between the image-side surface of the fourth lens element and the object-side surface of the fifth lens element in the optical axis direction, and ET45 is the thickness of the edge of the optically effective area of the fifth lens element in the optical axis direction.

The fourth lens element and the fifth lens element are matched to form a certain matching shape, the fifth lens element has negative refractive power, the fourth lens element has refractive power, and the matching of the fourth lens element and the fifth lens element has a good chromatic aberration correction effect and a good spherical aberration correction effect, so that the system has good resolution power improvement. In addition, the reduction in size provides the convenience of promoting compactness and compact optical length of the system.

The first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens are all made of plastic materials.

Thus, the plastic lens can reduce the weight of the optical imaging system and reduce the production cost.

In some embodiments, the optical imaging system further comprises a diaphragm disposed between the third lens and the fourth lens.

The design of the middle diaphragm provides possibility for realizing a large visual angle. And moreover, the structure of the optical imaging system is symmetrical due to the middle diaphragm, so that optical distortion is well controlled.

The embodiment of the invention provides an image capturing module, which comprises an optical imaging system in any embodiment; and the photosensitive element is arranged on the image side of the optical imaging system.

The image capturing module comprises an optical imaging system, and through the reasonable configuration of the lenses, the micro-design is met, the field angle is increased and is larger than that of a conventional lens, the relative brightness is improved, the viewing area is increased, and the image capturing module can realize higher pixels and good image quality.

An embodiment of the present invention provides an electronic device, including: the casing with the module of getting for instance of above-mentioned embodiment, get for instance the module and install on the casing.

The electronic device comprises the image capturing module and an optical imaging system in the image capturing module, and can realize higher pixels and good image quality while meeting the requirement of micro design through the reasonable configuration of the lenses.

Drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

fig. 1 is a schematic structural view of an optical imaging system according to a first embodiment of the present invention.

Fig. 2 is a schematic view of spherical aberration (mm), astigmatism (mm), and distortion (%) of the optical imaging system in the first embodiment of the present invention.

Fig. 3 is a schematic structural view of an optical imaging system according to a second embodiment of the present invention.

Fig. 4 is a schematic view of spherical aberration (mm), astigmatism (mm), and distortion (%) of an optical imaging system in a second embodiment of the present invention.

Fig. 5 is a schematic structural view of an optical imaging system according to a third embodiment of the present invention.

Fig. 6 is a schematic view of spherical aberration (mm), astigmatism (mm), and distortion (%) of an optical imaging system in a third embodiment of the present invention.

Fig. 7 is a schematic structural view of an optical imaging system according to a fourth embodiment of the present invention.

Fig. 8 is a schematic view of spherical aberration (mm), astigmatism (mm), and distortion (%) of an optical imaging system in a fourth embodiment of the present invention.

Fig. 9 is a schematic structural view of an optical imaging system according to a fifth embodiment of the present invention.

Fig. 10 is a schematic view of spherical aberration (mm), astigmatism (mm), and distortion (%) of an optical imaging system in a fifth embodiment of the present invention.

Fig. 11 is a schematic structural diagram of an image capturing module according to an embodiment of the invention.

Fig. 12 is a schematic structural diagram of an electronic device according to an embodiment of the invention.

Description of the main elements

Electronic device 1000

Image capturing module 100

Optical imaging system 10

First lens L1

Second lens L2

Third lens L3

Fourth lens L4

Fifth lens L5

Sixth lens L6

Seventh lens L7

Infrared filter L8

Stop STO

Object sides S1, S3, S5, S7, S9, S11, S13, S15

Like sides S2, S4, S6, S8, S10, S12, S14, S16

Image plane S17

Photosensitive element 20

Housing 200

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", and the like, indicate orientations and positional relationships based on those shown in the drawings, and are used only for convenience of description and simplicity of description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be considered as limiting the present invention. Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", may explicitly or implicitly include one or more of the described features. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; may be mechanically connected, may be electrically connected or may be in communication with each other; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the present invention, unless otherwise expressly stated or limited, "above" or "below" a first feature means that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact with each other via another feature therebetween. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly above and obliquely above the second feature, or simply meaning that the first feature is at a lesser level than the second feature.

The following disclosure provides many different embodiments or examples for implementing different features of the invention. To simplify the disclosure of the present invention, the components and arrangements of specific examples are described below. Of course, they are merely examples and are not intended to limit the present invention. Furthermore, the present invention may repeat reference numerals and/or letters in the various examples, such repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed. In addition, the present invention provides examples of various specific processes and materials, but one of ordinary skill in the art may recognize applications of other processes and/or uses of other materials.

Referring to fig. 1, the optical imaging system 10 includes, in order from an object side to an image side, a first lens element L1 with negative refractive power, a second lens element L2 with refractive power, a third lens element L3 with refractive power, a fourth lens element L4 with positive refractive power, a fifth lens element L5 with negative refractive power, a sixth lens element L6 with positive refractive power and a seventh lens element L7 with negative refractive power. The image side of the optical imaging system 10 is also an image plane S17, and preferably, the image plane S17 may be the receiving surface of the photosensitive element.

The first lens L1 has an object-side surface S1 and an image-side surface S2; the second lens L2 has an object-side surface S3 and an image-side surface S4; the third lens L3 has an object-side surface S5 and an image-side surface S6; the fourth lens element L4 has an object-side surface S7 and an image-side surface S8, wherein the object-side surface S7 is convex along the optical axis, and the image-side surface S8 is convex along the optical axis; the fifth lens L5 has an object-side surface S9 and an image-side surface S10; the sixth lens element L6 has an object-side surface S11 and an image-side surface S12, the image-side surface S12 being convex along the optical axis; the seventh lens element L7 has an object-side surface S13 and an image-side surface S14, wherein the object-side surface S13 is convex along the optical axis, and the image-side surface S14 is concave along the optical axis.

The optical imaging system 10 satisfies the following conditional expressions:

Almax≤30°；

the optical imaging system 10 includes first through seventh lenses L1 through L7, each of which has a tangent plane in an optically effective area of an object-side surface and an image-side surface, the tangent plane intersects a plane perpendicular to an optical axis to form an acute angle, and Almax is a maximum value of the acute angle.

The optical imaging system has the advantages that the above formula is satisfied, and the reasonable arrangement of the surface type bending degree enables the surface type complexity of all the lenses in the optical imaging system to be low, so that the increase of field curvature and distortion in the T direction is restrained to a certain extent; meanwhile, the forming difficulty is favorably reduced, and the integral image quality is improved.

In the optical imaging system 10 of the embodiment of the application, through the configuration of the above reasonable lenses, the micro-design is satisfied, and meanwhile, the field angle is increased, which is larger than that of a conventional lens, so that the relative brightness is improved, the viewing area is increased, and the optical imaging system 10 can realize higher pixels and good image quality.

In some embodiments, the optical imaging system 10 satisfies the following conditional expressions:

FOV≥110°；

FNO≤2.4。

where FOV is the maximum field angle of the optical imaging system 10 and FNO is the f-number of the optical imaging system 10. The FOV may be 110 °, 112 °, 116 °, 120 °, 124 °, etc., and the FNO may be 2.4, 2.35, 2.3, 2.25, 2.2, etc.

SD1/ImgH<0.57；

wherein SD1 is the vertical distance from the optical axis to the edge of the optically effective area of the object-side surface S1 of the first lens L1, ImgH is half of the image height corresponding to the maximum field angle of the optical imaging system 10, and SD1/ImgH may be 0.562, 0.560, and the like.

Satisfying the above formula, the aperture of the object side S1 of the first lens L1 can be relatively small, so that the ultra-wide angle is satisfied, and the small head characteristic is realized, thereby effectively reducing the cavity area required by the optical imaging system 10 for the electronic device, reducing the cost and the processing difficulty, further improving the yield, and making the electronic device more beautiful.

FOV/f>71°/mm；

where FOV is the maximum field angle of the optical imaging system 10, f is the focal length of the optical imaging system, and FOV/f may be 71.35/mm, 80.08/mm, 85.48/mm, 92.02/mm, 99.28/mm, etc.

Satisfying the above formula, the optical imaging system 10 can provide a field angle of over 110 °, and can effectively increase the viewing area of the screen. Furthermore, the field angle can reach 124 degrees, the effective focal length is reduced, and the optical imaging system 10 has certain macro capability while accommodating more image capturing areas; through reasonable refractive power configuration, the capturing capability of the system on low-frequency details can be improved, and the design requirement of high image quality is met.

SD1/AT12<6.1；

wherein SD1 is the vertical distance from the edge of the optically effective area of the object-side surface S1 of the first lens L1 to the optical axis, AT12 is the distance between the image-side surface S2 of the first lens L1 and the object-side surface S3 of the second lens L2 on the optical axis, and SD1/AT12 can be 2.962, 4.403, 6.022, 6.055, 3.663, etc.

SD1 represents the head size of the optical imaging system 10, affecting structural arrangement, assembly yield, etc.; the SD1 is effectively compressed, the size of the head can be reduced, the width of the optical imaging system 10 perpendicular to the optical axis direction is reduced, the integral volume is compressed to a greater extent by matching with the reduction of AT12, the compactness of the optical imaging system 10 is improved, and the ghost risk is reduced; on the other hand, the structure arrangement difficulty is reduced, and the assembly forming yield is improved.

0.64＜(|R62|+|R72|)/f＜0.94；

where R62 is a curvature radius of the image-side surface S12 of the sixth lens element L6 at the optical axis, R72 is a curvature radius of the image-side surface S14 of the seventh lens element L7 at the paraxial region, f is a focal length of the optical imaging system 10, (| R62| + | R72|)/f may be any value in the range of (0.64,0.94), for example, 0.873, 0.642, 0.661, 0.939, 0.785, etc.

Satisfying the above formula, the combined structure of the sixth lens L6 and the seventh lens L7 can cancel most of the distortion and coma generated by the front lens; through reasonable curvature radius setting, larger spherical aberration and vertical axis chromatic aberration can be avoided, so that reasonable distribution of primary aberration on each lens is facilitated, and tolerance sensitivity is reduced.

1.8＜(|f6|+|f7|)/f＜2.5；

where f6 is the focal length of the second lens, f7 is the focal length of the third lens, and f is the focal length of the optical imaging system, (| f6| + | f7|)/f can be any value in the range of (1.8, 2.5), such as 2.435, 1.890, 1.930, 2.399, 2.251, etc.

Satisfying the above formula, the sizes of the sixth lens L6 and the seventh lens L7 and the focal length of the optical imaging system 10 are reasonably configured, so that a large spherical aberration generated by the rear lens group can be avoided, and the overall resolving power of the optical imaging system 10 is improved; meanwhile, the complexity of the surface shape of the fifth lens group is reduced, and the yield of the optical imaging system 10 is improved.

1.3＜(|CT3|+|CT4|+|CT5|)/BF＜1.8；

wherein CT3 is the optical-axis thickness of the third lens L3, CT4 is the optical-axis thickness of the fourth lens L4, CT5 is the optical-axis thickness of the fifth lens L5, and BF is the minimum distance between the sixth lens L6 and the image plane S17 in the optical-axis direction. (| CT3| + | CT4| + | CT5|)/BF may be any value within the range of (1.3, 1.8), for example, 1.377, 1.591, 1.533, 1.669, 1.719, etc.

0.59＜|R71|/|f7|＜1.1；

wherein R71 is a radius of curvature of the object-side surface S13 of the seventh lens L7 at the optical axis, and f7 is a focal length of the seventh lens L7. | R71|/| f7| may be any value within the range (0.59, 1.1), such as 0.802, 0.643, 0.670, 1.104, 0.590, etc.

The seventh lens L7 has low surface complexity by setting reasonable focal power and curvature radius of the seventh lens L7, and the increase of field curvature and distortion in the T direction is restrained to a certain degree; the forming difficulty is favorably reduced, and the integral image quality is improved.

AT45/ET45<1.3；

AT45 is the distance between the image-side surface S8 of the fourth lens element L4 and the object-side surface S9 of the fifth lens element L5 in the optical axis direction, and ET45 is the thickness of the fifth lens element L5 in the optical axis direction AT the edge of the optically effective area. AT45/ET45 can be 0.761, 0.953, 0.932, 0.838, 1.288, etc.

The fourth lens element L4 and the fifth lens element L5 form a certain matching shape, the fifth lens element L5 has negative refractive power, the fourth lens element L4 has refractive power, and the matching of the fourth lens element L4 and the fifth lens element L5 has a very good chromatic aberration correction effect and a good spherical aberration correction effect, so that the system has good resolution enhancement. In addition, the reduction in size provides the convenience of promoting compactness and compact optical length of the system.

In some embodiments, the optical imaging system 10 further includes a stop STO. The stop STO may be disposed before the first lens L1, after the seventh lens L7, between any two lenses, or on the surface of any one lens. The stop STO is used to reduce stray light, which is helpful to improve image quality. For example, in some embodiments, stop STO is disposed between third lens L3 and fourth lens L4. The design of the middle diaphragm provides possibility for realizing a large visual angle. Moreover, the central diaphragm makes the structure of the optical imaging system 10 in a certain symmetry, so that the optical distortion is better controlled.

In some embodiments, optical imaging system 10 further includes an infrared filter L8, infrared filter L8 having an object side S15 and an image side S16. The infrared filter L8 is disposed on the image-side surface S14 of the seventh lens element L7 to filter out light in other wavelength bands, such as visible light, and only let infrared light pass through, so that the optical imaging system 10 can also image in a dark environment and other special application scenarios.

When the optical imaging system 10 is used for imaging, light rays emitted or reflected by a subject enter the optical imaging system 10 from the object side direction, pass through the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7 and the infrared filter L8 in sequence, and finally converge on the image plane S17.

In some embodiments, the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6 and the seventh lens L7 are all made of plastic. In this case, the plastic lens can reduce the weight of the optical imaging system 10 and reduce the production cost. In other embodiments, each lens may be made of glass, or any combination of plastic and glass.

In some embodiments, at least one surface of at least one lens in the optical imaging system 10 is aspheric, which is beneficial for correcting aberration and improving imaging quality. For example, in the first embodiment, the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, and the seventh lens L7 in the optical imaging system 10 are all aspheric. The aspheric lens can achieve more light refraction angles, so that the whole optical imaging system 10 achieves the requirement of high pixel.

The aspherical surface has a surface shape determined by the following formula:

wherein Z is the distance from the corresponding point on the aspheric surface to the plane tangent to the surface vertex, r is the distance from the corresponding point on the aspheric surface to the optical axis, c is the curvature of the aspheric surface vertex (at the optical axis), k is a conic constant, and Ai is the coefficient corresponding to the i-th high-order term in the aspheric surface type formula.

In this way, the optical imaging system 10 can effectively reduce the size of the optical imaging system 10, effectively correct aberration, and improve imaging quality by adjusting the curvature radius and aspheric coefficients of each lens surface.

In some embodiments, the object-side surface S1 of the first lens element L1 is convex at the circumference, and the image-side surface S2 is concave at the circumference; the object-side surface S3 of the second lens element L2 is concave at the circumference, and the image-side surface S4 is concave at the circumference; the object-side surface S7 of the fourth lens L4 is convex at the circumference; the object-side surface S9 of the fifth lens element L5 is concave at the circumference, and the image-side surface S10 is concave at the circumference; the object-side surface S11 of the sixth lens element L6 is convex at the circumference; the object-side surface S13 of the seventh lens element L7 is concave at the circumference, and the image-side surface S14 is convex at the circumference. Therefore, the surface shape of the lens at the circumference is reasonably configured to improve good image quality.

First embodiment

Referring to fig. 1 and 2, the optical imaging system 10 of the first embodiment includes, in order from an object side to an image side, a first lens element L1 with negative refractive power, a second lens element L2 with positive refractive power, a third lens element L3 with negative refractive power, a fourth lens element L4 with positive refractive power, a sixth lens element L6 with positive refractive power and a seventh lens element L7 with negative refractive power, where the fifth lens element L5 with negative refractive power has positive refractive power. Fig. 2 is a spherical aberration diagram (mm), an astigmatism diagram (mm), and a distortion diagram (%) of the optical imaging system 10 in the first embodiment, wherein the astigmatism diagram and the distortion diagram are data diagrams at a reference wavelength of 587.5618 nm.

The object-side surface S1 of the first lens element L1 is convex along the optical axis, and the image-side surface S2 is concave along the optical axis; the object-side surface S3 of the second lens element L2 is concave along the optical axis, and the image-side surface S4 is convex along the optical axis; the object-side surface S5 of the third lens element L3 is convex along the optical axis, and the image-side surface S6 is concave along the optical axis; the object-side surface S7 of the fourth lens element L4 is convex along the optical axis, and the image-side surface S8 is convex along the optical axis; the object-side surface S9 of the fifth lens element L5 is convex along the optical axis, and the image-side surface S10 is concave along the optical axis; the object-side surface S11 of the sixth lens element L6 is convex along the optical axis, and the image-side surface S12 is convex along the optical axis; the object-side surface S13 of the seventh lens element L7 is convex along the optical axis, and the image-side surface S14 is concave along the optical axis.

The object-side surface S1 of the first lens element L1 is convex at the circumference, and the image-side surface S2 is concave at the circumference; the object-side surface S3 of the second lens element L2 is concave at the circumference, and the image-side surface S4 is concave at the circumference; the object-side surface S5 of the third lens element L3 is convex at the circumference, and the image-side surface S6 is concave at the circumference; the object-side surface S7 of the fourth lens element L4 is convex at the circumference, and the image-side surface S8 is convex at the circumference; the object-side surface S9 of the fifth lens element L5 is concave at the circumference, and the image-side surface S10 is concave at the circumference; the object-side surface S11 of the sixth lens element L6 is convex at the circumference, and the image-side surface S12 is concave at the circumference; the object-side surface S13 of the seventh lens element L7 is concave at the circumference, and the image-side surface S14 is convex at the circumference.

The stop STO is disposed between the third lens L3 and the fourth lens L4.

In the first embodiment, the optical imaging system 10 satisfies the following condition: FOV 110 °, FNO 2.40, f 1.54mm, Almax 30 °, SD1/ImgH 0.562, FOV/f 71.35 °/mm, SD1/AT12 2.962, (| R62| + | R72|)/f 0.873, (| f6| + | f7|)/f 2.435, (| CT3| + | CT4| + | CT5|)/BF 1.377, | R71|/| f7| -0.802, AT45/ET45 | -0.761.

The reference wavelength in the first embodiment is 587nm, and the optical imaging system 10 in the first embodiment satisfies the conditions of the following table. The elements from the object plane to the image plane are sequentially arranged in the order of the elements from top to bottom in table 1. The surface numbers 1 and 2 are the object-side surface S1 and the image-side surface S2 of the first lens L1, respectively, that is, the surface with the smaller surface number is the object-side surface and the surface with the larger surface number is the image-side surface in the same lens. The Y radius in table 1 is the radius of curvature of the object-side surface or the image-side surface of the corresponding surface number at the optical axis. The first value in the "thickness" parameter column of the first lens element is the thickness of the lens element on the optical axis, and the second value is the distance from the image-side surface of the lens element to the object-side surface of the subsequent lens element on the optical axis. Table 2 is a table of relevant parameters of the aspherical surface of each lens in table 1, where K is a conic constant and Ai is a coefficient corresponding to the i-th high-order term in the aspherical surface type formula.

TABLE 1

It should be noted that f is the focal length of the optical imaging system 10, FNO is the f-number of the optical imaging system 10, FOV is the field angle of the optical imaging system 10, and TTL is the distance from the object-side surface S1 to the image surface S17 of the first lens L1 on the optical axis.

TABLE 2

Second embodiment

Referring to fig. 3 and 4, the optical imaging system 10 of the second embodiment includes, in order from an object side to an image side, a first lens element L1 with negative refractive power, a second lens element L2 with positive refractive power, a third lens element L3 with positive refractive power, a fourth lens element L4 with positive refractive power, a fifth lens element L5 with negative refractive power, a sixth lens element L6 with positive refractive power, and a seventh lens element L7 with negative refractive power. Fig. 4 is a spherical aberration diagram (mm), an astigmatism diagram (mm), and a distortion diagram (%) of the optical imaging system 10 in the second embodiment, wherein the astigmatism diagram and the distortion diagram are data diagrams at a reference wavelength of 587.5618 nm.

The object-side surface S1 of the first lens element L1 is concave along the optical axis, and the image-side surface S2 is concave along the optical axis; the object-side surface S3 of the second lens element L2 is convex along the optical axis, and the image-side surface S4 is concave along the optical axis; the object-side surface S5 of the third lens element L3 is concave along the optical axis, and the image-side surface S6 is convex along the optical axis; the object-side surface S7 of the fourth lens element L4 is convex along the optical axis, and the image-side surface S8 is convex along the optical axis; the object-side surface S9 of the fifth lens element L5 is concave along the optical axis, and the image-side surface S10 is concave along the optical axis; the object-side surface S11 of the sixth lens element L6 is convex along the optical axis, and the image-side surface S12 is convex along the optical axis; the object-side surface S13 of the seventh lens element L7 is convex along the optical axis, and the image-side surface S14 is concave along the optical axis.

The object-side surface S1 of the first lens element L1 is convex at the circumference, and the image-side surface S2 is concave at the circumference; the object-side surface S3 of the second lens element L2 is concave at the circumference, and the image-side surface S4 is concave at the circumference; the object-side surface S5 of the third lens element L3 is concave at the circumference, and the image-side surface S6 is convex at the circumference; the object-side surface S7 of the fourth lens element L4 is convex at the circumference, and the image-side surface S8 is convex at the circumference; the object-side surface S9 of the fifth lens element L5 is concave at the circumference, and the image-side surface S10 is concave at the circumference; the object-side surface S11 of the sixth lens element L6 is convex at the circumference, and the image-side surface S12 is convex at the circumference; the object-side surface S13 of the seventh lens element L7 is concave at the circumference, and the image-side surface S14 is convex at the circumference.

The stop STO is disposed between the third lens L3 and the fourth lens L4.

In the second embodiment, the optical imaging system 10 satisfies the following condition: FOV 112 °, FNO 2.35, f 1.40mm, Almax 30 °, SD1/ImgH 0.562, FOV/f 80.08 °/mm, SD1/AT12 4.403, (| R62| + | R72|)/f 0.642, (| f6| + | f7|)/f 1.890, (| CT3| + | CT4| + | CT5|)/BF 1.591, | R71|/| f7| ═ 0.643, AT 45/45 ET 0.953.

The reference wavelength in the second embodiment is 587nm, and the optical imaging system 10 in the second embodiment satisfies the conditions of the following table. The definitions of the parameters can be obtained from the first embodiment, and are not described herein again.

TABLE 3

TABLE 4

Third embodiment

Referring to fig. 5 and 6, the optical imaging system 10 of the third embodiment includes, in order from an object side to an image side, a first lens element L1 with positive refractive power, a second lens element L2 with negative refractive power, a third lens element L3 with positive refractive power, a fourth lens element L4 with negative refractive power, a fifth lens element L5 with positive refractive power, a sixth lens element L6 with negative refractive power, and a seventh lens element L7 with positive refractive power. Fig. 6 is a spherical aberration diagram (mm), an astigmatism diagram (mm), and a distortion diagram (%) of the optical imaging system 10 in the third embodiment, wherein the astigmatism diagram and the distortion diagram are data diagrams at a reference wavelength of 587.5618 nm.

The object-side surface S1 of the first lens element L1 is convex along the optical axis, and the image-side surface S2 is convex along the optical axis; the object-side surface S3 of the second lens element L2 is concave along the optical axis, and the image-side surface S4 is concave along the optical axis; the object-side surface S5 of the third lens element L3 is concave along the optical axis, and the image-side surface S6 is convex along the optical axis; the object-side surface S7 of the fourth lens element L4 is concave along the optical axis, and the image-side surface S8 is convex along the optical axis; the object-side surface S9 of the fifth lens element L5 is convex along the optical axis, and the image-side surface S10 is concave along the optical axis; the object-side surface S11 of the sixth lens element L6 is concave along the optical axis, and the image-side surface S12 is concave along the optical axis; the object-side surface S13 of the seventh lens element L7 is convex along the optical axis, and the image-side surface S14 is convex along the optical axis.

The object-side surface S1 of the first lens element L1 is convex at the circumference, and the image-side surface S2 is convex at the circumference; the object-side surface S3 of the second lens element L2 is concave at the circumference, and the image-side surface S4 is convex at the circumference; the object-side surface S5 of the third lens element L3 is concave at the circumference, and the image-side surface S6 is convex at the circumference; the object-side surface S7 of the fourth lens element L4 is convex at the circumference, and the image-side surface S8 is concave at the circumference; the object-side surface S9 of the fifth lens element L5 is convex at the circumference, and the image-side surface S10 is concave at the circumference; the object-side surface S11 of the sixth lens element L6 is concave at the circumference, and the image-side surface S12 is convex at the circumference; the object-side surface S13 of the seventh lens element L7 is concave at the circumference, and the image-side surface S14 is convex at the circumference.

The stop STO is disposed between the third lens L3 and the fourth lens L4.

In the third embodiment, the optical imaging system 10 satisfies the following condition: FOV 116 °, FNO 2.30, f 1.36mm, Almax 30 °, SD1/ImgH 0.562, FOV/f 85.48 °/mm, SD1/AT12 6.022, (| R62| + | R72|)/f 0.661, (| f6| + | f7|)/f 1.930, (| CT3| + | CT4| + | CT5|)/BF 1.533, | R71|/| f7| -0.670, AT45/ET45 | -0.932.

The reference wavelength in the third embodiment is 587nm, and the optical imaging system 10 in the third embodiment satisfies the conditions of the following table.

TABLE 5

TABLE 6

Fourth embodiment

Referring to fig. 7 and 8, the optical imaging system 10 of the fourth embodiment includes, in order from an object side to an image side, a first lens element L1 with negative refractive power, a second lens element L2 with negative refractive power, a third lens element L3 with positive refractive power, a fourth lens element L4 with positive refractive power, a fifth lens element L5 with negative refractive power, a sixth lens element L6 with positive refractive power, and a seventh lens element L7 with negative refractive power. Fig. 8 is a spherical aberration diagram (mm), an astigmatism diagram (mm), and a distortion diagram (%) of the optical imaging system 10 in the fourth embodiment, wherein the astigmatism diagram and the distortion diagram are data diagrams at a reference wavelength of 587.5618 nm.

The object-side surface S1 of the first lens element L1 is concave along the optical axis, and the image-side surface S2 is convex along the optical axis; the object-side surface S3 of the second lens element L2 is convex along the optical axis, and the image-side surface S4 is concave along the optical axis; the object-side surface S5 of the third lens element L3 is convex along the optical axis, and the image-side surface S6 is convex along the optical axis; the object-side surface S7 of the fourth lens element L4 is convex along the optical axis, and the image-side surface S8 is convex along the optical axis; the object-side surface S9 of the fifth lens element L5 is concave along the optical axis, and the image-side surface S10 is concave along the optical axis; the object-side surface S11 of the sixth lens element L6 is concave along the optical axis, and the image-side surface S12 is convex along the optical axis; the object-side surface S13 of the seventh lens element L7 is convex along the optical axis, and the image-side surface S14 is concave along the optical axis.

The object-side surface S1 of the first lens element L1 is convex at the circumference, and the image-side surface S2 is concave at the circumference; the object-side surface S3 of the second lens element L2 is concave at the circumference, and the image-side surface S4 is concave at the circumference; the object-side surface S5 of the third lens element L3 is convex at the circumference, and the image-side surface S6 is convex at the circumference; the object-side surface S7 of the fourth lens element L4 is convex at the circumference, and the image-side surface S8 is convex at the circumference; the object-side surface S9 of the fifth lens element L5 is concave at the circumference, and the image-side surface S10 is concave at the circumference; the object-side surface S11 of the sixth lens element L6 is convex at the circumference, and the image-side surface S12 is convex at the circumference; the object-side surface S13 of the seventh lens element L7 is concave at the circumference, and the image-side surface S14 is convex at the circumference.

The stop STO is disposed between the third lens L3 and the fourth lens L4.

In the fourth embodiment, the optical imaging system 10 satisfies the following condition: FOV 120 °, FNO 2.25, f 1.30mm, Almax 30 °, SD1/ImgH 0.562, FOV/f 92.02 °/mm, SD1/AT12 6.055, (| R62| + | R72|)/f 0.939, (| f6| + | f7|)/f 2.399, (| CT3| + | CT4| + | CT5|)/BF 1.669, | R71|/| f7| ═ 1.104, AT45/ET45 0.838.

The reference wavelength in the fourth embodiment is 587nm, and the optical imaging system 10 in the fourth embodiment satisfies the conditions of the following table.

TABLE 7

TABLE 8

Fifth embodiment

Referring to fig. 9 and 10, the optical imaging system 10 of the fifth embodiment includes, in order from an object side to an image side, a first lens element L1 with negative refractive power, a second lens element L2 with negative refractive power, a third lens element L3 with positive refractive power, a fourth lens element L4 with positive refractive power, a sixth lens element L6 with positive refractive power and a seventh lens element L7 with negative refractive power, wherein the fifth lens element L5 with negative refractive power has positive refractive power. Fig. 10 is a spherical aberration diagram (mm), an astigmatism diagram (mm), and a distortion diagram (%) of the optical imaging system 10 in the fifth embodiment, wherein the astigmatism diagram and the distortion diagram are data diagrams at a reference wavelength of 587.5618 nm.

The object-side surface S1 of the first lens element L1 is concave along the optical axis, and the image-side surface S2 is concave along the optical axis; the object-side surface S3 of the second lens element L2 is convex along the optical axis, and the image-side surface S4 is concave along the optical axis; the object-side surface S5 of the third lens element L3 is convex along the optical axis, and the image-side surface S6 is convex along the optical axis; the object-side surface S7 of the fourth lens element L4 is convex along the optical axis, and the image-side surface S8 is convex along the optical axis; the object-side surface S9 of the fifth lens element L5 is concave along the optical axis, and the image-side surface S10 is convex along the optical axis; the object-side surface S11 of the sixth lens element L6 is concave along the optical axis, and the image-side surface S12 is convex along the optical axis; the object-side surface S13 of the seventh lens element L7 is convex along the optical axis, and the image-side surface S14 is concave along the optical axis.

The object-side surface S1 of the first lens element L1 is convex at the circumference, and the image-side surface S2 is concave at the circumference; the object-side surface S3 of the second lens element L2 is concave at the circumference, and the image-side surface S4 is concave at the circumference; the object-side surface S5 of the third lens element L3 is convex at the circumference, and the image-side surface S6 is convex at the circumference; the object-side surface S7 of the fourth lens element L4 is convex at the circumference, and the image-side surface S8 is convex at the circumference; the object-side surface S9 of the fifth lens element L5 is concave at the circumference, and the image-side surface S10 is concave at the circumference; the object-side surface S11 of the sixth lens element L6 is convex at the circumference, and the image-side surface S12 is concave at the circumference; the object-side surface S13 of the seventh lens element L7 is concave at the circumference, and the image-side surface S14 is convex at the circumference.

The stop STO is disposed between the third lens L3 and the fourth lens L4.

In the fifth embodiment, the optical imaging system 10 satisfies the following condition: FOV 124 °, FNO 2.20, f 1.25mm, Almax 30 °, SD1/ImgH 0.560, FOV/f 99.28 °/mm, SD1/AT12 3.663, (| R62| + | R72|)/f 0.785, (| f6| + | f7|)/f 2.251, (| CT3| + | CT4| + | CT5|)/BF 1.719, | R71|/| f7| -0.590, AT45/ET45 1.288.

The reference wavelength in the fifth embodiment is 587nm, and the optical imaging system 10 in the fifth embodiment satisfies the conditions of the following table.

TABLE 9

Watch 10

Referring to fig. 11, an image capturing module 100 according to an embodiment of the present invention includes an optical imaging system 10 and a photosensitive element 20, wherein the photosensitive element 20 is disposed on an image side of the optical imaging system 10.

Specifically, the photosensitive element 20 may be a Complementary Metal Oxide Semiconductor (CMOS) image sensor or a Charge-coupled Device (CCD).

The optical imaging system 10 in the image capturing module 100 according to the embodiment of the present invention, with the above reasonable configuration of the lenses, satisfies the micro-design, increases the field angle, which is larger than that of a conventional lens, increases the relative brightness, increases the viewing area, and the optical imaging system 10 can realize higher pixels and good image quality.

Referring to fig. 12, an electronic device 1000 according to an embodiment of the invention includes a housing 200 and an image capturing module 100, wherein the image capturing module 100 is mounted on the housing 200.

The electronic device 1000 according to the embodiment of the present invention includes, but is not limited to, an imaging-enabled electronic device such as a smart phone, a tablet computer, a notebook computer, an electronic book reader, a Portable Multimedia Player (PMP), a portable phone, a video phone, a digital still camera, a mobile medical device, and a wearable device.

The optical imaging system 10 in the electronic device 1000 of the above embodiment, through the above reasonable configuration of the lenses, while satisfying the micro-design, increases the field angle, which is larger than that of a conventional lens, improves the relative brightness, and improves the viewing area, and the optical imaging system 10 can realize higher pixels and good image quality.

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

Finally, it should be noted that the above embodiments are only for illustrating the technical solutions of the present invention and not for limiting, and although the present invention is described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions may be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. An optical imaging system, comprising, in order from an object side to an image side:

a first lens element with negative refractive power;

a second lens element with refractive power;

a third lens element with refractive power;

the fourth lens element with positive refractive power has a convex object-side surface and a convex image-side surface;

a fifth lens element with negative refractive power;

the sixth lens element with positive refractive power has a convex image-side surface along an optical axis;

the seventh lens element with negative refractive power has a convex object-side surface and a concave image-side surface;

the optical imaging system satisfies the following conditional expression:

Almax≤30°；

the optical imaging system comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an optical imaging system and an optical imaging system, wherein the optical imaging system comprises an object side surface, an image side surface and an effective optical area of the first lens, the fourth lens and the seventh lens, the effective optical area of the object side surface and the effective optical area of the image side surface of the first.

2. The optical imaging system of claim 1, wherein the optical imaging system satisfies the following conditional expression:

FOV≥110°；

FNO≤2.4；

3. The optical imaging system of claim 1, wherein the optical imaging system satisfies the following conditional expression:

SD1/ImgH<0.57；

wherein SD1 is the vertical distance from the edge of the optically effective area of the object-side surface of the first lens to the optical axis, and ImgH is half the image height corresponding to the maximum field angle of the optical imaging system.

4. The optical imaging system of claim 1, wherein the optical imaging system satisfies the following conditional expression:

FOV/f>71°/mm；

5. The optical imaging system of claim 1, wherein the optical imaging system satisfies the following conditional expression:

SD1/AT12<6.1；

6. The optical imaging system of claim 1, wherein the optical imaging system satisfies the following conditional expression:

0.64＜(|R62|+|R72|)/f＜0.94；

wherein R62 is a radius of curvature of an image-side surface of the sixth lens element at an optical axis, R72 is a radius of curvature of an image-side surface of the seventh lens element at the optical axis, and f is a focal length of the optical imaging system.

7. The optical imaging system of claim 1, wherein the optical imaging system satisfies the following conditional expression:

1.8＜(|f6|+|f7|)/f＜2.5；

8. The optical imaging system of claim 1, wherein the optical imaging system satisfies the following conditional expression:

1.3＜(|CT3|+|CT4|+|CT5|)/BF＜1.8；

9. The optical imaging system of claim 1, wherein the optical imaging system satisfies the following conditional expression:

0.59＜|R71|/|f7|＜1.1；

10. The optical imaging system of claim 1, wherein the optical imaging system satisfies the following conditional expression:

AT45/ET45<1.3；

11. The optical imaging system of claim 1, wherein the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens are all made of plastic.

12. The optical imaging system of claim 1, further comprising an optical stop disposed between the third lens and the fourth lens.

13. An image capturing module, comprising:

the optical imaging system of any one of claims 1 to 12; and

the photosensitive element is arranged on the image side of the optical imaging system.

14. An electronic device, comprising:

a housing; and

the image capturing module of claim 13, wherein the image capturing module is mounted on the housing.