CN112162385A

CN112162385A - Optical imaging system, image capturing module and electronic device

Info

Publication number: CN112162385A
Application number: CN202011127808.8A
Authority: CN
Inventors: 党绪文; 刘彬彬; 李明; 邹海荣
Original assignee: Jiangxi Jingchao Optical Co Ltd
Current assignee: Jiangxi Jingchao Optical Co Ltd
Priority date: 2020-10-20
Filing date: 2020-10-20
Publication date: 2021-01-01

Abstract

The invention provides an optical imaging system, an image capturing module and an electronic device, wherein the optical imaging system sequentially comprises from an object side to an image side along an optical axis: the first lens element with positive refractive power has a convex object-side surface near an optical axis and a concave image-side surface near the optical axis; the second lens element with refractive power has a convex object-side surface near the optical axis; a third lens element with negative refractive power; the fourth lens element with refractive power has an object-side surface and an image-side surface which are both aspheric; the fifth lens element with refractive power has an aspheric object-side surface and an aspheric image-side surface, and at least one inflection point is disposed on at least one of the object-side surface and the image-side surface of the fifth lens element; and the light path steering piece is provided with a reflecting surface and is arranged on the object side of the first lens or between any two adjacent lenses of the first lens to the fourth lens.

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 innovation of the shooting effect of the camera lens in the electronic product becomes one of the focuses of people, and particularly relates to a long-focus imaging module with a long-distance camera shooting function.

In the process of implementing the present application, the inventor finds that at least the following problems exist in the prior art: the long focal length of the existing optical imaging system is usually realized by sacrificing the image plane size or increasing the f-number of the optical imaging system, but increasing the f-number of the optical imaging system or reducing the image plane size affects the image quality of the optical imaging system.

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, sequentially from an object side to an image side along an optical axis, comprising:

the first lens element with positive refractive power has a convex object-side surface near an optical axis and a concave image-side surface near the optical axis;

the second lens element with refractive power has a convex object-side surface near the optical axis;

a third lens element with negative refractive power;

the fourth lens element with refractive power has an object-side surface and an image-side surface which are both aspheric;

the fifth lens element with refractive power has an aspheric object-side surface and an aspheric image-side surface, and at least one inflection point is disposed on at least one of the object-side surface and the image-side surface of the fifth lens element;

and the optical path steering piece is provided with a reflecting surface and is arranged on the object side close to the first lens or between any two adjacent lenses from the first lens to the fourth lens.

Therefore, the optical imaging system keeps enough long focal length by combining the optical path steering piece and the lens, the image surface size is enlarged, and the large aperture effect is realized. By reasonably configuring the surface shapes and the refractive powers of the prisms and the distribution lenses, the optical imaging system has good image quality and light thinness.

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

57.0＜43*EFL/ImgH＜122.0；

and the EFL is the effective focal length of the optical imaging system, and the ImgH is the diameter of an effective imaging circle of the optical imaging system.

Therefore, the equivalent focal length is between 57mm and 122mm, the amplification effect of 2.4-5.1 times is achieved, a certain telephoto requirement can be met, the photosensitive chip with the maximum diagonal of 7.6mm can be supported, and the long focal end of the optical imaging system has the shooting function of high pixel and high resolution.

0.35＜TTL/(EFL*FNO)＜0.6；

when the optical path steering element with the reflecting surface is arranged on the object side of the first lens, the TTL is an on-axis distance from an intersection point of the optical path steering element with the reflecting surface and the object side of the optical axis to the image surface; when the light path steering piece is arranged between the first lens and the second lens, between the second lens and the third lens or between the third lens and the fourth lens, TTL is the on-axis distance from the intersection point of the object side surface of the first lens and the optical axis to the image surface, EFL is the effective focal length of the optical imaging system, and FNO is the f-number of the optical imaging system.

So, the diaphragm number FNO of rational configuration optical imaging system for optical imaging system provides sufficient light volume of advancing, promotes the shooting effect when light is not enough, makes optical imaging system have good lightness and thinness nature simultaneously.

f1/|R22|＜7.6；

wherein f1 is an effective focal length of the first lens, and R22 is a radius of curvature of an image side surface of the second lens at an optical axis.

Thus, the first lens element with positive refractive power can compress the infinite ray inwards to reduce the influence of large aperture caused by small diaphragm number due to increased focal length; the change of the curvature radius of the second lens provides possibility for the diversified placement of the light path steering piece; in addition, the combination of the first lens and the second lens further reduces the caliber of incident light, so that the light rays of the third lens and the fourth lens extend outwards more reasonably. The surface shapes and the refractive powers of the first lens and the second lens are reasonably configured so as to reduce the sensitivity and the processing difficulty of the optical imaging system.

7.5＜|f45|/ET45＜21.85；

wherein f45 is a combined focal length of the fourth lens and the fifth lens, and ET45 is an axial distance between an image side effective diameter of the fourth lens and an object side effective diameter of the fifth lens.

So, through placing different positions with the light path steering spare to make the combination of fourth lens and fifth lens produce different effects, with the small-bore light of second lens and third lens, through certain face type adjustment, the guide is with the small-angle incidence to the image side, and it is little to deflect on each lens face, make optical imaging system easily the various electronic sensitization chips of adaptation, let reflection energy loss little through deflecting the angle simultaneously, so that the image side obtains better relative luminance.

ET3/|f3|＜0.15；

wherein ET3 is the thickness at the third lens effective diameter, and f3 is the effective focal length of the third lens.

Thus, the third lens receives the light rays compressed inwards by the first lens and the second lens, provides negative refractive power and gradually diffuses the light rays; the object side surface generates concave-convex change of curvature radius on the shaft due to the addition of the light path steering piece, and the image side surface is totally in a C shape and is bent to the image surface to provide reasonable light deflection; the aberration introduced by the third lens wheel is not large, the surface shape is changed reasonably, the total aberration of the optical imaging system can be further reduced, the proper aberration amount is distributed to each lens, and the sensitivity of the optical imaging system is reduced.

Further, the optical imaging system satisfies the following conditional expression:

0.43/mm＜nL/(n2+CT1)＜0.8/mm；

wherein nL is a refractive index of the optical path turning member at 587nm, n2 is a refractive index of the second lens at 587nm, and CT1 is a thickness of the first lens on an optical axis.

Thus, the optical path deflecting member may be made of a glass material or a plastic material. The second lens is made of materials with different refractive indexes, so that excessive bending can be avoided, and the complex change of the surface shape is reduced; under the configuration of different light path steering pieces, the optical lens is matched with the first lens to change, the introduction of aberration is reduced, and the improvement of resolving power is facilitated through reasonable refractive power configuration.

BF/|R52|＜0.82；

wherein BF is a minimum axial distance between an image side surface and an object side surface of the fifth lens, and R52 is a curvature radius of the image side surface of the fifth lens at an optical axis.

Therefore, the telephoto lens has longer BF, and has stronger diversity in the structural design of the matching and supporting lens group of the chip, the BF range is 0.7 mm-2.42 mm, and the range can meet the requirements of different structures and matching aspects; the fifth lens expands light outwards and is of a reasonable curved surface type, so that aberrations such as spherical aberration, coma aberration, field curvature and the like are further balanced, and the integral aberration of an image plane is reduced; the change of the curvature radius of the fifth lens reduces the possibility of excessive bending of the surface type, improves the manufacturability of lens forming and is beneficial to assembly.

0.5＜ET4/CT4＜4.15；

wherein ET4 is a thickness of the effective diameter of the fourth lens element in the optical axis direction, and CT4 is a thickness of the fourth lens element in the optical axis direction.

Therefore, the thickness ratio of the fourth lens is reasonable, the forming difficulty of the lens is small through reasonable refractive power configuration, the deflection effect on the edge light is good, reflection and light leakage are not easy to cause, and the whole imaging quality can be improved.

The embodiment of the invention provides an image capturing module, which comprises the 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 the optical imaging system keeps enough long focal length through the combination of the light path steering piece and the lens, enlarges the size of an image plane and realizes the effect of a large aperture. By reasonably configuring the surface shapes and the refractive powers of the prisms and the distribution lenses, the optical imaging system has good image quality and light thinness.

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, wherein an optical imaging system in the image capturing module is combined with the lens through the light path steering piece, so that the electronic device can keep enough long focal length, enlarge the size of an image plane and realize the effect of a large aperture. By reasonably configuring the surface shapes and the refractive powers of the prisms and the distribution lenses, the optical imaging system has good image quality and light thinness.

Drawings

The above technical content and advantages of the present invention will be apparent from and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, in 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 view of an optical imaging system according to a sixth embodiment of the present invention.

Fig. 12 is a schematic view of spherical aberration (mm), astigmatism (mm), and distortion (%) of an optical imaging system in a sixth embodiment of the present invention.

Fig. 13 is a schematic structural diagram of an image capturing module according to an embodiment of the invention.

Fig. 14 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

Light path deflecting piece L6

Infrared filter L7

Stop STO

Object sides S1, S3, S5, S7, S9, S14

Like side faces S2, S4, S6, S8, S10, S15

Incident surface S11

Reflecting surface S12

Emission surface S13

Image plane S16

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, an optical imaging system 10 according to an embodiment of the present invention includes a first lens element L1 with positive refractive power, a second lens element L2 with refractive power, a third lens element L3 with negative refractive power, a fourth lens element L4 with refractive power, a fifth lens element L5 with refractive power, and an optical path turning element L6 with reflective surfaces, wherein the first lens element L1, the second lens element L2, the third lens element L3, the fourth lens element L4, and the fifth lens element L5 are sequentially disposed along an optical axis from an object side to an image side. The optical path diverter L6 may be located on the side near the object side of the first lens L1, between the first lens L1 and the second lens L2, between the second lens L2 and the third lens L3, or between the third lens L3 and the fourth lens L4.

The first lens element L1 has an object-side surface S1 and an image-side surface S2, wherein the object-side surface S1 is convex near the optical axis and the image-side surface S2 is concave near the optical axis; the second lens L2 has an object-side surface S3 and an image-side surface S4, the object-side surface S3 being convex in the vicinity of the optical axis; 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, and both the object-side surface S7 and the image-side surface S8 are aspheric; the fifth lens element L5 has an object-side surface S9 and an image-side surface S10, wherein the object-side surface S9 and the image-side surface S10 are aspheric, at least one inflection point is disposed on at least one of the object-side surface S9 and the image-side surface S10, the optical path turning element L6 is a rectangular prism, the optical path turning element L6 has an incident surface S11, a reflecting surface S12 and an exit surface S13, wherein the incident surface S11 is perpendicular to the exit surface S13, an included angle between the incident surface S11 and the exit surface S13 and the reflecting surface S12 is 45 degrees, and light enters through the incident surface S11, is reflected through the reflecting surface S12, and exits through the exit surface S13. It is understood that the light path direction-changing member L6 may be a plane mirror as long as the light path direction-changing member L6 has a reflecting surface to deflect the angle of the light in a predetermined direction.

In the optical imaging system 10 of the embodiment of the application, the optical imaging system 10 maintains a sufficient telephoto focal length by combining the optical path turning piece L6 with the lens, and the image plane size is enlarged, thereby realizing a large aperture effect. The optical imaging system 10 has good image quality and light weight by properly configuring the light path diverting member L6 and the surface shape and refractive power of the distribution lens.

The image side of the optical imaging system 10 is also an image plane S16, and preferably, the image plane S16 may be the receiving surface of the photosensitive element.

The optical imaging system 10 satisfies the following conditional expressions:

57.0＜43*EFL/ImgH＜122.0；

where EFL is the effective focal length of the optical imaging system 10 including the optical path diverter L6, and ImgH is the diameter of the effective imaging circle of the optical imaging system 10.

The conditional expression is that the optical imaging system 10 has an equivalent focal length compared with a 43mm frame lens, if the equivalent focal length is less than 57mm, the telephoto effect of the light path turning piece L6 is not obvious, the picture taken by the optical imaging system 10 cannot fully highlight the theme, and the telephoto capability is general; if the equivalent focal length is larger than 125mm, the telephoto effect of the light path steering piece L6 is sufficiently reflected, but the light path steering piece L6 is limited in application space and is difficult to maintain the anti-shake effect of the telephoto end; the equivalent focal length is between 57mm and 122mm, and compared with a conventional lens with the length of 24mm, the zoom lens has the zoom effect of about 2.4 to 5.1 times, and can meet a certain telephoto requirement; in addition, a maximum diagonal of 7.6mm of photo-chip support is provided so that the long focal end of the optical imaging system 10 also has high pixel and high resolution capture capability.

0.35＜TTL/(EFL*FNO)＜0.6；

when the optical path steering element L6 is disposed on the object side of the first lens L1, TTL is an on-axis distance from an intersection point of the optical path steering element L6 with the reflective surface and the optical axis to the image plane; when the optical path turning member L6 is disposed between the first lens L1 and the second lens L2, between the second lens L2 and the third lens L3, or between the third lens L3 and the fourth lens L4, TTL is an on-axis distance from an intersection point of an object side and an optical axis of the first lens L1 to an image plane, EFL is an effective focal length of the optical imaging system 10 including the optical path turning member L6, and FNO is an f-number of the optical imaging system 10. Further, if the optical path diverter L6 is a rectangular prism and is disposed on the object side surface S1 of the first lens L1, TTL is an on-axis distance from the incident surface S11 to the image surface S16 of the rectangular prism, and if the rectangular prism is disposed between the first lens L1 and the second lens L2, between the second lens L2 and the third lens L3, or between the third lens L3 and the fourth lens L4, TTL is an on-axis distance from the optical axis intersection point of the first lens L1 to the image surface S16.

Further, the FNO range is 1.99 ~ 2.6, and this range can provide sufficient light inlet for optical imaging system 10, promotes the shooting effect when light is not enough.

Satisfying the above formula, the optical imaging system 10 has good lightness and thinness.

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

f1/|R22|＜7.6；

Satisfying the above formula, the first lens element L1 with positive refractive power can compress the infinity light beam inward to reduce the effect of large aperture caused by small f-number due to increased focal length; the change of the curvature radius of the second lens L2 provides possibility for the diversified placement of the optical path steering element L6; in addition, the combination of the first lens L1 and the second lens L2 further reduces the aperture of incident light, and makes it more reasonable for the light rays of the third lens L3 and the fourth lens L4 to extend outwards. The surface shape and refractive power of the first lens element L1 and the second lens element L2 are properly configured to reduce the sensitivity and processing difficulty of the optical imaging system 10.

7.5＜|f45|/ET45＜21.85；

By placing the light path steering piece L6 at different positions, so that the combination of the fourth lens L4 and the fifth lens L5 produces different effects, the small-caliber light rays of the second lens L2 and the third lens L3 are guided to be incident on the image side surface at small angles through certain surface shape adjustment, and the deflection on each lens surface is small; so that the optical imaging system 10 can be easily adapted to various electronic photosensitive chips while the reflection energy loss is small by deflecting the angle to obtain better relative brightness of the image side.

ET3/|f3|＜0.15；

The third lens element L3 receives the light beams compressed inward by the first lens element L1 and the second lens element L2, and provides negative refractive power to gradually diffuse the light beams; the object side surface generates concave-convex change of curvature radius on the axis due to the addition of the light path steering piece L6, and the image side surface is totally C-shaped and is bent to the image surface to provide reasonable light deflection; the third lens L3 introduces a small amount of aberration, and the reasonable surface shape change can further reduce the overall aberration of the optical imaging system 10, allocate an appropriate amount of aberration for each lens, and reduce the sensitivity of the optical imaging system 10.

0.43/mm＜nL/(n2+CT1)＜0.8/mm；

wherein nL is a refractive index of the optical path turning member at 587nm, n2 is a refractive index of the second lens at 587nm, and CT1 is a thickness of the first lens at an optical axis.

The light path deflecting member L6 may be made of glass or plastic, and the light path deflecting member L6 is formed with a reflecting surface by coating to increase transmittance, wherein the plastic material is light in weight and is advantageous for practical use. The second lens L2 is made of materials with different refractive indexes, so that excessive bending can be avoided, and the complex change of the surface shape is reduced; under the configuration of different optical path steering pieces L6, the optical path steering pieces are matched with the first lens L1 to change, and the introduction of aberration is reduced; through reasonable arrangement of the refractive power, the improvement of the resolving power is facilitated.

BF/|R52|＜0.82；

BF is the minimum axial distance between the image side surface S10 and the object side surface S9 of the fifth lens L5, and R52 is the curvature radius of the image side surface S10 of the fifth lens L5 at the optical axis.

The telephoto lens has longer BF, has stronger diversity in the structural design of the matching and supporting lens group of the chip, and the BF range is 0.7 mm-2.42 mm, and can meet the requirements of different structures and matching aspects; the fifth lens L5 expands light outwards and is of a reasonable curved surface type, so that aberrations such as spherical aberration, coma aberration, field curvature and the like are further balanced, and the integral aberration of an image plane is reduced; the change of the curvature radius of the fifth lens L5 reduces the possibility of the surface type over-bending, improves the manufacturability of lens molding and facilitates the assembly.

0.5＜ET4/CT4＜4.15；

The thickness ratio of the fourth lens element L4 is reasonable, the lens forming difficulty is small through reasonable refractive power configuration, the deflection effect on the edge light is good, reflection and light leakage are not easy to cause, and the whole imaging quality can be improved.

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 fifth lens L5, 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 L7, infrared filter L7 having an object side S14 and an image side S15. The infrared filter L7 is disposed on the image side S10 of the fifth lens element L5 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 emitted or reflected by a subject enters the optical imaging system 10 from the object side direction, passes through the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5 and the infrared filter L7 in sequence, passes through the optical path diverter L6 located on one side close to the object side of the first lens L1 or between any two adjacent lenses of the first lens L1 to the fourth lens L4, and finally converges on the image plane S16.

In some embodiments, the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, and the fifth lens L5 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 fourth lens L4 and the fifth lens L5 in the optical imaging system 10 are both aspherical. 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:

z is the distance from a corresponding point on the aspheric surface to a 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 a 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.

First embodiment

Referring to fig. 1 and fig. 2, the optical imaging system 10 of the first embodiment sequentially includes, from an object side to an image side along an optical axis, a first lens element L1 with positive refractive power, a second lens element L2 with negative refractive power, a third lens element L3 with negative refractive power, a fourth lens element L4 with negative refractive power, a fifth lens element L5 with negative refractive power, and an optical path diverting element L6, wherein the optical path diverting element L6 is located between the second lens element L2 and the third lens element L3. Referring to fig. 2, fig. 2 shows a spherical aberration curve of the optical imaging system 10 at 650nm, 610nm, 587nm, 510nm, and 470nm, an astigmatism curve of the light at 587nm, and a distortion curve at 587nm in the first embodiment, and the optical imaging system 10 in the first embodiment satisfies the conditions of the following table. The optical path turning piece L6 is a right-angle prism having an incident surface S11, a reflecting surface S12, and an exit surface S13, wherein the incident surface S11 is perpendicular to the exit surface S13.

The object-side surface S1 of the first lens element L1 is convex near the optical axis, and the image-side surface S2 is concave near the optical axis; the object-side surface S3 of the second lens element L2 is convex near the optical axis, and the image-side surface S4 is concave near the optical axis; the object-side surface S5 of the third lens element L3 is convex near the optical axis, and the image-side surface S6 is concave near the optical axis; the object-side surface S7 of the fourth lens element L4 is concave around the optical axis, and the image-side surface S8 is concave around the optical axis; the object-side surface S9 of the fifth lens element L5 is convex near the optical axis, and the image-side surface S10 is concave near the optical axis.

The object-side surface S1 of the first lens element L1 is convex near the circumference, and the image-side surface S2 is convex near the circumference; the object-side surface S3 of the second lens element L2 is convex near the circumference, and the image-side surface S4 is concave near the circumference; the object-side surface S5 of the third lens element L3 is convex near the circumference, and the image-side surface S6 is concave near the circumference; the object-side surface S7 of the fourth lens element L4 is concave around the circumference, and the image-side surface S8 is convex around the circumference; the object-side surface S9 of the fifth lens element L5 is concave around the circumference, and the image-side surface S10 is concave around the circumference.

The stop STO is disposed on the side of the first lens L1 away from the second lens L2.

In the first embodiment, the optical imaging system 10 satisfies the following condition: 43 × EFL/Img ═ 113.30, TTL/(EFL × FNO) ═ 0.50, f1/| R22| ═ 1.7, | f45|/ET45 | -21.825, ET3/| f3| -0.009, nL/(n2+ CT1) | -0.433, BF/| R52| -0.447, ET4/CT4 | -1.000.

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, wherein the units of the Y radius and the thickness are both mm. 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 EFL is the focal length of the optical imaging system 10 including the optical path turning member L6, 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 S16 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 along an optical axis, a first lens element L1 with positive 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 negative refractive power, a fifth lens element L5 with positive refractive power, and an optical path turning element L6, where the optical path turning element L6 is located between the third lens element L3 and the fourth lens element L4. Referring to fig. 4, fig. 4 shows a spherical aberration curve of the optical imaging system 10 at 650nm, 610nm, 587nm, 510nm, and 470nm, an astigmatism curve of the light at 587nm, and a distortion curve at 587nm in the second embodiment, and the optical imaging system 10 in the second embodiment satisfies the conditions of the following table. The optical path turning piece L6 is a right-angle prism having an incident surface S11, a reflecting surface S12, and an exit surface S13, wherein the incident surface S11 is perpendicular to the exit surface S13.

The object-side surface S1 of the first lens element L1 is convex near the optical axis, and the image-side surface S2 is concave near the optical axis; the object-side surface S3 of the second lens element L2 is convex near the optical axis, and the image-side surface S4 is convex near the optical axis; the object-side surface S5 of the third lens element L3 is concave around the optical axis, and the image-side surface S6 is convex around the optical axis; the object-side surface S7 of the fourth lens element L4 is concave around the optical axis, and the image-side surface S8 is convex around the optical axis; the object-side surface S9 of the fifth lens element L5 is concave around the optical axis, and the image-side surface S10 is convex around the optical axis.

The object-side surface S1 of the first lens element L1 is convex near the circumference, and the image-side surface S2 is convex near the circumference; the object-side surface S3 of the second lens element L2 is convex near the circumference, and the image-side surface S4 is convex near the circumference; the object-side surface S5 of the third lens element L3 is convex near the circumference, and the image-side surface S6 is concave near the circumference; the object-side surface S7 of the fourth lens element L4 is concave around the circumference, and the image-side surface S8 is convex around the circumference; the object-side surface S9 of the fifth lens element L5 is concave around the circumference, and the image-side surface S10 is convex around the circumference.

The stop STO is disposed between the first lens L1 and the second lens L2.

In the second embodiment, the optical imaging system 10 satisfies the following condition: 43 × EFL/Img ═ 97.22, TTL/(EFL × FNO) ═ 0.418, f1/| R22| 0.129, | f45|/ET45 | -7.892, ET3/| f3| -0.13, nL/(n2+ CT1) | -0.594, BF/| R52| -0.77, ET4/CT4 | -1.049.

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

It should be noted that EFL is the focal length of the optical imaging system 10 including the optical path turning piece L6, 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 of the first lens L1 to the image surface S16 on the optical axis, where the unit of the Y radius and the thickness are both mm.

TABLE 4

Third embodiment

Referring to fig. 5 and 6, the optical imaging system 10 of the third embodiment includes, in order from the object side to the image side along the optical axis, a first lens element L1 with positive 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 fifth lens element L5 with negative refractive power, and an optical path turning element L6, where the optical path turning element L6 is located on a side of the first lens element L1 away from the second lens element L2. Referring to fig. 6, fig. 6 shows a spherical aberration curve of the optical imaging system 10 at wavelengths 650nm, 610nm, 587nm, 510nm and 470nm, an astigmatism curve of the light at a wavelength 587nm and a distortion curve at a wavelength 587nm in the third embodiment, and the optical imaging system 10 in the third embodiment satisfies the conditions of the following table, and the light path turning member L6 is a right-angle prism having an incident surface S11, a reflecting surface S12 and an exit surface S13, wherein the incident surface S11 is perpendicular to the exit surface S13.

The object-side surface S1 of the first lens element L1 is convex near the optical axis, and the image-side surface S2 is concave near the optical axis; the object-side surface S3 of the second lens element L2 is convex near the optical axis, and the image-side surface S4 is concave near the optical axis; the object-side surface S5 of the third lens element L3 is convex near the optical axis, and the image-side surface S6 is concave near the optical axis; the object-side surface S7 of the fourth lens element L4 is concave around the optical axis, and the image-side surface S8 is convex around the optical axis; the object-side surface S9 of the fifth lens element L5 is convex near the optical axis, and the image-side surface S10 is concave near the optical axis.

The object-side surface S1 of the first lens element L1 is convex near the circumference, and the image-side surface S2 is convex near the circumference; the object-side surface S3 of the second lens element L2 is concave around the circumference, and the image-side surface S4 is convex around the circumference; the object-side surface S5 of the third lens element L3 is convex near the circumference, and the image-side surface S6 is concave near the circumference; the object-side surface S7 of the fourth lens element L4 is concave around the circumference, and the image-side surface S8 is convex around the circumference; the object-side surface S9 of the fifth lens element L5 is concave around the circumference, and the image-side surface S10 is concave around the circumference.

The stop STO is disposed between the first lens L1 and the optical path changing member L6.

In the third embodiment, the optical imaging system 10 satisfies the following condition: 43 × EFL/Img ═ 57.71, TTL/(EFL × FNO) ═ 0.594, f1/| R22| -0.376, | f45|/ET45 | -15.176, ET3/| f3| -0.032, nL/(n2+ CT1) | -0.665, BF/| R52| -0.813, ET4/CT4 | -0.561.

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 along an optical axis, a first lens element L1 with positive refractive power, a second lens element L2 with negative refractive power, a third lens element L3 with negative refractive power, a fourth lens element L4 with positive refractive power, a fifth lens element L5 with negative refractive power, and an optical path turning element L6, where the optical path turning element L6 is located on a side of the first lens element L1 away from the second lens element L2. Referring to fig. 8, fig. 8 shows a spherical aberration curve of the optical imaging system 10 at 650nm, 610nm, 587nm, 510nm, and 470nm, an astigmatism curve of the light at 587nm, and a distortion curve at 587nm in the fourth embodiment, and the optical imaging system 10 in the fourth embodiment satisfies the conditions of the following table. The optical path turning piece L6 is a right-angle prism having an incident surface S11, a reflecting surface S12, and an exit surface S13, wherein the incident surface S11 is perpendicular to the exit surface S13.

The object-side surface S1 of the first lens element L1 is convex near the optical axis, and the image-side surface S2 is concave near the optical axis; the object-side surface S3 of the second lens element L2 is convex near the optical axis, and the image-side surface S4 is concave near the optical axis; the object-side surface S5 of the third lens element L3 is concave around the optical axis, and the image-side surface S6 is concave around the optical axis; the object-side surface S7 of the fourth lens element L4 is convex near the optical axis, and the image-side surface S8 is concave near the optical axis; the object-side surface S9 of the fifth lens element L5 is concave around the optical axis, and the image-side surface S10 is convex around the optical axis.

The object-side surface S1 of the first lens element L1 is convex near the circumference, and the image-side surface S2 is convex near the circumference; the object-side surface S3 of the second lens element L2 is convex near the circumference, and the image-side surface S4 is concave near the circumference; the object-side surface S5 of the third lens element L3 is concave around the circumference, and the image-side surface S6 is concave around the circumference; the object-side surface S7 of the fourth lens element L4 is convex near the circumference, and the image-side surface S8 is concave near the circumference; the object-side surface S9 of the fifth lens element L5 is convex near the circumference, and the image-side surface S10 is convex near the circumference.

The stop STO is disposed between the optical path changing member L6 and the first lens L1.

In the fourth embodiment, the optical imaging system 10 satisfies the following condition: 43 × EFL/Img ═ 59.89, TTL/(EFL × FNO) ═ 0.485, f1/| R22| > 0.441, | f45|/ET45 | -12.616, ET3/| f3| -0.09, nL/(n2+ CT1) | -0.52, BF/| R52| -0.025, ET4/CT4 | -0.9.

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 along an optical axis, a first lens element L1 with positive 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 negative refractive power, a fifth lens element L5 with negative refractive power, and an optical path turning element L6, where the optical path turning element L6 is located between the first lens element L1 and the second lens element L2. Referring to fig. 10, fig. 10 shows a graph of spherical aberration of light rays at 650nm, 610nm, 587nm, 510nm and 470nm, an astigmatism of light rays at 587nm and a distortion of light rays at 587nm of the optical imaging system 10 in the fifth embodiment, and the optical imaging system 10 in the fifth embodiment satisfies the conditions of the following table. The optical path turning piece L6 is a right-angle prism having an incident surface S11, a reflecting surface S12, and an exit surface S13, wherein the incident surface S11 is perpendicular to the exit surface S13.

The object-side surface S1 of the first lens element L1 is convex near the optical axis, and the image-side surface S2 is concave near the optical axis; the object-side surface S3 of the second lens element L2 is convex near the optical axis, and the image-side surface S4 is convex near the optical axis; the object-side surface S5 of the third lens element L3 is concave around the optical axis, and the image-side surface S6 is convex around the optical axis; the object-side surface S7 of the fourth lens element L4 is concave around the optical axis, and the image-side surface S8 is concave around the optical axis; the object-side surface S9 of the fifth lens element L5 is concave around the optical axis, and the image-side surface S10 is convex around the optical axis.

The object-side surface S1 of the first lens element L1 is concave around the circumference, and the image-side surface S2 is convex around the circumference; the object-side surface S3 of the second lens element L2 is convex near the circumference, and the image-side surface S4 is convex near the circumference; the object-side surface S5 of the third lens element L3 is concave around the circumference, and the image-side surface S6 is convex around the circumference; the object-side surface S7 of the fourth lens element L4 is concave around the circumference, and the image-side surface S8 is concave around the circumference; the object-side surface S9 of the fifth lens element L5 is convex near the circumference, and the image-side surface S10 is convex near the circumference.

The stop STO is disposed on the side of the first lens L1 away from the optical path changing member L6.

In the fifth embodiment, the optical imaging system 10 satisfies the following condition: 43 × EFL/Img ═ 87.25, TTL/(EFL × FNO) ═ 0.454, f1/| R22| ═ 7.546, | f45|/ET45 ═ 7.861, ET3/| f3| -0.066, nL/(n2+ CT1) ═ 0.793, BF/| R52| -0.417, ET4/CT4 | -4.103.

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

Sixth embodiment

Referring to fig. 11 and 12, the optical imaging system 10 of the sixth embodiment includes, in order from an object side to an image side along an optical axis, a first lens element L1 with positive refractive power, a second lens element L2 with negative refractive power, a third lens element L3 with negative refractive power, a fourth lens element L4 with negative refractive power, a fifth lens element L5 with negative refractive power, and an optical path turning element L6, where the optical path turning element L6 is located between the second lens element L2 and the third lens element L3. Referring to fig. 12, fig. 12 shows a spherical aberration curve of the optical imaging system 10 at 650nm, 610nm, 587nm, 510nm, and 470nm, an astigmatism curve of the light at 587nm, and a distortion curve at 587nm in the sixth embodiment, and the optical imaging system 10 in the sixth embodiment satisfies the conditions of the following table. The optical path turning piece L6 is a right-angle prism having an incident surface S11, a reflecting surface S12, and an exit surface S13, wherein the incident surface S11 is perpendicular to the exit surface S13.

The object-side surface S1 of the first lens element L1 is convex near the optical axis, and the image-side surface S2 is concave near the optical axis; the object-side surface S3 of the second lens element L2 is convex near the optical axis, and the image-side surface S4 is concave near the optical axis; the object-side surface S5 of the third lens element L3 is concave around the optical axis, and the image-side surface S6 is concave around the optical axis; the object-side surface S7 of the fourth lens element L4 is concave around the optical axis, and the image-side surface S8 is convex around the optical axis; the object-side surface S9 of the fifth lens element L5 is concave around the optical axis, and the image-side surface S10 is concave around the optical axis.

The object-side surface S1 of the first lens element L1 is convex near the circumference, and the image-side surface S2 is convex near the circumference; the object-side surface S3 of the second lens element L2 is convex near the circumference, and the image-side surface S4 is concave near the circumference; the object-side surface S5 of the third lens element L3 is concave around the circumference, and the image-side surface S6 is convex around the circumference; the object-side surface S7 of the fourth lens element L4 is concave around the circumference, and the image-side surface S8 is convex around the circumference; the object-side surface S9 of the fifth lens element L5 is concave around the circumference, and the image-side surface S10 is convex around the circumference.

In the sixth embodiment, the optical imaging system 10 satisfies the following condition: 43 × EFL/Img ═ 121.52, TTL/(EFL × FNO) ═ 0.359, f1/| R22| 1.992, | f45|/ET45 | -15.638, ET3/| f3| -0.019, nL/(n2+ CT1) | -0.46, BF/| R52| -0.307, and ET4/CT4 | -0.96.

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

TABLE 11

TABLE 12

Referring to fig. 13, 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 of the embodiment of the invention is combined with the lens through the light path turning piece L6, so that the optical imaging system 10 maintains a sufficient telephoto focal length, the image plane size is enlarged, and the large aperture effect is realized. The optical imaging system 10 has good image quality and light weight by properly configuring the light path diverting member L6 and the surface shape and refractive power of the distribution lens.

Referring to fig. 14, 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 is combined with the lens through the optical path turning member L6, so that the optical imaging system 10 maintains a sufficient telephoto focal length, enlarges the image plane size, and realizes a large aperture effect. The optical imaging system 10 has good image quality and light weight by properly configuring the light path diverting member L6 and the surface shape and refractive power of the distribution lens.

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 along an optical axis:

a third lens element with negative refractive power;

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

57.0＜43*EFL/ImgH＜122.0；

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

0.35＜TTL/(EFL*FNO)＜0.6；

when the optical path steering element is arranged at the object side of the first lens, TTL is the on-axis distance from the intersection point of the optical path steering element and the object side of the optical axis to the image plane; when the light path steering piece is arranged between the first lens and the second lens, between the second lens and the third lens or between the third lens and the fourth lens, TTL is the on-axis distance from the intersection point of the object side surface of the first lens and the optical axis to the image surface, EFL is the effective focal length of the optical imaging system, and FNO is the f-number of the optical imaging system.

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

f1/|R22|＜7.6；

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

7.5＜|f45|/ET45＜21.85；

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

ET3/|f3|＜0.15；

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

0.43/mm＜nL/(n2+CT1)＜0.8/mm；

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

BF/|R52|＜0.82；

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

0.5＜ET4/CT4＜4.15；

10. An image capturing module, comprising:

the optical imaging system of any one of claims 1 to 9; and

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

11. An electronic device, comprising:

a housing; and

the image capturing module as claimed in claim 10, wherein the image capturing module is mounted on the housing.