WO2022082443A1

WO2022082443A1 - Optical imaging system, image capture module, and electronic device

Info

Publication number: WO2022082443A1
Application number: PCT/CN2020/122239
Authority: WO
Inventors: 党绪文; 刘彬彬; 李明; 邹海荣
Original assignee: 欧菲光集团股份有限公司; 江西晶超光学有限公司
Priority date: 2020-10-20
Filing date: 2020-10-20
Publication date: 2022-04-28

Abstract

Disclosed are an optical imaging system (10), an image capture module (100) and an electronic device (1000), the optical imaging system (10) sequentially comprising, along an optical axis from an object side to an image side: a first lens (L1) having a positive refractive power, an object side surface (S1) of the first lens being convex near the optical axis, and an image side surface (S2) of the first lens (L1) being concave near the optical axis; a second lens (L2) having a refractive power, an object side surface (S3) of the second lens (L2) being convex near the optical axis; a third lens (L3) having a negative refractive power; a fourth lens (L4) having a refractive power, an object side surface (S7) and an image side surface (S8) of the fourth lens (L4) both being aspherical; a fifth lens (L5) having a refractive power, an object side surface (S9) and an image side surface (S10) of the fifth lens both being aspherical, and at least one of the object side surface (S9) and the image side surface (S10) of the fifth lens (L5) being provided with at least one point of inflexion; and a light path deflector (L6) having a reflective surface, the light path deflector being provided on the object side of the first lens (L1) or between any two adjacent lenses of the first lens (L1) to the fourth lens (L4).

Description

Optical imaging system, imaging module and electronic device

technical field

The present application relates to optical imaging technology, and in particular, to an optical imaging system, an imaging module and an electronic device.

Background technique

With the wide application of electronic products such as mobile phones, tablet computers, drones, and computers in life, various electronic products with shooting functions are constantly being introduced. Among them, the improvement and innovation of the shooting effect of the camera lens in electronic products has become one of the focus of attention, especially the telephoto imaging module with long-distance camera function. The telephoto imaging module reduces the shooting angle of view to keep the main surface away from the focal plane of the lens , resulting in a sufficiently long effective focal length, which can make distant objects form a magnified image on the image plane, and obtain the effect of zooming in.

In the process of realizing the present application, the applicant found that there are at least the following problems in the prior art: the long focal length of the existing optical imaging system is usually achieved by sacrificing the size of the image plane or increasing the aperture number of the optical imaging system, but increasing the optical The f-number of the imaging system or reducing the image size will affect the image quality of the optical imaging system.

SUMMARY OF THE INVENTION

In view of the above content, it is necessary to propose an optical imaging system, an imaging module and an electronic device to solve the above problems.

The embodiments of the present application provide an optical imaging system, which includes sequentially along the optical axis from the object side to the image side:

The first lens has a positive refractive power, the object side of the first lens is convex near the optical axis, and the image side of the first lens is concave near the optical axis;

The second lens has a refractive power, and the object side of the second lens is convex near the optical axis;

The third lens has negative refractive power;

The fourth lens has a refractive power, and the object side and the image side of the fourth lens are both aspherical;

The fifth lens has a refractive power, the object side and the image side of the fifth lens are both aspherical, and at least one of the object side and the image side of the fifth lens is provided with at least one inflection point;

An optical path turning member with a reflective surface, the optical path turning member is arranged near the object side of the first lens, or between any two adjacent lenses among the first to fourth lenses.

In this way, through the combination of the light path turning element and the lens, the optical imaging system maintains a sufficient telephoto focal length, enlarges the size of the image plane, and realizes the effect of large aperture. The optical imaging system has good image quality and thinness by rationally configuring the prism and distributing the surface shape and refractive power of the lens.

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

57.0<43*EFL/ImgH<122.0;

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

In this way, the equivalent focal length is between 57mm-122mm, with a magnification effect of 2.4 to 5.1 times, which can meet certain telephoto requirements, and can support a photosensitive chip with a maximum diagonal of 7.6mm, so that the telephoto end of the optical imaging system can be used. Shooting function with high pixel and high resolution.

0.35＜TTL/(EFL*FNO)＜0.6;

Wherein, when the optical path redirecting member with a reflective surface is arranged on the object side of the first lens, TTL is the on-axis distance from the intersection of the optical path redirecting member with a reflective surface and the optical axis near the object side to the image plane ; When the optical path redirecting member 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 of the object side and the optical axis of the first lens to the image plane, EFL is the effective focal length of the optical imaging system, and FNO is the aperture number of the optical imaging system.

In this way, the aperture number FNO of the optical imaging system is reasonably configured to provide sufficient light input for the optical imaging system, improve the shooting effect when the light is insufficient, and at the same time make the optical imaging system have good lightness and thinness.

f1/|R22|＜7.6;

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

In this way, the above formula is satisfied, the first lens has a positive refractive power, which can compress the infinite light inward, so as to reduce the influence of the large aperture problem caused by maintaining a small aperture due to the increase of the focal length; the radius of curvature of the second lens The change of , provides the possibility for the diversified placement of the light path turning elements; in addition, the combination of the first lens and the second lens further reduces the aperture of the incident light, so that the light of the third lens and the fourth lens extends outward more reasonably. The surface shape and refractive power of the first lens and the second lens are reasonably configured to reduce the sensitivity and processing difficulty of the optical imaging system.

7.5＜|f45|/ET45＜21.85;

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

In this way, by placing the light path turning elements in different positions, the combination of the fourth lens and the fifth lens can produce different effects, and the small-diameter light of the second lens and the third lens can be adjusted to guide the small-diameter light through a certain surface shape. Incident to the image side at a small angle, and the deflection on each lens surface is small, making the optical imaging system easy to adapt to various electronic photosensitive chips, and at the same time, the reflected energy loss is small by the angle deflection, so that the image side can obtain better image quality. relative brightness.

ET3/|f3|＜0.15;

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

In this way, the third lens receives the light compressed inward by the first lens and the second lens, provides negative refractive power, and gradually diffuses the light; the addition of the optical path redirecting member on the object side produces a concave and convex change in the curvature radius on the axis, and the image side generally presents a concave and convex change. "C" shape, curved to the image surface, providing reasonable light deflection; the amount of aberration introduced by the third lens wheel is not large, and the reasonable surface shape change can further reduce the overall aberration of the optical imaging system, which is the equivalent of each lens. Allocate an appropriate amount of aberration to reduce the sensitivity of the optical imaging system.

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

0.43/mm＜nL/(n2+CT1)＜0.8/mm;

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

In this way, the light path turning member can be made of glass material or plastic material. The second lens adopts different refractive index materials, which can avoid excessive bending and reduce the complex change of surface shape; under the configuration of different optical path diverters, it cooperates with the first lens to reduce the introduction of aberrations, and through reasonable refractive power configuration, Helps to improve resolution.

BF/|R52|＜0.82;

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

In this way, the telephoto lens itself has a long BF, and there is a strong diversity in the matching of the chip and the structural design of the supporting lens group. The fifth lens expands the light outward, and the reasonable curved surface shape further balances the spherical aberration, coma, field curvature and other aberrations, reducing the overall aberration of the image surface; the fifth lens curvature radius changes are reduced The possibility of excessive bending of the face shape improves the manufacturability of lens molding and facilitates assembly.

0.5＜ET4/CT4＜4.15;

Wherein, ET4 is the thickness of the effective diameter of the fourth lens along the optical axis, and CT4 is the thickness of the fourth lens along the optical axis.

In this way, the thickness ratio of the fourth lens is reasonable, and through a reasonable configuration of refractive power, the lens is less difficult to form, has a good deflection effect on edge light, is not easy to cause reflection and light leakage, and can improve the overall imaging quality.

The embodiments of the present application provide an imaging module, which includes the optical imaging system described in any of the embodiments; and a photosensitive element, and the photosensitive element is disposed on the image side of the optical imaging system.

The imaging module of the embodiment of the present application includes an optical imaging system, and the optical imaging system maintains a sufficient telephoto focal length through the combination of the optical path turning member and the lens, and enlarges the size of the image plane to achieve a large aperture effect. The optical imaging system has good image quality and thinness by rationally configuring the prism and distributing the surface shape and refractive power of the lens.

An embodiment of the present application provides an electronic device, which includes: a casing and the imaging module of the above-mentioned embodiment, where the imaging module is mounted on the casing.

The electronic device of the embodiment of the present application includes the above-mentioned imaging module, and the optical imaging system in the imaging module is combined with the lens through the optical path turning member, so that it can maintain a sufficient telephoto focal length, and expand the size of the image plane, realizing the Large aperture effect. The optical imaging system has good image quality and thinness by rationally configuring the prism and distributing the surface shape and refractive power of the lens.

Description of drawings

The above-mentioned technical contents and advantages of the present application can become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, wherein:

FIG. 1 is a schematic structural diagram of an optical imaging system according to a first embodiment of the present application.

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

FIG. 3 is a schematic structural diagram of an optical imaging system according to a second embodiment of the present application.

FIG. 4 is a schematic diagram of spherical aberration (mm), astigmatism (mm) and distortion (%) of the optical imaging system in the second embodiment of the present application.

FIG. 5 is a schematic structural diagram of an optical imaging system according to a third embodiment of the present application.

FIG. 6 is a schematic diagram of spherical aberration (mm), astigmatism (mm) and distortion (%) of the optical imaging system in the third embodiment of the present application.

FIG. 7 is a schematic structural diagram of an optical imaging system according to a fourth embodiment of the present application.

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

FIG. 9 is a schematic structural diagram of an optical imaging system according to a fifth embodiment of the present application.

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

FIG. 11 is a schematic structural diagram of an optical imaging system according to a sixth embodiment of the present application.

FIG. 12 is a schematic diagram of spherical aberration (mm), astigmatism (mm) and distortion (%) of the optical imaging system in the sixth embodiment of the present application.

FIG. 13 is a schematic structural diagram of an image capturing module according to an embodiment of the present application.

FIG. 14 is a schematic structural diagram of an electronic device according to an embodiment of the present application.

Description of main component symbols

Electronic device 1000

Image acquisition module 100

Optical imaging system 10

The first lens L1

Second lens L2

The third lens L3

Fourth lens L4

Fifth lens L5

Light path turning piece L6

Infrared filter L7

Aperture STO

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

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

Incident surface S11

Reflector S12

Exit surface S13

Like face S16

Photosensitive element 20

Shell 200

Detailed ways

In order to make the purpose, technical solutions and advantages of the present application more clearly understood, the present application will be described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application, but not to limit the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", " Rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outer", clockwise, "counterclockwise" The relationship is based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore Can not be construed as a limitation to the application. In addition, the terms "first" and "second" are only used for description purposes, and cannot be interpreted as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Thus , the features defined with "first" and "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "multiple" is two or more , unless otherwise specifically defined.

In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it may be a fixed connection or a detachable connection Connection, or integral connection; it can be mechanical connection, electrical connection or can communicate with each other; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal communication of two elements or the interaction of two elements relation. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific situations.

In this application, unless otherwise expressly specified and defined, a first feature "on" or "under" a second feature may include direct contact between the first and second features, or may include the first and second features Not directly but through additional features between them. Also, the first feature being "above", "over" and "above" the second feature includes the first feature being directly above and obliquely above the second feature, or simply means that the first feature is level higher than the second feature. The first feature is "below", "below" and "beneath" the second feature includes the first feature being directly above and obliquely above the second feature, or simply means that the first feature is level less than the second feature.

The following disclosure provides many different embodiments or examples for implementing different structures of the present application. To simplify the disclosure of the present application, the components and arrangements of specific examples are described below. Of course, they are only examples and are not intended to limit the application. Furthermore, this application may repeat reference numerals and/or reference letters in different instances for the purpose of simplicity and clarity, and does not in itself indicate a relationship between the various embodiments and/or arrangements discussed. In addition, this application provides examples of various specific processes and materials, but one of ordinary skill in the art will recognize the application of other processes and/or the use of other materials.

Referring to FIG. 1 , the optical imaging system 10 of the embodiment of the present application includes a first lens L1 with positive refractive power, a second lens L2 with refractive power, a third lens L3 with negative refractive power, and a fourth lens with refractive power The lens L4, the fifth lens L5 with refractive power, and the light-path turning member L6 with a reflective surface, wherein the first lens L1, the second lens L2, the third lens L3, the fourth lens L4 and the fifth lens L5 extend from the object side to the The image sides are arranged in sequence along the optical axis. The light path turning member L6 may be located on the side close to 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 between.

The first lens L1 has an object side S1 and an image side S2, the object side S1 is convex near the optical axis, and the image side S2 is concave near the optical axis; the second lens L2 has an object side S3 and an image side S4, and the object side S3 is in the vicinity of the optical axis. The vicinity of the optical axis is a convex surface; the third lens L3 has an object side S5 and an image side S6; the fourth lens L4 has an object side S7 and an image side S8, and the object side S7 and the image side S8 are both aspherical; the fifth lens L5 has an object side The side surface S9 and the image side surface S10, the object side surface S9 and the image side surface S10 are both aspherical and at least one of the object side surface S9 and the image side surface S10 is provided with at least one inflection point, and the light path turning member L6 can be a right angle prism, then the light path turns to The element L6 has an incident surface S11, a reflective surface S12 and an exit surface S13, wherein the incident surface S11 is perpendicular to the exit surface S13, the angle between the incident surface S11 and the exit surface S13 and the reflecting surface S12 is 45 degrees, and the light passes through the incident surface S11 The incident light is reflected through the reflection surface S12 and then emitted through the output surface S13. It can be understood that as long as the light path turning member L6 has a reflective surface, the angle of the light can be deflected according to a preset direction, that is, the light path turning member L6 can also be a plane mirror.

In the optical imaging system 10 of the embodiment of the present application, the optical path turning member L6 is combined with the lens, so that the optical imaging system 10 maintains a sufficient telephoto focal length, enlarges the size of the image plane, and achieves a large aperture effect. The optical imaging system 10 has good image quality and lightness by reasonably configuring the surface shape and refractive power of the light path turning member L6 and the distribution lens.

There is also an image plane S16 on the image side of the optical imaging system 10. Preferably, the image plane S16 can be the receiving plane of the photosensitive element.

The optical imaging system 10 satisfies the following conditional formula:

57.0<43*EFL/ImgH<122.0;

Wherein, EFL is the effective focal length of the optical imaging system 10 including the light path turning member L6 , and ImgH is the diameter of the effective imaging circle of the optical imaging system 10 .

This conditional formula is the equivalent focal length of the optical imaging system 10 compared to the 43mm format lens. If the equivalent focal length is less than 57mm, the telephoto effect of the optical path turning member L6 is not obvious, and the image captured by the optical imaging system 10 cannot fully highlight the subject. The telephoto capability is average; if the equivalent focal length is greater than 125mm, the telephoto effect of the light path turning element L6 is sufficiently reflected, but it is limited to the application space, and it is difficult to maintain the anti-shake effect at the telephoto end; the equivalent focal length is between 57mm-122mm, Compared with the 24mm conventional lens, it has a magnification effect of about 2.4 to 5.1 times, which can meet certain telephoto requirements; in addition, it provides the support of a photosensitive chip with a maximum diagonal of 7.6mm, so that the 10 telephoto end of the optical imaging system also has High-resolution and high-resolution shooting functions.

0.35＜TTL/(EFL*FNO)＜0.6;

Wherein, when the optical path diverting member L6 is arranged on the object side of the first lens L1, TTL is the on-axis distance from the intersection of the optical path diverting member L6 with the reflective surface and the near object side of the optical axis to the image plane; The light 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 third lens L3. Between the four lenses L4, TTL is the on-axis distance from the intersection of the object side and the optical axis of the first lens L1 to the image plane, EFL is the effective focal length of the optical imaging system 10 including the optical path turning element L6, and FNO is the optical The aperture number of the imaging system 10 . Further, if the light path turning member L6 is a right-angle prism and is arranged on the object side S1 of the first lens L1, then TTL is the axial distance from the incident surface S11 of the right-angle prism to the image surface S16, if the right-angle prism is arranged on the first lens L1. Between the 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 TTL is the axis from the intersection of the optical axis of the first lens L1 to the image plane S16 up the distance.

Further, the range of FNO is 1.99-2.6, which can provide sufficient light input for the optical imaging system 10 and improve the shooting effect when the light is insufficient.

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 formula:

f1/|R22|＜7.6;

Satisfying the above formula, the first lens L1 has a positive refractive power, which can compress the infinity light inward to reduce the influence of the large aperture problem caused by maintaining a small aperture due to the increase of the focal length; the curvature radius of the second lens L2 is changes, providing the possibility for the diversified placement of the light path turning member L6; in addition, the combination of the first lens L1 and the second lens L2 further reduces the diameter of the incident light, so that the light rays of the third lens L3 and the fourth lens L4 are directed outwards extension is more reasonable. The surface shape and refractive power of the first lens L1 and the second lens L2 are reasonably 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 turning member L6 at different positions, the combination of the fourth lens L4 and the fifth lens L5 can produce different effects, and the small-diameter light of the second lens L2 and the third lens L3 can be adjusted by a certain surface shape , guides the light to enter the image side at a small angle, and the deflection is small on each lens surface; the optical imaging system 10 is easy to adapt to various electronic photosensitive chips, and the reflected energy loss is small by the angle deflection, so that the image The sides get better relative brightness.

ET3/|f3|＜0.15;

The third lens L3 receives the light compressed inward by the first lens L1 and the second lens L2, provides negative refractive power, and diffuses the light gradually; The overall shape is "C", which is bent toward the image plane to provide reasonable light deflection; the third lens L3 introduces a small amount of aberration, and reasonable surface changes can further reduce the overall aberration of the optical imaging system 10, Allocating an appropriate amount of aberration to each lens reduces the sensitivity of the optical imaging system 10 .

0.43/mm＜nL/(n2+CT1)＜0.8/mm;

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

The light path turning member L6 can be made of glass material or plastic material, and the light path turning member L6 is coated to form a reflective surface to increase the transmittance, wherein the plastic material is light in weight, which is beneficial to practical applications. The second lens L2 adopts different refractive index materials, which can avoid excessive bending and reduce the complex change of the surface shape; under the configuration of different optical path turning elements L6, it can cooperate with the first lens L1 to change to reduce the introduction of aberrations; through reasonable refraction The power configuration helps to improve the resolution.

BF/|R52|＜0.82;

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

The telephoto lens itself has a long BF, and there is a strong diversity in the matching of the chip and the structural design of the supporting lens group. The BF ranges from 0.7mm to 2.42mm, which can meet the needs of different structures and matching. ; The fifth lens L5 expands the light outward, and the reasonable curved surface shape further balances the spherical aberration, coma, field curvature and other aberrations, reducing the overall aberration of the image surface; the change of the curvature radius of the fifth lens L5 reduces the surface The possibility of excessive bending of the mold improves the manufacturability of the lens molding and facilitates assembly.

0.5＜ET4/CT4＜4.15;

Satisfying the above formula, the thickness ratio of the fourth lens L4 is reasonable. Through reasonable refractive power configuration, the lens is less difficult to form, has a good deflection effect on edge light, is not easy to cause reflection and light leakage, and can improve the overall imaging quality.

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. Aperture STO is used to reduce stray light and help improve image quality. For example, in some embodiments, the stop STO is disposed between the third lens L3 and the fourth lens L4. The design of the center diaphragm makes it possible to realize a large viewing angle. In addition, the central diaphragm makes the structure of the optical imaging system 10 have a certain symmetry, so that the optical distortion can be better controlled.

In some embodiments, the optical imaging system 10 further includes an infrared filter L7, and the infrared filter L7 has an object side S14 and an image side S15. The infrared filter L7 is arranged on the image side S10 of the fifth lens L5 to filter out light in other wavelength bands such as visible light, and only allow infrared light to pass through, so that the optical imaging system 10 can be used in dark environments and other special applications The scene can also be imaged.

When the optical imaging system 10 is used for imaging, the light emitted or reflected by the object enters the optical imaging system 10 from the object side direction, and passes through the first lens L1, the second lens L2, the third lens L3, and the fourth lens in sequence L4, the fifth lens L5 and the infrared filter L7, and pass through the side located 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 The light path turning element L6 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 the production cost. In other embodiments, each lens can also 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 aspherical, which is conducive to correcting aberrations 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 aspherical lens can achieve more light refraction angles, so that the entire optical imaging system 10 can achieve high pixel requirements.

The shape of the aspheric surface is determined by the following formula:

where 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 vertex at the optical axis, k is the conic constant, Ai is the coefficient corresponding to the higher-order term of the i-th 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 by adjusting the curvature radius and aspheric coefficient of each lens surface, effectively correct the aberrations, and improve the imaging quality.

first embodiment

Referring to FIGS. 1 and 2 , the optical imaging system 10 of the first embodiment sequentially includes a first lens L1 with positive refractive power, a second lens L2 with negative refractive power, and a negative refractive power lens along the optical axis from the object side to the image side. The third lens L3 with refractive power, the fourth lens L4 with negative refractive power, the fifth lens L5 with negative refractive power, and the light path turning member L6, wherein the light path turning member L6 is located between the second lens L2 and the third lens L3 . Please refer to FIG. 2. FIG. 2 shows the spherical aberration curve of the optical imaging system 10 at wavelengths of 650nm, 610nm, 587nm, 510nm, and 470nm in the first embodiment, and the astigmatism diagram of the light at the wavelength of 587nm. Distortion graph at 587 nm, and the optical imaging system 10 in the first embodiment satisfies the conditions of the following table. The light path turning member L6 is a right angle prism, and has an incident surface S11, a reflection 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 L1 is a convex surface near the optical axis, and the image side surface S2 is a concave surface near the optical axis; the object side surface S3 of the second lens L2 is a convex surface near the optical axis, and the image side surface S4 is a concave surface near the optical axis; The object side S5 of the 3rd lens L3 is convex near the optical axis, and the image side S6 is concave near the optical axis; the object side S7 of the fourth lens L4 is concave near the optical axis, and the image side S8 is concave near the optical axis; The object side S9 of the fifth lens L5 is convex near the optical axis, and the image side S10 is concave near the optical axis.

The object side S1 of the first lens L1 is convex near the circumference, and the image side S2 is convex near the circumference; the object side S3 of the second lens L2 is convex near the circumference, and the image side S4 is concave near the circumference; the third lens L3 The object side S5 is convex near the circumference, and the object side S6 is concave near the circumference; the object side S7 of the fourth lens L4 is concave near the circumference, and the object side S8 is convex near the circumference; the object side S9 of the fifth lens L5 It is concave near the circumference, and the side surface S10 is concave near 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 conditions: 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 587 nm, 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 arranged in the order of the elements from top to bottom in Table 1.

Surface numbers

1 and 2 are the object side S1 and the image side S2 of the first lens L1 respectively, that is, in the same lens, the surface with the smaller surface number is the object side, and the surface with the larger surface number is the image side. The Y radius in Table 1 is the curvature radius of the object side or image side of the corresponding surface number at the optical axis. The first value in the "thickness" parameter column of the first lens is the thickness of the lens on the optical axis, and the second value is the distance from the image side of the lens to the object side of the following lens on the optical axis, where Y radius and thickness are in mm. Table 2 is a table of relevant parameters of the aspheric surfaces of each lens in Table 1, wherein K is the conic constant, and Ai is the coefficient corresponding to the i-th high-order term in the aspheric 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 aperture number of the optical imaging system 10, FOV is the field angle of the optical imaging system 10, and TTL is the object side of the first lens L1 The distance from S1 to the image plane S16 on the optical axis.

Table 2

Second Embodiment

Referring to FIGS. 3 and 4 , the optical imaging system 10 of the second embodiment sequentially includes a first lens L1 having a positive refractive power, a second lens L2 having a positive refractive power, a negative The third lens L3 with refractive power, the fourth lens L4 with negative refractive power, the fifth lens L5 with positive refractive power, and the light path turning member L6 are located between the third lens L3 and the fourth lens L4. Please refer to FIG. 4 . FIG. 4 shows a graph of spherical aberration of light of the optical imaging system 10 at wavelengths of 650 nm, 610 nm, 587 nm, 510 nm and 470 nm in the second embodiment, and a graph of astigmatism of light at a wavelength of 587 nm. Distortion graph at 587 nm, and the optical imaging system 10 in the second embodiment satisfies the conditions of the following table. The light path turning member L6 is a right angle prism, and has an incident surface S11, a reflection 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 L1 is a convex surface near the optical axis, and the image side surface S2 is a concave surface near the optical axis; the object side surface S3 of the second lens L2 is a convex surface near the optical axis, and the image side surface S4 is a convex surface near the optical axis; The object side S5 of the third lens L3 is concave near the optical axis, and the image side S6 is convex near the optical axis; the object side S7 of the fourth lens L4 is concave near the optical axis, and the image side S8 is convex near the optical axis; The object side S9 of the fifth lens L5 is concave near the optical axis, and the image side S10 is convex near the optical axis.

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

A stop STO is provided between the first lens L1 and the second lens L2.

In the second embodiment, the optical imaging system 10 satisfies the following conditions: 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 587 nm, and the optical imaging system 10 in the second embodiment satisfies the conditions of the following table. The definition of each parameter can be obtained from the first embodiment, which is not repeated here.

table 3

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 aperture number of the optical imaging system 10, FOV is the field angle of the optical imaging system 10, and TTL is the object side of the first lens L1 The distance from S1 to the image plane S16 on the optical axis, wherein the units of Y radius and thickness are mm.

Table 4

Third Embodiment

Referring to FIGS. 5 and 6 , the optical imaging system 10 of the third embodiment sequentially includes a first lens L1 having a positive refractive power, a second lens L2 having a positive refractive power, a negative The third lens L3 with refractive power, the fourth lens L4 with positive refractive power, the fifth lens L5 with negative refractive power, and the light path turning member L6, the light path turning member L6 is located on the side of the first lens L1 away from the second lens L2 . Please refer to FIG. 6. FIG. 6 shows the spherical aberration curve of the optical imaging system 10 at wavelengths of 650nm, 610nm, 587nm, 510nm, and 470nm in the third embodiment, and the astigmatism diagram of the light at the wavelength of 587nm. The distortion curve at 587 nm, and the optical imaging system 10 in the third embodiment satisfies the conditions in the following table, the light path turning member L6 is a right angle prism, and has an incident surface S11, a reflection surface S12 and an exit surface S13, wherein the incident surface S11 and the The exit surface S13 is perpendicular.

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

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

The stop STO is provided between the first lens L1 and the light path turning member L6.

In the third embodiment, the optical imaging system 10 satisfies the following conditions: 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 587 nm, 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 FIGS. 7 and 8 , the optical imaging system 10 of the fourth embodiment sequentially includes a first lens L1 with positive refractive power, a second lens L2 with negative refractive power, and a negative refractive power lens along the optical axis from the object side to the image side. The third lens L3 with refractive power, the fourth lens L4 with positive refractive power, the fifth lens L5 with negative refractive power, and the light path turning member L6, the light path turning member L6 is located on the side of the first lens L1 away from the second lens L2 . Please refer to FIG. 8 . FIG. 8 shows a graph of spherical aberration of light of the optical imaging system 10 at wavelengths of 650 nm, 610 nm, 587 nm, 510 nm and 470 nm, and a graph of astigmatism of light at a wavelength of 587 nm in the fourth embodiment. Distortion graph at 587 nm, and the optical imaging system 10 in the fourth embodiment satisfies the conditions of the following table. The light path turning member L6 is a right angle prism, and has an incident surface S11, a reflection 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 L1 is a convex surface near the optical axis, and the image side surface S2 is a concave surface near the optical axis; the object side surface S3 of the second lens L2 is a convex surface near the optical axis, and the image side surface S4 is a concave surface near the optical axis; The object side S5 of the third lens L3 is concave near the optical axis, and the image side S6 is concave near the optical axis; the object side S7 of the fourth lens L4 is convex near the optical axis, and the image side S8 is concave near the optical axis; The object side S9 of the fifth lens L5 is concave near the optical axis, and the image side S10 is convex near the optical axis.

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

The stop STO is provided between the light path turning member L6 and the first lens L1.

In the fourth embodiment, the optical imaging system 10 satisfies the following conditions: 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 587 nm, 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 FIGS. 9 and 10 , the optical imaging system 10 of the fifth embodiment sequentially includes a first lens L1 with positive refractive power, a second lens L2 with positive refractive power, and a negative refractive power along the optical axis from the object side to the image side. The third lens L3 with refractive power, the fourth lens L4 with negative refractive power, the fifth lens L5 with negative refractive power, and the light path turning member L6 are located between the first lens L1 and the second lens L2. Please refer to FIG. 10. FIG. 10 shows the spherical aberration curve of the optical imaging system 10 at wavelengths of 650nm, 610nm, 587nm, 510nm, and 470nm in the fifth embodiment, and the astigmatism diagram of the light at the wavelength of 587nm. Distortion graph at 587 nm, and the optical imaging system 10 in the fifth embodiment satisfies the conditions of the following table. The light path turning member L6 is a right angle prism, and has an incident surface S11, a reflection 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 L1 is a convex surface near the optical axis, and the image side surface S2 is a concave surface near the optical axis; the object side surface S3 of the second lens L2 is a convex surface near the optical axis, and the image side surface S4 is a convex surface near the optical axis; The object side S5 of the third lens L3 is concave near the optical axis, and the image side S6 is convex near the optical axis; the object side S7 of the fourth lens L4 is concave near the optical axis, and the image side S8 is concave near the optical axis; The object side S9 of the fifth lens L5 is concave near the optical axis, and the image side S10 is convex near the optical axis.

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

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

In the fifth embodiment, the optical imaging system 10 satisfies the following conditions: 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 587 nm, and the optical imaging system 10 in the fifth embodiment satisfies the conditions of the following table.

Table 9

Table 10

Sixth Embodiment

Referring to FIGS. 11 and 12 , the optical imaging system 10 of the sixth embodiment sequentially includes a first lens L1 with positive refractive power, a second lens L2 with negative refractive power, and a negative refractive power along the optical axis from the object side to the image side. The third lens L3 with refractive power, the fourth lens L4 with negative refractive power, the fifth lens L5 with negative refractive power, and the light path turning member L6 are located between the second lens L2 and the third lens L3. Please refer to FIG. 12. FIG. 12 shows the spherical aberration curve of the optical imaging system 10 at wavelengths of 650nm, 610nm, 587nm, 510nm, and 470nm, and the astigmatism diagram of the light at the wavelength of 587nm. Distortion graph at 587 nm, and the optical imaging system 10 in the sixth embodiment satisfies the conditions of the following table. The light path turning member L6 is a right angle prism, and has an incident surface S11, a reflection 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 L1 is a convex surface near the optical axis, and the image side surface S2 is a concave surface near the optical axis; the object side surface S3 of the second lens L2 is a convex surface near the optical axis, and the image side surface S4 is a concave surface near the optical axis; The object side S5 of the third lens L3 is concave near the optical axis, and the image side S6 is concave near the optical axis; the object side S7 of the fourth lens L4 is concave near the optical axis, and the image side S8 is convex near the optical axis; The object side surface S9 of the fifth lens L5 is concave near the optical axis, and the image side surface S10 is concave near the optical axis.

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

In the sixth embodiment, the optical imaging system 10 satisfies the following conditions: 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, ET4/CT4=0.96.

The reference wavelength in the sixth embodiment is 587 nm, 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 embodiment of the present application provides an imaging module 100 , which includes an optical imaging system 10 and a photosensitive element 20 , and the photosensitive element 20 is disposed on the image side of the optical imaging system 10 .

Specifically, the photosensitive element 20 can be a complementary metal oxide semiconductor (CMOS, Complementary Metal Oxide Semiconductor) image sensor or a charge-coupled device (CCD, Charge-coupled Device).

The optical imaging system 10 in the imaging module 100 of the embodiment of the present application is combined with the lens through the optical path turning member L6, so that the optical imaging system 10 maintains a sufficient long focal length, enlarges the size of the image plane, and achieves a large aperture effect. The optical imaging system 10 has good image quality and lightness by reasonably configuring the surface shape and refractive power of the light path turning member L6 and the distribution lens.

Referring to FIG. 14 , the electronic device 1000 according to the embodiment of the present application includes a casing 200 and an imaging module 100 , and the imaging module 100 is installed on the casing 200 .

The electronic device 1000 in the embodiment of the present application includes, but is not limited to, 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, and a mobile medical device , wearable devices and other electronic devices that support imaging.

The optical imaging system 10 in the electronic device 1000 of the above embodiment is combined with the lens through the light path turning member L6, so that the optical imaging system 10 maintains a sufficient long focal length, enlarges the size of the image plane, and achieves a large aperture effect. The optical imaging system 10 has good image quality and lightness by reasonably configuring the surface shape and refractive power of the light path turning member L6 and the distribution lens.

It will be apparent to those skilled in the art that the present application is not limited to the details of the above-described exemplary embodiments, but that the present application may be implemented in other specific forms without departing from the spirit or essential characteristics of the present application. Accordingly, the embodiments are to be regarded in all respects as illustrative and not restrictive, and the scope of the application is to be defined by the appended claims rather than the foregoing description, which is therefore intended to fall within the scope of the claims. All changes within the meaning and scope of the equivalents of , are included in this application.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application and not to limit them. Although the present application has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present application can be Modifications or equivalent substitutions can be made without departing from the spirit and scope of the technical solutions of the present application.

Claims

An optical imaging system, characterized in that, from the object side to the image side along the optical axis, it comprises:

The first lens has a positive refractive power, the object side of the first lens is convex near the optical axis, and the image side of the first lens is concave near the optical axis;

The second lens has a refractive power, and the object side of the second lens is convex near the optical axis;

The third lens has negative refractive power;

The fourth lens has a refractive power, and the object side and the image side of the fourth lens are both aspherical;

The fifth lens has a refractive power, the object side and the image side of the fifth lens are both aspherical, and at least one of the object side and the image side of the fifth lens is provided with at least one inflection point;

An optical path turning member with a reflective surface, the optical path turning member is arranged near the object side of the first lens, or between any two adjacent lenses among the first to fourth lenses.
The optical imaging system according to claim 1, wherein the optical imaging system satisfies the following conditional formula:

57.0<43*EFL/ImgH<122.0;

Wherein, EFL is the effective focal length of the optical imaging system, and ImgH is the diameter of the effective imaging circle of the optical imaging system.
The optical imaging system according to claim 1, wherein the optical imaging system satisfies the following conditional formula:

0.35＜TTL/(EFL*FNO)＜0.6;

Wherein, when the optical path diverting member is arranged on the object side of the first lens, TTL is the on-axis distance from the intersection of the optical path diverting member and the near object side of the optical axis to the image plane; When 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 first lens The on-axis distance from the intersection of the object side surface and the optical axis of a lens to the image plane, EFL is the effective focal length of the optical imaging system, and FNO is the aperture number of the optical imaging system.
The optical imaging system according to claim 1, wherein the optical imaging system satisfies the following conditional formula:

f1/|R22|＜7.6;

Wherein, f1 is the effective focal length of the first lens, and R22 is the radius of curvature of the image side of the second lens at the optical axis.
The optical imaging system according to claim 1, wherein the optical imaging system satisfies the following conditional formula:

7.5＜|f45|/ET45＜21.85;

Wherein, f45 is the combined focal length of the fourth lens and the fifth lens, and ET45 is the axial distance between the effective diameter on the image side of the fourth lens and the effective diameter on the object side of the fifth lens.
The optical imaging system according to claim 1, wherein the optical imaging system satisfies the following conditional formula:

ET3/|f3|＜0.15;

Wherein, ET3 is the thickness at the effective diameter of the third lens, and f3 is the effective focal length of the third lens.
The optical imaging system according to claim 1, wherein the optical imaging system satisfies the following conditional formula:

0.43/mm＜nL/(n2+CT1)＜0.8/mm;

Wherein, nL is the refractive index of the optical path turning member at 587 nm, n2 is the refractive index of the second lens at 587 nm, and CT1 is the thickness of the first lens on the optical axis.
The optical imaging system according to claim 1, wherein the optical imaging system satisfies the following conditional formula:

BF/|R52|＜0.82;

Wherein, BF is the minimum axial distance between the image side surface of the fifth lens and the object side surface, and R52 is the radius of curvature of the image side surface of the fifth lens at the optical axis.
The optical imaging system according to claim 1, wherein the optical imaging system satisfies the following conditional formula:

0.5＜ET4/CT4＜4.15;

Wherein, ET4 is the thickness of the effective diameter of the fourth lens along the optical axis, and CT4 is the thickness of the fourth lens along the optical axis.
An imaging module, characterized in that, comprising:

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

A photosensitive element, the photosensitive element is arranged on the image side of the optical imaging system.
An electronic device, comprising:

the shell; and

The imaging module according to claim 10, wherein the imaging module is mounted on the casing.