CN117492185B

CN117492185B - Optical imaging lens, camera module and terminal equipment

Info

Publication number: CN117492185B
Application number: CN202311841619.0A
Authority: CN
Inventors: 徐奉刚; 王新权
Original assignee: Honor Device Co Ltd
Current assignee: Honor Device Co Ltd
Priority date: 2023-12-29
Filing date: 2023-12-29
Publication date: 2024-05-28
Anticipated expiration: 2043-12-29
Also published as: CN117492185A

Abstract

The embodiment of the application relates to the technical field of optical imaging, and provides an optical imaging lens, an imaging module and terminal equipment, wherein the optical imaging lens comprises a first lens group, the first lens group comprises a first lens, an intermediate medium and a second lens which are sequentially arranged in the direction from an object side to an image side, the refractive index of the first lens is n1, the refractive index of the second lens is n2, and the refractive index of the intermediate medium is n3; wherein n1-n 3/n 2<0.15. The optical imaging lens provided by the embodiment of the application limits the refractive index of the first lens in the first lens group, the refractive index of the intermediate medium and the refractive index of the second lens, namely, satisfies the condition that |n1-n3|/n2<0.15, can balance the chromatic aberration of the optical imaging lens, improves the integral imaging quality of the optical imaging lens, and simultaneously can effectively reduce the occurrence probability of total reflection, thereby reducing the occurrence probability of 'lens ghost image' formed by total reflection.

Description

Optical imaging lens, camera module and terminal equipment

Technical Field

The present application relates to the field of optical imaging technologies, and in particular, to an optical imaging lens, a camera module, and a terminal device.

Background

In recent years, with the rapid development of intelligent mobile terminals (mobile phones, tablet computers, etc.), consumers have also been increasingly demanding on shooting experience and photo quality.

In a specific application scenario, for example, when a lens is used for shooting in a sunny day or at night when a street lamp is directly shot, a bright line or a bright arc with a distinct boundary appears in a picture at a specific viewing angle, and the bright line or the bright arc is called as "lens ghost image", which greatly affects the shooting experience and shooting quality of a user.

Disclosure of Invention

The embodiment of the application provides an optical imaging lens, an imaging module and terminal equipment, which can improve or reduce the technical problem of the probability of 'lens ghost image' of the optical imaging lens in the imaging process.

In order to achieve the above purpose, the embodiment of the present application adopts the following technical scheme:

in a first aspect, the present application provides an optical imaging lens, including a first lens group, where the first lens group includes a first lens, an intermediate medium, and a second lens sequentially disposed in a direction from an object side to an image side, the first lens has a refractive index n1, the second lens has a refractive index n2, and the intermediate medium has a refractive index n3;

wherein n1-n 3/n 2<0.15.

The intermediate medium may be a solid, liquid or gaseous medium, alternatively, the intermediate medium may be glass, plastic, numeric, aerogel, water, oil, alcohol, carbon dioxide, or the like.

The technical scheme provided by the embodiment of the application has at least the following technical effects or advantages:

The optical imaging lens provided by the embodiment of the application limits the refractive index of the first lens in the first lens group, the refractive index of the intermediate medium and the refractive index of the second lens, namely, satisfies the condition that |n1-n3|/n2<0.15, can balance the chromatic aberration of the optical imaging lens, improves the integral imaging quality of the optical imaging lens, and simultaneously can effectively reduce the occurrence probability of total reflection, thereby reducing the occurrence probability of 'lens ghost image' formed by total reflection.

In some embodiments, the first lens element has a first object-side surface facing the object-side surface and a first image-side surface facing the image-side surface, wherein the first object-side surface is convex at the optical axis of the optical imaging lens element and the first image-side surface is convex at the optical axis of the optical imaging lens element, such that the refractive power of the first lens element is positive;

the second lens element has a second object-side surface facing the object-side surface and a second image-side surface facing the image-side surface, wherein the second object-side surface is convex at the optical axis of the optical imaging lens element, and the second image-side surface is concave at the optical axis of the optical imaging lens element, such that the refractive power of the second lens element is negative.

In some embodiments, the first object-side surface has a radius of curvature R11 and the first image-side surface has a radius of curvature R12;

wherein, -0.5< R11/R12<0.

It can be appreciated that by controlling the ratio of the radius of curvature of the first object-side surface of the first lens to the radius of curvature of the first image-side surface of the first lens, the shape of the first lens can be effectively constrained, so that light is controlled to smoothly enter the first lens group from the object-side surface of the lens, and the imaging quality of the optical imaging lens is improved.

In some embodiments, the optical imaging lens further includes a second lens group, the second lens group being located on a side of the second lens facing the image side;

The effective focal length of the first lens group is FG1, and the effective focal length of the second lens group is FG2, -1< FG1/FG2<0.

It can be understood that by restricting the ratio of the effective focal length of the first lens group to the effective focal length of the second lens group, it is beneficial to balance the aberration of the optical imaging lens, improve the imaging quality, and at the same time, it is beneficial to limit the total length (restricting the overall dimension) of the whole lens, so that it has the characteristic of miniaturization.

In some embodiments, the second lens group includes a third lens, a fourth lens, a fifth lens and a sixth lens disposed in order in a direction from an object side to an image side;

The third lens element has a third object-side surface facing the object-side surface and a third image-side surface facing the image-side surface, wherein the third object-side surface is convex at the optical axis of the optical imaging lens element, and the third image-side surface is convex at the optical axis of the optical imaging lens element, so that the refractive power of the third lens element is positive;

The fourth lens element has a fourth object-side surface facing the object-side surface and a fourth image-side surface facing the image-side surface, wherein the fourth object-side surface is convex at the optical axis of the optical imaging lens element and the fourth image-side surface is concave at the optical axis of the optical imaging lens element, so that the refractive power of the fourth lens element is negative;

The fifth lens element has a fifth object-side surface facing the object-side surface and a fifth image-side surface facing the image-side surface, wherein the fifth object-side surface is convex at the optical axis of the optical imaging lens element, and the fifth image-side surface is convex at the optical axis of the optical imaging lens element, such that the refractive power of the fifth lens element is positive;

the sixth lens is provided with a sixth object side surface facing the object side and a sixth image side surface facing the image side, wherein the sixth object side surface is a convex surface at the optical axis of the optical imaging lens, and the sixth image side surface is a concave surface at the optical axis of the optical imaging lens; from this, the refractive power of the sixth lens element is negative.

In some embodiments, the effective focal length of the third lens is f3;

wherein, -2.5< f3/FG2< -0.5.

It can be appreciated that by restricting the effective focal length of the third lens and the effective focal length of the second lens group within the above ranges, light is facilitated to smoothly enter the second lens group from the first lens group, and meanwhile, lens processing manufacturability and assembly manufacturability of the third lens can be improved.

In some embodiments, the fifth lens has a center thickness of CT5, the sixth lens has a center thickness of CT6, and an air gap between the fifth lens and the sixth lens in the optical axis direction of the optical imaging lens is CT56;

wherein 1< (CT5+CT6)/CT 56<2.

It can be appreciated that by adopting the technical scheme, the fifth lens and the sixth lens are reasonably arranged on the optical axis, and an assembly space is reserved for the mechanical support structure.

In some embodiments, the total effective focal length of the optical imaging lens is f;

Wherein, -10< FG2/f < -3.

It can be appreciated that by constraining the ratio of the effective focal length of the second lens group to the total effective focal length of the optical imaging lens, reasonable distribution of optical power can be achieved, and the astigmatism and field curvature of the whole optical imaging lens are balanced, thereby improving imaging quality.

In some embodiments, the optical imaging lens has an entrance pupil diameter EPD,

Wherein 0<f/EPD <2.5.

It can be understood that by restricting the ratio of the total effective focal length of the whole optical imaging lens to the entrance pupil diameter of the optical imaging lens, the light flux of the optical imaging lens can be increased and the shallow depth effect of the main body can be enhanced on the premise of maintaining the focal length of the optical imaging lens.

In a second aspect, the present application provides an imaging module, including the optical imaging lens described above.

In a third aspect, the present application provides a terminal device, including the above-mentioned camera module.

It will be appreciated that the advantages of the second and third aspects may be found in the relevant description of the first aspect, and are not described in detail herein.

Drawings

Fig. 1 is a schematic structural diagram of a terminal device according to an embodiment of the present application;

FIG. 2 is a schematic diagram of an imaging principle according to an embodiment of the present application;

Fig. 3 is a schematic structural diagram of an optical imaging lens according to an embodiment of the present application;

FIG. 4 is an optical data table of an optical imaging lens according to a first embodiment of the present application;

FIG. 5 is an aspherical data table of each lens of an optical imaging lens according to an embodiment of the present application;

FIG. 6 is an astigmatic field curve of an optical imaging lens according to a first embodiment of the present application on an image plane;

fig. 7 is a diagram illustrating a distortion aberration of an optical imaging lens on an image plane according to a first embodiment of the present application;

Fig. 8 is an optical data table of an optical imaging lens according to a second embodiment of the present application;

fig. 9 is an aspherical data table of each lens of the optical imaging lens according to the second embodiment of the present application;

fig. 10 is an astigmatic field curve of an optical imaging lens provided in a second embodiment of the present application on an image plane;

Fig. 11 is a diagram illustrating a distortion aberration of an optical imaging lens on an image plane according to a second embodiment of the present application;

Fig. 12 is an optical data table of an optical imaging lens according to a third embodiment of the present application;

Fig. 13 is an aspherical data table of each lens of the optical imaging lens according to the third embodiment of the present application;

fig. 14 is an astigmatic field curve of an optical imaging lens according to a third embodiment of the present application on an image plane;

Fig. 15 is a diagram illustrating distortion aberration of an optical imaging lens on an image plane according to a third embodiment of the present application.

Wherein, each reference sign in the figure:

1000. A terminal device;

200. A camera module; 300. a housing; 400. a display screen;

100. An optical imaging lens; 101. an image sensor; 102. an analog-to-digital converter; 103. an image processor; 104. a memory;

10. a first lens group; 11. a first lens; 12. an intermediate medium; 13. a second lens;

20. a second lens group; 21. a third lens; 22. a fourth lens; 23. a fifth lens; 24. and a sixth lens.

A. an object side; B. an image side; 30. an aperture; 40. an image plane;

I. An optical axis;

E11, a first object side surface; e21, a second object side; e31, third object side; e41, fourth object side; e51, fifth object side surface; e61, sixth object side;

e12, a first image side surface; e22, a second image side surface; e32, a third image side surface; e42, a fourth image side surface; e52, fifth image side; e62, sixth image side surface.

Detailed Description

Embodiments of the present application are described in detail below, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements or elements having like or similar functions throughout. The embodiments described below by referring to the drawings are illustrative and intended to explain the present application and should not be construed as limiting the application.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The terms "comprising" and "having" and any variations thereof in the description of the application and the claims and the description of the drawings above are intended to cover a non-exclusive inclusion.

In the description of the present application, it should be understood that the terms "length," "width," "thickness," "top," "bottom," "inner," "outer," "upper," "lower," and the like indicate orientations or positional relationships based on the orientation or positional relationships shown in the drawings, are merely for convenience in describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present application.

The terms "first," "second," "third," "fourth," "fifth," "sixth," and the like are used solely for distinguishing between descriptions and not necessarily for indicating or implying a relative importance or implicitly indicating the number of features indicated. For example, the first deformation space and the second deformation space are merely for distinguishing between the different deformation spaces, and are not limited in their order, and the first deformation space may also be named as the second deformation space, and the second deformation space may also be named as the first deformation space, without departing from the scope of the various described embodiments. And the terms "first," "second," and the like, do not necessarily denote different quantities.

In the present application, unless explicitly specified and limited otherwise, the terms "connected," "connected," and the like are to be construed broadly, and may be fixedly connected, detachably connected, or integrally formed, for example; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art according to the specific circumstances.

In the present application, "and/or" is merely one association relationship describing the association object, meaning that three relationships may exist; for example, a and/or B may represent: a exists alone, A and B exist together, and B exists alone. In addition, the character "/" herein generally indicates that the front and rear associated objects are an "or" relationship.

It should be noted that, in the present application, words such as "in some embodiments," "illustratively," "for example," and the like are used to indicate examples, illustrations, or descriptions. Any embodiment or design described herein as "in some embodiments," "illustratively," "for example," should not be construed as preferred or advantageous over other embodiments or designs. Rather, the use of words such as "in some embodiments," "illustratively," "for example," and the like are intended to present related concepts in a concrete fashion.

The present application will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present application more apparent.

In a specific application scenario of the optical imaging lens, for example, when the lens is used for shooting in a sunny day or at night when a street lamp is directly shot, a bright line or a bright arc with a distinct boundary appears in a picture under a specific view angle, and the bright line or the bright arc is called as a "lens ghost image", which greatly affects the shooting experience and shooting quality of a user.

And, the main cause of the generation of the "lens ghost image" is the secondary reflection or the four-time reflection in the first lens of the optical imaging lens, and thus, the brightness level of the bright line or the bright arc appearing in the picture depends on the number of times of the total emission in the first lens of the optical imaging lens.

In view of this, the present application provides an optical imaging lens, wherein a first lens group includes a first lens, an intermediate medium, and a second lens disposed in order in a direction from an object side to an image side, a refractive index of the first lens is n1, a refractive index of the second lens is n2, a refractive index of the intermediate medium is n3, and refractive indexes of the respective lenses and the intermediate medium have the following relationship: the ratio of n1-n 3/n 2 is <0.15. Therefore, the chromatic aberration of the optical imaging lens can be balanced, the overall imaging quality of the optical imaging lens is improved, and meanwhile, the probability of occurrence of total reflection can be effectively reduced, so that the probability of occurrence of 'lens ghost images' formed by total reflection is reduced.

Terminal device 1000 can include a handheld device, an in-vehicle device, a wearable device, a computing device, or other processing device connected to a wireless modem. And may also include cellular phones (cellphones), smart phones (smart phones), personal Digital Assistants (PDA) computers, tablet computers, laptop computers (laptop computers), machine Type Communication (MTC) terminals, point of sale (POS), car computers, and other terminal devices 1000 with imaging capabilities.

For ease of understanding, the technical terms involved in the present application are explained and described first.

The optical axis, which is the direction in which the optical system conducts light, refers to the principal ray of the central field of view. For symmetrical transmission systems, it is common to coincide with the optical system rotation centerline. For off-axis and reflective systems, the optical axis will also appear as a fold line.

When light rays parallel to the optical axis enter the convex lens, the ideal convex lens is a point at which all the light rays are converged behind the lens, and the point at which all the light rays are converged is the focal point.

Focal length (focallength), also known as focal length, is a measure of the concentration or divergence of light in an optical system, and refers to the distance from the optical center of a lens or lens group to the focal point when a scene at infinity is brought into clear images at the focal plane by the lens or lens group, and can also be understood as the perpendicular distance from the optical center of the lens or lens group to the focal plane. The distance from the center of the lens to the imaging plane can be understood from a practical point of view. For a fixed focus lens, the position of the optical center of the fixed focus lens is fixed, so that the focal length is fixed; for a zoom lens, a change in the optical center of the lens brings about a change in the focal length of the lens, and thus the focal length can be adjusted.

The effective focal length refers to the distance between the position where the light is focused on the sensor or film after passing through the lens and the front end of the lens. The distance is affected by factors such as the optical path length, the thickness of the lens, and the refractive index.

According to the zoom range, the lens can be divided into super wide-angle lens (focal length is smaller than 21 mm), wide-angle lens (focal length is 21mm-35 mm), standard lens (focal length is 35mm-70 mm), mid-tele lens (focal length is 70mm-135 mm), tele lens (focal length is 135-500 mm+), and the like.

The zooming is helpful for amplifying a distant object during telescopic shooting, wherein an optical zooming (optical zoom) can support the imaging of an image main body, more pixels are added, the main body is enlarged, meanwhile, the main body is relatively clearer, and the resolution and the image quality of the main body are not changed. Optical zooming relies on the structure of an optical lens to achieve zooming, specifically by changing the position of the lens, object and focus. When the image plane moves in the horizontal direction, vision and focal length change, and a more distant scene becomes clearer. Optical zooming can enlarge or reduce a subject to be photographed by changing the focal length of a lens by changing the relative positions of lenses in the zoom lens. The image is amplified by physical principle, in the amplifying process, the photosensitive element is directly sensitive from the shot object and forms an image without any other electronic amplifying treatment, in the process, the photosensitive element is full-width imaging, and the original highest resolution of the image can be maintained. Therefore, the image obtained by the optical zoom not only enlarges the subject but also is relatively clearer. The larger the multiple of the optical zoom, the more far the scene can be photographed.

The focal length of the zoom lens has two readings, where the smaller the number is called the wide-angle end (the largest angle of view can be obtained), the larger the number is called the tele end (the longest focal length can be obtained), and either of the two focal length ends can be used in shooting, where the wider the wide-angle end of the lens focal length (i.e., the smaller the number), the wider the scene can be shot, and the longer the tele end (i.e., the larger the number) the more distant the scene can be shot. Dividing the number of the long focal length end by the number of the wide angle end to obtain the zoom multiple. For example, the optical zoom multiple is 2-5 times, namely, objects beyond 10 meters can be pulled to 5-2 meters; the lens with the zoom multiple of more than 20 times can shoot not only a large scene in front of eyes, but also objects beyond a long distance; the zoom multiple is 50 times, and shooting of scenes beyond 3000 meters is equivalent to shooting at 60 meters.

In the optical apparatus, a lens of the optical apparatus is taken as a vertex, and an included angle formed by two edges of a maximum range of an object image of a measured object can pass through the lens is called a field angle. The size of the angle of view determines the field of view of the optical instrument, and the larger the angle of view, the larger the field of view and the smaller the optical magnification. The shorter the focal length, the wider the horizontal field of view, and thus the smaller the image, the narrower the horizontal field of view with an increase in focal length, and the larger the subject.

Aberration, also called axial chromatic aberration, longitudinal chromatic aberration, or positional chromatic aberration, or axial aberration, is a phenomenon in which a bundle of rays parallel to the optical axis, after passing through a lens, is converged at different positions front and rear. This is because the lens images light of each wavelength at different positions, so that the focal planes of the light of different colors at the time of final imaging cannot coincide, and the light of multiple colors is scattered to form dispersion.

The optical path of light in the lens refers to the path that light travels from the incident surface of the lens to the image surface.

Spherical and aspherical surfaces are mainly used for lens geometry of lenses (various cameras, microscopes, etc.), glasses (including contact lenses), i.e. spherical lenses and aspherical lenses. The difference in geometry determines the difference in refraction direction of the parallel incident light, thereby affecting the imaging effect.

The spherical lens has spherical radian and arc cross section. When light rays with different wavelengths are incident on different positions on the lens in parallel with the optical axis, the light rays cannot be focused into a point on a film plane (a plane perpendicular to the line between the center of the lens and the focal point of the lens and passing through the focal point), so that the problem of aberration is formed, and the quality of an image is affected, for example, phenomena such as reduced definition and deformation occur.

The aspherical lens is not in spherical radian, but the edge part of the lens is cut off slightly, and the cross section of the aspherical lens is in a plane shape. When the light is incident on the aspherical mirror, the light can be focused on a point, namely, a film plane, so as to eliminate various aberrations.

Free-form surfaces, surfaces without an axis of rotational symmetry are generally referred to optically as free-form surfaces.

The object space is defined by the lens, and the space where the object is located is the object space.

The space of the image space, which is bounded by the lens and in which the light emitted by the shot object passes through the lens to form an image behind the lens, is the space of the image space.

Taking the lens as a boundary, the side where the shot object is located is the object side, and the surface of the lens close to the object side can be called as the object side; the side on which the image of the subject is located is the image side, bounded by the lens, and the surface of the lens near the image side may be referred to as the image side.

The determination of the surface shape of the optical axis region may also be performed by a determination method by a person skilled in the art, that is, by a sign of a paraxial radius of curvature (abbreviated as R value). The R value may be commonly used in optical design software, such as Zemax or CodeV. The R value is also commonly found in the lens data table (LENS DATA SHEET) of optical design software. When the R value is positive, the object side surface is judged to be a convex surface in the optical axis area of the object side surface; when the R value is negative, the optical axis area of the object side surface is judged to be a concave surface. On the contrary, when the R value is positive, the optical axis area of the image side surface is judged to be concave; when the R value is negative, it is determined that the optical axis area of the image side surface is convex. The result of the determination is consistent with the result of the determination mode by the intersection point of the light/light extension line and the optical axis, namely, the determination mode of the intersection point of the light/light extension line and the optical axis is to determine the surface shape concave-convex by using the focus of the light of a parallel optical axis to be positioned at the object side or the image side of the lens. As used herein, "a region is convex (or concave)," or "a region is convex (or concave)," may be used interchangeably.

Fig. 1 shows a schematic diagram of a terminal device 1000. Terminal device 1000 can be a terminal device with camera or photographing capabilities, such as a cellular phone (cellular phone), a cell phone, a smart phone (smart phone), a tablet, a laptop, a lap computer (laptop), a video camera, a video recorder, a camera, a smart watch (SMART WATCH), a smart bracelet (smart wristband), or other forms of devices with camera or photographing capabilities. The embodiment of the present application is not particularly limited to the specific form of the terminal device 1000 described above. The following description will take terminal device 1000 as an example of a mobile phone for convenience of explanation and understanding.

The terminal device 1000, as shown in fig. 1, may include a display 400 (DISPLAY PANEL, DP), a housing 300, a camera module 200 (camera compact module, CCM), and the like. The housing 300 is formed with an accommodation space in which the display screen 400 and the camera module 200 are disposed in the housing 300. The display screen 400 may be a Liquid CRYSTAL DISPLAY (LCD) screen, an Organic LIGHT EMITTING Diode (OLED) display screen, or the like, wherein the OLED display screen 400 may be a flexible display screen or a hard display screen.

The camera module 200 may be disposed only on the front side of the terminal device 1000, and is used for capturing a scene on one side of the front side of the terminal device 1000, and may be referred to as a front camera module in some embodiments; or may be disposed only on the back of the terminal device 1000, for capturing a scene on the back side of the terminal device 1000, and may be referred to as a rear camera module in some embodiments; the camera module 200 is disposed on the front side of the terminal device 1000, and the camera module 200 is disposed on the back side of the terminal device 1000, as shown in fig. 1, so that a scene on the front side of the terminal device 1000 or a scene on the back side of the terminal device 1000 can be captured, as long as the corresponding camera module is used during capturing.

It should be understood that the mounting location of the camera module 200 is merely illustrative. In some embodiments, when the camera module 200 is used as a front camera module, the camera module may be installed at other positions on the terminal device 1000, for example, at the left side of the earphone, at the middle position of the upper part of the terminal device 1000, at the lower part (or referred to as chin) of the terminal device 1000, or at four corners of the terminal device 1000; when the camera module 200 is used as a rear camera module, it may be mounted at an upper middle position or an upper right corner of the rear surface of the terminal device 1000. In other embodiments, camera module 200 may be disposed not on the body of terminal device 1000, but on an edge that protrudes from the body of terminal device 1000, or on a component that is movable or rotatable relative to terminal device 1000, e.g., that may extend, retract, rotate, etc. from the body of terminal device 1000. When the camera module 200 can rotate relative to the terminal device 1000, the camera module 200 is equivalent to a front camera module and a rear camera module, that is, by rotating the same camera module 200, a scene on the front side of the terminal device 1000 can be shot, and a scene on the back side of the terminal device 1000 can be shot. In other embodiments, when the display 400 is foldable, the camera module 200 may be used as a front camera module or a rear camera module, and the camera module 200 is used to capture a view on the front side of the terminal device 1000 or a view on the back side of the terminal device 1000 along with the folding of the display 400.

The number of the camera modules 200 provided in the embodiment of the present application is not limited, and may be one, two, four or more, for example, the terminal device 1000 may have one or more camera modules 200 provided on the front side and one or more camera modules 200 provided on the back side. The embodiment of the application does not limit the number of the camera modules, and does not limit the relative positions of the camera modules when the camera modules are arranged. When a plurality of image capturing modules 200 are provided, the plurality of image capturing modules 200 may be identical or different, for example, the plurality of image capturing modules 200 may include different numbers of lenses, different optical parameters of the lenses, different installation positions of the lenses, or the like.

The camera module 200 may be used to take video and/or pictures, may be used to take scenes at different ranges, for example the camera module 200 may be used to take scenes at far distances, may be used to take scenes at near distances, and may be used to take scenes at macro distances. The embodiment of the application is not particularly limited.

Optionally, the terminal device 1000 may further include a lens protection lens for protecting the camera module 200. The lens protection lens is disposed on the housing 300 and is used for covering the camera module 200. When the lens protection lens is used for protecting the front camera module, the lens protection lens can only cover the front camera module or cover the whole front face of the terminal device 1000, wherein when the lens protection lens covers the whole front face of the terminal device 1000, the lens protection lens can be used for protecting the front camera module and the display screen 400 at the same time, and the lens protection lens is Cover Glass (CG). When the lens protection lens is used for protecting the rear-mounted camera module, the lens protection lens can cover the whole back surface of the terminal device 1000, and can also be only arranged at the corresponding position of the rear-mounted camera module for protecting the rear-mounted camera module. The material of the lens protection lens can be glass, sapphire, ceramic and the like, and the embodiment of the application is not particularly limited. In some embodiments, the lens protection lens is transparent, so that light outside the terminal device 1000 can enter the camera module 200 through the lens protection lens.

It should be noted that, the front surface of terminal device 1000 in the embodiment of the present application may be understood as a side surface of terminal device 1000 facing the user when the user uses terminal device 1000, and the back surface of terminal device 1000 may be understood as a side surface of terminal device 1000 facing away from the user when the user uses terminal device 1000.

It should be understood that the terminal device 1000 shown in fig. 1 is not limited to include the above devices, but may include other devices, such as a battery, a flash, a fingerprint recognition module, a receiver, a key, a sensor, etc., and the embodiment of the present application is only described with reference to a terminal mounted with the camera module 200, but the elements mounted on the terminal device 1000 are not limited thereto.

Fig. 2 shows a schematic diagram of the imaging principle, where the light L reflected by the photographed object is projected onto the surface of an image sensor 101 (sensor) by generating an optical image by an optical imaging lens 100, the optical image is then converted into an electrical signal, i.e. an analog image signal S1, the analog image signal S1 is converted into a digital image signal S2 by an analog-to-digital converter 102A/D (may also be referred to as an a/D converter) 203, the digital image signal S2 is processed by an image processor 103, such as a digital signal processing chip (DIGITAL SIGNAL processing chip, DSP), to form a compressed image signal S3, which may be stored in a memory 104 for processing, and finally the image is displayed by a display or a display screen 400.

The optical lens affects imaging quality and imaging effect, and light of scenery passes through the optical lens to form clear image on focusing plane, and the image of scenery is recorded by photosensitive material or photoreceptor. The optical lens may be an integral body formed by combining one or more lenses through a system, and the lenses may be plastic (plastic) lenses or glass (glass) lenses, may be spherical lenses or aspherical lenses, and may be refractive lenses or reflective lenses. The optical lens in the embodiment of the application is a zoom lens, and the focal length of the optical lens can be adjusted by adjusting the relative positions of the lenses of the optical lens.

The image sensor 101 is a semiconductor chip, the surface of which contains hundreds of thousands to millions of photodiodes, and when irradiated with light, charges are generated, and the charges are converted into digital signals by the analog-to-digital converter 102. The image sensor 101 may be a charge coupled device (charge coupled device, CCD) or a complementary metal oxide conductor device (complementary metal-oxide semiconductor, CMOS). The CCD image sensor 101 is made of a semiconductor material with high sensitivity, and can convert light into electric charge, and convert the electric charge into digital signals through the chip of the analog-to-digital converter 102. CCDs are composed of a number of photosensitive units, typically in megapixels. When the CCD surface is irradiated by light, each photosensitive unit reflects charges on the component, and signals generated by all the photosensitive units are added together to form a complete picture. Complementary metal oxide semiconductor CMOS is mainly made of two elements, silicon and germanium, so that N (band-to-electricity) and P (band+electricity) level semiconductors coexist on the CMOS, and the current generated by the two complementary effects can be recorded and interpreted into an image by a processing chip. In some embodiments, the image sensor 101 may also be referred to as a photosensitive chip, a photosensitive element, or the like.

The function of the image processor 103 is to optimize the digital image signal by a series of complex mathematical algorithms and to finally pass the processed signal to the display. The image processor 103 may be an image processing chip or a digital signal processing chip (DSP), and its function is to timely and rapidly transfer the data obtained by the photosensitive chip to the central processing unit and refresh the photosensitive chip, so that the quality of the DSP chip directly affects the picture quality (such as color saturation, definition, etc.).

It should be understood that references to a "lens" in embodiments of the present application are to be understood as a unitary lens, including one or more lenses.

Fig. 3 shows a schematic structural diagram of an optical imaging lens 100, and the structure of the optical imaging lens 100 is described below in conjunction with fig. 3.

The optical imaging lens 100 provided by the application comprises a first lens group 10. The first lens group 10 includes a first lens 11, an intermediate medium 12 and a second lens 13 sequentially disposed in a direction from an object side a to an image side B, wherein a refractive index of the first lens 11 is n1, a refractive index of the second lens 13 is n2, and a refractive index of the intermediate medium 12 is n3; wherein n1-n 3/n 2<0.15.

It is understood that the intermediate medium 12 may be a solid, liquid or gaseous medium.

Alternatively, the intermediate medium 12 may be glass, plastic, numeric, aerogel, water, oil, alcohol, carbon dioxide, or the like. In this way, a difference in refractive index of the intermediate medium 12 from the first lens 11 is caused.

The optical imaging lens 100 provided in the embodiment of the present application limits the refractive index of the first lens 11, the refractive index of the intermediate medium 12 and the refractive index of the second lens 13 in the first lens group 10, that is, satisfies |n1-n3|/n2<0.15, can balance the chromatic aberration of the optical imaging lens 100, improves the overall imaging quality of the optical imaging lens 100, and simultaneously can effectively reduce the probability of occurrence of total reflection, thereby reducing the probability of occurrence of "lens ghost images" formed by total reflection.

Referring to fig. 3, in some embodiments, the first lens element 11 has a first object-side surface E11 facing the object-side surface a and a first image-side surface E12 facing the image-side surface B, the first object-side surface E11 is convex at the optical axis I of the optical imaging lens element 100, and the first image-side surface E12 is convex at the optical axis I of the optical imaging lens element 100, so that the refractive power of the first lens element 11 is positive;

The second lens element 13 has a second object-side surface E21 facing the object-side surface a and a second image-side surface E22 facing the image-side surface B, wherein the second object-side surface E21 is convex at the optical axis I of the optical imaging lens 100 and the second image-side surface E22 is concave at the optical axis I of the optical imaging lens 100, such that the refractive power of the second lens element 13 is negative.

In some embodiments, the radius of curvature of the first object-side surface E11 is R11, and the radius of curvature of the first image-side surface E12 is R12;

wherein, -0.5< R11/R12<0.

It can be appreciated that by controlling the ratio of the radius of curvature of the first object-side surface E11 of the first lens element 11 to the radius of curvature of the first image-side surface E12 of the first lens element 11, the shape of the first lens element 11 can be effectively constrained, so that light can be smoothly controlled to enter the first lens group 10 from the object-side surface a of the lens element, and the imaging quality of the optical imaging lens can be improved.

Referring to fig. 3, in some embodiments, the optical imaging lens 100 further includes a second lens group 20, and the second lens group 20 is located on a side of the second lens 13 facing the image side B;

Wherein the effective focal length of the first lens group 10 is FG1, and the effective focal length of the second lens group 20 is FG2, -1< FG1/FG2<0.

It can be appreciated that by restricting the ratio of the effective focal length of the first lens group 10 to the effective focal length of the second lens group 20, it is advantageous to balance the aberration of the optical imaging lens 100, to improve the imaging quality, and at the same time, to limit the total length (restricting the overall dimension) of the overall lens, so that it has the characteristic of miniaturization.

Here, the first lens group 10 and the second lens group 20 should be disposed along the optical axis I of the optical imaging lens 100.

The connection between the first lens group 10 and the second lens group 20 includes, but is not limited to, bonding, welding, riveting, screwing, snap-fitting, etc.

Referring to fig. 3, in some embodiments, the second lens group 20 includes a third lens element 21, a fourth lens element 22, a fifth lens element 23 and a sixth lens element 24 disposed in order in a direction from an object side a to an image side B;

The third lens element 21 has a third object-side surface E31 facing the object-side surface a and a third image-side surface E32 facing the image-side surface B, wherein the third object-side surface E31 is convex at the optical axis I of the optical imaging lens 100 and the third image-side surface E32 is convex at the optical axis I of the optical imaging lens 100, such that the refractive power of the third lens element 21 is positive;

The fourth lens element 22 has a fourth object-side surface E41 facing the object-side surface a and a fourth image-side surface E42 facing the image-side surface B, wherein the fourth object-side surface E41 is convex at the optical axis I of the optical imaging lens assembly 100 and the fourth image-side surface E42 is concave at the optical axis I of the optical imaging lens assembly 100, such that the refractive power of the fourth lens element 22 is negative;

The fifth lens element 23 has a fifth object-side surface E51 facing the object-side surface a and a fifth image-side surface E52 facing the image-side surface B, wherein the fifth object-side surface E51 is convex at the optical axis I of the optical imaging lens assembly 100 and the fifth image-side surface E52 is convex at the optical axis I of the optical imaging lens assembly 100, such that the refractive power of the fifth lens element 23 is positive;

the sixth lens element 24 has a sixth object-side surface E61 facing the object-side surface a and a sixth image-side surface E62 facing the image-side surface B, wherein the sixth object-side surface E61 is convex at the optical axis I of the optical imaging lens 100 and the sixth image-side surface E62 is concave at the optical axis I of the optical imaging lens 100; from this, the refractive power of the sixth lens element 24 is negative.

In some embodiments, the effective focal length of the third lens 21 is f3, and the effective focal length of the second lens group 20 is FG2;

wherein, -2.5< f3/FG2< -0.5.

It can be appreciated that by restricting the effective focal length of the third lens 21 and the effective focal length of the second lens group 20 within the above ranges, it is advantageous for light to smoothly enter the second lens group 20 from the first lens group 10, and at the same time, lens manufacturability and assembly manufacturability of the third lens 21 can be improved.

Similarly, the effective focal length of the first lens 11 is f1, the effective focal length of the second lens 13 is f2, the effective focal length of the fourth lens 22 is f4, the effective focal length of the fifth lens 23 is f5, and the effective focal length of the sixth lens 24 is f6.

In some embodiments, the center thickness of the fifth lens 23 is CT5, the center thickness of the sixth lens 24 is CT6, and the air gap of the fifth lens 23 and the sixth lens 24 in the optical axis I direction of the optical imaging lens 100 is CT56;

wherein 1< (CT5+CT6)/CT 56<2.

It can be appreciated that, by adopting the above technical solution, the fifth lens 23 and the sixth lens 24 are reasonably arranged on the optical axis I, and an assembly space is reserved for the mechanical support structure.

The center thickness of the lens refers to the minimum thickness of the lens at the optical axis I, and then the center thickness of the fifth lens 23 refers to the minimum thickness of the fifth lens 23 at the optical axis I; the center thickness of the sixth lens 24 refers to the minimum thickness of the sixth lens 24 at the optical axis I; the air space of the fifth lens 23 and the sixth lens 24 refers to the minimum distance between the fifth lens 23 and the sixth lens 24 at the optical axis I.

Similarly, the center thickness of the first lens 11 is CT1, the center thickness of the second lens 13 is CT2, the center thickness of the third lens 21 is CT3, and the center thickness of the fourth lens 22 is CT4.

In some embodiments, the total effective focal length of the optical imaging lens 100 is f, and the effective focal length of the second lens group 20 is FG2;

Wherein, -10< FG2/f < -3.

As can be appreciated, by constraining the ratio of the effective focal length of the second lens group 20 to the total effective focal length of the optical imaging lens 100, a reasonable distribution of optical power can be achieved, balancing the astigmatism and curvature of field of the optical imaging lens 100 as a whole, thereby improving imaging quality.

In some embodiments, the optical imaging lens 100 has an entrance pupil diameter EPD and the optical imaging lens 100 has a total effective focal length f;

Wherein 0<f/EPD <2.5.

It can be understood that by restricting the ratio of the total effective focal length of the entire optical imaging lens 100 to the entrance pupil diameter of the optical imaging lens 100, the light flux of the optical imaging lens 100 can be increased and the shallow depth of field effect of the main body can be enhanced while maintaining the focal length of the optical imaging lens 100.

Example 1

Referring to fig. 3 to 7, a first embodiment of an optical imaging lens 100 of the present application is illustrated.

In the present embodiment, the optical imaging lens 100 includes six lenses having refractive powers, an aperture stop 30, and an image plane 40 in total, which are sequentially arranged in the direction from the object side a to the image side B, with the first lens group 10 and the second lens group 20.

The first lens 11 has a positive refractive index. The first object-side surface E11 of the first lens element 11 is convex, and the first image-side surface E12 of the first lens element 11 is convex. The first object-side surface E11 and the first image-side surface E12 of the first lens element 11 are aspheric, but not limited thereto.

The second lens 13 has a negative refractive index. The second object-side surface E21 of the second lens element 13 is convex, and the second image-side surface E22 of the second lens element 13 is concave. The second object-side surface E21 and the second image-side surface E22 of the second lens element 13 are aspheric, but not limited thereto.

The third lens 21 has a positive refractive index. The third object-side surface E31 of the third lens element 21 is convex, and the third image-side surface E32 of the third lens element 21 is convex. The third object-side surface E31 and the third image-side surface E32 of the third lens element 21 are aspheric, but not limited thereto.

The fourth lens 22 has a negative refractive power. The fourth object-side surface E41 of the fourth lens element 22 is convex, and the fourth image-side surface E42 of the fourth lens element 22 is concave. The fourth object-side surface E41 and the fourth image-side surface E42 of the fourth lens element 22 are aspheric, but not limited thereto.

The fifth lens 23 has a positive refractive index. The fifth object-side surface E51 of the fifth lens element 23 is convex, and the fifth image-side surface E52 of the fifth lens element 23 is convex. The fifth object-side surface E51 and the fifth image-side surface E52 of the fifth lens element 23 are aspheric, but not limited thereto.

The sixth lens 24 has a negative refractive index. The sixth object-side surface E61 of the sixth lens 24 is convex, and the sixth image-side surface E62 of the sixth lens 24 is concave. The sixth object-side surface E61 and the sixth image-side surface E62 of the sixth lens element 24 are aspheric, but not limited thereto.

In the optical imaging lens 100 of the present embodiment, from the first lens 11 to the second lens 13, the object-side a-plane and the image-side B-plane of each lens add up to twelve curved surfaces. If each curved surface is an aspherical surface, the aspherical surfaces are defined by the following formula:

Wherein:

y represents the vertical distance between the point on the aspheric curved surface and the optical axis I;

Z represents the depth of the aspheric surface (the point on the aspheric surface that is Y from the optical axis I, which is perpendicular to the tangential plane to the vertex on the aspheric optical axis I);

R represents the radius of curvature at the paraxial I of the lens surface;

k is a conical surface coefficient (conic constant);

ai is the i-th order aspheric coefficient.

The optical data of the optical imaging lens 100 of the first embodiment is shown in fig. 4, and the aspherical data is shown in fig. 5. In the optical imaging lens 100 of the present embodiment, the ratio (f-number) of the focal length of the entire optical imaging lens 100 to the entrance pupil diameter is FNO, the entrance pupil diameter of the optical imaging lens 100 is EPD, the Field angle of View (FOV), the total effective focal length f of the optical imaging lens 100, and the distance between the first object side surface E11 of the first lens 11 and the image plane 40 in the optical axis I direction is TTL, wherein the units of the image height, the radius of curvature, the thickness, and the focal length of the optical imaging lens 100 are all millimeters (mm). In this embodiment, f=5.62 mm; FOV = 42.1 °; ttl=6.51 mm; fno=1.95; epd=2.88 mm.

And ,|n1-n3|/n2=0.03;FG1/FG2=-0.2;R11/R12=-0.22;f3/FG2=-1.29;FG2/f=-6.23;f/EPD=1.95;(CT5+CT6)/CT56=1.56.

Please refer to fig. 6 for an astigmatic field curve (ASTIGMATIC FIELD cutves) of the optical imaging lens 100 of the present embodiment on the image plane 40; and, please refer to fig. 7 for the distortion aberration (distortion aberration) of the optical imaging lens 100 on the image plane 40. As can be seen from the above two drawings, the optical imaging lens 100 according to the present embodiment has better imaging quality.

Example two

Referring to fig. 3 and 8 to 11, a second embodiment of an optical imaging lens 100 of the present application is illustrated.

The optical data of the optical imaging lens 100 of the first embodiment is shown in fig. 8, and the aspherical data is shown in fig. 9. In the optical imaging lens 100 of the present embodiment, the ratio (f-number) of the focal length of the entire optical imaging lens 100 to the entrance pupil diameter is FNO, the entrance pupil diameter of the optical imaging lens 100 is EPD, the Field angle of View (FOV), the total effective focal length f of the optical imaging lens 100, and the distance between the first object side surface E11 of the first lens 11 and the image plane 40 in the optical axis I direction is TTL, wherein the units of the image height, the radius of curvature, the thickness, and the focal length of the optical imaging lens 100 are all millimeters (mm). In this embodiment, f=5.61 mm; FOV = 42.1 °; ttl=6.57 mm; fno=1.97; epd=2.85 mm.

And ,|n1-n3|/n2=0.02;FG1/FG2=-0.21;R11/R12=-0.14;f3/FG2=-1.48;FG2/f=-5.92;f/EPD=1.97;(CT5+CT6)/CT56=1.53.

Please refer to fig. 10 for an astigmatic field curve (ASTIGMATIC FIELD cutves) of the optical imaging lens 100 of the present embodiment on the image plane 40; and, please refer to fig. 11 for the distortion aberration (distortion aberration) of the optical imaging lens 100 on the image plane 40. As can be seen from the above two drawings, the optical imaging lens 100 according to the present embodiment has better imaging quality.

Example III

Referring to fig. 3 and 12 to 15, a second embodiment of an optical imaging lens 100 of the present application is illustrated.

The optical data of the optical imaging lens 100 of the first embodiment is shown in fig. 12, and the aspherical data is shown in fig. 13. In the optical imaging lens 100 of the present embodiment, the ratio (f-number) of the focal length of the entire optical imaging lens 100 to the entrance pupil diameter is FNO, the entrance pupil diameter of the optical imaging lens 100 is EPD, the Field angle of View (FOV), the total effective focal length f of the optical imaging lens 100, and the distance between the first object side surface E11 of the first lens 11 and the image plane 40 in the optical axis I direction is TTL, wherein the units of the image height, the radius of curvature, the thickness, and the focal length of the optical imaging lens 100 are all millimeters (mm). In this embodiment, f=5.61 mm; FOV = 42.1 °; ttl=6.55 mm; fno=1.99; epd=2.82 mm.

And ,|n1-n3|/n2=0.03;FG1/FG2=-0.22;R11/R12=-0.07;f3/FG2=-1.61;FG2/f=-5.63;f/EPD=1.99;(CT5+CT6)/CT56=1.52.

Please refer to fig. 14 for an astigmatic field curve (ASTIGMATIC FIELD cutves) of the optical imaging lens 100 of the present embodiment on the image plane 40; and, please refer to fig. 15 for the distortion aberration (distortion aberration) of the optical imaging lens 100 on the image plane 40. As can be seen from the above two drawings, the optical imaging lens 100 according to the present embodiment has better imaging quality.

The foregoing is merely illustrative embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily think about variations or substitutions within the technical scope of the present application, and the application should be covered.

Claims

1. An optical imaging lens is characterized by comprising a first lens group and a second lens group which are sequentially arranged from an object side to an image side, wherein the number of the lens groups with refractive index in the optical imaging lens is two;

The first lens group consists of a first lens, an intermediate medium and a second lens which are sequentially arranged in the direction from an object side to an image side, wherein the refractive index of the first lens is n1, the refractive index of the second lens is n2, the refractive index of the intermediate medium is n3, wherein the refractive index of the intermediate medium is more than or equal to 0.02 and less than or equal to |n1-n3|/n2 is less than or equal to 0.03, the chromatic aberration of the optical imaging lens can be balanced, and the probability of total reflection is reduced;

The second lens group comprises a third lens, a fourth lens, a fifth lens and a sixth lens which are sequentially arranged in the direction from the object side to the image side, and the number of the lenses with refractive index in the second lens group is four;

The first lens has a positive refractive index, the second lens has a negative refractive index, the third lens has a positive refractive index, the fourth lens has a negative refractive index, the fifth lens has a positive refractive index, and the sixth lens has a negative refractive index;

The effective focal length of the first lens group is FG1, and the effective focal length of the second lens group is FG2, wherein FG1/FG2 is more than or equal to-0.22 and less than or equal to-0.2;

The total effective focal length of the optical imaging lens is f, wherein FG2/f is less than or equal to-6.23 and less than or equal to-5.63.

2. The optical imaging lens of claim 1, wherein: the first lens is provided with a first object side surface facing the object side and a first image side surface facing the image side, the first object side surface is a convex surface at the optical axis of the optical imaging lens, and the first image side surface is a convex surface at the optical axis of the optical imaging lens;

The second lens is provided with a second object side surface facing the object side and a second image side surface facing the image side, the second object side surface is a convex surface at the optical axis of the optical imaging lens, and the second image side surface is a concave surface at the optical axis of the optical imaging lens.

3. The optical imaging lens of claim 2, wherein: the curvature radius of the first object side surface is R11, and the curvature radius of the first image side surface is R12, wherein R11/R12 is more than or equal to-0.22 and less than or equal to-0.07.

4. The optical imaging lens of claim 1, wherein: the third lens is provided with a third object side surface facing the object side and a third image side surface facing the image side, the third object side surface is a convex surface at the optical axis of the optical imaging lens, and the third image side surface is a convex surface at the optical axis of the optical imaging lens;

The fourth lens is provided with a fourth object side surface facing the object side and a fourth image side surface facing the image side, the fourth object side surface is a convex surface at the optical axis of the optical imaging lens, and the fourth image side surface is a concave surface at the optical axis of the optical imaging lens;

the fifth lens is provided with a fifth object side surface facing the object side and a fifth image side surface facing the image side, the fifth object side surface is a convex surface at the optical axis of the optical imaging lens, and the fifth image side surface is a convex surface at the optical axis of the optical imaging lens;

the sixth lens is provided with a sixth object side surface facing the object side and a sixth image side surface facing the image side, wherein the sixth object side surface is a convex surface at the optical axis of the optical imaging lens, and the sixth image side surface is a concave surface at the optical axis of the optical imaging lens.

5. The optical imaging lens of claim 4, wherein: the effective focal length of the third lens is f3, wherein-1.61 is less than or equal to f3/FG2 is less than or equal to-1.29.

6. The optical imaging lens of claim 4, wherein: the center thickness of the fifth lens is CT5, the center thickness of the sixth lens is CT6, and the air interval between the fifth lens and the sixth lens in the optical axis direction of the optical imaging lens is CT56, wherein (CT 5+ CT 6)/CT 56 is more than or equal to 1.52 and less than or equal to 1.56.

7. The optical imaging lens of claim 1, wherein: the optical imaging lens has an entrance pupil diameter EPD,

Wherein, f/EPD is not less than 1.95 and not more than 1.99.

8. A camera module, its characterized in that: comprising an optical imaging lens as claimed in any one of claims 1 to 7.

9. A terminal device, characterized by: comprising the camera module of claim 8.