CN111308688A

CN111308688A - Lens system, imaging module and electronic device

Info

Publication number: CN111308688A
Application number: CN202010182577.4A
Authority: CN
Inventors: 华露; 杨健; 李明; 邹海荣
Original assignee: OFilm Tech Co Ltd
Current assignee: OFilm Group Co Ltd
Priority date: 2020-03-16
Filing date: 2020-03-16
Publication date: 2020-06-19

Abstract

The application relates to a lens system, an imaging module and an electronic device. The lens system includes a plurality of optical elements arranged along a folded optical axis thereof, including, in order from an object side to an image side, a first optical path folding element located on a first portion of the folded optical axis to direct light from the first portion of the folded optical axis to a second portion of the folded optical axis; a lens group on a second portion of the folded optical axis; a second optical path folding element to direct light from the second portion of the folded optical axis to a third portion of the folded optical axis; a third optical path folding element to direct light from a third portion of the folded optical axis to a fourth portion of the folded optical axis; the second, third and fourth portions of the folded optical axis lie in the same plane and the plane is perpendicular to the first portion of the folded optical axis. The lens system can be transversely arranged along the shell of the electronic product while realizing the long focal length, fully utilizes the space of the electronic product and meets the light and thin design requirements of the electronic product.

Description

Lens system, imaging module and electronic device

Technical Field

The present invention relates to the field of optical imaging technologies, and in particular, to a lens system, an imaging module and an electronic device.

Background

In recent years, with the development of science and technology, periscopic mobile phone lenses are increasingly applied to portable electronic products. The periscopic mobile phone lens is provided with a prism part capable of changing the trend of a light path, and the lens can be transversely arranged in the shell of an electronic product when being installed, so that the transverse length and the overall height of the lens are reduced, and the mobile phone is further lightened and thinned.

However, under the trend of light and thin electronic products, it is still difficult for the conventional periscopic lens to achieve a long focal length or an ultra-long focal length.

Disclosure of Invention

In view of the above, there is a need to provide an improved lens system for solving the problem that the conventional periscopic lens is difficult to realize a long focal length or an ultra-long focal length in a slim electronic product.

A lens system comprising a plurality of optical elements arranged along a folded optical axis of the lens system, comprising, in order from an object side to an image side:

a first optical path folding element located on a first portion of the folded optical axis, the first optical path folding element configured to direct light from the first portion of the folded optical axis to a second portion of the folded optical axis;

a lens group on a second portion of the folded optical axis;

a second optical path folding element configured to direct light from a second portion of the folded optical axis to a third portion of the folded optical axis; and the number of the first and second groups,

a third optical path folding element configured to direct light from a third portion of the folded optical axis to a fourth portion of the folded optical axis;

wherein the second, third and fourth portions of the folded optical axis lie in a same plane, and the plane is perpendicular to the first portion of the folded optical axis.

Above-mentioned lens system thereby makes lens system's optical axis fold into different parts through setting up a plurality of light path folding element to make the plane at folding optical axis first part and other parts places perpendicular, thereby can guarantee when realizing long focal length, make a plurality of light path folding element all along the transversal arrangement of electronic product shell, make full use of electronic product's space satisfies electronic product's frivolous design demand. In addition, the transverse total length of the lens system can be effectively shortened by folding the optical axis of the lens system, so that the transverse space of the electronic product is saved, and the arrangement of other elements in the electronic product is facilitated.

In one embodiment, the first optical path folding element is a prism; and/or the second light path folding element is a prism; and/or the third light path folding element is a prism.

Through setting up above-mentioned light path folding element into the prism, can utilize the total reflection effect of light at the prism plane of reflection to make the light turn over, can also adjust and then regulate and control the turn-over route of light to putting of light path folding element according to the total reflection angle of light simultaneously.

In one embodiment, the lens group includes, in order from an object side to an image side along the second portion of the folded optical axis, a first lens element with refractive power; a second lens element with refractive power; a third lens element with refractive power; in the first lens element to the third lens element, at least one of the object-side surface and the image-side surface of the at least one lens element is aspheric, and at least one of the object-side surface and the image-side surface of the at least one lens element includes at least one inflection point.

By arranging a proper number of lenses in the lens group and reasonably distributing the refractive power and the surface type of each lens and the effective focal length of each lens, the imaging resolving power of the lens system can be enhanced and the aberration can be effectively corrected. Meanwhile, the flexibility of lens design can be improved by setting the lens surface to be an aspheric surface so as to further correct aberration; in addition, an inflection point can be arranged on the aspheric surface, so that the incident angle of the principal ray is better matched with the photosensitive element, and the imaging quality of the lens system is improved.

In one embodiment, the lens system satisfies the following relationship: f/FNO is more than 3mm and less than 12 mm; where f denotes an effective focal length of the lens system, and FNO denotes an f-number of the lens system.

The effective focal length of the lens system and the diaphragm number of the lens system are controlled to meet the relation, the entrance pupil diameter of the lens system can be effectively regulated, the whole width of the lens system is effectively limited, miniaturization of the lens group is facilitated, and the space of an electronic product is saved.

In one embodiment, the lens system satisfies the following relationship: HFOV/TTL is more than 0.1 degree/mm; wherein HFOV denotes a half field angle in a diagonal direction of the lens system, and TTL denotes a distance on the folding optical axis from an object side surface of the first lens to an imaging surface of the lens system.

When the above relation is satisfied, the imaged image height and the total length of the lens system can be reasonably distributed, so that the total length of the lens system can be shortened, and miniaturization can be realized.

In one embodiment, the lens system satisfies the following relationship: TTL/f is less than 1.2; wherein, TTL represents a distance on the folding optical axis from the object-side surface of the first lens element to the imaging surface of the lens system, and f represents an effective focal length of the lens system.

When satisfying above-mentioned relation, can rational distribution lens system's effective focal length and lens system's overall length to not only can realize lens system's miniaturization, can also make the better focus of light on the imaging plane, promote imaging quality.

In one embodiment, the lens system satisfies the following relationship: f is more than 15 mm; wherein f represents the effective focal length of the lens system.

When the above relation is satisfied, the lens system can have a long focal length characteristic, so that clear imaging of a distant object can be realized.

In one embodiment, the lens system satisfies the following relationship: CT12/CT23 < 3; wherein CT12 represents a distance on the optical axis from the image-side surface of the first lens to the object-side surface of the second lens, and CT23 represents a distance on the optical axis from the image-side surface of the second lens to the object-side surface of the third lens.

When the relation is satisfied, the aberration of the lens system can be corrected, and the field curvature degree of the lens system can be controlled, so that the imaging quality can be improved.

In one embodiment, the lens system satisfies the following relationship: FNO is more than 2.2 and less than 6.8; wherein FNO denotes an f-number of the lens system.

When satisfying above-mentioned relation, can increase lens system's the light flux to reduce the marginal field of vision aberration of system, still can make lens system also can acquire the clear detailed information of the object of shooing under darker environment or the not enough condition of light simultaneously, promote the formation of image quality.

In one embodiment, the lens system satisfies the following relationship: D32/ImgH is less than 1.3; where D32 denotes an effective clear half aperture of the third lens, and ImgH denotes a half of a diagonal length of an effective pixel area on an imaging plane of the lens system.

When the relation is met, the size of the lens group can be effectively limited, the ultra-thinning of the lens system is facilitated, and the light and thin development requirements of electronic products are met.

The application also provides an imaging module.

An imaging module comprises the lens system and a photosensitive element, wherein the photosensitive element is arranged on the image side of the lens system.

The imaging module can be arranged along the transverse direction of an electronic product, and is convenient to adapt to devices with limited size, such as light and thin electronic equipment; simultaneously, this imaging module still possesses long focal length characteristic, can carry out clear formation of image to the object in a distance, satisfies the shooting demand of cell-phone, flat board better.

The application also provides an electronic device.

An electronic device comprises a shell and the imaging module, wherein the imaging module is installed on the shell.

The electronic device has the structural characteristics of lightness and thinness, and meanwhile has strong telephoto capability, and shooting experience of users is promoted.

Drawings

FIG. 1 shows a schematic top view of a lens system of example 1 of the present application;

FIG. 2 is a schematic front view of a lens system of example 1;

FIG. 3 is a schematic view showing a structure of a lens group according to embodiment 1;

FIG. 4 shows a longitudinal spherical aberration plot, an astigmatism plot, and a distortion plot, respectively, of the lens system of example 1;

FIG. 5 is a schematic top view of a lens system of example 2 of the present application;

FIG. 6 is a schematic front view showing a lens system of example 2;

FIG. 7 is a schematic view showing a structure of a lens group according to embodiment 2;

FIG. 8 shows a longitudinal spherical aberration plot, an astigmatism plot, and a distortion plot, respectively, for the lens system of example 2;

FIG. 9 is a schematic top view of a lens system of example 3 of the present application;

FIG. 10 is a schematic front view showing a lens system of example 3;

FIG. 11 is a schematic view showing a structure of a lens group according to embodiment 3;

FIG. 12 shows a longitudinal spherical aberration plot, an astigmatism plot, and a distortion plot, respectively, for a lens system of example 3;

FIG. 13 is a schematic top view of a lens system of example 4 of the present application;

FIG. 14 is a schematic front view of the lens system of example 4;

FIG. 15 is a schematic view showing a structure of a lens group according to embodiment 4;

FIG. 16 shows a longitudinal spherical aberration plot, an astigmatism plot, and a distortion plot, respectively, for the lens system of example 4;

FIG. 17 is a schematic top view of a lens system of example 5 of the present application;

FIG. 18 is a schematic front view of a lens system of example 5;

FIG. 19 is a schematic view showing a structure of a lens group according to embodiment 5;

FIG. 20 shows a longitudinal spherical aberration plot, an astigmatism plot, and a distortion plot, respectively, for the lens system of example 5;

FIG. 21 is a schematic top view of a lens system of example 6 of the present application;

FIG. 22 is a schematic front view of the lens system of example 6;

FIG. 23 is a schematic view showing a structure of a lens group according to embodiment 6;

FIG. 24 shows a longitudinal spherical aberration plot, an astigmatism plot, and a distortion plot, respectively, for the lens system of example 6;

FIG. 25 is a schematic top view of a lens system of example 7 of the present application;

FIG. 26 is a schematic front view showing a lens system of example 7;

FIG. 27 is a schematic view showing a structure of a lens group according to embodiment 7;

FIG. 28 shows a longitudinal spherical aberration plot, an astigmatism plot, and a distortion plot, respectively, for the lens system of example 7;

FIG. 29 is a schematic top view of a lens system according to example 8 of the present application;

FIG. 30 is a schematic front view of the lens system of example 8;

FIG. 31 is a schematic view showing a structure of a lens group according to embodiment 8;

FIG. 32 shows a longitudinal spherical aberration plot, an astigmatism plot, and a distortion plot, respectively, for the lens system of example 8;

FIG. 33 is a schematic top view of a lens system of example 9 of the present application;

FIG. 34 is a schematic front view of the lens system of example 9;

FIG. 35 is a schematic view showing a structure of a lens group according to embodiment 9;

FIG. 36 shows a longitudinal spherical aberration chart, an astigmatism chart and a distortion chart of the lens system of example 9, respectively;

FIG. 37 is a schematic top view of a lens system of example 10 of the present application;

FIG. 38 is a schematic front view of the lens system of example 10;

FIG. 39 is a schematic view showing a structure of a lens group according to embodiment 10;

FIG. 40 shows a longitudinal spherical aberration chart, an astigmatism chart and a distortion chart of the lens system of example 10, respectively;

FIG. 41 is a schematic top view of a lens system according to example 11 of the present application;

FIG. 42 is a schematic front view showing a lens system of example 11;

FIG. 43 is a schematic view showing a structure of a lens group according to embodiment 11;

FIG. 44 shows a longitudinal spherical aberration chart, an astigmatism chart and a distortion chart of the lens system of example 11, respectively;

FIG. 45 shows a schematic view of an imaging module according to an embodiment of the present application.

Detailed Description

To facilitate an understanding of the invention, the invention will now be described more fully with reference to the accompanying drawings. Preferred embodiments of the present invention are shown in the drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. As used herein, the terms "vertical," "horizontal," "left," "right," "upper," "lower," "front," "rear," "circumferential," and the like are based on the orientation or positional relationship shown in the drawings for ease of description and simplicity of description, and do not indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and are therefore not to be considered limiting of the present invention.

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 invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

In the present description, the expressions first, second, third and the like are used only for distinguishing one feature from another feature, and do not indicate any limitation on the features. Thus, the first lens discussed below may also be referred to as the second lens or the third lens without departing from the teachings of the present application. For ease of illustration, the shapes of the spherical or aspherical surfaces shown in the drawings are shown by way of example. That is, the shape of the spherical surface or the aspherical surface is not limited to the shape of the spherical surface or the aspherical surface shown in the drawings. The figures are purely diagrammatic and not drawn to scale.

In this specification, a space on a side of the optical element where the object is located is referred to as an object side of the optical element, and correspondingly, a space on a side of the optical element where the object is located is referred to as an image side of the optical element. The surface of each lens closest to the object is called the object side surface, and the surface of each lens closest to the image plane is called the image side surface.

In addition, in the following description, if a lens surface is convex and the convex position is not defined, it means that the lens surface is convex at least near the optical axis; if the lens surface is concave and the concave position is not defined, it means that the lens surface is concave at least at the position near the optical axis. Here, the paraxial region means a region near the optical axis.

Conventional periscopic lenses typically use one or two reflective prisms to achieve the deflection of the optical path. However, if the focal length of such a lens is increased, the thickness of the mobile phone is easily increased or the total length of the lens itself is increased, which affects the arrangement of other elements of the mobile phone. Therefore, the focal length of the conventional periscopic lens is usually not long, and it is difficult to satisfy the user's higher telephoto zoom photographing requirement.

The defects existing in the above solutions are the results obtained after the inventor has practiced and studied carefully, so the discovery process of the above problems and the solutions proposed by the following embodiments of the present application for the above problems should be the contribution of the inventor to the present application in the process of the present application.

The lens system of the embodiments of the present application includes a plurality of optical elements arranged along a folded optical axis thereof. The plurality of optical elements sequentially include a first optical path folding element, a lens group, a second optical path folding element and a third optical path folding element from the object side to the image side.

A first optical path folding element located on a first portion of the folded optical axis, the first optical path folding element configured to direct light from the first portion of the folded optical axis to a second portion of the folded optical axis; the lens group is positioned on the second part of the folded optical axis; the second optical path folding element is configured to direct light from the second portion of the folded optical axis to a third portion of the folded optical axis; the third optical path folding element is configured to direct light from a third portion of the folded optical axis to a fourth portion of the folded optical axis; and finally, the light is received by a photosensitive element on the fourth part of the folded optical axis.

The second part, the third part and the fourth part of the folded optical axis are positioned in the same plane, and the plane is vertical to the first part of the folded optical axis.

The lens system can enable the optical elements to be arranged along the transverse direction of the electronic product and not to be arranged along the thickness direction of the electronic equipment, so that the light and thin of the electronic product can be guaranteed while the long focal length of the lens is achieved. In addition, the transverse total length of the lens system can be effectively shortened by folding the optical axis of the lens system, so that the transverse space of the electronic product is saved, and the arrangement of other elements in the electronic product is facilitated.

In particular, the light folding element may be a prism. The prism comprises a light incident surface, a reflecting surface and a light emergent surface, and light rays are incident from the light incident surface, totally reflected on the reflecting surface and then emitted from the light emergent surface, so that the light path is folded. Furthermore, the prism can be a right-angle prism, so that the light can be turned to 90 degrees, and the turning path of the light in the lens system can be conveniently regulated and controlled.

Taking the lens system 10 shown in fig. 1 to 3 as an example, the lens system 10 includes a first right-angle prism P1, a lens group 100, a second right-angle prism P2, and a third right-angle prism P3 arranged along a folding optical axis thereof. The light incident surface S1 of the first right-angle prism P1, the light incident surface S12 of the second right-angle prism P2 and the light incident surface S15 of the third right-angle prism P3 are perpendicular to each other two by two, the light emitting surface S3 of the first right-angle prism P1 is perpendicular to the light emitting surface S14 of the second right-angle prism P2, and the light emitting surface S3 of the first right-angle prism P1 is parallel to the light emitting surface S17 of the third right-angle prism P3, so that the first portion AX1 (i.e., the X direction in the drawing) of the folding optical axis is perpendicular to the plane where the second portion AX2, the third portion AX3 and the fourth portion AX4 of the folding optical. Therefore, after light is incident along the optical axis AX1, the light can be redirected to the optical axis AX2, the optical axis AX3 and the optical axis AX4 in sequence to realize a long focal length, and meanwhile, the third right-angle prism P3 can be prevented from being arranged along the thickness direction of the electronic product (i.e., the optical axis AX1 direction in fig. 1), so that the trend of thinning and lightening of the electronic product is met.

In an exemplary embodiment, the lens group includes, in order from an object side to an image side along a second portion of the folded optical axis, a first lens element with refractive power, a second lens element with refractive power and a third lens element with refractive power. In the first lens element to the third lens element, at least one of the object-side surface and the image-side surface of the at least one lens element is aspheric, and at least one of the object-side surface and the image-side surface of the at least one lens element includes at least one inflection point.

In other embodiments, the object-side surface and the image-side surface of each lens of the lens group may be spherical. It should be noted that the above embodiments are merely examples of some embodiments of the present application, and in some embodiments, the surface of each lens in the lens group may be an aspheric surface or any combination of spherical surfaces.

Furthermore, a diaphragm is arranged in the lens group and is arranged on the object side of the lens group, namely between the first light path folding element and the first lens, so that the size of an incident light beam is better controlled, and the imaging quality of the lens system is improved. Specifically, the diaphragms include an aperture diaphragm and a field diaphragm. Preferably, the diaphragm is an aperture diaphragm. The aperture stop may be located on a surface of the lens (e.g., the object side and the image side) and in operative relationship with the lens, for example, by applying a light blocking coating to the surface of the lens to form the aperture stop at the surface; or the surface of the clamping lens is fixedly clamped by the clamping piece, and the structure of the clamping piece on the surface can limit the width of the imaging light beam of the on-axis object point, so that the aperture stop is formed on the surface.

When the lens system is used for imaging, light rays emitted or reflected by a shot object enter the lens system from the object side direction, sequentially pass through the first light path folding element, the first lens, the second lens, the third lens, the second light path folding element and the third light path folding element, and finally converge on an imaging surface.

In an exemplary embodiment, the lens system satisfies the following relationship: f/FNO is more than 3mm and less than 12 mm; where f denotes an effective focal length of the lens system, and FNO denotes an f-number of the lens system. The f/FNO may be 3.5, 4mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, 8mm, 8.5mm, 9mm, 9.5mm, 10mm, 10.5mm, or 11 mm. Under the condition of satisfying the above relation, can effectively regulate and control the entrance pupil diameter of lens system to effectively restrict the holistic width of lens system, be favorable to the miniaturization of lens group, save electronic product's space. When f/FNO is less than or equal to 3, the diameter of the entrance pupil of the system is reduced, the light entering quantity is reduced, and therefore, the image is easy to darken, the definition is reduced, and the imaging is not facilitated; and when f/FNO is larger than or equal to 12, the diameter of the entrance pupil of the system is larger, which is not beneficial to reducing the width of the system, so that the occupied space of the system is larger.

In an exemplary embodiment, the lens system satisfies the following relationship: HFOV/TTL is more than 0.1 degree/mm; wherein, HFOV represents a half field angle of the lens system in a diagonal direction, and TTL represents a distance on the optical axis from an object side surface of the first lens to an imaging surface of the lens system. HFOV/TTL may be 0.15, 0.17, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, 0.3 or 0.35 in degrees/mm. The HFOV/TTL can reasonably distribute the imaged image height and the total length of the lens system under the condition that the relationship is satisfied, thereby contributing to shortening the total length of the lens system and realizing miniaturization. And when the HFOV/TTL is less than or equal to 0.1, the total length of the system is larger, the field of view is smaller, and the imaging quality is easy to reduce.

In an exemplary embodiment, the lens system satisfies the following relationship: TTL/f is less than 1.2; wherein, TTL represents a distance on the optical axis from the object-side surface of the first lens element to the imaging surface of the lens system, and f represents an effective focal length of the lens system. TTL/f can be 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, or 1.0. Under the condition that satisfies above-mentioned relation, can the effective focal length of rational distribution lens system and the overall length of lens system to not only can realize lens system's miniaturization, can also make the better focus of light on the imaging plane, promote the imaging quality. And when TTL/f is more than or equal to 1.2, the total length of the system is longer, which is not beneficial to miniaturization.

In an exemplary embodiment, the lens system satisfies the following relationship: f is more than 15 mm; where f is the effective focal length of the lens system. f may be 20mm, 23mm, 25mm, 27mm, 29mm, 31mm, 33mm, 35mm, 37mm or 40 mm. Under the condition of satisfying the relation, the lens system can have long focal length characteristic, thereby realizing the clear imaging of a distant object. When f is 15mm or less, the focal length is short, and the long-distance photographing capability of the lens system is not high.

In an exemplary embodiment, the lens system satisfies the following relationship: CT12/CT23 < 3; wherein CT12 represents the distance on the optical axis from the image-side surface of the first lens to the object-side surface of the second lens, and CT23 represents the distance on the optical axis from the image-side surface of the second lens to the object-side surface of the third lens. CT12/CT23 can be 0.02, 0.03, 0.06, 0.09, 0.1, 0.2, 0.3, 0.4, 0.5, 1.0, 2.5, 2.9, or 2.95. Under the condition of meeting the relation, the aberration of the lens system can be corrected, the field curvature degree of the lens system can be controlled, and therefore the imaging quality is improved. When CT12/CT23 is equal to or greater than 3, the distance between the first lens and the second lens is relatively long, and the second lens and the third lens are relatively close, which is not favorable for correcting system aberration and controlling curvature of field, and is easy to affect imaging quality.

In an exemplary embodiment, the lens system satisfies the following relationship: FNO is more than 2.2 and less than 6.8; wherein FNO denotes an f-number of the lens system. The FNO can be 2.3, 2.5, 3, 3.3, 3.6, 3.9, 4.5, 4.9, 5.2, 5.5, 6, or 6.5. Under the condition that satisfies above-mentioned relation, can increase the light flux of lens system to reduce the marginal field of vision aberration of system, still can make lens system also can acquire the clear detailed information of shot object in darker environment or under the not enough condition of light simultaneously, promote the formation of image quality. When the FNO is less than or equal to 2.2, the depth of field of the system is likely to be reduced, which is not favorable for clearly showing details of the object.

In an exemplary embodiment, the lens system satisfies the following relationship: D32/ImgH is less than 1.3; where D32 denotes an effective clear half aperture of the third lens, and ImgH denotes a half of the diagonal length of the effective pixel area on the imaging plane of the lens system. D32/ImgH may be 0.5, 0.9, 1, 1.05, 1.1, 1.12, 1.14, 1.16, 1.18, 1.2, 1.25, 1.28 or 1.29. Under the condition of meeting the relation, the size of the lens group can be effectively limited, the ultra-thinning of the lens system is facilitated, and the light and thin development requirements of electronic products are met. When D32/ImgH is greater than or equal to 1.3, the effective clear half-aperture of the third lens is large, which is not suitable for the light and thin application of electronic products.

In an exemplary embodiment, each lens in the lens group may be made of glass or plastic, the plastic lens can reduce the weight and production cost of the lens system, and the glass lens can provide the lens system with good temperature tolerance characteristics and excellent optical performance. Further, when the lens system is applied to a portable electronic device such as a mobile phone or a tablet, a material of each lens is preferably plastic. It should be noted that the material of each lens in the lens group may also be any combination of glass and plastic, and is not necessarily all glass or all plastic.

In an exemplary embodiment, the lens group further includes an infrared filter. The infrared filter is arranged between the third lens and the second light path folding element and used for filtering incident light, specifically used for isolating infrared light and preventing the infrared light from being absorbed by the photosensitive element, thereby avoiding the influence of the infrared light on the color and the definition of a normal image and improving the imaging quality of the lens system.

The lens assembly of the above-described embodiments of the present application may employ a plurality of lenses, for example, three lenses as described above. Through rational distribution of focal length, refractive power, surface type, thickness of each lens and on-axis distance between each lens, the lens system can be guaranteed to have long focal length, and the system total length is little, the weight is lighter and have higher imaging quality, thereby can better satisfy the application demand of lightweight electronic equipment such as cell-phone, flat board. However, it will be appreciated by those skilled in the art that the number of lenses constituting a lens group may be varied to achieve the various results and advantages described in this specification without departing from the claimed subject matter.

Specific examples of lens systems that can be applied to the above-described embodiments are further described below with reference to the drawings.

Example 1

A lens system 10 of embodiment 1 of the present application is described below with reference to fig. 1 to 4.

As shown in fig. 1 to 3, the lens system 10 includes, in order from the object side to the image side along the folding optical axis, a first right prism P1, a first lens L1, a second lens L2, a third lens L3, a second right prism P2, a third right prism P3, and an image plane S18. The folded optical axis includes a first portion AX1, a second portion AX2, a third portion AX3, and a fourth portion AX4, and the first lens L1, the second lens L2, and the third lens L3 are located on the optical axis AX 2. Further, in FIG. 1, Y-Z coordinate axes are provided, and in FIG. 2, Y-X coordinate axes are provided, wherein the optical axis AX1 is parallel to the X-axis, the optical axis AX3 is parallel to the Y-axis, and the optical axes AX2 and AX4 are parallel to the Z-axis.

The first rectangular prism P1 has an incident surface S1, a reflecting surface S2 and an emergent surface S3.

The first lens element L1 with negative refractive power has an object-side surface S4 and an image-side surface S5 that are aspheric, wherein the object-side surface S4 is concave along the optical axis and convex along the circumference, and the image-side surface S5 is concave along the optical axis and concave along the circumference; the second lens element L2 with positive refractive power has an object-side surface S6 and an image-side surface S7 that are aspheric, wherein the object-side surface S6 is convex along the optical axis and concave along the circumference, and the image-side surface S7 is concave along the optical axis and convex along the circumference; the third lens element L3 with positive refractive power has an object-side surface S8 and an image-side surface S9 that are aspheric, wherein the object-side surface S8 is convex along an optical axis and convex along a circumference, and the image-side surface S9 is convex along the optical axis and concave along the circumference.

The second rectangular prism P2 has an incident surface S12, a reflecting surface S13 and an emergent surface S14.

The third rectangular prism P3 has an incident surface S15, a reflecting surface S16, and an exit surface S17.

The reflecting surface in each right-angle prism can reflect the light rays out after the light rays are bent by 90 degrees, so that the transverse total length of the system is shortened while the long focal length is realized. In this embodiment, after light is incident along the optical axis AX1 (i.e., the X-axis direction), and is reflected by the reflective surface S2 of the first right-angle prism P1, the light is refracted by 90 ° and directed to the optical axis AX2 (i.e., the Z-axis direction) and is projected to the lens group 100, and after being emitted from the lens group 100 and reflected by the reflective surface S13 of the second right-angle prism P2, the light is refracted by 90 ° and directed to the optical axis AX3 (i.e., the Y-axis direction), and finally, after being reflected by the reflective surface S16 of the third right-angle prism P3, the light is refracted by 90 ° and directed to the optical axis AX4 (i.e., the Z-axis direction) and is received by a photosensitive element (.

The object-side surface and the image-side surface of each of the first lens L1 to the third lens L3 are aspheric, which is advantageous for correcting aberrations and solving the problem of image surface distortion, and enables the lenses to achieve excellent optical imaging effects even when the lenses are small, thin, and flat, thereby enabling the lens system 10 to have a compact size.

The first lens L1 to the third lens L3 are made of plastic to reduce the weight of the lens system 10 and the production cost. A stop STO is further disposed between the first right-angle prism P1 and the first lens L1 to limit the size of an incident light beam, and further improve the imaging quality of the lens system 10. The lens system 10 further includes a filter 110 disposed on the image side of the third lens L3 and having an object-side surface S10 and an image-side surface S11. Light from the object OBJ sequentially passes through the respective surfaces S1 to S17 and is finally imaged on the imaging plane S18. Further, the optical filter 110 is an infrared filter for filtering out infrared light from the external light incident on the lens system 10, so as to avoid color distortion of the image. Specifically, the material of the filter 110 is glass.

Table 1 shows surface types, radii of curvature, thicknesses, materials, refractive indices, abbe numbers (i.e., abbe numbers), and effective focal lengths of the lenses of the respective optical elements of the lens system 10 of example 1, wherein the units of the radii of curvature, thicknesses, effective focal lengths of the lenses, Y-half apertures (effective clear half-apertures in the Y direction of the lens), and X-half apertures (effective clear half-apertures in the X direction of the lens) are all millimeters (mm). In addition, taking the first right-angle prism P1 as an example, we default that the vertical page is inward in the positive direction of the optical axis AX1, and outward in the negative direction of the optical axis AX 1; taking the first lens L1 as an example, the first numerical value in the "thickness" parameter row of the first lens L1 is the thickness of the lens on the optical axis AX2, the second numerical value is the distance between the image-side surface of the lens and the object-side surface of the subsequent lens in the image-side direction on the optical axis AX2, the direction from the object-side surface S4 of the first lens L1 to the image-side surface S9 of the third lens L3 is the positive direction of the optical axis AX2, the numerical value in the "thickness" parameter row of the stop ST0 is the distance from the stop ST0 to the vertex of the object-side surface of the subsequent lens (the vertex refers to the intersection point of the lens and the optical axis) on the optical axis AX2, when the value is negative, it indicates that the stop ST0 is disposed on the right side of the vertex of the object-side surface of the lens, and if the stop thickness is positive, the stop is on; taking the second right-angle prism P2 and the third right-angle prism P3 as an example, the direction from the surface S14 to the surface S15 is the negative direction of the optical axis AX 3; taking the third rectangular prism P3 as an example, the direction from the surface S17 to the image forming surface S18 is the positive direction of the optical axis AX 4.

TABLE 1

The aspherical surface shape of each lens is defined by the following formula:

wherein x is the rise of the distance from the aspheric surface vertex to the aspheric surface vertex when the aspheric surface is at the position with the height of h along the optical axis direction; c is the paraxial curvature of the aspheric surface, c being 1/R (i.e., paraxial curvature c is the inverse of radius of curvature R in table 1); k is a conic coefficient; ai is the ith order coefficient of the aspheric surface. Table 2 below gives the high-order term coefficients a4, a6, A8, a10, a12, a14, a16, a18, and a20 that can be used for the aspherical surfaces S4 to S9 of the lens in example 1.

TABLE 2

The half ImgH of the diagonal length of the effective pixel region on the imaging surface S18 of the lens system 10 of the present embodiment is 2.285 mm. As can be seen from the data in tables 1 and 2, the lens system 10 in example 1 satisfies:

4.082mm, where f represents the effective focal length of the lens system 10 and FNO represents the f-number of the lens system 10;

HFOV/TTL is 0.344 degrees/mm, where HFOV denotes a half field angle of the lens system 10 in a diagonal direction, and TTL denotes a distance on the folding optical axis from the object side surface S4 of the first lens L1 to the imaging surface S18 of the lens system 10;

TTL/f is 0.947, where TTL denotes an optical axis distance from the object-side surface S4 of the first lens L1 to the image plane S18 of the lens system 10, and f denotes an effective focal length of the lens system 10;

f 20mm, where f represents the effective focal length of the lens system 10;

CT12/CT23 is 0.522, where CT12 denotes a distance between the image-side surface S5 of the first lens L1 and the object-side surface S6 of the second lens L2 on the optical axis AX2, and CT23 denotes a distance between the image-side surface S7 of the second lens L2 and the object-side surface S8 of the third lens L3 on the optical axis AX 2;

FNO 4.9, where FNO denotes the f-number of the lens system 10;

D32/ImgH is 1.198, where D32 denotes the effective clear half aperture of the third lens L3 and ImgH denotes half the diagonal length of the effective pixel area on the imaging plane S18 of the lens system 10.

Fig. 4 shows a longitudinal spherical aberration graph, an astigmatism graph, and a distortion graph, respectively, of the lens system 10 of example 1, the reference wavelength of the lens system 10 being 555 nm. Wherein the longitudinal spherical aberration plots show the deviation of the focus of convergence for light rays having wavelengths of 470nm, 510nm, 555nm, 610nm, and 650nm after passing through the lens system 10; the astigmatism graphs show the meridional and sagittal image planes curvature of the lens system 10; the distortion plot shows the distortion of the lens system 10 for different image heights. As can be seen from fig. 4, the lens system 10 according to embodiment 1 can achieve good imaging quality.

Example 2

The lens system 10 of embodiment 2 of the present application is described below with reference to fig. 5 to 8. In this embodiment, a description of parts similar to those of embodiment 1 will be omitted for the sake of brevity.

As shown in fig. 5 to 7, the lens system 10 includes, in order from the object side to the image side along the optical axis, a first right prism P1, a first lens L1, a second lens L2, a third lens L3, a second right prism P2, a third right prism P3, and an image plane S18. The folded optical axis includes a first portion AX1, a second portion AX2, a third portion AX3, and a fourth portion AX4, and the first lens L1, the second lens L2, and the third lens L3 are located on the optical axis AX 2.

The first lens element L1 with negative refractive power has an object-side surface S4 and an image-side surface S5 that are aspheric, wherein the object-side surface S4 is convex along an optical axis and convex along a circumference, and the image-side surface S5 is concave along the optical axis and concave along the circumference; the second lens element L2 with negative refractive power has an object-side surface S6 and an image-side surface S7 that are aspheric, wherein the object-side surface S6 is convex along the optical axis and convex along the circumference, and the image-side surface S7 is concave along the optical axis and convex along the circumference; the third lens element L3 with positive refractive power has an object-side surface S8 and an image-side surface S9 that are aspheric, wherein the object-side surface S8 is convex along an optical axis and concave along a circumference, and the image-side surface S9 is convex along the optical axis and convex along the circumference.

The object-side surface and the image-side surface of the first lens L1 through the third lens L3 are each set to an aspherical surface. The first lens L1 to the third lens L3 are all made of plastic. A stop STO is further provided between the first rectangular prism P1 and the first lens L1. The lens system 10 further includes an infrared filter 110 disposed on the image side of the third lens L3 and having an object-side surface S10 and an image-side surface S11.

Table 3 shows the surface type, radius of curvature, thickness, material, refractive index, abbe number (i.e., abbe number), effective focal length, Y-half aperture, and X-half aperture of each lens of the lens system 10 of example 2, wherein the unit of the radius of curvature, thickness, effective focal length, Y-half aperture, and X-half aperture of each lens is millimeters (mm). Table 4 shows high-order term coefficients that can be used for the lens aspherical surfaces S4 to S9 in embodiment 2, wherein the aspherical surface type can be defined by formula (1) given in embodiment 1. Table 5 shows the values of the relevant parameters of the lens system 10 given in example 2.

TABLE 3

TABLE 4

TABLE 5

Fig. 8 shows a longitudinal spherical aberration graph, an astigmatism graph, and a distortion graph, respectively, of the lens system 10 of example 2, the reference wavelength of the lens system 10 being 555 nm. Wherein the longitudinal spherical aberration plots show the deviation of the focus of convergence for light rays having wavelengths of 470nm, 510nm, 555nm, 610nm, and 650nm after passing through the lens system 10; the astigmatism graphs show the meridional and sagittal image planes curvature of the lens system 10; the distortion plot shows the distortion of the lens system 10 for different image heights. As can be seen from fig. 8, the lens system 10 according to embodiment 2 can achieve good imaging quality.

Example 3

The lens system 10 of embodiment 3 of the present application is described below with reference to fig. 9 to 12. In this embodiment, a description of parts similar to those of embodiment 1 will be omitted for the sake of brevity.

As shown in fig. 9 to 11, the lens system 10 includes, in order from the object side to the image side along the optical axis, a first right prism P1, a first lens L1, a second lens L2, a third lens L3, a second right prism P2, a third right prism P3, and an image plane S18. The folded optical axis includes a first portion AX1, a second portion AX2, a third portion AX3, and a fourth portion AX4, and the first lens L1, the second lens L2, and the third lens L3 are located on the optical axis AX 2.

The first lens element L1 with positive refractive power has an object-side surface S4 and an image-side surface S5 that are aspheric, wherein the object-side surface S4 is convex along an optical axis and convex along a circumference, and the image-side surface S5 is convex along the optical axis and concave along the circumference; the second lens element L2 with negative refractive power has an object-side surface S6 and an image-side surface S7 that are aspheric, wherein the object-side surface S6 is convex along the optical axis and concave along the circumference, and the image-side surface S7 is concave along the optical axis and convex along the circumference; the third lens element L3 with positive refractive power has an object-side surface S8 and an image-side surface S9 that are aspheric, wherein the object-side surface S8 is concave along the optical axis and concave along the circumference, and the image-side surface S9 is convex along the optical axis and convex along the circumference.

Table 6 shows the surface type, radius of curvature, thickness, material, refractive index, abbe number (i.e., abbe number), effective focal length, Y-half aperture, and X-half aperture of each lens of the lens system 10 of example 3, wherein the unit of the radius of curvature, thickness, effective focal length, Y-half aperture, and X-half aperture of each lens is millimeters (mm). Table 7 shows high-order term coefficients that can be used for the lens aspherical surfaces S4 to S9 in embodiment 3, wherein the aspherical surface type can be defined by formula (1) given in embodiment 1. Table 8 shows the values of relevant parameters of the lens system 10 given in example 3.

TABLE 6

TABLE 7

TABLE 8

Fig. 12 shows a longitudinal spherical aberration graph, an astigmatism graph, and a distortion graph, respectively, of the lens system 10 of example 3, the reference wavelength of the lens system 10 being 555 nm. Wherein the longitudinal spherical aberration plots show the deviation of the focus of convergence for light rays having wavelengths of 470nm, 510nm, 555nm, 610nm, and 650nm after passing through the lens system 10; the astigmatism graphs show the meridional and sagittal image planes curvature of the lens system 10; the distortion plot shows the distortion of the lens system 10 for different image heights. As can be seen from fig. 12, the lens system 10 according to embodiment 3 can achieve good imaging quality.

Example 4

The lens system 10 of embodiment 4 of the present application is described below with reference to fig. 13 to 16. In this embodiment, a description of parts similar to those of embodiment 1 will be omitted for the sake of brevity.

As shown in fig. 13 to 15, the lens system 10 includes, in order from the object side to the image side along the optical axis, a first right prism P1, a first lens L1, a second lens L2, a third lens L3, a second right prism P2, a third right prism P3, and an image plane S18. The folded optical axis includes a first portion AX1, a second portion AX2, a third portion AX3, and a fourth portion AX4, and the first lens L1, the second lens L2, and the third lens L3 are located on the optical axis AX 2.

The first lens element L1 with positive refractive power has an object-side surface S4 and an image-side surface S5 that are aspheric, wherein the object-side surface S4 is convex along an optical axis and convex along a circumference, and the image-side surface S5 is concave along the optical axis and convex along the circumference; the second lens element L2 with negative refractive power has an object-side surface S6 and an image-side surface S7 that are aspheric, wherein the object-side surface S6 is convex along the optical axis and concave along the circumference, and the image-side surface S7 is concave along the optical axis and convex along the circumference; the third lens element L3 with negative refractive power has an object-side surface S8 and an image-side surface S9 that are aspheric, wherein the object-side surface S8 is concave along the optical axis and concave along the circumference, and the image-side surface S9 is convex along the optical axis and convex along the circumference.

Table 9 shows the surface type, radius of curvature, thickness, material, refractive index, abbe number (i.e., abbe number), effective focal length, Y-half aperture, and X-half aperture of each lens of the lens system 10 of example 4, wherein the unit of the radius of curvature, thickness, effective focal length, Y-half aperture, and X-half aperture of each lens is millimeters (mm). Table 10 shows high-order term coefficients that can be used for the lens aspherical surfaces S4 to S9 in embodiment 4, wherein the aspherical surface type can be defined by formula (1) given in embodiment 1. Table 11 shows the values of relevant parameters of the lens system 10 given in example 4.

TABLE 9

Watch 10

TABLE 11

Fig. 16 shows a longitudinal spherical aberration graph, an astigmatism graph, and a distortion graph, respectively, of the lens system 10 of example 4, the reference wavelength of the lens system 10 being 555 nm. Wherein the longitudinal spherical aberration plots show the deviation of the focus of convergence for light rays having wavelengths of 470nm, 510nm, 555nm, 610nm, and 650nm after passing through the lens system 10; the astigmatism graphs show the meridional and sagittal image planes curvature of the lens system 10; the distortion plot shows the distortion of the lens system 10 for different image heights. As can be seen from fig. 16, the lens system 10 according to embodiment 4 can achieve good imaging quality.

Example 5

The lens system 10 of embodiment 5 of the present application is described below with reference to fig. 17 to 20. In this embodiment, a description of parts similar to those of embodiment 1 will be omitted for the sake of brevity.

As shown in fig. 17 to 19, the lens system 10 includes, in order from the object side to the image side along the optical axis, a first right prism P1, a first lens L1, a second lens L2, a third lens L3, a second right prism P2, a third right prism P3, and an image plane S18. The folded optical axis includes a first portion AX1, a second portion AX2, a third portion AX3, and a fourth portion AX4, and the first lens L1, the second lens L2, and the third lens L3 are located on the optical axis AX 2.

The first lens element L1 with negative refractive power has an object-side surface S4 and an image-side surface S5 that are aspheric, wherein the object-side surface S4 is convex along an optical axis and convex along a circumference, and the image-side surface S5 is concave along the optical axis and convex along the circumference; the second lens element L2 with negative refractive power has an object-side surface S6 and an image-side surface S7 that are aspheric, wherein the object-side surface S6 is convex along the optical axis and concave along the circumference, and the image-side surface S7 is concave along the optical axis and convex along the circumference; the third lens element L3 with positive refractive power has an object-side surface S8 and an image-side surface S9 that are aspheric, wherein the object-side surface S8 is convex along an optical axis and concave along a circumference, and the image-side surface S9 is concave along the optical axis and concave along the circumference.

Table 12 shows the surface type, radius of curvature, thickness, material, refractive index, abbe number (i.e., abbe number), effective focal length, Y-half aperture, and X-half aperture of each lens of the lens system 10 of example 5, wherein the unit of the radius of curvature, thickness, effective focal length, Y-half aperture, and X-half aperture of each lens is millimeters (mm). Table 13 shows high-order term coefficients that can be used for the lens aspherical surfaces S4 to S9 in example 5, wherein the aspherical surface type can be defined by formula (1) given in example 1. Table 14 shows the values of the relevant parameters of the lens system 10 given in example 5.

TABLE 12

Watch 13

TABLE 14

Fig. 20 shows a longitudinal spherical aberration graph, an astigmatism graph, and a distortion graph, respectively, of the lens system 10 of example 5, the reference wavelength of the lens system 10 being 555 nm. Wherein the longitudinal spherical aberration plots show the deviation of the focus of convergence for light rays having wavelengths of 470nm, 510nm, 555nm, 610nm, and 650nm after passing through the lens system 10; the astigmatism graphs show the meridional and sagittal image planes curvature of the lens system 10; the distortion plot shows the distortion of the lens system 10 for different image heights. As can be seen from fig. 20, the lens system 10 according to embodiment 5 can achieve good imaging quality.

Example 6

The lens system 10 of embodiment 6 of the present application is described below with reference to fig. 21 to 24. In this embodiment, a description of parts similar to those of embodiment 1 will be omitted for the sake of brevity.

As shown in fig. 21 to 23, the lens system 10 includes, in order from the object side to the image side along the optical axis, a first right prism P1, a first lens L1, a second lens L2, a third lens L3, a second right prism P2, a third right prism P3, and an image plane S18. The folded optical axis includes a first portion AX1, a second portion AX2, a third portion AX3, and a fourth portion AX4, and the first lens L1, the second lens L2, and the third lens L3 are located on the optical axis AX 2.

The first lens element L1 with positive refractive power has an object-side surface S4 and an image-side surface S5 that are aspheric, wherein the object-side surface S4 is convex along an optical axis and convex along a circumference, and the image-side surface S5 is convex along the optical axis and convex along the circumference; the second lens element L2 with positive refractive power has an object-side surface S6 and an image-side surface S7 that are aspheric, wherein the object-side surface S6 is convex along an optical axis and concave along a circumference, and the image-side surface S7 is convex along the optical axis and convex along the circumference; the third lens element L3 with negative refractive power has an object-side surface S8 and an image-side surface S9 that are aspheric, wherein the object-side surface S8 is convex along the optical axis and convex along the circumference, and the image-side surface S9 is concave along the optical axis and concave along the circumference.

Table 15 shows the surface type, radius of curvature, thickness, material, refractive index, abbe number (i.e., abbe number), effective focal length, Y-half aperture, and X-half aperture of each lens of the lens system 10 of example 6, wherein the unit of the radius of curvature, thickness, effective focal length, Y-half aperture, and X-half aperture of each lens is millimeters (mm). Table 16 shows high-order term coefficients that can be used for the lens aspherical surfaces S4 to S9 in example 6, wherein the aspherical surface type can be defined by formula (1) given in example 1. Table 17 shows the values of relevant parameters of the lens system 10 given in example 6.

Watch 15

TABLE 16

TABLE 17

Fig. 24 shows a longitudinal spherical aberration chart, an astigmatism chart and a distortion chart of the lens system 10 of example 6, respectively, and the reference wavelength of the lens system 10 is 555 nm. Wherein the longitudinal spherical aberration plots show the deviation of the focus of convergence for light rays having wavelengths of 470nm, 510nm, 555nm, 610nm, and 650nm after passing through the lens system 10; the astigmatism graphs show the meridional and sagittal image planes curvature of the lens system 10; the distortion plot shows the distortion of the lens system 10 for different image heights. As can be seen from fig. 24, the lens system 10 according to embodiment 6 can achieve good imaging quality.

Example 7

The lens system 10 of embodiment 7 of the present application is described below with reference to fig. 25 to 28. In this embodiment, a description of parts similar to those of embodiment 1 will be omitted for the sake of brevity.

As shown in fig. 25 to 27, the lens system 10 includes, in order from the object side to the image side along the optical axis, a first right prism P1, a first lens L1, a second lens L2, a third lens L3, a second right prism P2, a third right prism P3, and an image plane S18. The folded optical axis includes a first portion AX1, a second portion AX2, a third portion AX3, and a fourth portion AX4, and the first lens L1, the second lens L2, and the third lens L3 are located on the optical axis AX 2.

The first lens element L1 with negative refractive power has an object-side surface S4 and an image-side surface S5 that are aspheric, wherein the object-side surface S4 is convex along an optical axis and convex along a circumference, and the image-side surface S5 is concave along the optical axis and concave along the circumference; the second lens element L2 with positive refractive power has an object-side surface S6 and an image-side surface S7 that are aspheric, wherein the object-side surface S6 is convex along the optical axis and concave along the circumference, and the image-side surface S7 is concave along the optical axis and convex along the circumference; the third lens element L3 with positive refractive power has an object-side surface S8 and an image-side surface S9 that are aspheric, wherein the object-side surface S8 is convex along the optical axis and convex along the circumference, and the image-side surface S9 is concave along the optical axis and concave along the circumference.

Table 18 shows the surface type, radius of curvature, thickness, material, refractive index, abbe number (i.e., abbe number), effective focal length, Y-half aperture, and X-half aperture of each lens of the lens system 10 of example 7, wherein the unit of the radius of curvature, thickness, effective focal length, Y-half aperture, and X-half aperture of each lens is millimeters (mm). Table 19 shows high-order term coefficients that can be used for the lens aspherical surfaces S4 to S9 in example 7, wherein the aspherical surface type can be defined by formula (1) given in example 1. Table 20 shows the values of the relevant parameters of the lens system 10 given in example 7.

Watch 18

Watch 19

Watch 20

Fig. 28 shows a longitudinal spherical aberration chart, an astigmatism chart and a distortion chart of the lens system 10 of example 7, respectively, and the reference wavelength of the lens system 10 is 555 nm. Wherein the longitudinal spherical aberration plots show the deviation of the focus of convergence for light rays having wavelengths of 470nm, 510nm, 555nm, 610nm, and 650nm after passing through the lens system 10; the astigmatism graphs show the meridional and sagittal image planes curvature of the lens system 10; the distortion plot shows the distortion of the lens system 10 for different image heights. As can be seen from fig. 28, the lens system 10 according to embodiment 7 can achieve good imaging quality.

Example 8

The lens system 10 of embodiment 8 of the present application is described below with reference to fig. 29 to 32. In this embodiment, a description of parts similar to those of embodiment 1 will be omitted for the sake of brevity.

As shown in fig. 29 to 31, the lens system 10 includes, in order from the object side to the image side along the optical axis, a first right prism P1, a first lens L1, a second lens L2, a third lens L3, a second right prism P2, a third right prism P3, and an image plane S18. The folded optical axis includes a first portion AX1, a second portion AX2, a third portion AX3, and a fourth portion AX4, and the first lens L1, the second lens L2, and the third lens L3 are located on the optical axis AX 2.

The first lens element L1 with positive refractive power has an object-side surface S4 and an image-side surface S5 that are aspheric, wherein the object-side surface S4 is convex along an optical axis and convex along a circumference, and the image-side surface S5 is concave along the optical axis and convex along the circumference; the second lens element L2 with negative refractive power has an object-side surface S6 and an image-side surface S7 that are aspheric, wherein the object-side surface S6 is convex along the optical axis and concave along the circumference, and the image-side surface S7 is concave along the optical axis and convex along the circumference; the third lens element L3 with positive refractive power has an object-side surface S8 and an image-side surface S9 that are aspheric, wherein the object-side surface S8 is convex along an optical axis and concave along a circumference, and the image-side surface S9 is concave along the optical axis and convex along the circumference.

Table 21 shows the surface type, radius of curvature, thickness, material, refractive index, abbe number (i.e., abbe number), effective focal length, Y-half aperture, and X-half aperture of each lens of the lens system 10 of example 8, where the unit of the radius of curvature, thickness, effective focal length, Y-half aperture, and X-half aperture of each lens is millimeters (mm). Table 22 shows high-order term coefficients that can be used for the lens aspherical surfaces S4 to S9 in embodiment 8, wherein the aspherical surface type can be defined by formula (1) given in embodiment 1. Table 23 shows the values of relevant parameters of the lens system 10 given in example 8.

TABLE 21

TABLE 22

TABLE 23

Fig. 32 shows a longitudinal spherical aberration chart, an astigmatism chart and a distortion chart of the lens system 10 of example 8, respectively, and the reference wavelength of the lens system 10 is 555 nm. . Wherein the longitudinal spherical aberration plots show the deviation of the focus of convergence for light rays having wavelengths of 470nm, 510nm, 555nm, 610nm, and 650nm after passing through the lens system 10; the astigmatism graphs show the meridional and sagittal image planes curvature of the lens system 10; the distortion plot shows the distortion of the lens system 10 for different image heights. As can be seen from fig. 32, the lens system 10 according to embodiment 8 can achieve good imaging quality.

Example 9

The lens system 10 of embodiment 9 of the present application is described below with reference to fig. 33 to 36. In this embodiment, a description of parts similar to those of embodiment 1 will be omitted for the sake of brevity.

As shown in fig. 31 to 35, the lens system 10 includes, in order from the object side to the image side along the optical axis, a first right prism P1, a first lens L1, a second lens L2, a third lens L3, a second right prism P2, a third right prism P3, and an image plane S18. The folded optical axis includes a first portion AX1, a second portion AX2, a third portion AX3, and a fourth portion AX4, and the first lens L1, the second lens L2, and the third lens L3 are located on the optical axis AX 2.

The first lens element L1 with positive refractive power has an object-side surface S4 and an image-side surface S5 that are aspheric, wherein the object-side surface S4 is convex along an optical axis and convex along a circumference, and the image-side surface S5 is convex along the optical axis and convex along the circumference; the second lens element L2 with negative refractive power has an object-side surface S6 and an image-side surface S7 that are aspheric, wherein the object-side surface S6 is concave along the optical axis and concave along the circumference, and the image-side surface S7 is convex along the optical axis and convex along the circumference; the third lens element L3 with negative refractive power has an object-side surface S8 and an image-side surface S9 that are aspheric, wherein the object-side surface S8 is convex along an optical axis and concave along a circumference, and the image-side surface S9 is concave along the optical axis and concave along the circumference.

Table 24 shows the surface type, radius of curvature, thickness, material, refractive index, abbe number (i.e., abbe number), effective focal length, Y-half aperture, and X-half aperture of each lens of the lens system 10 of example 9, wherein the unit of the radius of curvature, thickness, effective focal length, Y-half aperture, and X-half aperture of each lens is millimeters (mm). Table 25 shows high-order term coefficients that can be used for the lens aspherical surfaces S4 to S9 in example 9, wherein the aspherical surface type can be defined by formula (1) given in example 1. Table 26 shows the values of the relevant parameters of the lens system 10 given in example 9.

Watch 24

TABLE 25

Watch 26

Fig. 36 shows a longitudinal spherical aberration chart, an astigmatism chart and a distortion chart of the lens system 10 of example 9, respectively, and the reference wavelength of the lens system 10 is 555 nm. Wherein the longitudinal spherical aberration plots show the deviation of the focus of convergence for light rays having wavelengths of 470nm, 510nm, 555nm, 610nm, and 650nm after passing through the lens system 10; the astigmatism graphs show the meridional and sagittal image planes curvature of the lens system 10; the distortion plot shows the distortion of the lens system 10 for different image heights. As can be seen from fig. 36, the lens system 10 according to embodiment 9 can achieve good imaging quality.

Example 10

A lens system 10 of embodiment 10 of the present application is described below with reference to fig. 37 to 40. In this embodiment, a description of parts similar to those of embodiment 1 will be omitted for the sake of brevity.

As shown in fig. 37 to 39, the lens system 10 includes, in order from the object side to the image side along the optical axis, a first right prism P1, a first lens L1, a second lens L2, a third lens L3, a second right prism P2, a third right prism P3, and an image plane S18. The folded optical axis includes a first portion AX1, a second portion AX2, a third portion AX3, and a fourth portion AX4, and the first lens L1, the second lens L2, and the third lens L3 are located on the optical axis AX 2.

The first lens element L1 with positive refractive power has an object-side surface S4 and an image-side surface S5 that are aspheric, wherein the object-side surface S4 is convex along an optical axis and convex along a circumference, and the image-side surface S5 is concave along the optical axis and convex along the circumference; the second lens element L2 with negative refractive power has an object-side surface S6 and an image-side surface S7 that are aspheric, wherein the object-side surface S6 is concave along the optical axis and concave along the circumference, and the image-side surface S7 is concave along the optical axis and convex along the circumference; the third lens element L3 with positive refractive power has an object-side surface S8 and an image-side surface S9 that are aspheric, wherein the object-side surface S8 is convex along the optical axis and convex along the circumference, and the image-side surface S9 is concave along the optical axis and concave along the circumference.

Table 27 shows the surface type, radius of curvature, thickness, material, refractive index, abbe number (i.e., abbe number), effective focal length, Y-half aperture, and X-half aperture of each lens of the lens system 10 of example 10, where the unit of the radius of curvature, thickness, effective focal length, Y-half aperture, and X-half aperture of each lens is millimeters (mm). Table 28 shows high-order term coefficients that can be used for the lens aspherical surfaces S4 to S9 in embodiment 10, wherein the aspherical surface type can be defined by formula (1) given in embodiment 1. Table 29 shows the values of relevant parameters of the lens system 10 given in example 10.

Watch 27

Watch 28

Watch 29

Fig. 40 shows a longitudinal spherical aberration chart, an astigmatism chart and a distortion chart of the lens system 10 of example 10, respectively, and the reference wavelength of the lens system 10 is 555 nm. Wherein the longitudinal spherical aberration plots show the deviation of the focus of convergence for light rays having wavelengths of 470nm, 510nm, 555nm, 610nm, and 650nm after passing through the lens system 10; the astigmatism graphs show the meridional and sagittal image planes curvature of the lens system 10; the distortion plot shows the distortion of the lens system 10 for different image heights. As can be seen from fig. 40, the lens system 10 according to embodiment 10 can achieve good imaging quality.

Example 11

A lens system 10 of embodiment 11 of the present application is described below with reference to fig. 41 to 44. In this embodiment, a description of parts similar to those of embodiment 1 will be omitted for the sake of brevity.

As shown in fig. 41 to 43, the lens system 10 includes, in order from the object side to the image side along the optical axis, a first right prism P1, a first lens L1, a second lens L2, a third lens L3, a second right prism P2, a third right prism P3, and an image plane S18. The folded optical axis includes a first portion AX1, a second portion AX2, a third portion AX3, and a fourth portion AX4, and the first lens L1, the second lens L2, and the third lens L3 are located on the optical axis AX 2.

The first lens element L1 with positive refractive power has an object-side surface S4 and an image-side surface S5 that are aspheric, wherein the object-side surface S4 is convex along an optical axis and convex along a circumference, and the image-side surface S5 is concave along the optical axis and concave along the circumference; the second lens element L2 with negative refractive power has an object-side surface S6 and an image-side surface S7 that are aspheric, wherein the object-side surface S6 is convex along the optical axis and concave along the circumference, and the image-side surface S7 is concave along the optical axis and convex along the circumference; the third lens element L3 with positive refractive power has an object-side surface S8 and an image-side surface S9 that are aspheric, wherein the object-side surface S8 is concave along the optical axis and concave along the circumference, and the image-side surface S9 is convex along the optical axis and convex along the circumference.

Table 30 shows the surface type, radius of curvature, thickness, material, refractive index, abbe number (i.e., abbe number), effective focal length, Y-half aperture, and X-half aperture of each lens of the lens system 10 of example 11, wherein the unit of the radius of curvature, thickness, effective focal length, Y-half aperture, and X-half aperture of each lens is millimeters (mm). Table 31 shows the high-order term coefficients that can be used for the lens aspherical surfaces S4 to S9 in example 11, wherein the aspherical surface type can be defined by formula (1) given in example 1. Table 32 shows the values of the relevant parameters of the lens system 10 given in example 11.

Watch 30

Watch 31

Watch 32

Fig. 44 shows a longitudinal spherical aberration chart, an astigmatism chart and a distortion chart of the lens system 10 of example 11, respectively, and the reference wavelength of the lens system 10 is 555 nm. Wherein the longitudinal spherical aberration plots show the deviation of the focus of convergence for light rays having wavelengths of 470nm, 510nm, 555nm, 610nm, and 650nm after passing through the lens system 10; the astigmatism graphs show the meridional and sagittal image planes curvature of the lens system 10; the distortion plot shows the distortion of the lens system 10 for different image heights. As can be seen from fig. 44, the lens system 10 according to embodiment 11 can achieve good imaging quality.

As shown in fig. 45, the present application further provides an imaging module 20 comprising the lens system 10 as described above; and a light sensing element 210, the light sensing element 210 being disposed on the image side of the lens system 10, the light sensing surface of the light sensing element 210 coinciding with the image forming surface S13. Specifically, the photosensitive element 210 may be a Complementary Metal Oxide Semiconductor (CMOS) image sensor or a Charge-coupled Device (CCD) image sensor.

The imaging module 20 can be arranged along the transverse direction of the electronic product, and is convenient to adapt to devices with limited size, such as light and thin electronic equipment; simultaneously, this imaging module 20 still possesses long focal length characteristic, can carry out clear formation of image to the object in a distance, satisfies the remote shooting demand of cell-phone, flat board better.

In other embodiments, each optical element and the photosensitive element 210 in the imaging module 20 may further be respectively provided with a driving element to drive the corresponding optical element and the photosensitive element 210 to focus light on the imaging surface, so as to implement at least one function of zooming, focusing or anti-shake of the imaging module 20.

The present application further provides an electronic device, which includes a housing and the imaging module 20 as described above, wherein the imaging module 20 is mounted on the housing. Specifically, imaging module 20 sets up in the casing and exposes in order to obtain the image from the casing, and the casing can provide protection such as dustproof, waterproof falling of preventing for imaging module 20, offers the hole that corresponds with imaging module 20 on the casing to make light penetrate or wear out the casing from the hole.

The electronic device has the structural characteristics of lightness and thinness, and also has strong telephoto capability, so that the shooting experience of a user can be improved.

In other embodiments, the use of "electronic device" may also include, but is not limited to, devices configured to receive or transmit communication signals via a wired connection and/or via a wireless interface. Electronic devices arranged to communicate over a wireless interface may be referred to as "wireless communication terminals", "wireless terminals", or "mobile terminals". Examples of mobile terminals include, but are not limited to, satellite or cellular telephones; personal Communication System (PCS) terminals that may combine a cellular radiotelephone with data processing, facsimile and data communication capabilities; personal Digital Assistants (PDAs) that may include radiotelephones, pagers, internet/intranet access, Web browsers, notepads, and/or Global Positioning System (GPS) receivers; and conventional laptop and/or palmtop receivers or other electronic devices that include a radiotelephone transceiver.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. A lens system comprising a plurality of optical elements arranged along a folded optical axis of the lens system, in order from an object side to an image side:

a lens group on a second portion of the folded optical axis;

2. The lens system of claim 1,

the first light path folding element is a prism; and/or the presence of a catalyst in the reaction mixture,

the second light path folding element is a prism; and/or the presence of a catalyst in the reaction mixture,

the third light path folding element is a prism.

3. The lens system of claim 1 or 2, wherein the lens group comprises, in order from object side to image side along the second portion of the folded optical axis:

a first lens element with refractive power;

a second lens element with refractive power;

a third lens element with refractive power;

in the first lens element to the third lens element, at least one of the object-side surface and the image-side surface of the at least one lens element is aspheric, and at least one of the object-side surface and the image-side surface of the at least one lens element includes at least one inflection point.

4. The lens system of claim 3, wherein the lens system satisfies the following relationship:

3mm＜f/FNO＜12mm；

where f denotes an effective focal length of the lens system, and FNO denotes an f-number of the lens system.

5. The lens system of claim 3, wherein the lens system satisfies the following relationship:

HFOV/TTL is more than 0.1 degree/mm;

wherein, HFOV represents a half field angle of the lens system in a diagonal direction, and TTL represents a distance on the optical axis of the folded optical axis from an object side surface of the first lens to an image plane of the lens system.

6. The lens system of claim 3, wherein the lens system satisfies the following relationship:

TTL/f＜1.2；

wherein, TTL represents a distance on the folding optical axis from the object-side surface of the first lens element to the imaging surface of the lens system, and f represents an effective focal length of the lens system.

7. The lens system of claim 3, wherein the lens system satisfies the following relationship:

f＞15mm；

wherein f represents the effective focal length of the lens system.

8. The lens system of claim 3, wherein the lens system satisfies the following relationship:

CT12/CT23＜3；

wherein CT12 represents a distance on the optical axis from the image-side surface of the first lens to the object-side surface of the second lens, and CT23 represents a distance on the optical axis from the image-side surface of the second lens to the object-side surface of the third lens.

9. The lens system of claim 3, wherein the lens system satisfies the following relationship:

2.2＜FNO＜6.8；

wherein FNO denotes an f-number of the lens system.

10. The lens system of claim 3, wherein the lens system satisfies the following relationship:

D32/ImgH＜1.3；

where D32 denotes an effective clear half aperture of the third lens, and ImgH denotes a half of a diagonal length of an effective pixel area on an imaging plane of the lens system.

11. An imaging module comprising the lens system of any one of claims 1-10 and a photosensitive element disposed on an image side of the lens system.

12. An electronic device comprising a housing and the imaging module of claim 11, wherein the imaging module is mounted on the housing.