CN211554456U

CN211554456U - Lens group, camera lens, camera module and electronic equipment

Info

Publication number: CN211554456U
Application number: CN202020321185.7U
Authority: CN
Inventors: 华露; 杨健; 李明; 邹海荣
Original assignee: OFilm Tech Co Ltd
Current assignee: Jiangxi Jingchao Optical Co Ltd
Priority date: 2020-03-13
Filing date: 2020-03-13
Publication date: 2020-09-22
Anticipated expiration: 2030-03-13

Abstract

The application provides a lens group, camera lens, module and electronic equipment make a video recording. The lens group sequentially comprises from an object side to an image side along an optical axis direction: a first lens element with refractive power; a second lens element with positive refractive power; a third lens element with negative refractive power; the image side surface of the third lens at the position close to the optical axis is a concave surface; a fourth lens element with positive refractive power; the object side surface of the fourth lens at the paraxial axis is a concave surface, and the image side surface of the fourth lens at the paraxial axis is a convex surface; the fifth lens element with negative refractive power has a convex object-side surface at the paraxial axis thereof, a concave image-side surface at the paraxial axis thereof, and at least one of the object-side surface and the image-side surface thereof is provided with at least one inflection point; the lens group satisfies the conditional expression: SD2/ImgH < 0.26. Through the face type and the refractive power of each lens element of the first to the fifth lens elements of reasonable configuration, the lens group of the present application can meet the requirements of large aperture and high pixel, and simultaneously realize the miniaturization of the lens group.

Description

Lens group, camera lens, camera module and electronic equipment

Technical Field

The application belongs to the technical field of optical imaging, especially, relate to a lens group, camera lens, module and electronic equipment of making a video recording.

Background

In recent years, a full-screen mobile phone is popular in the market, so that the high screen occupation ratio becomes a development trend, and how to improve the screen occupation ratio to a greater extent is a way to reduce the head of a camera lens. Under the trend, the size of the photographing lens also meets the miniaturization requirement, and meanwhile, the high imaging quality is also ensured, so that the requirement on the specification of the lens is higher and higher.

At present, although the traditional camera lens carried on a portable electronic product can meet the miniaturization requirement, the head of the lens is large, which is not beneficial to the under-screen packaging of the camera module, and the screen of the electronic equipment using the lens is large in open hole, which is not beneficial to the improvement of the screen occupation ratio of the electronic equipment.

SUMMERY OF THE UTILITY MODEL

An object of the application is to provide a lens group, camera lens, make a video recording module and electronic equipment for solve above-mentioned technical problem.

In order to achieve the purpose of the application, the application provides the following technical scheme:

in a first aspect, the present application provides a lens set. The lens group sequentially comprises from an object side to an image side along an optical axis direction: the first lens element with refractive power has a convex object-side surface at a paraxial region thereof. The second lens element with positive refractive power has a convex image-side surface at the paraxial region thereof. The third lens element with negative refractive power has a concave image-side surface at the paraxial region thereof. The fourth lens element with positive refractive power has a concave object-side surface at a paraxial region thereof, and has a convex image-side surface at a paraxial region thereof. The fifth lens element with negative refractive power has a convex object-side surface at a paraxial region thereof, a concave image-side surface at a paraxial region thereof, and at least one of the object-side surface and the image-side surface of the fifth lens element has at least one inflection point. The lens group satisfies the conditional expression: SD2/ImgH < 0.26; the SD2 is an optical effective radius of the image-side surface of the first lens element, and the ImgH is a half of a diagonal length of an effective imaging area of the lens assembly on an imaging surface. When ImgH is larger, it means that the matched photosensitive element size is larger.

In the embodiment of the application, when SD2/ImgH is less than 0.26, the size of the photosensitive element that the lens can be matched with is limited, which is beneficial to the miniaturization design of the lens, and the optical aperture of the image side surface of the first lens is small, so that the diameter of the lens head is small, the size of the opening of the screen of the electronic device is reduced, and the screen occupation ratio of the electronic device is improved. When the ratio of SD2 to ImgH is greater than 0.26, the diameter of the lens head is large, which increases the size of the opening of the screen of the electronic device, and is not favorable for the under-screen packaging of the imaging module. In addition, the ratio of SD2/ImgH is reasonably configured, and the miniaturization of the lens head can be realized when a high-pixel large-size photosensitive element is matched.

In one embodiment, the lens group satisfies the conditional expression: 0.65< EPD/SD42< 1.05; the EPD is the diameter of the entrance pupil of the lens group, and the SD42 is the maximum effective half aperture of the image side surface of the fourth lens.

In the embodiment of the application, when the lens group satisfies the above conditional expression, not only the head of the lens has a smaller diameter, but also the light deflection angle can be reduced, and the aperture of the lens is gently transited from the first lens to the fifth lens. Accordingly, when EPD/SD42 is <0.65, the maximum effective half aperture of the fourth lens is too large to achieve miniaturization of the lens head; when EPD/SD42>1.05, the light deflection angle is increased, which is not favorable for the camera module applying the lens to correct aberration.

In one embodiment, the first lens to the fifth lens are aspheric. When all the lenses of the lens group are aspheric structures, spherical aberration correction can be better performed, and when the aspheric lenses are used, the additional aberration correction supports the lens group to achieve high luminous flux coefficient design and still maintain good image quality.

In one embodiment, tan (FOV/2) > 1; wherein the FOV is the maximum field angle of the lens group. Wherein tan (FOV/2) is the sine of the maximum half field angle of the lens set.

In this embodiment, when the lens group satisfies tan (FOV/2) >1, the lens has a larger field angle, so that wide-angle shooting can be realized, foreground objects are highlighted to a greater extent, and shooting experience of a user is satisfied.

In one embodiment, the lens assembly satisfies the following conditional expression: FNO < 2.6; wherein FNO is the f-number of the lens group. The electronic equipment can guarantee that the luminous flux of the lens group in unit time meets requirements by adjusting the size of the aperture of the lens group, so that the lens group can achieve a clear imaging effect when being shot in a dark environment.

In this embodiment, when FNO <2.6, under the prerequisite that maintains the camera lens head and have less diameter for lens group has sufficient luminous flux in unit interval, reduces marginal field of view aberration, makes to shoot also can acquire the clear detailed information of measured object under darker environment, thereby promotes the imaging quality of the module of making a video recording. It can be understood that, when FNO >2.6, the light flux of lens group in the unit interval is less, and marginal field of view aberration is great, and the module formation of image quality of making a video recording is relatively poor, can't bring good experience of shooing for the user.

In one embodiment, the lens assembly satisfies the following conditional expression: TT/f < 1.8; and TT is the distance from the object side surface of the first lens element to the imaging surface of the lens group along the optical axis. f is the effective focal length of the lens group.

In this embodiment, when TT/f <1.8, through the total length of reasonable control lens group and the ratio of effective focal length, not only can realize the miniaturization of lens group, also can guarantee that light is better assembles in photosensitive element's photosurface, improves the imaging quality of the module of making a video recording.

In one embodiment, the lens assembly satisfies the following conditional expression: r11/f < 0.25; wherein R11 is the curvature radius of the fifth lens element at paraxial region thereof, and f is the total effective focal length of the lens assembly.

In this embodiment, when R11/f is less than 0.25, the paraxial region of the image-side surface of the fifth lens element is concave to provide negative refractive power, and the fifth lens element at least includes an inflection point, which is not only beneficial for the correction of chromatic aberration of the camera module, but also can effectively correct curvature of field by adjusting the back focal length, thereby improving the imaging quality of the camera module. When R11/f >0.25, the curvature radius of the image side surface of the fifth lens at the paraxial position is too large, so that aberration is easy to generate, and the light convergence is not facilitated, thereby ensuring that the imaging quality of the camera module is poor.

In one embodiment, the lens assembly satisfies the following conditional expression: TT/ImgH < 1.53; TT is the distance from the object side surface of the first lens to the imaging surface of the lens group along the optical axis; ImgH is half of the diagonal length of the effective pixel area on the imaging surface of the lens group. ImgH determines the size of the photosensitive element. It will be appreciated that the larger ImgH, the larger the size of the photosensitive element, and thus the larger the camera module. When TT/ImgH is less than 1.53, the aberration of the marginal field of view can be reduced, the size of the lens group is effectively compressed, and the ultrathin property and the miniaturization of the lens are facilitated. When TT/ImgH >1.53, not only the lens size is larger, but also the size of the photosensitive element is larger, which is not beneficial to the miniaturization of the camera module.

In this embodiment, through the overall length of rational arrangement lens group and the size of formation of image for the compacter of module of making a video recording's structure not only is favorable to making a video recording the miniaturization of module, also is favorable to improving the imaging quality of the module of making a video recording.

In one embodiment, the lens assembly satisfies the following conditional expression: (CT2+ CT3)/(T23+ T34) < 4.5; wherein CT2 is a central thickness of the second lens element, CT3 is a central thickness of the third lens element, T23 is an axial distance between an image-side surface of the first lens element and an object-side surface of the second lens element, and T34 is an axial distance between an image-side surface of the third lens element and an object-side surface of the fourth lens element.

In this embodiment, the center thicknesses of the second lens element and the third lens element, the air gap between the second lens element and the third lens element, and the air gap between the third lens element and the fourth lens element are reasonably configured, so that when the relationship satisfies (CT2+ CT3)/(T23+ T34) <4.5, the total length of the lens assembly can be effectively shortened, which is not only beneficial to the miniaturization of the lens assembly, but also avoids the problem that the lens assembly is too small to facilitate the assembly, thereby increasing the sensitivity of the lens assembly. When (CT2+ CT3)/(T23+ T34) >4.5, the sizes of the lenses in the lens group are not uniformly distributed, so that the difference is large, and the difficulty in manufacturing and assembling the lens group is increased.

In one embodiment, the lens assembly satisfies the following conditional expression: 5< R2/R11< 8; wherein R2 is a radius of curvature at an object side optical axis of the first lens, and R11 is a radius of curvature at an image side optical axis of the fifth lens.

In the present embodiment, when 5< R2/R11<8, the lens can widen the incident angle of light entering the lens, so that the lens can obtain a large angle of view, and wide-angle shooting of the image pickup module is realized. In addition, since the image side of the fifth lens is sensitive to astigmatism and distortion, when R2/R11<5, the radius of curvature at the image side optical axis of the fifth lens is too small, which is not favorable for correcting the distortion and astigmatism generated by the first to fourth lenses.

In a second aspect, the present application further provides a lens barrel, which includes a lens barrel and the lens group as described above, wherein the lens group is installed in the lens barrel.

In the embodiment of the application, the lens group is adopted by the lens, so that the miniaturization of the lens can be realized while the high pixels are ensured, and the miniaturization of the head of the lens can also be realized.

In a third aspect, the present application further provides a camera module. The camera module comprises a photosensitive element and the lens, wherein the photosensitive element is opposite to the lens, and the photosensitive element is positioned on one side of the fifth lens, which is far away from the first lens.

In this application embodiment, the module of making a video recording adopts above-mentioned camera lens for the module of making a video recording realizes making a video recording the miniaturization of module when guaranteeing imaging quality.

In a fourth aspect, the present application further provides an electronic device, which includes a housing and the lens described above, wherein the camera module is mounted on the housing.

In this application embodiment, electronic equipment includes above-mentioned module of making a video recording for electronic equipment reduces the trompil size of electronic equipment screen when satisfying high pixel and shoot the requirement, has improved electronic equipment's screen and has accounted for the ratio.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1a is a schematic view of a first embodiment of a lens set;

FIG. 1b is a longitudinal spherical aberration curve, an astigmatism curve and a distortion curve of the first embodiment;

FIG. 2a is a schematic view of a second embodiment of a lens set;

FIG. 2b is a longitudinal spherical aberration curve, an astigmatism curve and a distortion curve of the second embodiment;

FIG. 3a is a schematic view of a third embodiment of a lens set;

FIG. 3b is a longitudinal spherical aberration curve, an astigmatism curve and a distortion curve of the third embodiment;

FIG. 4a is a schematic view of a fourth embodiment of a lens set;

FIG. 4b is a longitudinal spherical aberration curve, an astigmatism curve and a distortion curve of the fourth embodiment;

fig. 5a is a schematic structural view of a lens set of the fifth embodiment;

FIG. 5b is a longitudinal spherical aberration curve, an astigmatism curve and a distortion curve of the fifth embodiment;

fig. 6a is a schematic structural view of a lens group of a sixth embodiment;

FIG. 6b is a longitudinal spherical aberration curve, an astigmatism curve and a distortion curve of the sixth embodiment;

FIG. 7a is a schematic view of a lens set of the seventh embodiment;

FIG. 7b is a longitudinal spherical aberration curve, an astigmatism curve and a distortion curve of the seventh embodiment;

fig. 8a is a schematic structural view of a lens set of the eighth embodiment;

FIG. 8b is a longitudinal spherical aberration curve, an astigmatism curve and a distortion curve of the eighth embodiment;

fig. 9a is a schematic structural view of a lens group of the ninth embodiment;

fig. 9b is a longitudinal spherical aberration curve, an astigmatism curve and a distortion curve of the ninth embodiment.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

The embodiment of the application provides electronic equipment. The electronic device may be a cell phone, Personal Digital Assistant (PDA), tablet computer, smart watch, drone, electronic book reader, automobile data recorder, wearable device, or the like. In the embodiment of the present application, the electronic device is described as a mobile phone.

The electronic equipment comprises a shell and a camera module. The camera module is installed on the shell. The camera module can enable the electronic equipment to achieve the functions of acquiring images or instant video calls and the like. The camera module comprises a photosensitive element and a lens. The photosensitive element is arranged opposite to the lens. The external light passes through the lens and is finally imaged on the photosensitive element. The photosensitive element may be a Complementary Metal Oxide Semiconductor (CMOS) or a charge-coupled device (CCD).

The lens comprises a lens barrel and a lens group. The lens group is arranged in the lens cone. The photosensitive element is arranged on the image side of the lens group. The lens cone is a hollow structure with two ends, so that light rays penetrate through the lens group from one opening of the lens cone and then are projected to the photosensitive element from the other opening. The lens group comprises a plurality of lenses. This application is through the face type and the power of refracting of each lens of rational configuration lens group for the head of lens group is little and the angle of vision is big, thereby reduces the trompil size of electronic equipment screen, is favorable to the module of making a video recording of electronic equipment to encapsulate under the screen, thereby makes electronic equipment reach the visual effect of full face screen.

The lens group sequentially includes a first lens element, a second lens element, a third lens element, a fourth lens element and a fifth lens element from an object side to an image side along an optical axis. It is understood that the first lens element is located on a side of the fifth lens element away from the light sensing element, that is, the first lens element is the lens element of the lens group farthest from the light sensing element. In the first to fifth lenses, any two adjacent lenses may have an air space therebetween.

Specifically, the specific shape and structure of the five lenses are as follows:

the first lens element with refractive power has a convex object-side surface at a paraxial region thereof. The second lens element with positive refractive power has a convex image-side surface at the paraxial region thereof. A third lens element with negative refractive power; the image side surface of the third lens at the position close to the optical axis is a concave surface. A fourth lens element with positive refractive power; the object side surface of the fourth lens at the paraxial axis is a concave surface, and the image side surface of the fourth lens at the paraxial axis is a convex surface. The fifth lens element with negative refractive power has a convex object-side surface at a paraxial region thereof, a concave image-side surface at a paraxial region thereof, and at least one of the object-side surface and the image-side surface of the fifth lens element has at least one inflection point.

Further, the lens group satisfies the conditional expression: SD2/ImgH < 0.26; the SD2 is an optical effective radius of the image-side surface of the first lens element, and the ImgH is a half of a diagonal length of an effective imaging area of the lens assembly on an imaging surface. When ImgH is larger, it means that the matched photosensitive element size is larger.

In the embodiment of the application, when the lens group satisfies the above conditional expression, not only the head of the lens has a smaller diameter, but also the light deflection angle can be reduced, and the aperture of the lens is gently transited from the first lens to the fifth lens. Accordingly, when EPD/SD42 is less than 0.65, the maximum effective half aperture of the image-side surface of the fourth lens is too large, which is not favorable for realizing the miniaturization of the lens head; when EPD/SD42>1.05, the light deflection angle is increased, which is not favorable for the camera module applying the lens to correct aberration.

In one embodiment, the lens group satisfies the conditional expression: tan (FOV/2) > 1; wherein the FOV is the maximum field angle of the lens group. It will be appreciated that tan (FOV/2) is the sine of the maximum half field angle of the set of mirrors.

In one embodiment, the lens assembly satisfies the following conditional expression: (CT2+ CT3)/(T23+ T34) < 4.5; wherein CT2 is a central thickness of the second lens element, CT3 is a central thickness of the third lens element, T23 is an axial distance between an image-side surface of the first lens element and an object-side surface of the second lens element, and T34 is an axial distance between an image-side surface of the third lens element and an object-side surface of the fourth lens element. It is understood that T23 is the air separation distance between the first lens and the second lens on the optical axis, and T34 is the air separation distance between the third lens and the fourth lens on the optical axis.

In this embodiment, the center thicknesses of the second lens element and the third lens element, the gap between the second lens element and the third lens element, and the relationship between the gap between the third lens element and the fourth lens element are reasonably configured, so that when the relationship satisfies (CT2+ CT3)/(T23+ T34) <4.5, the total length of the lens assembly can be effectively shortened, which is not only beneficial to the miniaturization of the lens assembly, but also avoids the problem that the lens assembly is too small to facilitate the assembly, thereby increasing the sensitivity of the lens assembly. When (CT2+ CT3)/(T23+ T34) >4.5, the sizes of the lenses in the lens group are not uniformly distributed, so that the difference is large, and the difficulty in manufacturing and assembling the lens group is increased.

In a first embodiment of the present invention, the first,

referring to fig. 1a and fig. 1b, the lens assembly of the present embodiment includes, in order from an object side to an image side along an optical axis:

the first lens element L1 with positive refractive power has a convex object-side surface S1 and a concave image-side surface S2 at a paraxial region of the first lens element L1; the object-side surface S1 of the first lens element L1 is concave at the near circumference, and the image-side surface S2 is convex at the near circumference.

The second lens element L2 with positive refractive power has a convex object-side surface S3 and a convex image-side surface S4 at the paraxial region of the second lens element L2; the object-side surface S3 of the second lens element L2 near the circumference is convex, and the image-side surface S4 is concave.

The third lens L3 with negative bending force has a concave object-side surface S5 and a concave image-side surface S6 at the paraxial axis of the third lens L3; the object-side surface S5 of the third lens element L3 at a paraxial region thereof is convex, and the image-side surface S6 is concave.

The fourth lens element L4 with positive refractive power has a concave object-side surface S7 and a convex image-side surface S8 at the paraxial region of the fourth lens element L4; the object-side surface S7 of the fourth lens element L4 near the circumference is concave, and the image-side surface S8 is convex.

The fifth lens element L5 with negative refractive power has a convex object-side surface S9 and a concave image-side surface S10 at the paraxial region of the fifth lens element L5; the object-side surface S9 and the image-side surface S10 of the fifth lens element L5 near the circumference are convex.

The first lens element L1 to the fifth lens element L5 are all made of Plastic (Plastic).

The lens group further includes a stop STO, an infrared filter L6, and an image plane S13. The stop STO is provided on the side of the first lens L1 away from the second lens L2, and controls the amount of light entering. In other embodiments, the stop STO can be disposed between two adjacent lenses, or on other lenses. The infrared filter L6 is disposed on the image side of the fifth lens L5 and includes an object side surface S11 and an image side surface S12, and the infrared filter L6 is configured to filter infrared light such that the light incident on the image plane S13 is visible light having a wavelength of 380nm to 780 nm. The infrared filter L6 is made of Glass (Glass), and may be coated on the Glass. The image formation surface S13 is an effective pixel area of the photosensitive element.

Table 1a shows a table of characteristics of the lens array of this example in which data was obtained using light having a wavelength of 555nm, and the Y radius, thickness and focal length are all in millimeters (mm).

TABLE 1a

Wherein f is the effective focal length of the lens group, FNO is the f-number of the lens group, FOV is the field angle of the lens group, and TTL is the distance on the optical axis from the object side surface of the first lens element to the imaging surface of the lens group.

In the present embodiment, the object-side surface and the image-side surface of any one of the first lens L1 to the fifth lens L5 are aspheric surfaces, and the surface shape x of each aspheric lens can be defined by, but is not limited to, the following aspheric surface 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 R of Y in table 1a above); k is a conic coefficient; ai is the correction coefficient of the i-th order of the aspherical surface. Table 1b shows the high-order coefficient A4, A6, A8, A10, A12, A14, A16, A18 and A20 that can be used for each of the aspherical mirrors S1-S16 in the first embodiment.

TABLE 1b

Fig. 1b shows the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the lens set of the first embodiment. The longitudinal spherical aberration curve represents the deviation of the convergence focus of the light rays with different wavelengths after passing through each lens of the lens group; the astigmatism curves represent meridional image surface curvature and sagittal image surface curvature; the distortion curve represents the distortion magnitude values corresponding to different angles of view. As can be seen from fig. 1b, the lens assembly of the first embodiment can achieve good imaging quality.

Second embodiment

Referring to fig. 2a and fig. 2b, the lens assembly of the present embodiment includes, in order from an object side to an image side along an optical axis:

The second lens element L2 with positive refractive power has a convex object-side surface S3 and a convex image-side surface S4 at the paraxial region of the second lens element L2; the object-side surface S3 of the second lens element L2 near the circumference is convex-concave, and the image-side surface S4 is convex.

The third lens L3 with negative bending force has a concave object-side surface S5 and a concave image-side surface S6 at the paraxial axis of the third lens L3; the object-side surface S5 and the image-side surface S6 of the third lens element L3 are convex in the paraxial region.

The fifth lens element L5 with negative refractive power has a convex object-side surface S9 and a concave image-side surface S10 at the paraxial region of the fifth lens element L5; the object-side surface S9 of the fifth lens element L5 near the circumference is concave, and the image-side surface S10 is convex.

Other structures of the second embodiment are the same as those of the first embodiment, and reference may be made thereto.

Table 2a shows a table of characteristics of the lens array of this example in which data was obtained using light having a wavelength of 555nm, and the Y radius, thickness and focal length are all in millimeters (mm).

TABLE 2a

Wherein the values of the parameters in Table 2a are the same as those of the first embodiment.

Table 2b gives the coefficients of high order terms that can be used for each aspherical mirror in the second embodiment, wherein each aspherical mirror type can be defined by the formula given in the first embodiment.

TABLE 2b

Fig. 2b shows the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the lens set of the second embodiment. As can be seen from fig. 2b, the lens assembly of the second embodiment can achieve good imaging quality.

Third embodiment

Referring to fig. 3a and 3b, the lens assembly of the present embodiment includes, in order from an object side to an image side along an optical axis:

the first lens element L1 with negative refractive power has a convex object-side surface S1 and a concave image-side surface S2 at a paraxial region of the first lens element L1; the object-side surface S1 of the first lens element L1 is concave at the near circumference, and the image-side surface S2 is convex at the near circumference.

Other structures of the third embodiment are the same as those of the second embodiment, and reference may be made thereto.

Table 3a shows a table of characteristics of the lens lot of this example, wherein the data was obtained using light having a wavelength of 555nm, and the units of Y radius, thickness and focal length are millimeters (mm).

TABLE 3a

Wherein the values of the parameters in Table 3a are the same as those of the first embodiment.

Table 3b gives the coefficients of high-order terms that can be used for each aspherical mirror surface in the third embodiment, wherein each aspherical mirror surface type can be defined by the formula given in the first embodiment.

TABLE 3b

Figure 3b shows the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the lens set of the third embodiment. As can be seen from fig. 3b, the lens assembly of the third embodiment can achieve good imaging quality.

Fourth embodiment

Referring to fig. 4a and 4b, the lens assembly of the present embodiment includes, in order from an object side to an image side along an optical axis:

Other structures of the fourth embodiment are the same as those of the first embodiment, and reference may be made thereto.

Table 4a shows a table of characteristics of the lens lot of this example, wherein the data was obtained using light having a wavelength of 555nm, and the units of Y radius, thickness and focal length are millimeters (mm).

TABLE 4a

Wherein the values of the parameters in Table 4a are the same as those of the first embodiment.

Table 4b gives the coefficients of high-order terms that can be used for each aspherical mirror surface in the fourth embodiment, wherein each aspherical mirror surface type can be defined by the formula given in the first embodiment.

TABLE 4b

Figure 4b shows the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the lens set of the fourth embodiment. As can be seen from fig. 4b, the lens assembly of the fourth embodiment can achieve good imaging quality.

Fifth embodiment

Referring to fig. 5a and 5b, the lens assembly of the present embodiment includes, in order from an object side to an image side along an optical axis:

The second lens element L2 with positive refractive power has a concave object-side surface S3 and a convex image-side surface S4 at the paraxial region of the second lens element L2; the object-side surface S3 of the second lens element L2 near the circumference is convex, and the image-side surface S4 is concave.

The third lens L3 with negative bending force has a concave object-side surface S5 and a concave image-side surface S6 at the paraxial axis of the third lens L3; the object-side surface S5 of the third lens element L3 at a paraxial region thereof is concave, and the image-side surface S6 is convex.

The fourth lens element L4 with positive refractive power has a concave object-side surface S7 and a convex image-side surface S8 at the paraxial region of the fourth lens element L4; the object-side surface S7 and the image-side surface S8 of the fourth lens element L4 are concave at the near-circumference.

The other structure of the fifth embodiment is the same as that of the first embodiment, and reference may be made thereto.

Table 5a shows a table of characteristics of the lens lot of this example, wherein the data was obtained using light having a wavelength of 555nm, and the units of Y radius, thickness and focal length are millimeters (mm).

TABLE 5a

Wherein the meanings of the parameters in Table 5a are the same as those of the first embodiment.

Table 5b shows the high-order term coefficients that can be used for each aspherical mirror surface in the fifth embodiment, wherein each aspherical mirror surface type can be defined by the formula given in the first embodiment.

TABLE 5b

Fig. 5b shows a longitudinal spherical aberration curve, an astigmatism curve and a distortion curve of the lens group of the fifth embodiment. As can be seen from fig. 5b, the lens assembly of the fifth embodiment can achieve good imaging quality.

Sixth embodiment

Referring to fig. 6a and 6b, the lens assembly of the present embodiment includes, in order from an object side to an image side along an optical axis:

The fifth lens element L5 with negative refractive power has a convex object-side surface S9 and a concave image-side surface S10 at the paraxial region of the fifth lens element L5; the object-side surface S9 of the fifth lens element L5 near the circumference is convex, and the image-side surface S10 is concave.

Other structures of the sixth embodiment are the same as those of the first embodiment, and reference may be made thereto.

Table 6a shows a table of characteristics of the lens array of this example in which data was obtained using light having a wavelength of 555nm, and the Y radius, thickness and focal length are all in millimeters (mm).

TABLE 6a

Wherein the values of the parameters in Table 6a are the same as those of the first embodiment.

Table 6b shows the high-order term coefficients that can be used for each aspherical mirror surface in the sixth embodiment, wherein each aspherical mirror surface type can be defined by the formula given in the first embodiment.

TABLE 6b

Figure 6b shows the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the set of lenses of the sixth embodiment. As can be seen from fig. 6b, the lens assembly of the sixth embodiment can achieve good imaging quality.

Seventh embodiment

Referring to fig. 7a and 7b, the lens assembly of the present embodiment includes, in order from an object side to an image side along an optical axis:

the first lens element L1 with positive refractive power has a convex object-side surface S1 and a convex image-side surface S2 at a paraxial region of the first lens element L1; the object-side surface S1 of the first lens element L1 is concave at the near circumference, and the image-side surface S2 is convex at the near circumference.

The other structure of the seventh embodiment is the same as that of the first embodiment, and reference may be made thereto.

Table 7a shows a table of characteristics of the lens lot of this example, wherein the data was obtained using light having a wavelength of 555nm, and the units of Y radius, thickness and focal length are millimeters (mm).

TABLE 7a

Wherein the meanings of the parameters in Table 7a are the same as those of the first embodiment.

Table 7b shows the high-order term coefficients that can be used for each aspherical mirror surface in the seventh embodiment, wherein each aspherical mirror surface type can be defined by the formula given in the first embodiment.

TABLE 7b

Figure 7b shows the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the set of lenses of the seventh embodiment. As can be seen from fig. 7b, the lens assembly of the seventh embodiment can achieve good imaging quality.

Eighth embodiment

Referring to fig. 8a and 8b, the lens assembly of the present embodiment, in order from an object side to an image side along an optical axis, includes:

The third lens element L3 with negative refractive power has a convex object-side surface S5 and a concave image-side surface S6 at the paraxial region of the third lens element L3; the object-side surface S5 of the third lens element L3 at a paraxial region thereof is convex, and the image-side surface S6 is concave.

The other structure of the eighth embodiment is the same as that of the first embodiment, and reference may be made thereto.

Table 8a shows a table of characteristics of the lens lot of this example, wherein the data was obtained using light having a wavelength of 555nm, and the units of Y radius, thickness and focal length are millimeters (mm).

TABLE 8a

Wherein the meanings of the respective parameters in Table 8a are the same as those of the first embodiment.

Table 8b shows the high-order term coefficients that can be used for each aspherical mirror surface in the eighth embodiment, wherein each aspherical mirror surface type can be defined by the formula given in the first embodiment.

TABLE 8b

Figure 8b shows the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the lens group of the eighth embodiment. As can be seen from fig. 8b, the lens assembly of the eighth embodiment can achieve good imaging quality.

Ninth embodiment

Referring to fig. 9a and 9b, the lens assembly of the present embodiment includes, in order from an object side to an image side along an optical axis:

The second lens element L2 with positive refractive power has a convex object-side surface S3 and a convex image-side surface S4 at the paraxial region of the second lens element L2; the object-side surface S3 of the second lens element L2 near the circumference is concave, and the image-side surface S4 is convex.

The fourth lens element L4 with positive refractive power has a concave object-side surface S7 and a convex image-side surface S8 at the paraxial region of the fourth lens element L4; the object-side surface S7 of the fourth lens element L4 near the circumference is convex, and the image-side surface S8 is concave.

The other structure of the ninth embodiment is the same as that of the first embodiment, and reference may be made thereto.

Table 9a shows a table of characteristics of the lens sets of this example in which data was obtained using light having a wavelength of 555nm, and the Y radius, thickness and focal length are all in millimeters (mm).

TABLE 9a

Wherein the meanings of the respective parameters in Table 9a are the same as those of the first embodiment.

Table 9b shows the high-order term coefficients that can be used for each aspherical mirror surface in the ninth embodiment, wherein each aspherical mirror surface type can be defined by the formula given in the first embodiment.

TABLE 9b

Figure 9b shows the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the set of lenses of the ninth embodiment. As can be seen from fig. 9b, the lens assembly of the ninth embodiment can achieve good imaging quality.

Table 10 shows the values of SD2/ImgH, FNO, EPD/SD42, tan (FOV/2), TT/f, R11/f, TT/ImgH, (CT2+ CT3)/(T23+ T34), 5< R2/R11 for the lens sets of the first to ninth embodiments.

Watch 10

As can be seen from table 10, each example satisfies the following conditional expression: SD2/ImgH <0.26, 0.65< EPD/SD42<1.05, tan (FOV/2) >1, FNO ≦ 2.6, TT/f <1.8, R11/f <0.25, TT/ImgH <1.53, (CT2+ CT3)/(T23+ T34) <4.5, 5< R2/R11< 8.

The technical features of the above embodiments may be arbitrarily combined, and for the sake of brief description, all possible combinations of the technical features in the above embodiments 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 examples only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the scope of the present application. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present application shall be subject to the appended claims.

Claims

1. A lens assembly, in order from an object side to an image side along an optical axis, comprising:

the first lens element with refractive power has a convex object-side surface at a paraxial region thereof;

the second lens element with positive refractive power has a convex image-side surface at the paraxial region thereof;

the third lens element with negative refractive power has a concave image-side surface at the paraxial region thereof;

the fourth lens element with positive refractive power has a concave object-side surface at a paraxial region thereof and a convex image-side surface at the paraxial region thereof;

the fifth lens element with negative refractive power has a convex object-side surface at a paraxial region thereof, a concave image-side surface at the paraxial region thereof, and at least one of the object-side surface and the image-side surface thereof is provided with at least one inflection point;

the lens group satisfies the conditional expression: SD2/ImgH < 0.26;

the SD2 is an optical effective radius of the image-side surface of the first lens element, and the ImgH is a half of a diagonal length of an effective imaging area of the lens assembly on an imaging surface.

2. The set of lenses of claim 1, wherein the set satisfies the conditional expression: 0.65< EPD/SD42< 1.05;

the EPD is the diameter of the entrance pupil of the lens group, and the SD42 is the maximum effective half aperture of the image side surface of the fourth lens.

3. The set of lenses of claim 1, wherein the set satisfies the conditional expression:

tan(FOV/2)>1；

wherein the FOV is the maximum field angle of the lens group.

4. The set of lenses of claim 1, wherein the set satisfies the conditional expression:

FNO<2.6；

and the FNO is the f-number of the lens group.

5. The set of lenses of claim 1, wherein the set satisfies the conditional expression:

TT/f<1.8；

and TT is the distance from the object side surface of the first lens element to an imaging surface of the lens group along an optical axis, and f is the effective focal length of the lens group.

6. The set of lenses of claim 1, wherein the set satisfies the conditional expression:

R11/f<0.25；

wherein R11 is the curvature radius of the fifth lens element at paraxial region thereof, and f is the total effective focal length of the lens assembly.

7. The set of lenses of claim 1, wherein the set satisfies the conditional expression:

TT/ImgH<1.53；

TT is the distance from the object side surface of the first lens to the imaging surface of the lens group along the optical axis; ImgH is half of the diagonal length of the effective pixel area on the imaging surface of the lens group.

8. The set of lenses of claim 1, wherein the set satisfies the conditional expression:

(CT2+CT3)/(T23+T34)<4.5；

wherein CT2 is a thickness of the second lens element, CT3 is a thickness of the third lens element, T23 is an axial distance between an image-side surface of the first lens element and an object-side surface of the second lens element, and T34 is an axial distance between an image-side surface of the third lens element and an object-side surface of the fourth lens element.

9. The set of lenses of claim 1, wherein the set satisfies the conditional expression:

5<R2/R11<8；

wherein R2 is a radius of curvature at an object side optical axis of the first lens, and R11 is a radius of curvature at an image side optical axis of the fifth lens.

10. A lens barrel comprising the lens group of any one of claims 1 to 9 and a lens barrel, wherein the lens group is mounted in the lens barrel.

11. A camera module, comprising a photosensitive element and the lens barrel of claim 10, wherein the photosensitive element is disposed opposite to the lens barrel, and the photosensitive element is located on a side of the fifth lens element away from the first lens element.

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