CN212540866U

CN212540866U - Optical imaging system, image capturing module and electronic device

Info

Publication number: CN212540866U
Application number: CN202022078448.9U
Authority: CN
Inventors: 杨健; 李明
Original assignee: Jiangxi Jingchao Optical Co Ltd
Current assignee: Jiangxi Jingchao Optical Co Ltd
Priority date: 2020-09-21
Filing date: 2020-09-21
Publication date: 2021-02-12
Anticipated expiration: 2030-09-21

Abstract

The utility model discloses an optical imaging system, get for instance module and electron device. The optical imaging system comprises the following components in sequence from an object side to an image side: a first lens element with positive refractive power having a convex object-side surface at a paraxial region and a concave image-side surface at a paraxial region; a second lens element with positive refractive power, the second lens element having a convex object-side surface at paraxial region; a third lens element with negative refractive power, the image-side surface of the third lens element being concave at paraxial region; a fourth lens having a bending force; a fifth lens having a bending force; a sixth lens having a bending force; and a seventh lens having a negative refracting power; the optical imaging system satisfies the following conditional expression: 0.5< (L72p1-L72p2)/L72 c. The optical imaging system increases the focal length, improves the relative brightness, can achieve a clear imaging effect when being used for shooting in a dark environment, can be used for shooting a long-range view, improves the magnification, and has the functions of blurring the background, highlighting the shot object and the like when meeting the requirement of micro design.

Description

Optical imaging system, image capturing module and electronic device

Technical Field

The utility model relates to an optical imaging technical field, concretely relates to optical imaging system, get for instance module and electron device.

Background

Along with the wide application of electronic products such as cell-phone, panel computer, unmanned aerial vehicle, computer in the life, various science and technology products improve gradually and show up new, wherein get for instance the improvement innovation of module shooting effect among the electronic product and become one of the focus that people are concerned about, have also become an important content that science and technology improved.

In the process of implementing the present application, the inventor finds that at least the following problems exist in the prior art: with the improvement of the performance of photosensitive elements such as a Charge-coupled Device (CCD) and a Complementary Metal Oxide Semiconductor (CMOS) image sensor, higher requirements are put on an optical imaging system, and whether a picture with high picture quality, high resolution and high definition can be shot by using the optical imaging system, even whether a picture with clear picture quality can be shot under a dark light condition becomes a key factor for modern people to select which electronic product.

SUMMERY OF THE UTILITY MODEL

In view of the above, it is desirable to provide an optical imaging system, an image capturing module and an electronic device to solve the above problems.

An embodiment of the present application provides an optical imaging system, sequentially from an object side to an image side, comprising:

a first lens element with positive refractive power having a convex object-side surface at a paraxial region and a concave image-side surface at a paraxial region;

a second lens element with positive refractive power, the second lens element having a convex object-side surface at paraxial region;

a third lens element with negative refracting power, an image-side surface of the third lens element being concave at a paraxial region;

a fourth lens having a bending force;

a fifth lens having a bending force;

a sixth lens having a bending force; and

a seventh lens having a negative refracting power;

the optical imaging system satisfies the following conditional expression:

0.5<(L72p1-L72p2)/L72c；

wherein L72c denotes a maximum effective aperture in a direction perpendicular to the optical axis when a central light beam, which is a light beam incident to the center of an imaging plane of the optical imaging system, passes through the image side of the seventh lens;

l72p1 represents the maximum perpendicular distance from the optical axis of the intersection point of the edge beam, which is the beam incident on the imaging surface of the optical imaging system at the point farthest from the optical axis, and the image-side surface of the seventh lens, and L72p2 represents the minimum perpendicular distance from the optical axis of the intersection point of the edge beam, which is the beam incident on the imaging surface of the optical imaging system, and the image-side surface of the seventh lens.

The optical imaging system increases the focal length while meeting the requirement of micro design, the field angle is smaller than that of a conventional optical imaging system, the relative brightness is improved, the clear imaging effect can be achieved when the system is used for shooting in a dark environment, the magnification is improved, and the functions of blurring the background, highlighting the shot object and the like are achieved.

In some embodiments, the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens are all aspheric.

Therefore, the total length of the optical imaging system is effectively reduced by adjusting the curvature radius and the aspheric surface coefficient of each lens surface, the aberration of the optical imaging system can be effectively corrected, and the imaging quality is improved.

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

TTL/Imgh<2.7；

wherein TTL is a distance on an optical axis from an object-side surface of the first lens element to an image plane of the optical imaging system, and Imgh is an image height corresponding to half of a maximum field angle of the optical imaging system.

Therefore, the total length of the optical imaging system can be ensured to be smaller under the condition of fixed image surface, and the miniaturization of the optical imaging system is realized.

TTL/f<1.2；

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

Therefore, under the condition that TTL is fixed and miniaturization is met, the effective focal length has a lower limit value, the long focal length characteristic of an optical imaging system can be guaranteed, and the functions of large magnification, depth of field blurring and the like are achieved.

-1.7<f1_2/f3_7<-0.5；

wherein f1_2 is a combined focal length of the first lens to the second lens; f3_7 is a combined focal length of the third lens to the seventh lens.

Therefore, the reasonable distribution of the bending force of the two parts of the optical imaging system is facilitated, the chromatic aberration of the optical imaging system can be better corrected, and the performance of the optical imaging system is improved.

FNO<1.9；

wherein FNO is an f-number of the optical imaging system.

Therefore, the large light flux of the optical imaging system can be realized on the premise of maintaining the long-focus performance of the optical imaging system, and when the light flux of the optical imaging system in unit time is large, the clear imaging effect can be achieved even if the optical imaging system shoots in a dark environment.

Imgh/tan(HFOV)>6mm；

wherein Imgh is an image height corresponding to half of the maximum field angle of the optical imaging system, and HFOV is half of the maximum field angle of the optical imaging system.

Thus, the telephoto characteristic of the optical imaging system can be maintained, and the imaging magnification can be increased.

ct1/et1<3.5；

wherein ct1 is the thickness of the first lens element along the optical axis, and et1 is the edge thickness of the first lens element along the optical axis.

Thus, the lens is easy to form and low in cost in terms of manufacturability.

An embodiment of the present application provides an get for instance module, includes:

the optical imaging system described above; and

a photosensitive element disposed on an image side of the optical imaging system.

The optical imaging system in the image capturing module increases the focal length while meeting the requirement of micro design, the field angle is smaller than that of a conventional optical imaging system, the relative brightness is improved, the clear imaging effect can be achieved when the image capturing module is used for capturing in a dark environment, the magnification ratio is improved, and the functions of blurring a background, highlighting a captured object and the like are achieved.

An embodiment of the present application provides an electronic apparatus, including:

a housing; and

the image capturing module is mounted on the shell.

The optical imaging system in the electronic device increases the focal length while meeting the requirement of micro design, the field angle is smaller than that of a conventional optical imaging system, the relative brightness is improved, the clear imaging effect can be achieved when the electronic device is used for shooting in a dark environment, the magnification ratio is improved, and the electronic device has the functions of blurring a background, highlighting a shot object and the like.

Additional aspects and advantages of embodiments of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

Drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

fig. 1 is a schematic optical path diagram of an optical imaging system according to an embodiment of the present invention.

Fig. 2 is a schematic structural diagram of an optical imaging system according to a first embodiment of the present invention.

Fig. 3 is a schematic view of spherical aberration, astigmatism and distortion according to a first embodiment of the present invention.

Fig. 4 is a schematic structural diagram of an optical imaging system according to a second embodiment of the present invention.

Fig. 5 is a schematic view of spherical aberration, astigmatism and distortion according to a second embodiment of the present invention.

Fig. 6 is a schematic structural diagram of an optical imaging system according to a third embodiment of the present invention.

Fig. 7 is a schematic view of spherical aberration, astigmatism and distortion according to a third embodiment of the present invention.

Fig. 8 is a schematic structural diagram of an optical imaging system according to a fourth embodiment of the present invention.

Fig. 9 is a schematic view of spherical aberration, astigmatism and distortion according to a fourth embodiment of the present invention.

Fig. 10 is a schematic structural diagram of an optical imaging system according to a fifth embodiment of the present invention.

Fig. 11 is a schematic view of spherical aberration, astigmatism and distortion according to a fifth embodiment of the present invention.

Fig. 12 is a schematic structural diagram of an optical imaging system according to a sixth embodiment of the present invention.

Fig. 13 is a schematic view of spherical aberration, astigmatism and distortion according to a sixth embodiment of the present invention.

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

Description of the main elements

Electronic device 1000

Image capturing module 100

Optical imaging system 10

First lens L1

Second lens L2

Third lens L3

Fourth lens L4

Fifth lens L5

Sixth lens L6

Seventh lens L7

Infrared cut-off filter L8

Stop STO

Object sides S1, S3, S5, S7, S9, S11, S13, S15

Like sides S2, S4, S6, S8, S10, S12, S14, S16

Image plane S17

Photosensitive element 20

Housing 200

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are exemplary only for the purpose of explaining the present invention, and should not be construed as limiting the present invention.

Referring to fig. 1, the following is a description of terms involved in embodiments of the present application:

field of view (FOV): in an optical device, an angle formed by two edges of a lens, at which an object image of a subject can pass through the maximum range, is called a field of view. The size of the field of view determines the field of view of the optical instrument, the larger the field of view. That is, objects within the field of view may be captured through the lens, while objects outside the field of view are not visible. The whole visual range corresponds to an imaging surface of an optical instrument one by one, N parts are uniformly distributed outwards from an optical axis on the imaging surface, light rays of a central view field (central light beams) are converged at the optical axis and recorded as a 0 view field, light rays of an edge view field (edge light beams) are converged at an off-axis farthest point and recorded as a 1.0 view field, 0-0.5 is an inner view field, and 0.6-1.0 is an outer view field.

Referring to fig. 2, the present invention provides an optical imaging system 10, which includes, in order from an object side to an image side, a first lens L1 with positive bending force, a second lens L2 with positive bending force, a third lens L3 with negative bending force, a fourth lens L4 with bending force, a fifth lens L5 with bending force, a sixth lens L6 with bending force, and a seventh lens L7 with negative bending force.

The first lens element L1 has an object-side surface S1 and an image-side surface S2, wherein the object-side surface S1 of the first lens element L1 is convex at a paraxial region and the image-side surface S2 is concave at the paraxial region; the second lens element L2 has an object-side surface S3 and an image-side surface S4, and the object-side surface S3 of the second lens element L2 is convex at the paraxial region; the third lens element L3 has an object-side surface S5 and an image-side surface S6, wherein the image-side surface S6 of the third lens element L3 is concave at a paraxial region; the fourth lens L4 has an object-side surface S7 and an image-side surface S8; the fifth lens L5 has an object-side surface S9 and an image-side surface S10; the sixth lens L6 has an object-side surface S11 and an image-side surface S12; the seventh lens L7 has an object side surface S13 and an image side surface S14.

The optical imaging system 10 satisfies the following conditional expressions:

0.5<(L72p1-L72p2)/L72c；

wherein, as shown in fig. 1, L72c represents the maximum effective aperture in the direction perpendicular to the optical axis when the central light beam, which is the light beam incident to the center of the imaging plane of the optical imaging system 10, passes through the image side surface S14 of the seventh lens L7;

l72p1 represents the maximum perpendicular distance from the optical axis of the intersection point of the edge beam, which is the beam incident on the farthest point from the optical axis of the imaging surface of the optical imaging system 10, and the image-side surface S14 of the seventh lens L7, and L72p2 represents the minimum perpendicular distance from the optical axis of the intersection point of the edge beam, which is the beam incident on the farthest point from the optical axis of the imaging surface of the seventh lens L7, and the image-side surface S14 of the seventh lens L7.

The optical imaging system 10 increases the focal length while satisfying the micro design, has a smaller field angle than a conventional optical imaging system, improves the relative brightness, can achieve a clear imaging effect even when being shot in a dark environment, can be used for shooting a long shot, improves the magnification, and has the functions of blurring a background, highlighting a shot object and the like. However, when (L72p1-L72p2)/L72c do not satisfy the above conditional expression, the edge luminance of the optical imaging system 10 is insufficient, and a dark corner is liable to occur.

In some embodiments, the optical imaging system 10 further includes a stop STO. The stop STO may be disposed on the surface of any one of the lenses, or before the first lens L1, or between any two of the lenses, or on the image-side surface S14 of the seventh lens L7. For example, in fig. 2, the stop STO is disposed on the object side surface S1 of the first lens L1.

In some embodiments, the optical imaging system 10 further includes an infrared cut filter L8, the infrared cut filter L8 having an object side S15 and an image side S16. The ir-cut filter L8 is disposed at the image side of the seventh lens element L7 to filter out light in other wavelength bands, such as visible light, and only let infrared light pass through, so that the optical imaging system 10 can also image in dark environment and other special application scenarios.

In some embodiments, the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, and the seventh lens L7 are all aspheric.

Thus, by adjusting the curvature radius and the aspheric surface coefficient of each lens surface, the total length of the optical imaging system 10 is effectively reduced, and the aberration of the optical imaging system 10 can be effectively corrected, thereby improving the imaging quality.

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

TTL/Imgh<2.7；

wherein TTL is the distance on the optical axis from the object-side surface S1 of the first lens element L1 to the image plane S17 of the optical imaging system 10, and Imgh is the image height corresponding to half of the maximum field angle of the optical imaging system 10.

In this way, the total length of the optical imaging system 10 can be ensured to be small when the image plane S17 is fixed, and the optical imaging system 10 can be miniaturized.

TTL/f<1.2；

wherein, TTL is an axial distance from the object-side surface S1 of the first lens element L1 to the image plane S17 of the optical imaging system 10, and f is an effective focal length of the optical imaging system 10.

Thus, under the condition that the TTL is fixed and the TTL is miniaturized, the effective focal length has a lower limit value, which can ensure the long focal length characteristic of the optical imaging system 10, and realize the functions of large magnification, depth of field blurring, and the like. However, when TTL/f does not satisfy the above conditional expression, the telephoto characteristic of the optical imaging system 10 cannot be satisfied.

-1.7<f1_2/f3_7<-0.5；

wherein f1_2 is the combined focal length of the first lens L1 to the second lens L2; f3_7 is the combined focal length of the third lens L3 through the seventh lens L7.

In this way, it is helpful to reasonably distribute the bending force of the two parts of the optical imaging system 10, so as to better correct the chromatic aberration of the optical imaging system 10 and improve the performance of the optical imaging system 10, wherein the first part includes the first lens L1 to the second lens L2, and the second part includes the third lens L3 to the seventh lens L7. However, when f1_2/f3_7 does not satisfy the above conditional expression, the bending forces of the two parts cannot be matched reasonably, so that the sensitivity of MTF (modulation transfer function) of one part is increased, which is not favorable for practical production and processing.

FNO<1.9；

wherein FNO is the f-number of the optical imaging system 10.

Thus, a large light flux of the optical imaging system 10 can be realized on the premise of maintaining the long-focus property of the optical imaging system 10, and when the light flux of the optical imaging system 10 per unit time is large, a clear imaging effect can be achieved even when shooting is performed in a dark environment. However, when FNO does not satisfy the above conditional expression, the photographing effect is not good in a dark environment.

Imgh/tan(HFOV)>6mm；

where Imgh is an image height corresponding to half of the maximum field angle of the optical imaging system 10, and HFOV is half of the maximum field angle of the optical imaging system 10.

In this way, the telephoto characteristic of the optical imaging system 10 can be maintained, and the magnification of imaging can be increased. However, when Imgh/tan (hfov) does not satisfy the above conditional expression, the telephoto characteristic of the optical imaging system 10 cannot be ensured.

ct1/et1<3.5；

wherein ct1 is the thickness of the first lens element L1 along the optical axis, and et1 is the edge thickness of the first lens element L1 along the optical axis.

Thus, the lens is easy to form and low in cost in terms of manufacturability. However, when ct1/et1 does not satisfy the above conditional expression, the lens is difficult to mold in actual production and is not easy to be mass-produced.

First embodiment

Referring to fig. 2 and 3, the optical imaging system 10 in the embodiment includes, from the object side to the image side, a stop STO, a first lens L1 with positive bending force, a second lens L2 with positive bending force, a third lens L3 with negative bending force, a fourth lens L4 with negative bending force, a fifth lens L5 with positive bending force, a sixth lens L6 with positive bending force, a seventh lens L7 with negative bending force, and an ir-cut filter L8.

An object-side surface S1 of the first lens element L1 is convex at a paraxial region, an image-side surface S2 of the first lens element L1 is concave at a paraxial region, an object-side surface S3 of the second lens element L2 is convex at a paraxial region, an image-side surface S4 of the second lens element L2 is concave at a paraxial region, an object-side surface S5 of the third lens element L3 is convex at a paraxial region, an image-side surface S6 of the third lens element L3 is concave at a paraxial region, an object-side surface S7 of the fourth lens element L4 is convex at a paraxial region, an image-side surface S8 of the fourth lens element L4 is concave at a paraxial region, an object-side surface S8 of the fifth lens element L8 is convex at a paraxial region, an image-side surface S8 of the fifth lens element L8 is concave at a paraxial region, an object-side surface S8 of the sixth lens element L8 is convex at a paraxial region, a second image-side surface S8 of the sixth lens element L8 is convex at a paraxial region, a paraxial region of the seventh lens element L8 is concave at a paraxial region.

An object-side surface S1 of the first lens L1 is concave at a near circumference, an image-side surface S2 of the first lens L1 is convex at a near circumference, an object-side surface S3 of the second lens L2 is concave at a near circumference, an image-side surface S4 of the second lens L2 is convex at a near circumference, an object-side surface S5 of the third lens L3 is convex at a near circumference, an image-side surface S6 of the third lens L3 is convex at a near circumference, an object-side surface S7 of the fourth lens L4 is concave at a near circumference, an image-side surface S8 of the fourth lens L4 is convex at a near circumference, an object-side surface S8 of the fifth lens L8 is concave at a near circumference, an image-side surface S8 of the sixth lens L8 is convex at a near circumference, an image-side surface S8 of the sixth lens L8 is concave at a near circumference, and a seventh image-side surface S8 is concave at a near circumference.

When the optical imaging system 10 is used for imaging, light emitted or reflected by a subject enters the optical imaging system 10 from the object side direction, passes through the stop STO, the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7 and the infrared cutoff filter L8 in sequence, and finally converges on the image plane S17

Table 1 shows a table of characteristics of the optical imaging system of the present embodiment, in which the reference wavelength of the focal length is 555nm, the reference wavelengths of the refractive index and the abbe number are 587.56nm, and the units of the Y radius, the thickness, and the focal length are millimeters (mm).

Table 1

Where f is an effective focal length of the optical imaging system 10, FNO is an f-number of the optical imaging system 10, FOV is a maximum field angle of the optical imaging system 10, and TTL is a distance on the optical axis from the object-side surface S1 of the first lens L1 to the image surface S17 of the optical imaging system 10.

In the present embodiment, the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6 and the seventh lens L7 are all aspheric surfaces, and the surface shape Z of each spherical lens can be defined by, but is not limited to, the following aspheric surface formula.

Where Z is the longitudinal distance from any point on the aspherical surface to the surface vertex, r is the distance from any point on the aspherical surface to the optical axis, c is the vertex curvature (reciprocal of the radius of curvature), k is a conic constant, and Ai is a correction coefficient of the i-th order of the aspherical surface, and table 2 gives the high-order term coefficients K, A4, a6, a8, a10 … … that can be used for each of the spherical mirror surfaces S1-S14 in the first embodiment.

Table 2

Table 2 shows a longitudinal spherical aberration curve, an astigmatism curve, and a distortion curve of the optical imaging system 10 of the first embodiment, wherein the longitudinal spherical aberration curve represents the convergent focus deviation of light rays of different wavelengths after passing through each lens of the optical imaging system 10; 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 table 2, the optical imaging system 10 according to the first embodiment can achieve good imaging quality.

Second embodiment

Referring to fig. 4 and 5, the optical imaging system 10 in the embodiment includes, from the object side to the image side, a stop STO, a first lens L1 with positive bending force, a second lens L2 with positive bending force, a third lens L3 with negative bending force, a fourth lens L4 with positive bending force, a fifth lens L5 with positive bending force, a sixth lens L6 with positive bending force, a seventh lens L7 with negative bending force, and an ir-cut filter L8.

An object-side surface S1 of the first lens element L1 is convex at a paraxial region, an image-side surface S2 of the first lens element L1 is concave at a paraxial region, an object-side surface S3 of the second lens element L2 is convex at a paraxial region, an image-side surface S4 of the second lens element L2 is convex at a paraxial region, an object-side surface S5 of the third lens element L3 is convex at a paraxial region, an image-side surface S6 of the third lens element L3 is concave at a paraxial region, an object-side surface S7 of the fourth lens element L4 is concave at a paraxial region, an image-side surface S8 of the fourth lens element L4 is convex at a paraxial region, an object-side surface S8 of the fifth lens element L8 is convex at a paraxial region, an image-side surface S8 of the fifth lens element L8 is concave at a paraxial region, an object-side surface S8 of the sixth lens element L8 is convex at a paraxial region, a second image-side surface S8 of the sixth lens element L8 is concave at a paraxial region, a paraxial region of the second lens element L8.

An object-side surface S1 of the first lens L1 is concave at a near circumference, an image-side surface S2 of the first lens L1 is convex at a near circumference, an object-side surface S3 of the second lens L2 is concave at a near circumference, an image-side surface S4 of the second lens L2 is convex at a near circumference, an object-side surface S5 of the third lens L3 is convex at a near circumference, an image-side surface S6 of the third lens L3 is concave at a near circumference, an object-side surface S7 of the fourth lens L4 is concave at a near circumference, an image-side surface S8 of the fourth lens L4 is concave at a near circumference, an object-side surface S8 of the fifth lens L8 is concave at a near circumference, an image-side surface S8 of the fifth lens L8 is convex at a near circumference, an object-side surface S8 of the sixth lens L8 is concave at a near circumference, an image-side surface S8 of the sixth lens L8 is concave at a near circumference, a seventh image-side surface S8 is concave at a near circumference, and a seventh image-side surface S8 is concave at a near circumference.

When the optical imaging system 10 is used for imaging, light rays emitted or reflected by a subject enter the optical imaging system 10 from the object side direction, pass through the stop STO, the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, and the infrared cutoff filter L8 in sequence, and finally converge on the image surface S17.

Table 3 shows a table of characteristics of the optical imaging system 10 of the present embodiment, in which the reference wavelength of the focal length is 555nm, the reference wavelengths of the refractive index and the abbe number are 587.56nm, and the units of the Y radius, the thickness, and the focal length are millimeters (mm).

Table 3

Where Z is the longitudinal distance from any point on the aspherical surface to the surface vertex, r is the distance from any point on the aspherical surface to the optical axis, c is the vertex curvature (reciprocal of the radius of curvature), k is a conic constant, and Ai is a correction coefficient of the i-th order of the aspherical surface, and table 4 gives the high-order term coefficients K, A4, a6, a8, a10 … … that can be used for each of the spherical mirror surfaces S1-S14 in the second embodiment.

Table 4

Table 4 shows a longitudinal spherical aberration curve, an astigmatism curve, and a distortion curve of the optical imaging system 10 of the second embodiment, wherein the longitudinal spherical aberration curve represents the convergent focus deviation of light rays of different wavelengths after passing through each lens of the optical imaging system 10; 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 table 4, the optical imaging system 10 according to the second embodiment can achieve good imaging quality.

Third embodiment

Referring to fig. 6 and 7, the optical imaging system 10 in the embodiment includes, from the object side to the image side, a stop STO, a first lens L1 with positive refractive power, a second lens L2 with positive refractive power, a third lens L3 with negative refractive power, a fourth lens L4 with negative refractive power, a fifth lens L5 with positive refractive power, a sixth lens L6 with negative refractive power, a seventh lens L7 with negative refractive power, and an ir-cut filter L8.

An object-side surface S1 of the first lens element L1 is convex at a paraxial region, an image-side surface S2 of the first lens element L1 is concave at a paraxial region, an object-side surface S3 of the second lens element L2 is convex at a paraxial region, an image-side surface S4 of the second lens element L2 is concave at a paraxial region, an object-side surface S5 of the third lens element L3 is convex at a paraxial region, an image-side surface S6 of the third lens element L3 is concave at a paraxial region, an object-side surface S7 of the fourth lens element L4 is convex at a paraxial region, an image-side surface S8 of the fourth lens element L4 is concave at a paraxial region, an object-side surface S8 of the fifth lens element L8 is convex at a paraxial region, an image-side surface S8 of the fifth lens element L8 is convex at a paraxial region, an object-side surface S8 of the sixth lens element L8 is convex at a paraxial region, a second image-side surface S8 of the sixth lens element L8 is convex at a paraxial region, a paraxial region of the seventh lens element L8, a paraxial region of the sixth lens element L8 is concave at a paraxial region.

An object-side surface S1 of the first lens L1 is concave at a near circumference, an image-side surface S2 of the first lens L1 is convex at a near circumference, an object-side surface S3 of the second lens L2 is convex at a near circumference, an image-side surface S4 of the second lens L2 is concave at a near circumference, an object-side surface S5 of the third lens L3 is convex at a near circumference, an image-side surface S6 of the third lens L3 is concave at a near circumference, an object-side surface S7 of the fourth lens L4 is concave at a near circumference, an image-side surface S8 of the fourth lens L4 is convex at a near circumference, an object-side surface S8 of the fifth lens L8 is concave at a near circumference, an image-side surface S8 of the sixth lens L8 is convex at a near circumference, an image-side surface S8 of the sixth lens L8 is concave at a near circumference, and a seventh image-side surface S8 is concave at a near circumference.

Table 5 shows a table of characteristics of the optical imaging system 10 of the present embodiment, in which the reference wavelength of the focal length is 555nm, the reference wavelengths of the refractive index and the abbe number are 587.56nm, and the units of the Y radius, the thickness, and the focal length are millimeters (mm).

Table 5

Where Z is the longitudinal distance from any point on the aspherical surface to the surface vertex, r is the distance from any point on the aspherical surface to the optical axis, c is the vertex curvature (reciprocal of the radius of curvature), k is a conic constant, and Ai is a correction coefficient of the i-th order of the aspherical surface, and table 6 gives the high-order term coefficients K, A4, a6, a8, a10 … … that can be used for each of the spherical mirror surfaces S1-S14 in the third embodiment.

Table 6

Number of noodles	K	A4	A6	A8	A10
						S1	-0.7263	0.0016	0.0000	0.0001	-0.0001
S2	-5.0303	-0.0170	0.0172	-0.0105	0.0043
						S3	0.5112	-0.0213	0.0179	-0.0106	0.0041
S4	-18.0000	-0.0448	0.0458	-0.0323	0.0165
						S5	19.4127	-0.0449	0.0443	-0.0339	0.0193
S6	0.9450	-0.0050	0.0072	-0.0094	0.0080
						S7	-38.0000	-0.0108	-0.0017	-0.0013	0.0010
S8	0.0000	-0.0223	-0.0001	0.0018	-0.0045
						S9	-38.0000	-0.0115	-0.0036	0.0030	-0.0046
S10	-3.4610	-0.0159	0.0002	-0.0003	-0.0003
						S11	1.0730	-0.0126	-0.0029	-0.0022	0.0028
S12	-38.0000	-0.0014	-0.0023	-0.0027	0.0025
						S13	1.2080	-0.0558	0.0243	-0.0139	0.0063
S14	-17.5480	-0.0129	-0.0032	0.0021	-0.0006
						Number of noodles	A12	A14	A16	A18	A20
S1	0.0000	0.0000	0.0000	0.0000	0.0000
						S2	-0.0012	0.0002	0.0000	0.0000	0.0000
S3	-0.0010	0.0002	0.0000	0.0000	0.0000
						S4	-0.0060	0.0015	-0.0002	0.0000	0.0000
S5	-0.0078	0.0021	-0.0004	0.0000	0.0000
						S6	-0.0044	0.0017	-0.0004	0.0001	0.0000
S7	-0.0005	0.0002	-0.0001	0.0000	0.0000
						S8	0.0043	-0.0022	0.0007	-0.0001	0.0000
S9	0.0033	-0.0016	0.0005	-0.0001	0.0000
						S10	0.0001	-0.0001	0.0000	0.0000	0.0000
S11	-0.0015	0.0004	-0.0001	0.0000	0.0000
						S12	-0.0010	0.0003	0.0000	0.0000	0.0000
S13	-0.0020	0.0004	-0.0001	0.0000	0.0000
						S14	0.0001	0.0000	0.0000	0.0000	0.0000

Table 6 shows a longitudinal spherical aberration curve, an astigmatism curve, and a distortion curve of the optical imaging system 10 of the third embodiment, in which the longitudinal spherical aberration curves represent convergent focus deviations of light rays of different wavelengths after passing through the respective lenses of the optical imaging system 10; 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 table 6, the optical imaging system 10 according to the third embodiment can achieve good imaging quality.

Fourth embodiment

Referring to fig. 8 and 9, the optical imaging system 10 of the present embodiment includes, from the object side to the image side, a stop STO, a first lens L1 with positive bending force, a second lens L2 with positive bending force, a third lens L3 with negative bending force, a fourth lens L4 with positive bending force, a fifth lens L5 with negative bending force, a sixth lens L6 with positive bending force, a seventh lens L7 with negative bending force, and an ir-cut filter L8.

An object-side surface S1 of the first lens element L1 is convex at the paraxial region, an image-side surface S2 of the first lens element L1 is concave at the paraxial region, an object-side surface S3 of the second lens element L2 is convex at the paraxial region, an image-side surface S4 of the second lens element L2 is convex at the paraxial region, an object-side surface S5 of the third lens element L3 is concave at the paraxial region, an image-side surface S6 of the third lens element L3 is concave at the paraxial region, an object-side surface S7 of the fourth lens element L4 is convex at the paraxial region, an image-side surface S8 of the fourth lens element L4 is concave at the paraxial region, an object-side surface S8 of the fifth lens element L8 is concave at the paraxial region, an image-side surface S8 of the fifth lens element L8 is convex at the paraxial region, an object-side surface S8 of the sixth lens element L8 is convex at the paraxial region, a second image-side surface S8 of the seventh lens element L8 is convex at the paraxial region, a paraxial region.

An object-side surface S1 of the first lens L1 is convex at a near circumference, an image-side surface S2 of the first lens L1 is convex at a near circumference, an object-side surface S3 of the second lens L2 is convex at a near circumference, an image-side surface S4 of the second lens L2 is concave at a near circumference, an object-side surface S5 of the third lens L3 is concave at a near circumference, an image-side surface S6 of the third lens L3 is concave at a near circumference, an object-side surface S7 of the fourth lens L4 is concave at a near circumference, an image-side surface S8 of the fourth lens L4 is convex at a near circumference, an object-side surface S8 of the fifth lens L8 is concave at a near circumference, an image-side surface S8 of the fifth lens L8 is convex at a near circumference, an object-side surface S8 of the sixth lens L8 is concave at a near circumference, an image-side surface S8 of the sixth lens L8 is concave at a near circumference, and a seventh image-side surface S8 is convex at a near circumference.

Table 7 shows a table of characteristics of the optical imaging system 10 of the present embodiment, in which the reference wavelength of the focal length is 555nm, the reference wavelengths of the refractive index and the abbe number are 587.56nm, and the units of the Y radius, the thickness, and the focal length are millimeters (mm).

Table 7

Where Z is the longitudinal distance from any point on the aspherical surface to the surface vertex, r is the distance from any point on the aspherical surface to the optical axis, c is the vertex curvature (reciprocal of the radius of curvature), k is a conic constant, and Ai is a correction coefficient of the i-th order of the aspherical surface, and table 8 gives the high-order term coefficients K, A4, a6, a8, a10 … … that can be used for each of the spherical mirror surfaces S1-S14 in the fourth embodiment.

Table 8

Table 8 shows a longitudinal spherical aberration curve, an astigmatism curve, and a distortion curve of the optical imaging system 10 of the fourth embodiment, in which the longitudinal spherical aberration curves represent convergent focus deviations of light rays of different wavelengths after passing through the respective lenses of the optical imaging system 10; 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 table 8, the optical imaging system 10 according to the fourth embodiment can achieve good imaging quality.

Fifth embodiment

Referring to fig. 10 and 11, the optical imaging system 10 in this embodiment includes, from the object side to the image side, a stop STO, a first lens L1 with positive bending force, a second lens L2 with positive bending force, a third lens L3 with negative bending force, a fourth lens L4 with negative bending force, a fifth lens L5 with positive bending force, a sixth lens L6 with positive bending force, a seventh lens L7 with negative bending force, and an ir-cut filter L8.

An object-side surface S1 of the first lens element L1 is convex at a paraxial region, an image-side surface S2 of the first lens element L1 is concave at a paraxial region, an object-side surface S3 of the second lens element L2 is convex at a paraxial region, an image-side surface S4 of the second lens element L2 is convex at a paraxial region, an object-side surface S5 of the third lens element L3 is convex at a paraxial region, an image-side surface S6 of the third lens element L3 is concave at a paraxial region, an object-side surface S7 of the fourth lens element L4 is concave at a paraxial region, an image-side surface S8 of the fourth lens element L4 is convex at a paraxial region, an object-side surface S8 of the fifth lens element L8 is convex at a paraxial region, an image-side surface S8 of the fifth lens element L8 is convex at a paraxial region, a second image-side surface S8 of the sixth lens element L8 is convex at a paraxial region, a paraxial region of the sixth lens element L8 is convex region, a paraxial region of the seventh region of the image-side surface S36.

Table 9 shows a table of characteristics of the optical imaging system 10 of the present embodiment, in which the reference wavelength of the focal length is 555nm, the reference wavelengths of the refractive index and the abbe number are 587.56nm, and the units of the Y radius, the thickness, and the focal length are millimeters (mm).

Table 9

Where Z is the longitudinal distance from any point on the aspherical surface to the surface vertex, r is the distance from any point on the aspherical surface to the optical axis, c is the vertex curvature (reciprocal of the radius of curvature), k is a conic constant, and Ai is a correction coefficient of the i-th order of the aspherical surface, and table 10 gives the high-order term coefficients K, A4, a6, a8, a10 … … that can be used for each of the spherical mirror surfaces S1-S14 in the fifth embodiment.

Table 10

Table 10 shows a longitudinal spherical aberration curve, an astigmatism curve, and a distortion curve of the optical imaging system 10 of the fifth embodiment, in which the longitudinal spherical aberration curve represents the convergent focus deviation of light rays of different wavelengths after passing through each lens of the optical imaging system 10; 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 table 10, the optical imaging system 10 according to the fifth embodiment can achieve good imaging quality.

Sixth embodiment

Referring to fig. 12 and 13, the optical imaging system 10 in this embodiment includes, from the object side to the image side, a stop STO, a first lens L1 with positive bending force, a second lens L2 with positive bending force, a third lens L3 with negative bending force, a fourth lens L4 with negative bending force, a fifth lens L5 with positive bending force, a sixth lens L6 with positive bending force, a seventh lens L7 with negative bending force, and an ir-cut filter L8.

An object-side surface S1 of the first lens element L1 is convex at a paraxial region, an image-side surface S2 of the first lens element L1 is concave at a paraxial region, an object-side surface S3 of the second lens element L2 is convex at a paraxial region, an image-side surface S4 of the second lens element L2 is concave at a paraxial region, an object-side surface S5 of the third lens element L3 is convex at a paraxial region, an image-side surface S6 of the third lens element L3 is concave at a paraxial region, an object-side surface S7 of the fourth lens element L4 is concave at a paraxial region, an image-side surface S8 of the fourth lens element L4 is concave at a paraxial region, an object-side surface S8 of the fifth lens element L8 is convex at a paraxial region, an image-side surface S8 of the fifth lens element L8 is concave at a paraxial region, an object-side surface S8 of the sixth lens element L8 is convex at a paraxial region, a second image-side surface S8 of the sixth lens element L8 is convex at a paraxial region, a paraxial region of the seventh lens element L8 is concave at a paraxial region.

An object-side surface S1 of the first lens L1 is concave at a near circumference, an image-side surface S2 of the first lens L1 is convex at a near circumference, an object-side surface S3 of the second lens L2 is concave at a near circumference, an image-side surface S4 of the second lens L2 is convex at a near circumference, an object-side surface S5 of the third lens L3 is convex at a near circumference, an image-side surface S6 of the third lens L3 is concave at a near circumference, an object-side surface S7 of the fourth lens L4 is concave at a near circumference, an image-side surface S8 of the fourth lens L4 is convex at a near circumference, an object-side surface S8 of the fifth lens L8 is concave at a near circumference, an image-side surface S8 of the fifth lens L8 is convex at a near circumference, an object-side surface S8 of the sixth lens L8 is concave at a near circumference, an image-side surface S8 of the sixth lens L8 is concave at a near circumference, and a seventh image-side surface S8 is concave at a near circumference.

Table 11 shows a table of characteristics of the optical imaging system 10 of the present embodiment, in which the reference wavelength of the focal length is 555nm, the reference wavelengths of the refractive index and the abbe number are 587.56nm, and the units of the Y radius, the thickness, and the focal length are millimeters (mm).

Table 11

Where Z is the longitudinal distance from any point on the aspherical surface to the surface vertex, r is the distance from any point on the aspherical surface to the optical axis, c is the vertex curvature (reciprocal of the radius of curvature), k is a conic constant, and Ai is a correction coefficient of the i-th order of the aspherical surface, and table 12 gives the high-order term coefficients K, A4, a6, a8, a10 … … that can be used for each of the spherical mirror surfaces S1-S14 in the sixth embodiment.

Table 12

Table 12 shows a longitudinal spherical aberration curve, an astigmatism curve, and a distortion curve of the optical imaging system 10 of the sixth embodiment, in which the longitudinal spherical aberration curves represent convergent focus deviations of light rays of different wavelengths after passing through the respective lenses of the optical imaging system 10; 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 table 12, the optical imaging system 10 according to the sixth embodiment can achieve good imaging quality.

Table 13 shows values of TTL/Imgh, f12/f, TTL/f, f1_2/f3_7, FNO, (L72p1-L72p2)/L72c, Imgh/tan (hfov), and ct1/et1 in the optical imaging systems of the first to sixth embodiments.

Table 13

	TTL/Imgh	TTL/f	f1_2/f3_7	FNO
					First embodiment	2.51	1.12	-1.05	1.36
Second embodiment	2.51	1.13	-1.12	1.42
					Third embodiment	2.51	1.13	-1.09	1.52
Fourth embodiment	2.51	1.13	-1.22	1.62
					Fifth embodiment	2.47	1.11	-1.20	1.72
Sixth embodiment	2.48	1.12	-1.15	1.55
						(L72p1-L72p2)/L72c	Imgh/tan(HFOV)(mm)	ct1/et1
First embodiment	0.71	8.11	2.98
					Second embodiment	1.81	8.01	2.32
Third embodiment	0.65	8.03	2.09
					Fourth embodiment	0.86	8.03	1.83
Fifth embodiment	0.61	8.03	1.71
					Sixth embodiment	0.65	8.02	2.01

Referring to fig. 14, the optical imaging system 10 of the embodiment of the present invention can be applied to the image capturing module 100 of the embodiment of the present invention. The image capturing module 100 includes a photosensitive element 20 and the optical imaging system 10 of any of the above embodiments. The photosensitive element 20 is disposed on the image side of the optical imaging system 10.

The photosensitive element 20 may be a Complementary Metal Oxide Semiconductor (CMOS) image sensor or a Charge-coupled Device (CCD).

The optical imaging system 10 in the image capturing module 100 increases the focal length while satisfying the micro design, has a smaller field angle than a conventional optical imaging system, improves the relative brightness, can achieve a clear imaging effect even when being taken in a dark environment, can be used for taking a long shot, improves the magnification, and has the functions of blurring a background, highlighting a shot object, and the like.

Referring to fig. 14, the image capturing module 100 according to the embodiment of the present invention can be applied to the electronic device 1000 according to the embodiment of the present invention. The electronic device 1000 includes a housing 200 and an image capturing module 100, wherein the image capturing module 100 is mounted on the housing 200.

The utility model discloses on-vehicle, autopilot and monitoring device can be applied to electronic device 1000 of embodiment, wherein electronic device 1000 includes but is not limited to for vehicle event data recorder, smart mobile phone, panel computer, notebook computer, electron books read ware, Portable Multimedia Player (PMP), portable phone, videophone, digital still camera, mobile medical device, wearable equipment etc. support the electron device of formation of image.

The optical imaging system 10 in the electronic device 1000 satisfies the micro-design, increases the focal length, has a smaller field angle than a conventional optical imaging system, improves the relative brightness, can achieve a clear imaging effect even when being shot in a dark environment, can be used for shooting a long-distance scene, improves the magnification, and has the functions of blurring a background, highlighting a shot object, and the like.

It is obvious to a person skilled in the art that the invention is not restricted to details of the above-described exemplary embodiments, but that it can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

Finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the present invention and not for limiting, and although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions can be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. An optical imaging system, comprising, in order from an object side to an image side:

a fourth lens having a bending force;

a fifth lens having a bending force;

a sixth lens having a bending force; and

a seventh lens having a negative refracting power;

the optical imaging system satisfies the following conditional expression:

0.5<(L72p1-L72p2)/L72c；

2. The optical imaging system of claim 1, wherein the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens are all aspheric.

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

TTL/Imgh<2.7；

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

TTL/f<1.2；

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

-1.7<f1_2/f3_7<-0.5；

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

FNO<1.9；

wherein FNO is an f-number of the optical imaging system.

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

Imgh/tan(HFOV)>6mm；

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

ct1/et1<3.5；

9. An image capturing module, comprising:

the optical imaging system of any one of claims 1 to 8; and

10. An electronic device, comprising:

a housing; and

the image capturing module of claim 9, wherein the image capturing module is mounted on the housing.