CN211478748U

CN211478748U - Optical system, camera module and automobile

Info

Publication number: CN211478748U
Application number: CN201921542962.4U
Authority: CN
Inventors: 邹海荣; 乐宇明; 俞炳泽; 兰宾利
Original assignee: OFilm Tech Co Ltd
Current assignee: Jiangxi Jingchao Optical Co Ltd
Priority date: 2019-09-17
Filing date: 2019-09-17
Publication date: 2020-09-11
Anticipated expiration: 2029-09-17

Abstract

The application relates to an optical system, a camera module and an automobile. The optical system includes in order from an object side to an image side: a first lens element with negative refractive power having a convex object-side surface and a concave image-side surface; a second lens element with negative refractive power having a concave image-side surface; a third lens element with positive refractive power having convex object-side and image-side surfaces; a fourth lens element with positive refractive power having convex object-side and image-side surfaces; a lens unit with refractive power; a diaphragm disposed on an object side of the fourth lens; the optical system satisfies the relationship: FOV/CRA > 10; the FOV is a field angle in a diagonal direction of an imaging surface of the optical system, and the CRA is an incident angle of a principal ray. In this case, the optical system has a large angle of view, and the angle at which light enters the imaging plane of the optical system can be reduced, thereby improving the image sharpness.

Description

Optical system, camera module and automobile

Technical Field

The utility model relates to an optical imaging field especially relates to an optical system, module and car of making a video recording.

Background

The existing common camera generally has the problem of small field angle, so when the camera is used as a vehicle-mounted camera device, a vehicle still has a large blind area, a driver cannot obtain enough peripheral images of the vehicle body, and particularly when the vehicle is in a high-speed driving state and changes lanes, the vehicle information at the side and the rear cannot be obtained in time, so that potential safety hazards are easy to occur.

SUMMERY OF THE UTILITY MODEL

In view of the above, it is necessary to provide an optical system, an image pickup module, and an automobile, in order to solve the problem of how to obtain a wider field of view.

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

the lens comprises a first lens element with negative refractive power having a convex object-side surface and a concave image-side surface;

the second lens element with negative refractive power has a concave image-side surface;

a third lens element with positive refractive power having convex object-side and image-side surfaces, respectively;

a fourth lens element with positive refractive power having convex object-side and image-side surfaces, respectively;

a lens unit with refractive power;

a diaphragm disposed on an object side of the fourth lens;

the optical system satisfies the following relationship:

FOV/CRA＞10；

the FOV is a field angle of an imaging surface of the optical system in a diagonal direction, and the CRA is an incident angle of a chief ray.

When the above relation is satisfied, the optical system has a larger field angle to satisfy the requirement of electronic products such as mobile phones, vehicle-mounted equipment, monitoring equipment, medical equipment and the like on a large viewing angle, and simultaneously can reduce the angle of light incident to an imaging surface of the optical system, thereby improving the imaging definition.

In one embodiment, the optical system comprises any one of:

the lens unit comprises a fifth lens element with refractive power, and the image side surface of the fifth lens element is convex;

the lens unit comprises a fifth lens element with refractive power and a sixth lens element with negative refractive power, the sixth lens element is disposed on the image side of the fifth lens element, the image-side surface of the fifth lens element is convex, the object-side surface of the sixth lens element is concave, and the image-side surface of the sixth lens element is convex.

In one embodiment, the optical system satisfies the following relationship:

BFL/TTL＞0.2；

the BFL is an optical back focus of the optical system, and the TTL is a distance from an object side surface of the first lens to an imaging surface of the optical system on an optical axis. When the relation is met, the optical system has larger optical back focus, so that the telecentric effect is achieved, and meanwhile, the sensitivity and the length of the optical system can be reduced, so that the volume of the optical system is smaller.

In one embodiment, the optical system satisfies the following relationship:

(SD S2)/(RDY S2)＜0.95；

wherein SD S2 is a Y-direction half aperture of the image-side surface of the first lens, and RDY S2 is a radius of curvature of the image-side surface of the first lens. When the relation is met, the curvature radius of the image side surface of the first lens and the Y-direction half aperture can be controlled, so that the bending degree of the first lens is effectively controlled, the processing difficulty of the first lens is reduced, the problem of uneven coating caused by overlarge bending degree of the first lens is avoided, and the risk of generating ghost is reduced.

In one embodiment, the optical system satisfies the following relationship:

-65≤Dist≤65；

where Dist is the optical distortion of the optical system in%. When the above relation is satisfied, the distortion amount of the optical system can be controlled to reduce the phenomenon of excessive distortion commonly existing in the wide-angle lens.

In one embodiment, the optical system satisfies the following relationship:

Nd1＜1.8；Vd1＞25；

the Nd1 is a refractive index of the first lens under d light, and the Vd1 is an Abbe number of the first lens under d light. When the above relation is satisfied, it is advantageous to correct the off-axis chromatic aberration of the optical system, thereby improving the resolution of the optical system.

In one embodiment, the object side surface of the first lens is plated with a protective film layer and/or the optical system satisfies the following relationship:

H_K＞500；F_A＞50；

wherein H_KIs the hardness of the first lens, H_KHas a unit of 10⁷Pa，F_AIs the degree of abrasion of the first lens, F_AThe unit is%. When satisfying above-mentioned relation, first lens possess higher hardness and degree of wear, simultaneously, through setting up the protection rete so that first lens possess waterproof anti-scratch function, can effectively prevent first lens receives the fish tail, prevents to influence the imaging quality because of problems such as scratch, water droplet adhesion, and improves optical system's life.

In one embodiment, the optical system satisfies the following relationship:

Nd2＞1.9；Vd2＜25；

wherein Nd2 is a d-optical refractive index of a lens closest to the image side in the optical system, and Vd2 is a d-optical abbe number of the lens closest to the image side in the optical system. When the above relation is satisfied, it is advantageous to correct the off-axis chromatic aberration of the optical system, thereby improving the resolution of the optical system.

In one embodiment, the lens unit includes a fifth lens, an image side surface of the fifth lens is a convex surface, the fourth lens and the fifth lens form a cemented lens, and the optical system satisfies at least one of the following relationships:

|((cuy s1)*(map s1)-(cuy s2)*(map s2))/2|＞0.12；

0＜FH/f＜10；

ET S6＞0.5；

the cumy S1 is the reciprocal of the curvature radius of the object-side surface of the fifth lens element, the map S1 is the Y-direction half aperture of the object-side surface of the fifth lens element, the cumy S2 is the reciprocal of the curvature radius of the image-side surface of the fifth lens element, the map S2 is the Y-direction half aperture of the image-side surface of the fifth lens element, FH is the focal length of the cemented lens element, f is the effective focal length of the optical system, and ET S6 is the thickness of the fourth lens element at the maximum effective radius. When the first relation is met, the processing difficulty of the fifth lens can be reduced by controlling the curvature radius and the Y-direction half aperture of the fifth lens; when the second relationship is satisfied, the cemented lens can provide positive refractive power for the optical system, so that the optical system has the characteristics of wide viewing angle, low sensitivity and miniaturization; when the above third relationship is satisfied, the difficulty of processing the cemented lens can be reduced by controlling the thickness of the edge of the fourth lens (the thickness at the maximum effective radius).

In one embodiment, the lens unit includes a fifth lens element with refractive power and a sixth lens element with negative refractive power, the sixth lens element is disposed on the image side of the fifth lens element, the image-side surface of the fifth lens element is convex, the object-side surface of the sixth lens element is concave, the image-side surface of the sixth lens element is convex, the fifth lens element and the sixth lens element form a cemented lens element, and the optical system satisfies at least one of the following relationships:

|((cuy s1)*(map s1)-(cuy s2)*(map s2))/2|＞0.12；

0＜FH/f＜10；

ET S6＞0.5；

the cumy S1 is the reciprocal of the curvature radius of the object-side surface of the sixth lens element, the map S1 is the Y-direction half aperture of the object-side surface of the sixth lens element, the cumy S2 is the reciprocal of the curvature radius of the image-side surface of the sixth lens element, the map S2 is the Y-direction half aperture of the image-side surface of the sixth lens element, FH is the focal length of the cemented lens element, f is the effective focal length of the optical system, ET S6 is the thickness of the fifth lens element at the maximum effective radius, and ET S6 is expressed in mm. When the first relation is met, the processing difficulty of the sixth lens can be reduced by controlling the curvature radius and the Y-direction half aperture of the sixth lens; when the second relationship is satisfied, the cemented lens can provide positive refractive power for the optical system, so that the optical system has the characteristics of wide viewing angle, low sensitivity and miniaturization; when the above third relationship is satisfied, the difficulty of processing the cemented lens can be reduced by controlling the thickness of the edge of the fifth lens (the thickness at the maximum effective radius).

An image capturing module includes a photosensitive element and the optical system of any of the above embodiments, wherein the photosensitive element is disposed on an image side of the optical system.

The utility model provides an automobile, includes automobile body and the above-mentioned embodiment the module of making a video recording, the module of making a video recording set up in on the automobile body, the module of making a video recording can acquire the environmental information around the automobile.

Drawings

FIG. 1 is a schematic diagram of an optical system provided in a first embodiment of the present application;

fig. 2 is a spherical aberration diagram (mm), an astigmatism diagram (mm), and a distortion diagram (%);

FIG. 3 is a schematic view of an optical system provided in a second embodiment of the present application;

fig. 4 is a spherical aberration diagram (mm), an astigmatism diagram (mm), and a distortion diagram (%);

FIG. 5 is a schematic view of an optical system provided in a third embodiment of the present application;

fig. 6 is a spherical aberration diagram (mm), an astigmatism diagram (mm), and a distortion diagram (%);

FIG. 7 is a schematic view of an optical system provided in a fourth embodiment of the present application;

fig. 8 is a spherical aberration diagram (mm), an astigmatism diagram (mm), and a distortion diagram (%);

fig. 9 is a schematic view of a camera module using an optical system according to an embodiment of the present disclosure;

fig. 10 is a schematic view of an automobile using a camera module according to an embodiment of the present application.

Detailed Description

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

It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. In contrast, when an element is referred to as being "directly on" another element, there are no intervening elements present. The terms "vertical," "horizontal," "left," "right," and the like as used herein are for illustrative purposes only.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

The existing common camera generally has the problem of small field angle, so when the camera is used as a vehicle-mounted camera device, a vehicle still has a large blind area in the field of view, so that a driver cannot obtain enough peripheral images of the vehicle body, for example, when the vehicle is in a high-speed driving state and changes lanes, the information of the vehicle behind and beside the vehicle cannot be obtained in time, and thus potential safety hazards are easy to occur. In addition, the camera of the same kind also has the problem of low overall definition of the shot image. Therefore, the optical system, the camera module and the automobile are provided to solve the problems.

Referring to fig. 1, an optical system 100 in an embodiment of the present application sequentially includes, from an object side to an image side: a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, and a lens unit 110. The lens unit 110 in some embodiments includes a fifth lens L5, in which case the optical system 100 has a five-piece construction. In other embodiments, the lens unit 110 includes a fifth lens L5 and a sixth lens L6, and the optical system 100 has a six-piece structure.

The first lens L1 includes an object side surface S1 and an image side surface S2, the second lens L2 includes an object side surface S3 and an image side surface S4, the third lens L3 includes an object side surface S5 and an image side surface S6, the fourth lens L4 includes an object side surface S7 and an image side surface S8, the fifth lens L5 includes an object side surface S9 and an image side surface S10, and the sixth lens L6 includes an object side surface S11 and an image side surface S12. In addition, the optical system 100 further has an imaging surface S17, the imaging surface S17 is located on the image side of the sixth lens L6, and the imaging surface S17 can be understood as the photosensitive surface of the photosensitive element. It should be noted that the five-piece structure or the six-piece structure does not mean that only five lenses or six lenses are included in the optical system 100, and in some embodiments, at least one of the first lens, the second lens, the third lens, the fourth lens, the fifth lens or the sixth lens may be a cemented lens composed of two or more lenses, that is, the optical system 100 of the five-piece structure may actually include six, seven or more lenses, and the optical system 100 of the six-piece structure may actually include seven, eight or more lenses.

In some embodiments, an optical stop STO is disposed in the optical system 100, and the optical stop STO is disposed on the object side of the fourth lens L4. Specifically, the stop STO in some embodiments may be disposed between the second lens L2 and the third lens L3, or between the third lens L3 and the fourth lens L4.

The object-side surface and the image-side surface of the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, and the sixth lens L6 may all be spherical or all be aspherical. In other embodiments, the object-side surface and the image-side surface of the first lens L1, the second lens L2, the third lens L3, the fifth lens L5 and the sixth lens L6 are all spherical, and the object-side surface S7 and the image-side surface S8 of the fourth lens L4 are both aspheric.

When the object-side surface or the image-side surface of the lens is aspheric, reference may be made to the aspheric formula:

wherein Z is a distance from a corresponding point on the aspherical surface to a plane tangent to the surface vertex, r is a distance from a corresponding point on the aspherical surface to the optical axis, c is a curvature of the aspherical surface vertex, k is a conic constant, and Ai is a coefficient corresponding to the i-th high-order term in the aspherical surface type formula.

In some embodiments, the first lens L1 is made of glass, and the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5 and the sixth lens L6 are made of plastic, so that the first lens L1 closest to the object side (outside) can better withstand the influence of the ambient temperature on the object side, and the optical system 100 can have a lower production cost because other lenses are made of plastic.

In addition to the above-mentioned material relationship of the lenses, in some embodiments, the materials of the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5 and the sixth lens L6 are all plastic, and in this case, the plastic lens can reduce the weight of the optical system 100 and reduce the production cost. In some embodiments, the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5 and the sixth lens L6 are all made of glass, and thus the optical system 100 can endure high temperature and has excellent optical performance.

It should be noted that, referring to fig. 5, the sixth lens L6 may not be provided in the optical system 100 of some embodiments, in which case the optical system 100 will include the first lens L1, the second lens L2, the third lens L3, the fourth lens L4 and the fifth lens L5, that is, the optical system 100 has a five-piece structure.

For the optical system 100 having the five-plate structure described above, a stop STO may also be provided, the stop STO being provided on the object side of the fourth lens L4. Specifically, the stop STO may be disposed between the second lens L2 and the third lens L3.

For the optical system 100 having the five-piece structure, in some embodiments, the object-side surface and the image-side surface of the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, and the fifth lens L5 may all be spherical or all be aspheric. In other embodiments, the object-side surface and the image-side surface of the first lens L1, the third lens L3, the fourth lens L4, and the fifth lens L5 are all spherical, and the object-side surface S3 and the image-side surface S4 of the second lens L2 are both aspheric.

In addition, in the optical system 100 with the five-piece structure, the material of the first lens L1 may be glass, and the materials of the second lens L2, the third lens L3, the fourth lens L4, and the fifth lens L5 may be plastic, so that the first lens L1 closest to the object side (outside) can better withstand the influence of the ambient temperature on the object side, and the other lenses are plastic, so that the optical system 100 has a low production cost.

Further, in some embodiments, the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, and the fifth lens L5 are all made of plastic, and in this case, the plastic lens can reduce the weight of the optical system 100 and reduce the production cost. In some embodiments, the first lens L1, the second lens L2, the third lens L3, the fourth lens L4 and the fifth lens L5 are made of glass, and the optical system 100 can endure high temperature and has excellent optical performance. In other embodiments, the first lens element L1, the third lens element L3, the fourth lens element L4, and the fifth lens element L5 are made of glass, and the second lens element L2 is made of plastic.

In some embodiments, a glass infrared filter L7 is disposed on the image side of the lens unit 110. In the optical system 100 having the five-piece structure, the infrared filter L7 is disposed on the image side of the fifth lens element L5; in the optical system 100 having a six-piece structure, the infrared filter L7 is disposed on the image side of the sixth lens L6. The infrared filter L7 includes an object side S13 and an image side S14. The infrared filter L7 is used for filtering infrared light and preventing the infrared light from reaching the imaging surface S17, thereby preventing the infrared light from affecting the imaging of normal images. The infrared filter L7 may be incorporated with each lens as part of the optical system 100, or may be incorporated between the optical system 100 and the light receiving element when the optical system 100 and the light receiving element are assembled into a module. In some embodiments, an infrared filter L7 may also be disposed on the object side of the first lens L1.

In some embodiments, a protective glass L8 is disposed on the image side of the last lens of the optical system 100, and a protective glass L8 is disposed on the image side of the infrared filter L7 to be close to the photosensitive elements when assembled, thereby protecting the photosensitive elements. Cover glass L8 includes object side S15 and image side S16.

In addition, the optical system 100 may include elements such as a stop STO, a filter, a cover glass, a photosensitive element, and a mirror for changing an incident light path, in addition to the lens having refractive power.

It should be noted that the following embodiments related to relational expressions include the case where the optical system 100 has a five-piece structure and a six-piece structure, respectively.

In some embodiments, optical system 100 satisfies the relationship:

FOV/CRA > 10. The FOV is a field angle in a diagonal direction of an imaging surface of the optical system 100, and the CRA is an incident angle of a principal ray. The FOV/CRA may be 10.5, 10.6, 10.7, 10.8 or 10.9. When the above relationship is satisfied, the optical system 100 has a large field angle to satisfy the requirement of electronic products such as mobile phones, vehicle-mounted devices, monitoring devices, medical devices and the like for a large viewing angle, and simultaneously, the angle of light incident on the imaging surface S17 of the optical system 100 can be reduced, thereby improving the imaging definition.

In some embodiments, optical system 100 satisfies the relationship: l (((cus 1) (maps 1) - (cus 2) (mps 2))/2| > 0.12. In the embodiment of the five-piece structure, the cumy 1 is the reciprocal of the radius of curvature (at the optical axis) of the object-side surface S9 of the fifth lens L5, the map S1 is the Y-direction half aperture of the object-side surface S9 of the fifth lens L5, the cumy 2 is the reciprocal of the radius of curvature (at the optical axis) of the image-side surface S10 of the fifth lens L5, and the map S2 is the Y-direction half aperture of the image-side surface S10 of the fifth lens L5. In the six-piece embodiment, the cumy 1 is the reciprocal of the radius of curvature (at the optical axis) of the object-side surface S11 of the sixth lens L6, the map S1 is the Y-direction half aperture of the object-side surface S11 of the sixth lens L6, the cumy 2 is the reciprocal of the radius of curvature (at the optical axis) of the image-side surface S12 of the sixth lens L6, and the map S2 is the Y-direction half aperture of the image-side surface S12 of the sixth lens L6. L (((cus 1) ((map s1) - (cus 2) ((map s2))/2| may be 0.22, 0.24, 0.25, 0.26, 0.27 or 0.28. When the above relation is satisfied, the processing difficulty of the fifth lens L5 can be reduced by controlling the curvature radius and the Y-direction half aperture of the fifth lens L5 in the five-piece structure; the processing difficulty of the sixth lens L6 can also be reduced by controlling the radius of curvature and the Y-direction half aperture of the sixth lens L6 in the six-piece structure.

It is to be noted that, in the embodiment of the present application relating to the cemented lens 111, when the optical system 100 has a five-piece structure, the cemented lens 111 is constituted by the fourth lens L4 and the fifth lens L5; when the optical system 100 has a six-piece structure, the cemented lens 111 is constituted by the fifth lens L5 and the sixth lens L6.

In some embodiments, optical system 100 satisfies the relationship: 0 < FH/f < 10. Where FH is the focal length of the cemented lens 111 and f is the effective focal length of the optical system 100. FH/f may be 4.70, 4.75, 4.80, 5.00, 5.30, 5.70, 5.90, 6.10, 6.15, or 6.20. When the above relationship is satisfied, the cemented lens 111 can provide positive refractive power for the optical system 100, so that the optical system 100 has the characteristics of wide viewing angle, low sensitivity and miniaturization.

In some embodiments, optical system 100 satisfies the relationship: ET S6 > 0.5, and ET S6 is in mm. Wherein, in the embodiment of the five-piece structure, ET S6 is the thickness of the fourth lens L4 at the maximum effective radius; in the six-piece embodiment, ET S6 is the thickness of the fifth lens L5 at the maximum effective radius. ET S6 may be 1.5, 1.6, 1.7, or 1.8. When the above relationship is satisfied, the difficulty of processing the cemented lens 111 can be reduced by controlling the edge thickness of the fifth lens L5 in the five-piece structure or the sixth lens L6 in the six-piece structure (the thickness of the lens at the maximum effective radius).

In some embodiments, optical system 100 satisfies the relationship: BFL/TTL is more than 0.2. Wherein BFL is an optical back focus of the optical system 100, and 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 system 100. The BFL/TTL can be 0.24, 0.25 or 0.26. When the above relationship is satisfied, the optical system 100 has a larger optical back focus, and further has a telecentric effect, and at the same time, the sensitivity and the length of the optical system 100 can be reduced, so that the volume of the optical system 100 is smaller. The optical back focus is a distance on the optical axis from the image side surface of the last lens in the optical system 100 to the image plane S17, where the last lens is the lens closest to the image plane S17 in the optical system 100. In the five-piece structure, the optical back focus of the optical system 100 is the distance on the optical axis from the image-side surface S10 to the image-forming surface S17 of the fifth lens L5; in the six-piece structure, the optical back focus of the optical system 100 is the distance on the optical axis from the image side surface S12 to the image plane S17 of the sixth lens element L6.

In some embodiments, optical system 100 satisfies the relationship: (SD S2)/(RDY S2) < 0.95. Here, SD S2 is a Y-direction half aperture of the image side surface S2 of the first lens L1, and RDY S2 is a curvature radius of the image side surface S2 of the first lens L1 at the optical axis. (SD S2)/(RDY S2) may be 0.908, 0.912, 0.915, 0.917, or 0.918. When the relation is satisfied, the curvature radius of the image side surface S2 of the first lens L1 and the Y-direction half aperture can be controlled to effectively control the bending degree of the first lens L1, the processing difficulty of the first lens L1 is reduced, the problem of uneven coating caused by the fact that the first lens L1 is too large in bending degree is avoided, and the risk of generating ghost images is reduced.

In some embodiments, optical system 100 satisfies the relationship: dist is more than or equal to-65 and less than or equal to 65. Where Dist is the optical distortion of the optical system 100 in%. Dist can be-64, -63, -62, -61, 62, 63, or 64. When the above relationship is satisfied, the distortion amount of the optical system 100 can be controlled to reduce the phenomenon of excessive distortion commonly existing in the wide-angle lens.

In some embodiments, optical system 100 satisfies the relationship: nd1 is less than 1.8; vd1 > 25. Wherein Nd1 is the refractive index of the first lens L1 under d light, and Vd1 is the abbe number of the first lens L1 under d light. Nd1 may be 1.600, 1.610, 1.630, 1.660, 1.700, 1.730, 1.740, 1.760 or 1.765. Vd1 may be 50.00, 61.00, 53.00, 57.00, 60.00, 60.80, 61.00, or 62.00. Satisfying the above relationship is advantageous for correcting the off-axis chromatic aberration of the optical system 100, thereby improving the resolution of the optical system 100.

In some embodiments, optical system 100 satisfies the relationship: nd2 is more than 1.9; vd2 < 25. The Nd2 represents the refractive index of d light of the lens closest to the image side in the optical system 100 (in the case of the five-piece structure, the lens closest to the image side is the fifth lens L5; in the case of the six-piece structure, the lens closest to the image side is the sixth lens L6), Vd2 represents the abbe number of d light of the lens closest to the image side in the optical system 100, and the wavelength of d light is 587.56 nm. Nd2 may be 1.928, 1.930, 1.935, 1.950, 1.970, 1.980, or 1.950. The Vd2 may be 19.40, 19.50, 19.70, 20.00, 20.30, 20.60, 20.70, 20.80, or 20.85. Satisfying the above relationship is advantageous for correcting the off-axis chromatic aberration of the optical system 100, thereby improving the resolution of the optical system 100.

In some embodiments, the object side S1 of the first lens L1 is plated with a protective film. In some embodiments, optical system 100 satisfies the relationship: h_K＞500；F_AIs greater than 50. Wherein H_KHardness of the first lens L1, H_KHas a unit of 10⁷Pa，F_AThe degree of abrasion of the first lens L1, F_AThe unit is%. H_KMay be 600, 610, 620, 650, 680 or 690. F_AAnd may be 70, 75, 80, 90, 100, 105, 110 or 113. When the above relationship is satisfied, the first lens L1 has high hardness and abrasion resistance, and the protective film layer is provided to provide the first lens L1 with protectionThe function is prevented scraping by water, can prevent effectively that first lens L1 from receiving the fish tail, prevents to influence the imaging quality because of problems such as scratch, water droplet adhesion to improve optical system 100's life.

First embodiment

In the first embodiment shown in fig. 1, the optical system 100 includes, in order from the object side to the image side, the first lens element L1 with negative refractive power, the second lens element L2 with negative refractive power, the third lens element L3 with positive refractive power, the stop STO, the fourth lens element L4 with positive refractive power, the fifth lens element L5 with positive refractive power, and the sixth lens element L6 with negative refractive power, so that the optical system 100 has a six-lens structure. In addition, the fifth lens L5 is cemented with the sixth lens L6 to constitute a cemented lens 111. The image side of the sixth lens element L6 is further provided with an infrared filter L7 and a protective glass L8 in this order, and the infrared filter L7 and the protective glass L8 may or may not belong to the optical system 100. When the infrared filter L7 and the protective glass L8 are not provided, the distance from the image side surface S12 of the sixth lens L6 to the image plane S17 is still 5.499 mm. Similarly to the following embodiments, the distance from the image-side surface S12 of the sixth lens L6 to the image-forming surface S17 is independent of whether the infrared filter L7 or the cover glass L8 is provided. Fig. 2 is a spherical aberration diagram (mm), an astigmatism diagram (mm), and a distortion diagram (%) of the optical system 100 in the first embodiment, wherein the astigmatism diagram and the distortion diagram are data diagrams at a reference wavelength. The reference wavelength in each of the following examples is 587.56nm, and the unit of the ordinate IMG HT in the astigmatism diagrams and the distortion diagrams in each of the following examples is mm.

The object-side surface S1 of the first lens element L1 is convex, and the image-side surface S2 of the first lens element L1 is concave.

The object-side surface S3 of the second lens element L2 is convex; the image-side surface S4 of the second lens L2 is concave.

The object-side surface S5 of the third lens element L3 is convex, and the image-side surface S6 of the third lens element L3 is convex.

The object-side surface S7 of the fourth lens element L4 is convex, and the image-side surface S8 of the fourth lens element L4 is convex.

The object-side surface S9 of the fifth lens element L5 is convex, and the image-side surface S10 of the fifth lens element L5 is convex.

The object-side surface S11 of the sixth lens element L6 is concave, and the image-side surface S12 of the sixth lens element L6 is convex.

The object-side surface and the image-side surface of the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, and the sixth lens L6 are all spherical.

The first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5 and the sixth lens L6 are all made of glass.

The optical system 100 satisfies the following relationship:

FOV/CRA is 10.4. The FOV is a field angle in a diagonal direction of an imaging surface of the optical system 100, and the CRA is an incident angle of a principal ray. When the above relationship is satisfied, the optical system 100 has a large field angle to satisfy the requirement of electronic products such as mobile phones, vehicle-mounted devices, monitoring devices, and medical devices for a large viewing angle, and at the same time, the angle at which light enters the photosensitive element located on the image side of the optical system 100 can be reduced, thereby improving the imaging definition.

The optical system 100 satisfies the relationship: l (((cus 1) (maps 1) - (cus 2) ((map s2))/2|, 0.21. Here, the cums 1 is the reciprocal of the radius of curvature (at the optical axis) of the object-side surface S11 of the sixth lens L6, the map S1 is the Y-direction half aperture of the object-side surface S11 of the sixth lens L6, the cums 2 is the reciprocal of the radius of curvature (at the optical axis) of the image-side surface S12 of the sixth lens L6, and the map S2 is the Y-direction half aperture of the image-side surface S12 of the sixth lens L6. When the above relationship is satisfied, the processing difficulty of the sixth lens L6 can be reduced by controlling the radius of curvature and the Y-direction half aperture of the sixth lens L6. It is to be noted that, in the embodiment of the present application relating to the cemented lens 111, when the optical system 100 has a five-piece structure, the cemented lens 111 is constituted by the fourth lens L4 and the fifth lens L5; when the optical system 100 has a six-piece structure, the cemented lens 111 is constituted by the fifth lens L5 and the sixth lens L6.

The optical system 100 satisfies the relationship: FH/f is 4.63. Where FH is the focal length of the cemented lens 111 and f is the effective focal length of the optical system 100. When the above relationship is satisfied, the cemented lens 111 can provide positive refractive power for the optical system 100, so that the optical system 100 has the characteristics of wide viewing angle, low sensitivity and miniaturization.

The optical system 100 satisfies the relationship: ET S6 is 1.5, ET S6 is the thickness of the fifth lens L5 at the maximum effective radius, and ET S6 is in mm. When the above relationship is satisfied, the difficulty of processing the cemented lens 111 can be reduced by controlling the edge thickness of the sixth lens L6 (the thickness of the lens at the maximum effective radius).

The optical system 100 satisfies the relationship: BFL/TTL is 0.26. Wherein BFL is an optical back focus of the optical system 100, and 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 system 100. When the above relationship is satisfied, the optical system 100 has a larger optical back focus, and further has a telecentric effect, and at the same time, the sensitivity and the length of the optical system 100 can be reduced, so that the volume of the optical system 100 is smaller.

The optical system 100 satisfies the relationship: (SD S2)/(RDY S2) ═ 0.906. Here, SD S2 is a Y-direction half aperture of the image side surface S2 of the first lens L1, and RDY S2 is a curvature radius of the image side surface S2 of the first lens L1 at the optical axis. When the relation is satisfied, the curvature radius of the image side surface S2 of the first lens L1 and the Y-direction half aperture can be controlled to effectively control the bending degree of the first lens L1, reduce the processing difficulty of the first lens L1, avoid the problem of uneven coating film caused by the excessive bending degree of the first lens L1, and reduce the risk of generating ghost.

The optical system 100 satisfies the relationship: dist ═ 65. Where Dist is the optical distortion of the optical system 100 in%. When the above relationship is satisfied, the distortion amount of the optical system 100 can be controlled to reduce the phenomenon of excessive distortion commonly existing in the wide-angle lens.

The optical system 100 satisfies the relationship: nd1 ═ 1.773; vd 1-49.62. Wherein Nd1 is the refractive index of the first lens L1 under d light, and Vd1 is the abbe number of the first lens L1 under d light. Satisfying the above relationship is advantageous for correcting the off-axis chromatic aberration of the optical system 100, thereby improving the resolution of the optical system 100.

The optical system 100 satisfies the relationship: nd2 ═ 2.003; vd2 ═ 19.32. Where Nd2 is a d-optical refractive index of a lens closest to the image side in the optical system 100 (the fifth lens L5 in the case of the five-piece structure, and the sixth lens L6 in the case of the six-piece structure), and Vd2 is a d-optical abbe number of the lens closest to the image side in the optical system 100. Satisfying the above relationship is advantageous for correcting the off-axis chromatic aberration of the optical system 100, thereby improving the resolution of the optical system 100.

The object-side surface S1 of the first lens L1 is coated with a protective film layer and the optical system 100 satisfies the relationship: h_K＝700；F_A65. Wherein H_KHardness of the first lens L1, H_KHas a unit of 10⁷Pa，F_AThe degree of abrasion of the first lens L1, F_AThe unit is%. When satisfying above-mentioned relation, first lens L1 possesses higher hardness and degree of wear, simultaneously, through setting up the protection rete so that first lens L1 possesses waterproof scratch-resistant function, can prevent effectively that first lens L1 from receiving the fish tail, prevents to influence the imaging quality because of scratch, water droplet adhesion scheduling problem to improve optical system 100's life.

In the first embodiment, the focal length f of the optical system 100 is 2.8923mm, the aperture value FNO is 2.1, and the half of the diagonal field angle (1/2) FOV is 73 degrees (deg.).

In addition, the respective parameters of the optical system 100 are given by table 1. The elements from the object plane to the image plane S17 were arranged in the order of the elements from top to bottom in table 1. Surface numbers 1 and 2 respectively indicate an object-side surface S1 and an image-side surface S2 of the first lens L1, that is, a surface having a smaller surface number is an object-side surface and a surface having a larger surface number is an image-side surface in the same lens. The Y radius in table 1 is the radius of curvature of the object side or image side at the paraxial position of the corresponding face number. The first value in the "thickness" parameter list of the first lens element L1 is the thickness of the lens element along the optical axis, and the second value is the distance from the image-side surface of the lens element to the object-side surface of the subsequent lens element along the optical axis. The "thickness" parameter in the face number 6 is the distance from the image-side face S6 of the third lens L3 to the stop STO. The numerical value of the stop STO in the "thickness" parameter column is the distance on the optical axis from the stop STO to the vertex of the object-side surface of the subsequent lens (the vertex refers to the intersection point of the lens and the optical axis), the direction from the object-side surface of the first lens L1 to the image-side surface of the last lens is the positive direction of the optical axis by default, when the value is negative, it indicates that the stop STO is arranged on the right side of the vertex of the object-side surface of the lens, and when the "thickness" parameter of the stop STO is positive, the stop STO is arranged on the left side of the vertex of the object-side. The "thickness" parameter value in the surface number 12 is the distance on the optical axis from the image-side surface S12 of the sixth lens L6 to the object-side surface S13 of the infrared filter L7. The value corresponding to the plane number 13 in the "thickness" parameter of the infrared filter L7 is the distance on the optical axis from the image-side surface S14 of the infrared filter L7 to the object-side surface S15 of the protective glass L8.

In the following examples, the refractive index, abbe number, and focal length of each lens are numerical values at a reference wavelength, which is 587.56 nm.

TABLE 1

Second embodiment

In the second embodiment shown in fig. 3, the optical system 100 includes, in order from the object side to the image side, the first lens element L1 with negative refractive power, the second lens element L2 with negative refractive power, the third lens element L3 with positive refractive power, the stop STO, the fourth lens element L4 with positive refractive power, the fifth lens element L5 with positive refractive power, and the sixth lens element L6 with negative refractive power, so that the optical system 100 has a six-lens structure. In addition, the fifth lens L5 is cemented with the sixth lens L6 to constitute a cemented lens 111. The image side of the sixth lens element L6 is further provided with an infrared filter L7 and a protective glass L8 in this order, and the infrared filter L7 and the protective glass L8 may or may not belong to the optical system 100. Fig. 4 is a spherical aberration diagram (mm), an astigmatism diagram (mm), and a distortion diagram (%) of the optical system 100 in the second embodiment, wherein the astigmatism diagram and the distortion diagram are data diagrams at a reference wavelength.

The object side S3 of the second lens L2 is concave; the image-side surface S4 of the second lens L2 is concave.

The object-side surface and the image-side surface of the second lens L2, the third lens L3, the fifth lens L5, and the sixth lens L6 of the first lens L1 are all spherical, and the object-side surface S7 and the image-side surface S8 of the fourth lens L4 are aspheric.

In the second embodiment, the effective focal length f of the optical system 100 is 2.8761mm, the aperture value FNO is 2.1, and the half of the diagonal field angle (1/2) FOV is 71 degrees (deg.).

In addition, the parameters of the optical system 100 are given in tables 3 and 4, and the definitions of the parameters can be obtained from the first embodiment, which is not repeated herein. Table 4 is a table of correlation parameters of the aspherical surface of each lens in table 3, k is a conic constant, and Ai is a coefficient corresponding to the i-th high-order term in the aspherical surface type formula.

TABLE 3

TABLE 4

The following data can be derived according to the provided parameter information:

third embodiment

In the third embodiment shown in fig. 5, the optical system 100 includes, in order from the object side to the image side, the first lens element L1 with negative refractive power, the second lens element L2 with negative refractive power, the stop STO, the third lens element L3 with positive refractive power, the fourth lens element L4 with positive refractive power, and the fifth lens element L5 with negative refractive power, so that the optical system 100 has a five-lens structure. In addition, the fourth lens L4 is cemented with the fifth lens L5 to constitute a cemented lens 111. An infrared filter L7 and a protective glass L8 are further provided on the image side of the fifth lens L5 in this order, and the infrared filter L7 and the protective glass L8 may or may not belong to the optical system 100. Fig. 6 is a spherical aberration diagram (mm), an astigmatism diagram (mm), and a distortion diagram (%) of the optical system 100 in the third embodiment, wherein the astigmatism diagram and the distortion diagram are data diagrams at a reference wavelength.

The object-side surface S9 of the fifth lens element L5 is concave, and the image-side surface S10 of the fifth lens element L5 is convex.

The object-side surface and the image-side surface of the first lens L1, the third lens L3, the fourth lens L4, and the fifth lens L5 are all spherical, and the object-side surface S3 and the image-side surface S4 of the second lens L2 are aspheric.

The first lens L1, the second lens L2, the third lens L3, the fourth lens L4 and the fifth lens L5 are all made of glass.

In the third embodiment, the effective focal length f of the optical system 100 is 3.0mm, the aperture value FNO is 2.0, and the half of the diagonal field angle (1/2) FOV is 72 degrees (deg.).

In addition, the parameters of the optical system 100 are given in tables 5 and 6, and the definitions of the parameters can be obtained from the first embodiment, which is not repeated herein. Table 6 is a table of correlation parameters of the aspherical surface of each lens in table 5, k is a conic constant, and Ai is a coefficient corresponding to the i-th high-order term in the aspherical surface type formula.

TABLE 5

TABLE 6

fourth embodiment

In the fourth embodiment shown in fig. 7, the optical system 100 includes, in order from the object side to the image side, the first lens element L1 with negative refractive power, the second lens element L2 with negative refractive power, the stop STO, the third lens element L3 with positive refractive power, the fourth lens element L4 with positive refractive power, and the fifth lens element L5 with negative refractive power, so that the optical system 100 has a five-lens structure. In addition, the fourth lens L4 is cemented with the fifth lens L5 to constitute a cemented lens 111. An infrared filter L7 and a protective glass L8 are further provided on the image side of the fifth lens L5 in this order, and the infrared filter L7 and the protective glass L8 may or may not belong to the optical system 100. Fig. 8 is a spherical aberration diagram (mm), an astigmatism diagram (mm), and a distortion diagram (%) of the optical system 100 in the fourth embodiment, wherein the astigmatism diagram and the distortion diagram are data diagrams at a reference wavelength.

The first lens L1, the third lens L3, the fourth lens L4 and the fifth lens L5 are all made of glass, and the second lens L2 is made of plastic.

In the fourth embodiment, the effective focal length f of the optical system 100 is 2.99mm, the aperture value FNO is 2.0, and the half of the diagonal field angle (1/2) FOV is 71.9 degrees (deg.).

In addition, the parameters of the optical system 100 are given in tables 7 and 8, and the definitions of the parameters can be obtained from the first embodiment, which is not repeated herein. Table 8 is a table of correlation parameters of the aspherical surface of each lens in table 7, K is a conic constant, and Ai is a coefficient corresponding to the i-th high-order term in the aspherical surface type formula.

TABLE 7

TABLE 8

referring to fig. 9, in some embodiments, the optical system 100 may be assembled into the image module 200 together with the photosensitive element 210, and the photosensitive element 210 is disposed at the image side of the optical system 100. The photosensitive element 210 may be a CCD (Charge coupled device) or a CMOS (Complementary Metal Oxide Semiconductor). By adopting the optical system 100, the image pickup module 200 has a large viewing angle characteristic and can improve the image sharpness.

In some embodiments, the lens of the optical system 100 and the photosensitive element 210 are fixed relatively, and the image capturing module 200 is a fixed focus module. In other embodiments, the driving motor may be configured to enable the photosensitive element 210 to move relative to the lens in the optical system 100, so as to implement the focusing function.

The camera module 200 can be applied to the fields of smart phones, smart watches, automobiles, monitoring, medical treatment and the like, and can be specifically used as a mobile phone camera module, a vehicle-mounted camera module or a monitoring camera module. When the camera module 200 is applied to the equipment, the equipment has a large viewing angle characteristic, and the imaging definition can be improved.

Referring to fig. 10, in some embodiments, when the camera module 200 is applied to the automobile 30 as an in-vehicle camera, the camera module 200 may be used as a front-view camera, a rear-view camera, or a side-view camera of the automobile 30. Specifically, the automobile 30 includes a body 310, and the camera module 200 can be mounted on any position of the front side (e.g., at an air intake grille) of the body 310, such as a left headlight, a right headlight, a left rearview mirror, a right rearview mirror, a trunk lid, a roof, etc. Secondly, also can set up display device in car 30, make a video recording module 200 and display device communication connection to, the image that the module 200 that makes a video recording on automobile body 310 obtained can show on display device in real time, lets the driver can obtain the environmental information of automobile body 310 in a wider range all around, makes the driver more convenient and safe when driving and parking. When a plurality of camera modules 200 are provided to acquire scenes in different directions, image information obtained by the camera modules 200 can be synthesized and can be presented on a display apparatus in the form of a top view.

Specifically, the automobile 30 includes at least four camera modules 200, and the camera modules 200 are respectively installed at the front side (e.g., at the air intake grille), the left side (e.g., at the left rear view mirror), the right side (e.g., at the right rear view mirror) and the rear side (e.g., at the trunk lid) of the automobile body 310 to construct an automobile all-round viewing system. The automobile all-round system comprises four (or more) camera modules 200 which are arranged on the front, the back, the left and the right of an automobile body 310, wherein the plurality of camera modules 200 can simultaneously collect images around an automobile 30, then the image information collected by the camera modules 200 is subjected to steps of distortion reduction, visual angle conversion, image splicing, image enhancement and the like through an image processing unit, and finally a seamless 360-degree panoramic top view around the automobile 30 is formed and displayed on a display device. Of course, instead of displaying a panoramic view, a single-sided view of any orientation may be displayed. In addition, a scale line corresponding to the display image can be configured on the display device so as to facilitate the driver to accurately determine the direction and distance of the obstacle.

By adopting the camera module 200, the visual field blind area of the driver can be effectively reduced, so that the driver can obtain more road condition information of the periphery of the vehicle body, and the potential safety hazard of the vehicle during lane changing, parking, turning and other operations can be reduced.

In some embodiments, a driving recorder is installed in the automobile 30, and the image information obtained by the camera module 200 can be stored in the driving recorder.

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

The above-mentioned embodiments only represent some embodiments of the present invention, and the description thereof is specific and detailed, but not to be construed as limiting the scope of the present invention. It should be noted that, for those skilled in the art, without departing from the spirit of the present invention, several variations and modifications can be made, which are within the scope of the present invention. Therefore, the protection scope of the present invention should be subject to the appended claims.

Claims

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

a lens unit with refractive power;

a diaphragm disposed on an object side of the fourth lens;

and the optical system satisfies the following relationship:

FOV/CRA＞10；

BFL/TTL＞0.2；

the FOV is a field angle of an imaging surface of the optical system in a diagonal direction, the CRA is an incident angle of a chief ray, the BFL is an optical back focus of the optical system, and the TTL is a distance from an object side surface of the first lens to the imaging surface of the optical system on an optical axis.

2. The optical system of claim 1, comprising any one of:

3. The optical system of claim 2, wherein the BFL/TTL is in a relationship of 0.24, 0.25, or 0.26.

4. The optical system according to claim 2, wherein the following relationship is satisfied:

(SD S2)/(RDY S2)＜0.95；

wherein SD S2 is a Y-direction half aperture of the image-side surface of the first lens, and RDY S2 is a radius of curvature of the image-side surface of the first lens.

5. The optical system according to claim 2, wherein the following relationship is satisfied:

-65≤Dist≤65；

where Dist is the optical distortion of the optical system in%.

6. The optical system according to claim 2, wherein the following relationship is satisfied:

Nd1＜1.8；Vd1＞25；

the Nd1 is a refractive index of the first lens under d light, and the Vd1 is an Abbe number of the first lens under d light.

7. The optical system of claim 2, wherein the object side surface of the first lens is coated with a protective film and/or the optical system satisfies the following relationship:

H_K＞500；F_A＞50；

wherein H_KIs the hardness of the first lens, H_KHas a unit of 10⁷Pa，F_AIs the degree of abrasion of the first lens, F_AThe unit is%.

8. The optical system according to claim 2, wherein the optical system satisfies the following relationship:

Nd2＞1.9；Vd2＜25；

wherein Nd2 is a d-optical refractive index of a lens closest to the image side in the optical system, and Vd2 is a d-optical abbe number of the lens closest to the image side in the optical system.

9. The optical system according to claim 1, wherein the lens unit comprises a fifth lens, an image side surface of the fifth lens is a convex surface, the fourth lens and the fifth lens form a cemented lens, and the optical system satisfies at least one of the following relationships:

|((cuy s1)*(map s1)-(cuy s2)*(map s2))/2|＞0.12；

0＜FH/f＜10；

ET S6＞0.5；

the cumy S1 is the reciprocal of the curvature radius of the object-side surface of the fifth lens element, the map S1 is the Y-direction half aperture of the object-side surface of the fifth lens element, the cumy S2 is the reciprocal of the curvature radius of the image-side surface of the fifth lens element, the map S2 is the Y-direction half aperture of the image-side surface of the fifth lens element, FH is the focal length of the cemented lens element, f is the effective focal length of the optical system, ET S6 is the thickness of the fourth lens element at the maximum effective radius, and ET S6 is expressed in mm.

10. The optical system as claimed in claim 1, wherein the lens unit includes a fifth lens element with refractive power and a sixth lens element with negative refractive power, the sixth lens element is disposed on the image side of the fifth lens element, the fifth lens element has a convex image-side surface, the sixth lens element has a concave object-side surface, the sixth lens element has a convex image-side surface, the fifth lens element and the sixth lens element form a cemented lens element, and the optical system satisfies at least one of the following relationships:

|((cuy s1)*(map s1)-(cuy s2)*(map s2))/2|＞0.12；

0＜FH/f＜10；

ET S6＞0.5；

the cumy S1 is the reciprocal of the curvature radius of the object-side surface of the sixth lens element, the map S1 is the Y-direction half aperture of the object-side surface of the sixth lens element, the cumy S2 is the reciprocal of the curvature radius of the image-side surface of the sixth lens element, the map S2 is the Y-direction half aperture of the image-side surface of the sixth lens element, FH is the focal length of the cemented lens element, f is the effective focal length of the optical system, ET S6 is the thickness of the fifth lens element at the maximum effective radius, and ET S6 is expressed in mm.

11. An image pickup module comprising a photosensitive element and the optical system according to any one of claims 1 to 10, wherein the photosensitive element is disposed on an image side of the optical system.

12. An automobile, characterized by comprising an automobile body and the camera module set forth in claim 11, wherein the camera module set is arranged on the automobile body, and the camera module set can acquire environmental information around the automobile.