CN212540837U

CN212540837U - Optical system, image capturing module and electronic device

Info

Publication number: CN212540837U
Application number: CN202020781549.XU
Authority: CN
Inventors: 李明; 邹海荣
Original assignee: Jiangxi Jingchao Optical Co Ltd
Current assignee: Jiangxi Jingchao Optical Co Ltd
Priority date: 2020-05-12
Filing date: 2020-05-12
Publication date: 2021-02-12
Anticipated expiration: 2030-05-12

Abstract

The application relates to an optical system, an image capturing module and an electronic device. The optical system sequentially comprises a first lens element with positive refractive power from an object side to an image side along an optical axis, wherein the object side surface at a paraxial region is convex, and the image side surface at a paraxial region is concave; a second lens element with refractive power having a convex object-side surface at the paraxial region and a concave image-side surface at the paraxial region; a third lens element with refractive power; a fourth lens element with refractive power; a fifth lens element with refractive power; a sixth lens element with refractive power; the seventh lens element with negative refractive power has a concave image-side surface at the paraxial region thereof, and at least one of the object-side surface and the image-side surface thereof has at least one inflection point. The optical system can give consideration to the imaging characteristics of a large aperture and a high pixel when satisfying a specific relationship, and has the characteristic of miniaturization.

Description

Optical system, image capturing module and electronic device

Technical Field

The utility model relates to an optical imaging technology field especially relates to an optical system, gets for instance module and electron device.

Background

In recent years, with the advance of science and technology, consumers have higher requirements for the imaging quality of mobile electronic products, and meanwhile, the performance of photosensitive elements such as a CCD (charge coupled device) and a CMOS (complementary metal oxide semiconductor) of a photoelectric coupler is gradually improved, so that the possibility of shooting high-quality images is provided. Therefore, the performance improvement of the optical system design becomes a key factor for improving the shooting quality of the current camera.

However, although the conventional five-piece optical system has a mature manufacturing process, the aperture is small, the aberration improvement capability is weak, and the shooting requirement of consumers cannot be met.

SUMMERY OF THE UTILITY MODEL

In view of the above, there is a need to provide an improved optical system for solving the problems of small aperture and low image quality of the conventional optical system.

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

the first lens element with positive refractive power has a convex object-side surface at a paraxial region and a concave image-side surface at a paraxial region; the second lens element with refractive power has a convex object-side surface at the paraxial region and a concave image-side surface at the paraxial region; a third lens element with refractive power; a fourth lens element with refractive power; a fifth lens element with refractive power; a sixth lens element with refractive power; the seventh lens element with negative refractive power has a concave image-side surface at the paraxial region thereof, and at least one of the object-side surface and the image-side surface thereof comprises at least one inflection point;

the optical system satisfies the following relation:

f*tan(HFOV)＞5.15mm；

where f denotes an effective focal length of the optical system, and HFOV denotes a half of a diagonal field angle of the optical system.

According to the optical system, the system aberration can be effectively corrected by selecting a proper number of lenses and reasonably distributing the refractive power and the surface shape of each lens and the effective focal length of each lens, so that the imaging quality is improved; meanwhile, when the relation is met, the optical system further has a larger image plane, so that more pixel units on the photosensitive element can be covered, the imaging characteristic of high pixels is realized, and the imaging definition is improved.

In one embodiment, the optical system satisfies the following relationship: TTL/ImgH is less than 1.7; wherein, TTL represents a distance on an optical axis from an object-side surface of the first lens element to an imaging surface of the optical system, and ImgH represents a half of a diagonal length of an effective pixel area on the imaging surface of the optical system.

When the relation is satisfied, the total length of the system and the size of the image plane can be controlled within a reasonable range, so that the total length of the system is shortened on the premise of ensuring a large image plane, and the ultra-thinness and miniaturization of the system are realized.

In one embodiment, the optical system satisfies the following relationship: TTL/f is more than 1 and less than 1.5; wherein TTL represents a distance on an optical axis from an object-side surface of the first lens element to an image plane of the optical system.

When the upper limit of the relational expression is satisfied, the optical system has smaller total length, which is beneficial to realizing the miniaturization of the system; when the lower limit of the relation is met, the total length of the system can not be too small, so that the sensitivity of the system is favorably reduced, the lens assembly is convenient, and the production yield is improved.

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

0.5 < | RS5/RS6| < 1.5; wherein RS5 denotes a radius of curvature of an object-side surface of the third lens at an optical axis, and RS6 denotes a radius of curvature of an image-side surface of the third lens at the optical axis.

When the relation is satisfied, the curvature radiuses of the object side surface and the image side surface of the third lens at the optical axis can be reasonably configured, so that the bending degree of the third lens is favorably controlled, the third lens is prevented from being bent excessively, the sensitivity of the third lens is reduced, and the third lens is convenient to machine and form.

In one embodiment, the optical system satisfies the following relationship: i f1/f 5I < 2; wherein f1 denotes an effective focal length of the first lens, and f5 denotes an effective focal length of the fifth lens.

When the relation is satisfied, the effective focal lengths of the first lens and the fifth lens are favorably and reasonably distributed, so that the position chromatic aberration of the optical system is effectively corrected.

In one embodiment, the optical system satisfies the following relationship: CT2 is more than or equal to 0.3 mm; wherein CT2 represents the thickness of the second lens on the optical axis.

When the relational expression is satisfied, the processing and the molding of the second lens are facilitated, the production yield is improved, and meanwhile, the total length of the optical system can be ensured to be in a reasonable range.

In one embodiment, the optical system satisfies the following relationship: TTL/f1 is less than or equal to 1.5; wherein TTL denotes an optical axis distance from an object side surface of the first lens element to an image plane of the optical system, and f1 denotes an effective focal length of the first lens element.

When the above relation is satisfied, the total length of the optical system and the effective focal length of the first lens element can be reasonably configured, so that the refractive power of the first lens element can be controlled, high-order aberration caused by excessive deflection of marginal field rays due to excessive refractive power of the first lens element can be avoided, the total length of the system can be controlled within a smaller range under the condition of ensuring image quality, and the miniaturization of the system can be realized.

In one embodiment, the optical system satisfies the following relationship: f/EPD is less than 1.7; wherein EPD represents an entrance pupil diameter of the optical system.

When the relation is satisfied, the system has a larger clear aperture, thereby being beneficial to increasing the light inlet quantity and enhancing the dark light shooting capability of the system.

In one embodiment, the optical system satisfies the following relationship: f1/RS1 is less than 3.5; where f1 denotes an effective focal length of the first lens, and RS1 denotes a radius of curvature of an object side surface of the first lens at an optical axis.

When the above relation is satisfied, the effective focal length of the first lens and the curvature radius of the object side surface of the first lens at the optical axis can be reasonably configured, so that the object side surface of the first lens is prevented from being over-bent, and the reduction of the sensitivity of the optical system is facilitated.

The application also provides an image capturing module.

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

The image capturing module has a larger light transmission aperture to obtain a larger light transmission amount, can shoot and obtain an image with bright field of view and high pixels, is suitable for shooting in environments such as night scenes, rainy days, starry sky and the like, and has a better imaging effect; meanwhile, the image capturing module has the structural characteristics of miniaturization and light weight, and is convenient to adapt to devices with limited sizes such as mobile phones, flat plates and vehicle-mounted lenses.

The application also provides an electronic device.

An electronic device comprises a shell and the image capturing module, wherein the image capturing module is arranged on the shell.

Above-mentioned electronic device utilizes aforementioned getting for instance module can shoot and obtain the image that the visual field is bright, the pixel is high, can satisfy the shooting demand of different scenes, has promoted user's shooting experience.

Drawings

Fig. 1 shows a schematic structural view of an optical system of embodiment 1 of the present application;

fig. 2 shows a longitudinal spherical aberration graph, an astigmatism graph, and a distortion graph, respectively, of the optical system of example 1;

fig. 3 is a schematic structural view showing an optical system of embodiment 2 of the present application;

fig. 4 shows a longitudinal spherical aberration graph, an astigmatism graph, and a distortion graph, respectively, of the optical system of example 2;

fig. 5 is a schematic structural view showing an optical system of embodiment 3 of the present application;

fig. 6 shows a longitudinal spherical aberration graph, an astigmatism graph, and a distortion graph, respectively, of the optical system of example 3;

fig. 7 is a schematic structural view showing an optical system of embodiment 4 of the present application;

fig. 8 shows a longitudinal spherical aberration graph, an astigmatism graph, and a distortion graph, respectively, of the optical system of example 4;

fig. 9 is a schematic structural view showing an optical system of embodiment 5 of the present application;

fig. 10 shows a longitudinal spherical aberration graph, an astigmatism graph, and a distortion graph, respectively, of the optical system of example 5;

fig. 11 is a schematic structural view showing an optical system of embodiment 6 of the present application;

fig. 12 shows a longitudinal spherical aberration graph, an astigmatism graph, and a distortion graph, respectively, of the optical system of example 6;

fig. 13 is a schematic structural view showing an optical system of embodiment 7 of the present application;

fig. 14 shows a longitudinal spherical aberration graph, an astigmatism graph, and a distortion graph, respectively, of the optical system of example 7;

fig. 15 is a schematic structural view showing an optical system of embodiment 8 of the present application;

fig. 16 shows a longitudinal spherical aberration graph, an astigmatism graph, and a distortion graph of the optical system of example 8;

fig. 17 is a schematic structural view showing an optical system of embodiment 9 of the present application;

fig. 18 shows a longitudinal spherical aberration graph, an astigmatism graph, and a distortion graph of the optical system of example 9;

fig. 19 is a schematic structural view showing an optical system of embodiment 10 of the present application;

fig. 20 shows a longitudinal spherical aberration graph, an astigmatism graph, and a distortion graph of the optical system of example 10;

fig. 21 is a schematic diagram illustrating an image capturing 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. The 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. As used herein, the terms "vertical," "horizontal," "left," "right," "upper," "lower," "front," "rear," "circumferential," and the like are based on the orientation or positional relationship shown in the drawings and are intended to facilitate the description of the invention and to simplify the description, but do not indicate or imply that the device or element so referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus should not be construed as limiting the invention.

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

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

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

In addition, in the following description, if it appears that a lens surface is convex and the convex position is not defined, it means that the lens surface is convex at least near the optical axis; if the lens surface is concave and the concave position is not defined, it means that the lens surface is concave at least at the position near the optical axis. Here, the paraxial region means a region near the optical axis. Specifically, the irregularity of the lens surface region is determined on the image side or the object side by the intersection point of the light ray passing through the region in parallel with the optical axis. For example, when the parallel light passes through the region, the light is focused toward the image side, and the intersection point of the light and the optical axis is located at the image side, the region is a convex surface; on the contrary, if the light ray passes through the region, the light ray is diverged, and the intersection point of the extension line of the light ray and the optical axis is at the object side, the region is a concave surface. In addition, the lens includes an optical axis vicinity region, a circumference vicinity region, and an extension portion for fixing the lens. Ideally, the imaging light does not pass through the extension portion, and therefore the range from the region near the optical axis to the region near the circumference can be defined as the effective aperture range of the lens. The following embodiments omit portions of the extensions for clarity of the drawings. Further, the method of determining the range of the optical axis vicinity region, the circumference vicinity region, or the plurality of regions is as follows:

first, a central point is defined as an intersection point of the lens surface and the optical axis, the distance from the central point to the boundary of the effective aperture range of the lens is the effective semi-aperture of the lens, and a point of inflection is located on the lens surface and is not located on the optical axis, and a tangent line passing through the point of inflection is perpendicular to the optical axis (i.e. the surface types of both sides of the point of inflection on the lens surface are opposite). If there are several points of inflection from the central point to the outside in the radial direction of the lens, the points of inflection are the first point of inflection and the second point of inflection in sequence, and the point of inflection farthest from the central point in the effective aperture range of the lens is the Nth point of inflection. Defining the range between the central point and the first inflection point as an area near the optical axis, defining an area radially outward of the Nth inflection point as an area near the circumference, and dividing the area between the first inflection point and the Nth inflection point into different areas according to the inflection points; if there is no inflection point on the lens surface, the region near the optical axis is defined as a region corresponding to 0 to 50% of the effective half-aperture, and the region near the circumference is defined as a region corresponding to 50 to 100% of the effective half-aperture.

The features, principles and other aspects of the present application are described in detail below.

Referring to fig. 1, fig. 3, fig. 5, fig. 7, fig. 9, fig. 11, fig. 13, fig. 15, fig. 17, and fig. 19, an optical system with a large aperture, a high pixel size, and a small size is provided according to an embodiment of the present disclosure. Specifically, the optical system includes seven lens elements with refractive power, namely a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element, a sixth lens element and a fourth lens element. The seven lenses are arranged in sequence from the object side to the image side along the optical axis, and an imaging surface of the optical system is positioned at the image side of the seventh lens.

The first lens element can have positive refractive power, so that the light can be effectively transmitted to the image plane by adjusting the refractive power of the first lens element, and the spherical aberration of the optical system can be reduced. In addition, the object side surface of the first lens is convex at the position close to the optical axis, so that the incident angle of light on the first lens can be favorably reduced and the formation of stray light can be reduced by controlling the shape of the object side surface of the first lens; the image side surface of the first lens is concave at the position close to the optical axis, so that the shape of the image side surface of the first lens is controlled, the light rays incident at a large angle can enter the system, and the sensitivity of the optical system is further reduced.

The second lens can have refractive power, and when the second lens has positive refractive power, the light rays can be further converged, so that the total length of the system can be shortened, and the miniaturization and the ultra-thinness of the system can be realized; when the second lens element has negative refractive power, the refractive power of the first lens element is balanced, so that the peripheral field of view light is smoothly transferred to the third lens element. In addition, the object side surface of the second lens is arranged to be convex at the position close to the optical axis, so that aberration generated by the light rays which are refracted and converted by the first lens can be corrected, and the imaging quality of the system is improved; the image side surface of the second lens is concave at the position close to the optical axis, which is beneficial to correcting chromatic aberration so as to improve the imaging quality.

The third lens element with refractive power, the fourth lens element with refractive power, the fifth lens element with refractive power and the sixth lens element with refractive power. The lenses can have positive refractive power and negative refractive power, and the refractive power matching among the lenses is favorable for enhancing the resolving power of the system, effectively correcting the aberration and improving the imaging quality of the system.

The seventh lens element with negative refractive power helps to balance the refractive power distribution at the image-side end of the optical system to reduce aberrations, and helps to shorten the back focal length of the system, thereby reducing the size of the optical system and achieving miniaturization. In addition, the image side surface of the seventh lens is concave at the paraxial region, so that off-axis aberration can be corrected to improve imaging quality. Furthermore, at least one surface of the object side surface and/or the image side surface of the seventh lens comprises at least one inflection point, so that the miniaturization of a system is realized by shortening a back focal length, the field curvature is corrected, the incidence angle of a main ray of an off-axis view field on an imaging surface is effectively inhibited, the photosensitive performance of a pixel unit in the edge area of a photosensitive chip is enhanced, and the image quality of a peripheral view field is improved.

The optical system is also provided with a diaphragm. In the embodiment of the application, the diaphragm is arranged at the object side of the optical system to better control the size of an incident beam, reduce stray light and improve the imaging quality of the optical system; in addition, the diaphragm is arranged in front, so that the total length of the system can be further shortened, the application requirement of miniaturization is met, and meanwhile, the optical system can have a telecentric effect. In other embodiments, the diaphragm may be further disposed between the first lens and the imaging surface, and coma aberration of the off-axis light may be corrected by adjusting the position of the diaphragm, so as to further improve the imaging quality and facilitate expanding the field angle of the system. Specifically, the diaphragms include an aperture diaphragm and a field diaphragm. Preferably, the diaphragm is an aperture diaphragm. The aperture stop may be located on a surface of the lens (e.g., the object side and the image side) and in operative relationship with the lens, for example, by applying a light blocking coating to the surface of the lens to form the aperture stop at the surface; or the surface of the clamping lens is fixedly clamped by the clamping piece, and the structure of the clamping piece on the surface can limit the width of the imaging light beam of the on-axis object point, so that the aperture stop is formed on the surface.

Specifically, the optical system further satisfies the following relation: f tan (hfov) > 5.15 mm; the HFOV represents a half of a diagonal angle of view of the optical system. f tan (hfov) may be 5.16mm, 5.17mm, 5.18mm, 5.19mm, 5.20mm or 5.21 mm. When the relation is met, the optical system has a larger image surface, so that more pixel units on the photosensitive element can be covered, the imaging characteristic of high pixels is realized, and the imaging definition is improved.

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

According to the optical system, the imaging analysis capability of the system can be enhanced and the aberration can be effectively corrected by selecting a proper number of lenses and reasonably distributing the refractive power and the surface shape of each lens and the effective focal length of each lens, so that the resolution of the system is improved, and the definition of an image is ensured; meanwhile, the control system meets the relation, and is favorable for enabling the system to have a larger image surface, so that the imaging characteristic of high pixels is realized, and the imaging quality of the system in a dark light environment is ensured.

In an exemplary embodiment, the optical system satisfies the following relationship: TTL/ImgH is less than 1.7; wherein, TTL represents a distance on the optical axis from the object-side surface of the first lens element to the imaging surface of the optical system, and ImgH represents a half of the length of the diagonal line of the effective pixel area on the imaging surface of the optical system. TTL/ImgH can be 1.56, 1.57, 1.58, 1.59, 1.60, 1.62, 1.63, 1.64, or 1.65. When the relation is satisfied, the total length of the system and the size of the image plane can be controlled within a reasonable range, so that the total length of the system is shortened on the premise of ensuring a large image plane, and the ultra-thinness and miniaturization of the system are realized. On the other hand, when TTL/ImgH is 1.7 or more, the total length of the system is likely to be long, which is not favorable for the miniaturization of the system.

In an exemplary embodiment, the optical system satisfies the following relationship: TTL/f is more than 1 and less than 1.5; wherein, TTL represents a distance on the optical axis from the object-side surface of the first lens element to the imaging surface of the optical system. TTL/f can be 1.3, 1.31, 1.32, 1.33, 1.34, 1.35, 1.36, 1.37, 1.38, 1.4, or 1.45. When the upper limit of the relational expression is satisfied, the optical system has smaller total length, which is beneficial to realizing the miniaturization of the system; when the lower limit of the relation is met, the total length of the system can not be too small, so that the sensitivity of the system is favorably reduced, the lens assembly is convenient, and the production yield is improved.

In an exemplary embodiment, the optical system satisfies the following relationship: 0.5 < | RS5/RS6| < 1.5; wherein RS5 denotes a radius of curvature of the object-side surface of the third lens at the optical axis, and RS6 denotes a radius of curvature of the image-side surface of the third lens at the optical axis. | RS5/RS6| can be 0.01, 0.55, 0.58, 0.61, 0.65, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, or 1.4. When the relation is satisfied, the curvature radiuses of the object side surface and the image side surface of the third lens at the optical axis can be reasonably configured, so that the bending degree of the third lens is favorably controlled, the third lens is prevented from being bent excessively, the sensitivity of the third lens is reduced, and the third lens is convenient to machine and form. When RS5/RS6 is less than or equal to 0.5 or more than or equal to 1.5, the third lens is easy to be over-bent, which is not favorable for reducing the sensitivity of the lens and processing and molding the lens.

In an exemplary embodiment, the optical system satisfies the following relationship: i f1/f 5I < 2; where f1 denotes an effective focal length of the first lens, and f5 denotes an effective focal length of the fifth lens. If 1/f5 can be 0.05, 0.5, 0.6, 0.7, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, or 1.6. When the relation is satisfied, the effective focal lengths of the first lens and the fifth lens are favorably and reasonably distributed, so that the position chromatic aberration of the optical system is effectively corrected. When the refractive power of the first lens element is too small or the refractive power of the fifth lens element is too large, it is easy to correct the chromatic aberration of the system when the refractive power of the fifth lens element is larger than or equal to 2.

In an exemplary embodiment, the optical system satisfies the following relationship: CT2 is more than or equal to 0.3 mm; where CT2 denotes the thickness of the second lens on the optical axis. CT2 may be 0.3mm, 0.31mm, 0.32mm, 0.33mm, 0.34mm, 0.35mm, 0.36mm or 0.37 mm. When the relational expression is satisfied, the processing and the molding of the second lens are facilitated, the production yield is improved, and meanwhile, the total length of the optical system can be ensured to be in a reasonable range. When CT2 is smaller than 0.3mm, the second lens element is too thin, which is not favorable for the refractive power configuration of the system and is also not favorable for the processing and molding of the second lens element.

In an exemplary embodiment, the optical system satisfies the following relationship: TTL/f1 is less than or equal to 1.5; wherein TTL denotes a distance on the optical axis from the object side surface of the first lens to the imaging surface of the optical system, and f1 denotes an effective focal length of the first lens. TTL/f1 can be 1.1, 1.2, 1.3, 1.31, 1.32, 1.33, 1.34, 1.35, 1.36, 1.37, or 1.4. When the above relation is satisfied, the total length of the optical system and the effective focal length of the first lens element can be reasonably configured, so that the refractive power of the first lens element can be controlled, high-order aberration caused by excessive deflection of marginal field rays due to excessive refractive power of the first lens element can be avoided, the total length of the system can be controlled within a smaller range under the condition of ensuring image quality, and the miniaturization of the system can be realized. When TTL/f1 is larger than 1.5, the total length of the system is easily overlong, which is not beneficial to miniaturization; or the refractive power of the first lens element is too large, which tends to cause excessive light deflection and thus high-order aberration.

In an exemplary embodiment, the optical system satisfies the following relationship: f/EPD is less than 1.7; where f denotes an effective focal length of the optical system, and EPD denotes an entrance pupil diameter of the optical system. The f/EPD may be 1.66, 1.67, 1.68, or 1.69. When the relation is satisfied, the system can have a larger clear aperture to obtain a larger light inlet quantity, the image surface brightness is improved, and the dark light shooting capability of the system is enhanced.

In an exemplary embodiment, the optical system satisfies the following relationship: f1/RS1 is less than 3.5; where f1 denotes an effective focal length of the first lens, and RS1 denotes a radius of curvature of the object side surface of the first lens at the optical axis. f1/RS1 can be 1.9, 2.0, 2.1, 2.2, 2.5, 2.7, 2.9, 3.1, 3.2, 3.4, or 3.45. When the above relation is satisfied, the effective focal length of the first lens and the curvature radius of the object side surface of the first lens at the optical axis can be reasonably configured, so that the object side surface of the first lens is prevented from being over-bent, and the reduction of the sensitivity of the optical system is facilitated. When f1/RS1 is greater than or equal to 2.5, the refractive power of the first lens element is easily reduced, which is not favorable for light transmission and convergence; and meanwhile, the object side of the first lens is easy to be over-bent, so that the sensitivity of the system is increased.

In an exemplary embodiment, an optical filter is further disposed between the seventh lens and the imaging surface of the optical system, and is used for filtering light rays in a non-working wavelength band, so that a phenomenon of generating false colors or ripples due to interference of light rays in the non-working wavelength band is prevented, and distortion of imaging colors is avoided. Specifically, the optical filter may be an infrared filter, and the material of the optical filter is glass.

In an exemplary embodiment, each lens in the optical system may be made of glass or plastic, the plastic lens can reduce the weight and production cost of the optical system, and the glass lens can provide the optical system with better temperature tolerance and excellent optical performance. Furthermore, when the optical system is applied to electronic devices such as mobile phones and flat panels, the material of each lens is preferably plastic, so that the electronic devices meet the development requirements of being light and thin. It should be noted that the material of each lens in the optical system may be any combination of glass and plastic, and is not necessarily all glass or all plastic.

In an exemplary embodiment, the optical system may further include a protective glass. The protective glass is arranged at the image side of the sixth lens or the image side of the optical filter, plays a role in protecting the photosensitive element, and can also prevent the photosensitive element from being polluted and dust falling, thereby further ensuring the imaging quality. When the optical system is applied to an electronic device such as a mobile phone or a tablet, the cover glass may not be provided, so as to further reduce the weight of the electronic device.

The optical system of the above-described embodiments of the present application may employ a plurality of lenses, such as the seven lenses described above. Through rational distribution of focal length, refractive power, surface type, thickness of each lens and on-axis distance between each lens, the optical system can be guaranteed to have a larger aperture (FNO can be 1.66), the dark light shooting capability of the optical system is improved, and the optical system has a smaller total length, lighter weight, higher imaging resolution and a larger field angle, so that the application requirements of light-weight electronic equipment such as mobile phones and flat plates and the shooting requirements of users are better met. However, it will be understood by those skilled in the art that the number of lenses constituting the optical system may be varied to obtain the respective results and advantages described in the present specification without departing from the technical solutions claimed in the present application.

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

Example 1

An optical system 100 of embodiment 1 of the present application is described below with reference to fig. 1 to 2.

Fig. 1 shows a schematic configuration diagram of an optical system 100 of embodiment 1. As shown in fig. 1, the optical system 100 includes, in order from an object side to an image side along an optical axis, a first lens element L1, a second lens element L2, a third lens element L3, a fourth lens element L4, a fifth lens element L5, a sixth lens element L6, a seventh lens element L7, and an image plane S17.

The first lens element L1 with positive refractive power has an object-side surface S1 and an image-side surface S2 that are aspheric, wherein the object-side surface S1 is convex along an optical axis and convex along a circumference, and the image-side surface S2 is concave along the optical axis and concave along the circumference.

The second lens element L2 with negative refractive power has an object-side surface S3 and an image-side surface S4 that are aspheric, wherein the object-side surface S3 is convex along the optical axis and convex along the circumference, and the image-side surface S4 is concave along the optical axis and concave along the circumference.

The third lens element L3 with positive refractive power has an object-side surface S5 and an image-side surface S6 that are aspheric, wherein the object-side surface S5 is convex along an optical axis and concave along a circumference, and the image-side surface S6 is convex along the optical axis and convex along the circumference.

The fourth lens element L4 with negative refractive power has an object-side surface S7 and an image-side surface S8 that are aspheric, wherein the object-side surface S7 is concave along the optical axis and concave along the circumference, and the image-side surface S8 is concave along the optical axis and convex along the circumference.

The fifth lens element L5 with positive refractive power has an object-side surface S9 and an image-side surface S10 that are aspheric, wherein the object-side surface S9 is concave along the optical axis and concave along the circumference, and the image-side surface S10 is convex along the optical axis and convex along the circumference.

The sixth lens element L6 with positive refractive power has an object-side surface S11 and an image-side surface S12 that are aspheric, wherein the object-side surface S11 is convex along an optical axis and concave along a circumference, and the image-side surface S12 is concave along the optical axis and convex along the circumference.

The seventh lens element L7 with negative refractive power has an object-side surface S13 and an image-side surface S14 that are aspheric, wherein the object-side surface S13 is convex along an optical axis and concave along a circumference, and the image-side surface S14 is concave along the optical axis and convex along the circumference.

The object-side surface and the image-side surface of each of the first lens L1 to the seventh lens L7 are aspheric, which is advantageous for correcting aberrations and solving the problem of image surface distortion, and enables the lenses to achieve excellent optical imaging effects even when the lenses are small, thin, and flat, thereby enabling the optical system 100 to have a compact size.

The first lens L1 to the seventh lens L7 are made of plastic, and the use of plastic lenses can reduce the weight of the optical system 100 and reduce the production cost.

The object side of the optical system 100 is further provided with a stop STO to limit the size of the incident light beam, thereby further improving the imaging quality of the optical system 100. The optical system 100 further includes a filter 110 disposed on the image side of the seventh lens L7 and having an object-side surface S15 and an image-side surface S16. Light from the object OBJ sequentially passes through the respective surfaces S1 to S16 and is finally imaged on the imaging plane S17. The optical filter 110 is used for filtering the light rays in the non-working wavelength band, thereby preventing the phenomenon of generating false color or moire caused by the interference of the light rays in the non-working wavelength band, and avoiding the distortion of the imaging color. Specifically, the filter 110 is an infrared cut filter, and is made of glass.

Table 1 shows the surface type, radius of curvature, thickness, material, refractive index, abbe number (i.e., abbe number), and effective focal length of the lens of the optical system 100 of example 1, where the unit of the radius of curvature, thickness, and effective focal length of the lens are all millimeters (mm). In addition, taking the first lens element L1 as an example, the first numerical value in the "thickness" parameter sequence of the first lens element L1 is the thickness of the lens element on the optical axis, and the second numerical value is the distance between the image-side surface of the lens element and the object-side surface of the subsequent lens element in the image-side direction; the numerical value of the stop ST0 in the "thickness" parameter column is the distance on the optical axis from the stop ST0 to the vertex of the object-side surface of the subsequent lens (the vertex refers to the intersection point of the lens surface and the optical axis), and we default that the direction from the object-side surface to the image-side surface of the last lens of the first lens L1 is the positive direction of the optical axis, when the value is negative, it indicates that the stop ST0 is disposed on the right side of the vertex of the object-side surface of the lens in fig. 1, and when the thickness of the stop STO is positive, the stop is on the left side of the vertex of the object-.

TABLE 1

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

wherein x is the rise of the distance from the aspheric surface vertex to the aspheric surface vertex when the aspheric surface is at the position with the height of h along the optical axis direction; c is the paraxial curvature of the aspheric surface, c being 1/R (i.e., paraxial curvature c is the inverse of radius of curvature R in table 1); k is a conic coefficient; ai is the ith order coefficient of the aspheric surface. Table 2 below gives the high-order term coefficients a4, a6, A8, a10, a12, a14, a16, a18, and a20 that can be used for the aspherical surfaces S1 to S14 of the lens in example 1.

TABLE 2

TTL indicates that the distance on the optical axis from the object side surface S1 of the first lens L1 to the imaging surface S17 of the optical system 100 is 8.6mm, and ImgH, which is half the diagonal length of the effective pixel region on the imaging surface S17 of the optical system 100, is 5.29 mm. As can be seen from the data in tables 1 and 2, the optical system 100 in example 1 satisfies:

f tan (HFOV) ═ 5.19mm, where f denotes the effective focal length of the optical system 100, and HFOV denotes half the diagonal field angle of the optical system 100;

TTL/ImgH＝1.63；

TTL/f＝1.32；

l RS5/RS6| ═ 0.61, where RS5 denotes a radius of curvature of the object-side surface S5 of the third lens L3 at the optical axis, and RS6 denotes a radius of curvature of the image-side surface S6 of the third lens L3 at the optical axis;

i f1/f5| ═ 0.72, where f1 denotes the effective focal length of the first lens L1, and f5 denotes the effective focal length of the fifth lens L5;

CT2 ═ 0.33mm, where CT2 denotes the thickness of the second lens L2 on the optical axis;

TTL/f1 is 1.26, where f1 denotes an effective focal length of the first lens L1;

f/EPD is 1.66, where EPD represents the entrance pupil diameter of the optical system 100;

f1/RS1 is 2.12, where f1 denotes an effective focal length of the first lens L1, and RS1 denotes a radius of curvature of the object-side surface S1 of the first lens L1 at the optical axis.

Fig. 2 shows a longitudinal spherical aberration graph, an astigmatism graph, and a distortion graph, respectively, of the optical system 100 of example 1, the reference wavelength of the optical system 100 being 555 nm. Wherein the longitudinal spherical aberration plots show the convergent focus shifts of light rays having wavelengths of 470nm, 510nm, 555nm, 610nm, and 650nm after passing through the optical system 100; the astigmatism graph shows meridional field curvature and sagittal field curvature of a light ray with a wavelength of 555nm after passing through the optical system 100; the distortion plot shows the distortion of light with a wavelength of 555nm at different image heights after passing through the optical system 100. As can be seen from fig. 2, the optical system 100 according to embodiment 1 can achieve good image quality.

Example 2

The optical system 100 of embodiment 2 of the present application is described below with reference to fig. 3 to 4. In this embodiment, a description of parts similar to those of embodiment 1 will be omitted for the sake of brevity. Fig. 3 shows a schematic structural diagram of the optical system 100 according to embodiment 2 of the present application.

As shown in fig. 3, the optical system 100 includes, in order from an object side to an image side along an optical axis, a first lens element L1, a second lens element L2, a third lens element L3, a fourth lens element L4, a fifth lens element L5, a sixth lens element L6, a seventh lens element L7, and an image plane S17.

The third lens element L3 with positive refractive power has an object-side surface S5 and an image-side surface S6 that are aspheric, wherein the object-side surface S5 is convex along an optical axis and concave along a circumference, and the image-side surface S6 is concave along the optical axis and convex along the circumference.

The object-side surface and the image-side surface of the first lens L1 through the seventh lens L7 are each set to an aspherical surface. The first lens L1 to the seventh lens L7 are all made of plastic. The object side of the optical system 100 is further provided with a stop STO to limit the size of the incident light beam, thereby further improving the imaging quality of the optical system 100. The optical system 100 further includes a filter 110 disposed on the image side of the seventh lens L7 and having an object-side surface S15 and an image-side surface S16. Light from the object OBJ sequentially passes through the respective surfaces S1 to S16 and is finally imaged on the imaging plane S17. Specifically, the filter 110 is an infrared cut filter, and is made of glass.

Table 3 shows the surface type, radius of curvature, thickness, material, refractive index, abbe number (i.e., abbe number), and effective focal length of each lens of the optical system 100 of example 2, wherein the unit of the radius of curvature, thickness, and effective focal length of each lens is millimeters (mm); table 4 shows high-order term coefficients that can be used for the lens aspheres S1-S14 in example 2, in which the aspherical surface types can be defined by formula (1) given in example 1; table 5 shows the values of relevant parameters of the optical system 100 given in example 2.

TABLE 3

TABLE 4

TABLE 5

Fig. 4 shows a longitudinal spherical aberration graph, an astigmatism graph, and a distortion graph, respectively, of the optical system 100 of example 2, the reference wavelength of the optical system 100 being 555 nm. Wherein the longitudinal spherical aberration plots show the convergent focus shifts of light rays having wavelengths of 470nm, 510nm, 555nm, 610nm, and 650nm after passing through the optical system 100; the astigmatism graph shows meridional field curvature and sagittal field curvature of a light ray with a wavelength of 555nm after passing through the optical system 100; the distortion plot shows the distortion of light with a wavelength of 555nm at different image heights after passing through the optical system 100. As can be seen from fig. 4, the optical system 100 according to embodiment 2 can achieve good imaging quality.

Example 3

The optical system 100 of embodiment 3 of the present application is described below with reference to fig. 5 to 6. In this embodiment, a description of parts similar to those of embodiment 1 will be omitted for the sake of brevity. Fig. 5 shows a schematic structural diagram of an optical system 100 according to embodiment 3 of the present application.

As shown in fig. 5, the optical system 100 includes, in order from an object side to an image side along an optical axis, a first lens element L1, a second lens element L2, a third lens element L3, a fourth lens element L4, a fifth lens element L5, a sixth lens element L6, a seventh lens element L7, and an image plane S17.

The sixth lens element L6 with negative refractive power has an object-side surface S11 and an image-side surface S12 that are aspheric, wherein the object-side surface S11 is convex along an optical axis and concave along a circumference, and the image-side surface S12 is concave along the optical axis and convex along the circumference.

Table 6 shows the surface type, radius of curvature, thickness, material, refractive index, abbe number (i.e., abbe number), and effective focal length of each lens of the optical system 100 of example 3, wherein the unit of the radius of curvature, thickness, and effective focal length of each lens is millimeters (mm); table 7 shows high-order term coefficients that can be used for the lens aspherical surfaces S1 to S14 in embodiment 3, wherein the aspherical surface type can be defined by formula (1) given in embodiment 1; table 8 shows the values of relevant parameters of the optical system 100 given in example 3.

TABLE 6

TABLE 7

TABLE 8

Fig. 6 shows a longitudinal spherical aberration graph, an astigmatism graph, and a distortion graph, respectively, of the optical system 100 of example 3, the reference wavelength of the optical system 100 being 555 nm. Wherein the longitudinal spherical aberration plots show the convergent focus shifts of light rays having wavelengths of 470nm, 510nm, 555nm, 610nm, and 650nm after passing through the optical system 100; the astigmatism graph shows meridional field curvature and sagittal field curvature of a light ray with a wavelength of 555nm after passing through the optical system 100; the distortion plot shows the distortion of light with a wavelength of 555nm at different image heights after passing through the optical system 100. As can be seen from fig. 6, the optical system 100 according to embodiment 3 can achieve good imaging quality.

Example 4

The optical system 100 of embodiment 4 of the present application is described below with reference to fig. 7 to 8. In this embodiment, a description of parts similar to those of embodiment 1 will be omitted for the sake of brevity. Fig. 7 shows a schematic structural diagram of an optical system 100 according to embodiment 4 of the present application.

As shown in fig. 7, the optical system 100 includes, in order from an object side to an image side along an optical axis, a first lens element L1, a second lens element L2, a third lens element L3, a fourth lens element L4, a fifth lens element L5, a sixth lens element L6, a seventh lens element L7, and an image plane S17.

The fourth lens element L4 with positive refractive power has an object-side surface S7 and an image-side surface S8 that are aspheric, wherein the object-side surface S7 is concave along the optical axis and concave along the circumference, and the image-side surface S8 is convex along the optical axis and convex along the circumference.

Table 9 shows the surface type, radius of curvature, thickness, material, refractive index, abbe number (i.e., abbe number), and effective focal length of each lens of the optical system 100 of example 4, wherein the unit of the radius of curvature, thickness, and effective focal length of each lens is millimeters (mm); table 10 shows high-order term coefficients that can be used for the lens aspherical surfaces S1 to S14 in embodiment 4, wherein the aspherical surface types can be defined by formula (1) given in embodiment 1; table 11 shows the values of relevant parameters of the optical system 100 given in example 4.

TABLE 9

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TABLE 11

Fig. 8 shows a longitudinal spherical aberration graph, an astigmatism graph, and a distortion graph, respectively, of the optical system 100 of example 4, the reference wavelength of the optical system 100 being 555 nm. Wherein the longitudinal spherical aberration plots show the convergent focus shifts of light rays having wavelengths of 470nm, 510nm, 555nm, 610nm, and 650nm after passing through the optical system 100; the astigmatism graph shows meridional field curvature and sagittal field curvature of a light ray with a wavelength of 555nm after passing through the optical system 100; the distortion plot shows the distortion of light with a wavelength of 555nm at different image heights after passing through the optical system 100. As can be seen from fig. 8, the optical system 100 according to embodiment 4 can achieve good imaging quality.

Example 5

An optical system 100 of embodiment 5 of the present application is described below with reference to fig. 9 to 10. In this embodiment, a description of parts similar to those of embodiment 1 will be omitted for the sake of brevity. Fig. 9 shows a schematic structural diagram of an optical system 100 according to embodiment 5 of the present application.

As shown in fig. 9, the optical system 100 includes, in order from an object side to an image side along an optical axis, a first lens element L1, a second lens element L2, a third lens element L3, a fourth lens element L4, a fifth lens element L5, a sixth lens element L6, a seventh lens element L7, and an image plane S17.

The fourth lens element L4 with negative refractive power has an object-side surface S7 and an image-side surface S8 that are aspheric, wherein the object-side surface S7 is concave along the optical axis and concave along the circumference, and the image-side surface S8 is convex along the optical axis and convex along the circumference.

The fifth lens element L5 with negative refractive power has an object-side surface S9 and an image-side surface S10 that are aspheric, wherein the object-side surface S9 is concave along the optical axis and concave along the circumference, and the image-side surface S10 is convex along the optical axis and concave along the circumference.

Table 12 shows the surface type, radius of curvature, thickness, material, refractive index, abbe number (i.e., abbe number), and effective focal length of each lens of the optical system 100 of example 5, wherein the unit of the radius of curvature, thickness, and effective focal length of each lens is millimeters (mm); table 13 shows high-order term coefficients that can be used for the lens aspherical surfaces S1 to S14 in example 5, wherein the aspherical surface type can be defined by formula (1) given in example 1; table 14 shows the values of relevant parameters of the optical system 100 given in example 5.

TABLE 12

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TABLE 14

Fig. 10 shows a longitudinal spherical aberration graph, an astigmatism graph, and a distortion graph, respectively, of the optical system 100 of example 5, the reference wavelength of the optical system 100 being 555 nm. Wherein the longitudinal spherical aberration plots show the convergent focus shifts of light rays having wavelengths of 470nm, 510nm, 555nm, 610nm, and 650nm after passing through the optical system 100; the astigmatism graph shows meridional field curvature and sagittal field curvature of a light ray with a wavelength of 555nm after passing through the optical system 100; the distortion plot shows the distortion of light with a wavelength of 555nm at different image heights after passing through the optical system 100. As can be seen from fig. 10, the optical system 100 according to embodiment 5 can achieve good image quality.

Example 6

An optical system 100 of embodiment 6 of the present application is described below with reference to fig. 11 to 12. In this embodiment, a description of parts similar to those of embodiment 1 will be omitted for the sake of brevity. Fig. 11 shows a schematic structural diagram of an optical system 100 according to embodiment 6 of the present application.

As shown in fig. 11, the optical system 100 includes, in order from an object side to an image side along an optical axis, a first lens element L1, a second lens element L2, a third lens element L3, a fourth lens element L4, a fifth lens element L5, a sixth lens element L6, a seventh lens element L7, and an image plane S17.

The third lens element L3 with negative refractive power has an object-side surface S5 and an image-side surface S6 that are aspheric, wherein the object-side surface S5 is concave along the optical axis and concave along the circumference, and the image-side surface S6 is convex along the optical axis and convex along the circumference.

The fifth lens element L5 with positive refractive power has an object-side surface S9 and an image-side surface S10 that are aspheric, wherein the object-side surface S9 is convex along an optical axis and concave along a circumference, and the image-side surface S10 is convex along the optical axis and convex along the circumference.

Table 15 shows the surface type, radius of curvature, thickness, material, refractive index, abbe number (i.e., abbe number), and effective focal length of each lens of the optical system 100 of example 6, wherein the unit of the radius of curvature, thickness, and effective focal length of each lens is millimeters (mm); table 16 shows high-order term coefficients that can be used for the lens aspherical surfaces S1 to S14 in example 6, wherein the aspherical surface types can be defined by formula (1) given in example 1; table 17 shows the values of relevant parameters of the optical system 100 given in example 6.

Watch 15

TABLE 16

TABLE 17

Fig. 12 shows a longitudinal spherical aberration graph, an astigmatism graph, and a distortion graph, respectively, of the optical system 100 of example 6, the reference wavelength of the optical system 100 being 555 nm. Wherein the longitudinal spherical aberration plots show the convergent focus shifts of light rays having wavelengths of 470nm, 510nm, 555nm, 610nm, and 650nm after passing through the optical system 100; the astigmatism graph shows meridional field curvature and sagittal field curvature of a light ray with a wavelength of 555nm after passing through the optical system 100; the distortion plot shows the distortion of light with a wavelength of 555nm at different image heights after passing through the optical system 100. As can be seen from fig. 12, the optical system 100 according to embodiment 6 can achieve good imaging quality.

Example 7

An optical system 100 of embodiment 7 of the present application is described below with reference to fig. 13 to 14. In this embodiment, a description of parts similar to those of embodiment 1 will be omitted for the sake of brevity. Fig. 13 is a schematic structural view showing an optical system 100 according to embodiment 7 of the present application.

As shown in fig. 13, the optical system 100 includes, in order from an object side to an image side along an optical axis, a first lens element L1, a second lens element L2, a third lens element L3, a fourth lens element L4, a fifth lens element L5, a sixth lens element L6, a seventh lens element L7, and an image plane S17.

The second lens element L2 with positive refractive power has an object-side surface S3 and an image-side surface S4 that are aspheric, wherein the object-side surface S3 is convex along the optical axis and convex along the circumference, and the image-side surface S4 is concave along the optical axis and concave along the circumference.

Table 18 shows the surface type, radius of curvature, thickness, material, refractive index, abbe number (i.e., abbe number), and effective focal length of each lens of the optical system 100 of example 7, wherein the unit of the radius of curvature, thickness, and effective focal length of each lens is millimeters (mm); table 19 shows high-order term coefficients that can be used for the lens aspherical surfaces S1 to S14 in example 7, wherein the aspherical surface types can be defined by formula (1) given in example 1; table 20 shows the values of relevant parameters of the optical system 100 given in example 7.

Watch 18

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Fig. 14 shows a longitudinal spherical aberration graph, an astigmatism graph, and a distortion graph, respectively, of the optical system 100 of example 7, the reference wavelength of the optical system 100 being 555 nm. Wherein the longitudinal spherical aberration plots show the convergent focus shifts of light rays having wavelengths of 470nm, 510nm, 555nm, 610nm, and 650nm after passing through the optical system 100; the astigmatism graph shows meridional field curvature and sagittal field curvature of a light ray with a wavelength of 555nm after passing through the optical system 100; the distortion plot shows the distortion of light with a wavelength of 555nm at different image heights after passing through the optical system 100. As can be seen from fig. 14, the optical system 100 according to embodiment 7 can achieve good image quality.

Example 8

An optical system 100 of embodiment 8 of the present application is described below with reference to fig. 15 to 16. In this embodiment, a description of parts similar to those of embodiment 1 will be omitted for the sake of brevity. Fig. 15 shows a schematic structural diagram of an optical system 100 according to embodiment 8 of the present application.

As shown in fig. 15, the optical system 100 includes, in order from an object side to an image side along an optical axis, a first lens element L1, a second lens element L2, a third lens element L3, a fourth lens element L4, a fifth lens element L5, a sixth lens element L6, a seventh lens element L7, and an image plane S17.

Table 21 shows the surface type, radius of curvature, thickness, material, refractive index, abbe number (i.e., abbe number), and effective focal length of each lens of the optical system 100 of example 8, wherein the unit of the radius of curvature, thickness, and effective focal length of each lens is millimeters (mm); table 22 shows high-order term coefficients that can be used for the lens aspherical surfaces S1 to S14 in embodiment 8, wherein the aspherical surface types can be defined by formula (1) given in embodiment 1; table 23 shows the values of relevant parameters of the optical system 100 given in example 8.

TABLE 21

TABLE 22

TABLE 23

Fig. 16 shows a longitudinal spherical aberration graph, an astigmatism graph, and a distortion graph, respectively, of the optical system 100 of example 8, the reference wavelength of the optical system 100 being 555 nm. Wherein the longitudinal spherical aberration plots show the convergent focus shifts of light rays having wavelengths of 470nm, 510nm, 555nm, 610nm, and 650nm after passing through the optical system 100; the astigmatism graph shows meridional field curvature and sagittal field curvature of a light ray with a wavelength of 555nm after passing through the optical system 100; the distortion plot shows the distortion of light with a wavelength of 555nm at different image heights after passing through the optical system 100. As can be seen from fig. 16, the optical system 100 according to embodiment 8 can achieve good image quality.

Example 9

An optical system 100 of embodiment 9 of the present application is described below with reference to fig. 17 to 18. In this embodiment, a description of parts similar to those of embodiment 1 will be omitted for the sake of brevity. Fig. 17 shows a schematic structural diagram of an optical system 100 according to embodiment 9 of the present application.

As shown in fig. 17, the optical system 100 includes, in order from an object side to an image side along an optical axis, a first lens element L1, a second lens element L2, a third lens element L3, a fourth lens element L4, a fifth lens element L5, a sixth lens element L6, a seventh lens element L7, and an image plane S17.

The fourth lens element L4 with negative refractive power has an object-side surface S7 and an image-side surface S8 that are aspheric, wherein the object-side surface S7 is convex along the optical axis and concave along the circumference, and the image-side surface S8 is concave along the optical axis and convex along the circumference.

Table 24 shows the surface type, radius of curvature, thickness, material, refractive index, abbe number (i.e., abbe number), and effective focal length of each lens of the optical system 100 of example 9, wherein the unit of the radius of curvature, thickness, and effective focal length of each lens is millimeters (mm); table 25 shows high-order term coefficients that can be used for the lens aspherical surfaces S1 to S14 in example 9, wherein the aspherical surface types can be defined by formula (1) given in example 1; table 26 shows the values of relevant parameters of the optical system 100 given in example 9.

Watch 24

TABLE 25

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Fig. 18 shows a longitudinal spherical aberration graph, an astigmatism graph, and a distortion graph, respectively, of the optical system 100 of example 9, the reference wavelength of the optical system 100 being 555 nm. Wherein the longitudinal spherical aberration plots show the convergent focus shifts of light rays having wavelengths of 470nm, 510nm, 555nm, 610nm, and 650nm after passing through the optical system 100; the astigmatism graph shows meridional field curvature and sagittal field curvature of a light ray with a wavelength of 555nm after passing through the optical system 100; the distortion plot shows the distortion of light with a wavelength of 555nm at different image heights after passing through the optical system 100. As can be seen from fig. 18, the optical system 100 according to embodiment 9 can achieve good image quality.

Example 10

An optical system 100 of embodiment 10 of the present application is described below with reference to fig. 19 to 20. In this embodiment, a description of parts similar to those of embodiment 1 will be omitted for the sake of brevity. Fig. 19 shows a schematic structural diagram of an optical system 100 according to embodiment 10 of the present application.

As shown in fig. 19, the optical system 100 includes, in order from an object side to an image side along an optical axis, a first lens element L1, a second lens element L2, a third lens element L3, a fourth lens element L4, a fifth lens element L5, a sixth lens element L6, a seventh lens element L7, and an image plane S17.

The sixth lens element L6 with negative refractive power has an object-side surface S11 and an image-side surface S12 that are aspheric, wherein the object-side surface S11 is concave along the optical axis and concave along the circumference, and the image-side surface S12 is concave along the optical axis and convex along the circumference.

Table 27 shows the surface type, radius of curvature, thickness, material, refractive index, abbe number (i.e., abbe number), and effective focal length of each lens of the optical system 100 of example 10, wherein the unit of the radius of curvature, thickness, and effective focal length of each lens is millimeters (mm); table 28 shows high-order term coefficients that can be used for the lens aspherical surfaces S1 to S14 in embodiment 10, wherein the aspherical surface types can be defined by formula (1) given in embodiment 1; table 29 shows the values of relevant parameters of the optical system 100 given in example 10.

Watch 27

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Fig. 20 shows a longitudinal spherical aberration graph, an astigmatism graph, and a distortion graph, respectively, of the optical system 100 of example 10, the reference wavelength of the optical system 100 being 555 nm. Wherein the longitudinal spherical aberration plots show the convergent focus shifts of light rays having wavelengths of 470nm, 510nm, 555nm, 610nm, and 650nm after passing through the optical system 100; the astigmatism graph shows meridional field curvature and sagittal field curvature of a light ray with a wavelength of 555nm after passing through the optical system 100; the distortion plot shows the distortion of light with a wavelength of 555nm at different image heights after passing through the optical system 100. As can be seen from fig. 20, the optical system 100 according to embodiment 10 can achieve good image quality.

As shown in fig. 21, the present application further provides an image capturing module 200, which includes the optical system 100 (shown in fig. 1) as described above; and a photosensitive element 210, the photosensitive element 210 being disposed on the image side of the optical system 100, a photosensitive surface of the photosensitive element 210 coinciding with the image forming surface S17. The photosensitive element 210 may be a Complementary Metal Oxide Semiconductor (CMOS) image sensor or a Charge-coupled Device (CCD) image sensor with good photosensitive performance and low noise, and the imaging surface S17 may be a plane or a curved surface with any curvature, especially a curved surface with a concave surface facing the object side, depending on the photosensitive element 210.

In other embodiments, the image capturing module 200 further includes a lens barrel (not shown) for carrying the optical system 100 and a corresponding supporting device (not shown).

In addition, the image capturing module 200 further includes a driving device (not shown) and an image stabilizing module (not shown). The driving device may have an Auto-focus (Auto-focus) function, and the driving method may use a driving system such as a Voice Coil Motor (VCM), a Micro Electro-Mechanical Systems (MEMS), a Piezoelectric system (piezo electric), and a Memory metal (Shape Memory Alloy). The driving device can make the optical system 100 obtain a better imaging position, so that the shot object can be shot to obtain a clear image under the state of different object distances; the image stabilization module may be an accelerometer, a gyroscope, or a Hall Effect Sensor. The driving device and the Image stabilizing module together serve as an optical anti-shake device (OIS), and compensate a blurred Image caused by shaking at the moment of shooting by adjusting the displacement of the optical axis of the optical system 100, or provide an Electronic anti-shake function (EIS) by using an Image compensation technology in Image software, so as to further improve the imaging quality of shooting of dynamic and low-illumination scenes.

The image capturing module 200 has a large light transmission aperture to obtain a large light transmission amount, can capture an image with a bright field of view and high pixels, is suitable for capturing in environments such as night scenes, rainy days, starry sky and the like, has a good imaging effect, has the structural characteristics of miniaturization and light weight, can be applied to the fields of cameras, mobile phones, automobiles, monitoring and the like, and can be used as a camera lens, a mobile phone camera, a vehicle-mounted camera, a monitoring camera and the like.

The present application further provides an electronic device, which includes a housing and the image capturing module 200 as described above, wherein the image capturing module 200 is mounted on the housing. Specifically, get for instance module 200 sets up in the casing and expose from the casing in order to acquire the image, and the casing can provide protection such as dustproof, waterproof falling for getting for instance module 200, has seted up the hole that corresponds with getting for instance module 200 on the casing to make light penetrate or wear out the casing from the hole.

Above-mentioned electronic device utilizes aforementioned module 200 of getting for instance can shoot and obtain the image that the visual field is bright, the pixel is high, can satisfy the shooting demand of different scenes, has promoted user's shooting experience. In other embodiments, the electronic device is further provided with a corresponding processing system, and the electronic device can transmit the image to the corresponding processing system in time after the image of the object is captured, so that the system can make accurate analysis and judgment.

In other embodiments, an "electronic device" as used may include devices configured to receive or transmit communication signals via a wireline connection and/or via a wireless interface. Electronic devices in which communication is arranged over a wireless interface may be referred to as "wireless communication terminals", "wireless terminals" or "mobile terminals". Examples of mobile terminals include, but are not limited to, satellite or cellular telephones; personal Communication System (PCS) terminals that may combine a cellular radiotelephone with data processing, facsimile and data communication capabilities; personal Digital Assistants (PDAs) that may include radiotelephones, pagers, internet/intranet access, Web browsers, notepads, calendars, and/or Global Positioning System (GPS) receivers; conventional laptop and/or palmtop receivers or include radiotelephone transceivers; other electronic devices. In addition, the "electronic device" may further include a three-dimensional image capturing device, a digital camera, a tablet computer, a smart television, a network monitoring device, a car recorder, a car backing developing device, a multi-lens device, an identification system, a motion sensing game machine, a wearable device, and the like. The electronic device is only an exemplary embodiment of the present invention, and the application scope of the image capturing module of the present invention is not limited.

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, in order from an object side to an image side along an optical axis,

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

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

a third lens element with refractive power;

a fourth lens element with refractive power;

a fifth lens element with refractive power;

a sixth lens element with refractive power;

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

the optical system satisfies the following relation:

f*tan(HFOV)＞5.15mm；

2. The optical system according to claim 1, wherein the optical system satisfies the following relation:

TTL/ImgH＜1.7；

wherein, TTL represents a distance on an optical axis from an object-side surface of the first lens element to an imaging surface of the optical system, and ImgH represents a half of a diagonal length of an effective pixel area on the imaging surface of the optical system.

3. The optical system according to claim 1, wherein the optical system satisfies the following relation:

1＜TTL/f＜1.5；

wherein TTL represents a distance on an optical axis from an object-side surface of the first lens element to an image plane of the optical system.

4. The optical system according to claim 1, wherein the optical system satisfies the following relation:

0.5＜|RS5/RS6|＜1.5；

wherein RS5 denotes a radius of curvature of an object-side surface of the third lens at an optical axis, and RS6 denotes a radius of curvature of an image-side surface of the third lens at the optical axis.

5. The optical system according to claim 1, wherein the optical system satisfies the following relation:

|f1/f5|＜2；

wherein f1 denotes an effective focal length of the first lens, and f5 denotes an effective focal length of the fifth lens.

6. The optical system according to claim 1, wherein the optical system satisfies the following relation:

CT2≥0.3mm；

wherein CT2 represents the thickness of the second lens on the optical axis.

7. The optical system according to claim 1, wherein the optical system satisfies the following relation:

TTL/f1≤1.5；

wherein TTL denotes an optical axis distance from an object side surface of the first lens element to an image plane of the optical system, and f1 denotes an effective focal length of the first lens element.

8. The optical system according to claim 1, wherein the optical system satisfies the following relation:

f/EPD＜1.7；

wherein EPD represents an entrance pupil diameter of the optical system.

9. The optical system according to claim 1, wherein the optical system satisfies the following relation:

f1/RS1＜3.5；

where f1 denotes an effective focal length of the first lens, and RS1 denotes a radius of curvature of an object side surface of the first lens at an optical axis.

10. An image capturing module, comprising the optical system according to any one of claims 1 to 9 and a photosensitive element, wherein the photosensitive element is disposed on an image side of the optical system.

11. An electronic device, comprising a housing and the image capturing module as claimed in claim 10, wherein the image capturing module is mounted on the housing.