CN114153051B - Optical system, camera module and electronic equipment - Google Patents
Optical system, camera module and electronic equipment Download PDFInfo
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- CN114153051B CN114153051B CN202111509176.6A CN202111509176A CN114153051B CN 114153051 B CN114153051 B CN 114153051B CN 202111509176 A CN202111509176 A CN 202111509176A CN 114153051 B CN114153051 B CN 114153051B
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B13/00—Optical objectives specially designed for the purposes specified below
- G02B13/001—Miniaturised objectives for electronic devices, e.g. portable telephones, webcams, PDAs, small digital cameras
- G02B13/0015—Miniaturised objectives for electronic devices, e.g. portable telephones, webcams, PDAs, small digital cameras characterised by the lens design
- G02B13/002—Miniaturised objectives for electronic devices, e.g. portable telephones, webcams, PDAs, small digital cameras characterised by the lens design having at least one aspherical surface
- G02B13/0045—Miniaturised objectives for electronic devices, e.g. portable telephones, webcams, PDAs, small digital cameras characterised by the lens design having at least one aspherical surface having five or more lenses
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B13/00—Optical objectives specially designed for the purposes specified below
- G02B13/18—Optical objectives specially designed for the purposes specified below with lenses having one or more non-spherical faces, e.g. for reducing geometrical aberration
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- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
- G03B30/00—Camera modules comprising integrated lens units and imaging units, specially adapted for being embedded in other devices, e.g. mobile phones or vehicles
Abstract
The invention discloses an optical system, a camera module and electronic equipment. The optical system includes: the object side surface and the image side surface of the first lens are respectively a convex surface and a concave surface at a paraxial region; the object side surface and the image side surface of the fifth lens are respectively a convex surface and a concave surface at a paraxial region; a sixth lens element with positive refractive power, wherein an object-side surface of the sixth lens element is convex at a paraxial region; a seventh lens element with negative refractive power having a concave image-side surface at a paraxial region, wherein at least one inflection point is disposed on each of the object-side surface and the image-side surface of the seventh lens element; the optical system satisfies the relationship: 2< f 7/(sab71+sab72) <4. According to the optical system provided by the embodiment of the invention, the miniaturization design can be realized, and good imaging quality is achieved.
Description
Technical Field
The present invention relates to the field of photography imaging technology, and in particular, to an optical system, a camera module, and an electronic device.
Background
With the market demand of portable electronic devices such as smart phones, smart watches, smart glasses and the like greatly increasing, consumers have higher and higher demands on quality, functions and the like of lenses, and the lenses can acquire image information, so that the portable electronic devices are main modules for realizing image shooting. With the rapid improvement of the living standard of people and the rapid development of scientific technology, the pixel size of the image sensor closely matched with the lens is continuously reduced, so that the lens needs to realize a higher-quality imaging effect.
By adding the number of lenses to the lens to correct aberrations, the lens can be made to achieve higher imaging quality. However, the increase of the number of lenses increases the difficulty of design and processing, molding and assembling, and the multi-piece imaging module often belongs to a larger structure in the electronic device, while the traditional compression method (such as reducing the number of lenses) can shorten the size of the imaging module, but often leads to the reduction of image quality, so that it is difficult to satisfy the requirement that the electronic device maintains good imaging quality in the miniaturized design process, and it is difficult to satisfy the requirement of consumers.
Therefore, how to realize the miniaturized design of the camera module and to achieve good imaging quality is one of the urgent problems to be solved in the industry.
Disclosure of Invention
The present invention aims to solve at least one of the technical problems existing in the prior art. Therefore, the first aspect of the present application proposes an optical system, which can effectively solve the problem of achieving a miniaturized design while achieving good imaging quality.
The second aspect of the present invention further provides an image capturing module.
The third aspect of the present invention also proposes an electronic device.
The optical system according to an embodiment of the first aspect of the present application includes, in order from an object side to an image side along an optical axis: a first lens element with positive refractive power having a convex object-side surface at a paraxial region and a concave image-side surface at a paraxial region; a second lens element with a refractive power having a convex object-side surface at a paraxial region and a concave image-side surface at a paraxial region; a third lens having a bending force; a fourth lens having a bending force; a fifth lens element with a convex object-side surface at a paraxial region and a concave image-side surface at a paraxial region; a sixth lens element with positive refractive power having a convex object-side surface at a paraxial region; the image side surface of the seventh lens is concave at a paraxial region, and at least one inflection point is arranged in each of the object side surface and the image side surface of the seventh lens.
In the optical system, through the positive bending force of the first lens and the convex-concave design at the paraxial region, the convex-concave design of the second lens at the paraxial region is matched, so that the incident light rays with large angles can enter the optical system and can be effectively converged; meanwhile, the bending force design of the third lens and the fourth lens is matched, the incident light rays can be further smoothly transmitted by the complex square lens (namely the first lens and the second lens), and the central and edge view field light rays can be further converged, so that the total length of the optical system can be favorably compressed. The bending force provided by the fifth lens and the corresponding convex-concave design can balance the aberration which is difficult to correct and is brought by each lens on the object side when converging incident light rays, and the correction pressure of the rear lens group (namely the sixth lens and the seventh lens) is reduced. The positive bending force of the sixth lens can correct the aberration generated when the light passes through the fifth lens, and the positive bending force and the negative bending force can offset the aberration generated by the lenses, so that the negative bending force of the seventh lens can offset the aberration generated when the light passes through the sixth lens, and the convex surface type design of the object side surface of the sixth lens at the paraxial region can further converge the light of the central view field by matching with the concave surface type design of the image side surface of the seventh lens at the paraxial region, thereby compressing the total length of the optical system, and simultaneously, the spherical aberration can be well restrained. At least one inflection point is arranged in the object side surface and the image side surface of the seventh lens, the inflection point can effectively press the angle of incidence of off-axis view field rays on the image sensor, the response efficiency of the image sensor is improved, meanwhile, correction of peripheral distortion of an image and improvement of relative illumination are facilitated, and in addition, aberration of astigmatism and off-axis view field can be effectively corrected.
In one embodiment, the optical system satisfies the relationship: f 7/(SAG71+SAG72) is less than or equal to 2 and less than or equal to 4; f7 is an effective focal length of the seventh lens element, sag71 is a sagittal height of the object-side surface of the seventh lens element at the maximum effective aperture, which is a distance between the object-side surface of the seventh lens element at the maximum effective aperture and an intersection point of the object-side surface of the seventh lens element and the optical axis in the optical axis direction, and sag72 is a sagittal height of the image-side surface of the seventh lens element at the maximum effective aperture, which is a distance between the image-side surface of the seventh lens element at the maximum effective aperture and an intersection point of the image-side surface of the seventh lens element and the optical axis in the optical axis direction.
The seventh lens is used as a lens closest to the imaging surface, the deflection angle of the light rays influences the imaging quality, the above relational conditions are further met under the condition of having the bending force and the surface type design, the bending force and the surface type of the seventh lens can be reasonably controlled, namely, when the seventh lens has enough bending force, the sagittal height of the object side surface and the image side surface of the seventh lens at the maximum effective caliber is controlled, the surface type of the seventh lens is favorably and effectively restrained, the sufficient deflection angle of the edge view field light rays when the edge view field light rays pass through the seventh lens is ensured, the incidence angle of the light rays when the light rays are incident to the imaging surface is ensured to be smaller, the optical system is ensured to have larger relative illuminance, and the imaging quality of the optical system is favorably improved. When the ratio is lower than the lower limit of the relation, namely f 7/(SAG71+SAG72) < 2, the sagittal height of the object side surface and the image side surface of the seventh lens at the maximum effective caliber is too large, so that the surface shape of the seventh lens is excessively distorted, the forming and the assembling of the seventh lens are not facilitated, and the miniaturization design of the optical system is also not facilitated; when f 7/(sab71+sab72) > 4 is higher than the upper limit of the relation, the sagittal height of the object side surface and the image side surface of the seventh lens at the maximum effective aperture is too small, which results in too gentle surface shape of the seventh lens, which is unfavorable for deflecting fringe field light, and is inconvenient for the optical system to obtain enough relative illumination, resulting in reduced imaging quality.
In one embodiment, the optical system satisfies the relationship: (sd 72-sd 52)/(sd 51-sd 31) less than or equal to 1.8 and less than or equal to 3; sd72 is half of the maximum effective aperture of the seventh lens image-side surface, sd52 is half of the maximum effective aperture of the fifth lens image-side surface, sd51 is half of the maximum effective aperture of the fifth lens object-side surface, and sd31 is half of the maximum effective aperture of the third lens object-side surface.
The above conditions are satisfied, that is, the maximum effective aperture difference between the image side surface of the seventh lens and the image side surface of the fifth lens and the ratio of the maximum effective aperture difference between the object side surface of the fifth lens and the object side surface of the third lens are controlled within a reasonable range, which is favorable for reducing the deflection angle of the marginal view field light at the edge of each lens, ensuring that the light can be smoothly transmitted at the edge of each lens, ensuring that the marginal view field has excellent imaging quality, and is favorable for uniformly distributing the maximum effective aperture of each lens in the optical system, reducing the aperture gradient difference of each lens, being favorable for compact miniaturization of the optical system and improving the assembly stability between lenses.
In one embodiment, the optical system satisfies the relationship: r51/r52 is more than or equal to 1 and less than or equal to 3; r51 is a radius of curvature of the object side surface of the fifth lens element at the optical axis, and r52 is a radius of curvature of the image side surface of the fifth lens element at the optical axis.
The object side surface and the image side surface of the fifth lens are provided with enough bending degrees of freedom, smooth transmission of light rays is facilitated, and better correction of aberration such as astigmatism and field curvature of the optical system is facilitated. When the ratio is lower than the lower limit of the relation, namely r51/r52 is less than 1, the object side surface and the image side surface of the fifth lens are too small in bending difference, light rays cannot be effectively transmitted in the lens, and marginal visual field aberration is easy to generate and is not beneficial to aberration correction; when the upper limit of the relation is higher than the upper limit of r51/r52 > 2.5, the bending degree of freedom of the image side of the fifth lens is insufficient, the bending difference between the object side and the image side of the fifth lens is too large, which can cause too large deflection angle of the marginal view rays, and marginal view aberration is easily generated, and the processing and forming of the fifth lens are also unfavorable.
In one embodiment, the optical system satisfies the relationship: f/EPD is less than or equal to 1.6; f is the effective focal length of the optical system, EPD is the entrance pupil diameter of the optical system.
The optical system has larger clear aperture and higher light flux, thereby being beneficial to improving the brightness of an image surface of the optical system and improving the imaging definition, thereby improving the photosensitivity of the image sensor, improving the imaging effect of the optical system when working in dark environment, and being beneficial to increasing the light beam of the edge view field, reducing the aberration of the edge view field and inhibiting the dark angle phenomenon.
In one embodiment, the optical system satisfies the relationship: TTL/ImgH is less than or equal to 1.42; TTL is the distance between the object side surface of the first lens and the imaging surface of the optical system on the optical axis, and Imgh is half of the image height corresponding to the maximum field angle of the optical system.
By reasonably configuring the ratio of the relational expression, the total optical length of the optical system can be effectively controlled, and the assembly sensitivity of the optical system is reduced; meanwhile, the optical system is favorable for balancing between miniaturization and a large image surface, so that the optical system has a small size and can also have a large enough image surface to match with an image sensor with a higher pixel, and further more details of an object can be shot.
In one embodiment, the optical system satisfies the relationship: r12/f1 is more than or equal to 0.5 and less than or equal to 1.8; r12 is a radius of curvature of the image side surface of the first lens element at the optical axis, and f1 is an effective focal length of the first lens element.
The bending force of the first lens can be controlled within a reasonable range by meeting the conditional expression, so that the first lens is beneficial to contributing proper positive bending force to the whole optical system, incident light rays with large angles can be effectively converged to enter the optical system, the large aperture characteristic is convenient to realize, and the optical total length of the optical system is primarily shortened; and simultaneously, the curvature change of the image side surface of the first lens is reasonably controlled, so that the first lens can be prevented from generating aberration which is difficult to correct, and the head size of the optical system can be effectively reduced, so that the optical system has a small head. When the image side surface of the first lens is too curved and is unfavorable for the forming of the first lens when the image side surface of the first lens is lower than the lower limit of the relation, namely r12/f1 is less than 0.5; above the upper limit of the relation, i.e. r12/f1 > 2, the image side of the first lens is too gentle, which is detrimental to aberration correction of the lens group behind the optical system (i.e. the second lens to the seventh lens). In addition, the first lens closest to the object side is made of glass, and the influence of the environmental temperature change on the optical system can be effectively reduced by utilizing the temperature elimination and drift effect of the glass material of the first lens, so that better and more stable imaging quality is maintained.
In one embodiment, the optical system satisfies the relationship: f/f6 is more than or equal to 1.2 and less than or equal to 1.5; f is the effective focal length of the optical system, and f6 is the effective focal length of the sixth lens.
By configuring the bending force of the sixth lens to be within a reasonable range, that is, when the above relation is satisfied, the sixth lens can provide a proper positive bending force, so that spherical aberration generated by the front lens group (that is, the first lens to the fifth lens) can be effectively corrected, and the imaging resolution of the optical system can be improved; in addition, the positive bending force can also realize reasonable deflection on the light rays entering at a large angle, which is beneficial to the size compression of the sixth lens on the whole optical system, thereby promoting the formation of the miniaturization characteristic of the optical system.
In one embodiment, the optical system satisfies the relationship: (r21+r22)/ct 2 is more than or equal to 30 and less than or equal to 60; r21 is a radius of curvature of the object side surface of the second lens element at the optical axis, r22 is a radius of curvature of the image side surface of the second lens element at the optical axis, and ct2 is a thickness of the second lens element on the optical axis.
The ratio of the relational expressions is controlled within a reasonable range, so that the curvature radiuses of the object side surface and the image side surface of the second lens are matched, the off-axis aberration of the optical system is corrected, the on-axis aberration of the optical system is balanced, the optical sensitivity of the optical system can be reduced, and further, good imaging quality is ensured. When the upper limit of the relation is higher than the upper limit of the relation, namely (r21+r22)/ct 2 is more than 60, the center thickness of the second lens is too small, and the lens surface shape is too curved, so that the production stability of the second lens is reduced, and the forming and the assembly of the second lens are not facilitated; when the ratio is lower than the lower limit of the relation, that is, (r21+r22)/ct 2 is less than 30, the center thickness of the second lens is too large, which affects the total optical length of the optical system and is not beneficial to aberration correction and improvement of the imaging quality of the optical system.
In one embodiment, the optical system satisfies the relationship: f is less than or equal to 5.1mm, tan (HFOV) is less than or equal to 5.4mm; f is the effective focal length of the optical system and the HFOV is half the maximum field angle of the optical system.
Through satisfying the above conditional expression, can retrain the effective focal length and the biggest angle of field of optical system keep in reasonable within range, be favorable to the optical system obtains great imaging plane, improves the pixel of taking the picture, on having the basis of big imaging plane, the optical system has big visual angle to can converge a wide range of light, be convenient for realize big aperture characteristic.
In one embodiment, the optical system satisfies the relationship: 1.2 is less than or equal to (ct1+ct2)/(ct3+ct4) is less than or equal to 1.5; ct1 is the thickness of the first lens element on the optical axis, ct2 is the thickness of the second lens element on the optical axis, ct3 is the thickness of the third lens element on the optical axis, and ct4 is the thickness of the fourth lens element on the optical axis.
The thickness relation between the first lens and the fourth lens can be reasonably configured by restraining the ratio of the sum of the thicknesses of the centers of the first lens and the second lens to the sum of the thicknesses of the centers of the third lens and the fourth lens, and the lens surfaces can be reasonably configured, so that the bending force distribution between the first lens and the fourth lens can be controlled, the field bending contribution of each view field in the optical system can be controlled within a reasonable range, and the field bending generated by the lens groups (namely the fifth lens to the seventh lens) after balancing is facilitated, so that the imaging resolution of the optical system is improved; in addition, the tolerance sensitivity of the first lens to the fourth lens can be reduced, the lens assembly yield can be improved, and the miniaturized design of the optical system can be realized.
According to a second aspect of the present application, an image capturing module includes an image sensor and any one of the above optical systems, where the image sensor is disposed on an image side of the optical system. By adopting the optical system, the camera module can have good imaging quality while keeping a miniaturized design.
According to the electronic equipment of the embodiment of the third aspect of the application, the electronic equipment comprises the fixing piece and the camera shooting module, wherein the camera shooting module is arranged on the fixing piece. The camera module can provide good camera quality for the electronic equipment and keep small occupied volume, so that the obstruction to the miniaturization design of the electronic equipment can be reduced.
Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.
Drawings
Fig. 1 is a schematic structural diagram of an optical system according to a first embodiment of the present application;
FIG. 2 includes a longitudinal spherical aberration diagram, an astigmatic diagram, and a distortion diagram of the optical system in the first embodiment;
fig. 3 is a schematic structural diagram of an optical system according to a second embodiment of the present application;
FIG. 4 includes a longitudinal spherical aberration diagram, an astigmatic diagram, and a distortion diagram of the optical system in the second embodiment;
Fig. 5 is a schematic structural diagram of an optical system according to a third embodiment of the present application;
FIG. 6 includes a longitudinal spherical aberration diagram, an astigmatic diagram, and a distortion diagram of an optical system in a third embodiment;
fig. 7 is a schematic structural view of an optical system according to a fourth embodiment of the present application;
fig. 8 includes a longitudinal spherical aberration diagram, an astigmatic diagram, and a distortion diagram of the optical system in the fourth embodiment;
fig. 9 is a schematic structural view of an optical system according to a fifth embodiment of the present application;
fig. 10 includes a longitudinal spherical aberration diagram, an astigmatic diagram, and a distortion diagram of the optical system in the fifth embodiment;
fig. 11 is a schematic structural view of an optical system according to a sixth embodiment of the present application;
fig. 12 includes a longitudinal spherical aberration diagram, an astigmatic diagram, and a distortion diagram of the optical system in the sixth embodiment;
fig. 13 is a schematic structural view of an optical system according to a seventh embodiment of the present application;
fig. 14 includes a longitudinal spherical aberration diagram, an astigmatism diagram, and a distortion diagram of the optical system in the seventh embodiment;
FIG. 15 is a schematic diagram of a camera module according to an embodiment of the present disclosure;
fig. 16 is a schematic structural diagram of an image capturing apparatus according to an embodiment of the present application.
Detailed Description
Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements or elements having like or similar functions throughout. The embodiments described below by referring to the drawings are illustrative and intended to explain the present invention and should not be construed as limiting the invention.
An optical system 10 according to a specific embodiment of the present invention will be described below with reference to the accompanying drawings.
Referring to fig. 1, an embodiment of the present application provides an optical system 10 having a seven-piece lens design, the optical system 10 including, in order from an object side to an image side along an optical axis 101, a first lens L1 having a positive bending force, a second lens L2 having a positive bending force or a negative bending force, a third lens L3 having a positive bending force or a negative bending force, a fourth lens L4 having a positive bending force or a negative bending force, a fifth lens L5 having a positive bending force or a negative bending force, a sixth lens L6 having a positive bending force, and a seventh lens L7 having a negative bending force. The lenses in the optical system 10 should be coaxially disposed, and each lens can be mounted in a lens barrel to form an imaging lens.
The first lens element L1 has an object-side surface S1 and an image-side surface S2, the second lens element L2 has an object-side surface S3 and an image-side surface S4, the third lens element L3 has an object-side surface S5 and an image-side surface S6, the fourth lens element L4 has an object-side surface S7 and an image-side surface S8, the fifth lens element L5 has an object-side surface S9 and an image-side surface S10, the sixth lens element L6 has an object-side surface S11 and an image-side surface S12, and the seventh lens element L7 has an object-side surface S13 and an image-side surface S14. Meanwhile, the optical system 10 further has an imaging surface S17, the imaging surface S17 is located at the image side of the seventh lens L7, and the light emitted from the on-axis object point at the corresponding object distance can be imaged on the imaging surface S17 after being adjusted by each lens of the optical system 10.
In general, the imaging surface S17 of the optical system 10 coincides with the photosensitive surface of the image sensor. It should be noted that, in some embodiments, the optical system 10 may be matched to an image sensor having a rectangular photosurface, and the imaging surface S17 of the optical system 10 coincides with the rectangular photosurface of the image sensor. At this time, the effective pixel area on the imaging surface S17 of the optical system 10 has a horizontal direction, a vertical direction, and a diagonal direction, and in this application, the maximum field angle of the optical system 10 may be understood as the maximum field angle of the diagonal direction of the optical system 10, and ImgH may be understood as half the length of the effective pixel area on the imaging surface S17 of the optical system 10 in the diagonal direction. In the embodiment of the application, the object-side surface S1 of the first lens element L1 is convex at the paraxial region 101, and the image-side surface S2 is concave at the paraxial region 101; the object side surface S3 of the second lens element L2 is convex at the paraxial region 101, and the image side surface S4 is concave at the paraxial region 101; the object-side surface S5 and the image-side surface S6 of the third lens element L3 may be convex or concave at a paraxial region; the object-side surface S7 and the image-side surface S8 of the fourth lens element L4 may be convex or concave at a paraxial region; the object side surface S9 of the fifth lens element L5 is convex at the paraxial region 101, and the image side surface S10 is concave at the paraxial region 101; the object side surface S11 of the sixth lens element L6 is convex at a paraxial region 101, and the image side surface S12 is convex or concave at a paraxial region 101; the image-side surface S14 of the seventh lens L7 is concave at the paraxial region 101. When describing that the lens surface has a certain profile at the paraxial region 101, i.e., the lens surface has such a profile near the optical axis 101; when describing a lens surface having a certain profile near the maximum effective aperture, i.e. the lens surface has such a profile radially and near the maximum effective aperture. In the optical system 10, the positive bending force of the first lens L1 and the concave-convex design at the paraxial region 101 are combined with the concave-convex design of the second lens L2 at the paraxial region 101, so that the incident light rays with a large angle can enter the optical system 10 and be effectively converged; meanwhile, the bending force design of the third lens L3 and the fourth lens L4 is matched, so that incident light rays can be further smoothly transmitted by the complex square lenses (namely the first lens L1 and the second lens L2), and the central and edge view field light rays can be further converged, so that the total length of the optical system 10 is favorably compressed. The bending force provided by the fifth lens L5 and the corresponding convex-concave design can balance the aberration of each lens on the object side, which is difficult to correct when converging the incident light, and reduce the correction pressure of the rear lens group (i.e. the sixth lens L6 and the seventh lens L7). The positive bending force of the sixth lens L6 can correct the aberration generated when the light passes through the fifth lens L5, and the positive and negative bending force lenses can cancel each other out, so that the negative bending force of the seventh lens L7 can cancel the aberration generated when the light passes through the sixth lens L6, and the convex surface type design of the object side surface S11 of the sixth lens L6 at the paraxial region 101 is matched with the concave surface type design of the image side surface S14 of the seventh lens L7 at the paraxial region 101, so that the light of the central field of view can be further converged, thereby compressing the total length of the optical system 10, and meanwhile, the spherical aberration can be well suppressed, in addition, the incident angle of the incident light on the imaging surface S17 can be reduced, the generation of the chromatic aberration can be reduced, and the imaging quality of the optical system 10 can be improved. At least one inflection point is arranged in the object side surface S13 and the image side surface S14 of the seventh lens L7, the inflection point can effectively suppress the angle of incidence of off-axis view field rays on the image sensor, the response efficiency of the image sensor is improved, meanwhile, the peripheral distortion of an image can be corrected, the relative illumination can be improved, and in addition, the aberration of astigmatism and off-axis view field can be effectively corrected.
In the embodiments of the present application, the optical system 10 also satisfies the relational condition: f 7/(SAG71+SAG72) is less than or equal to 2 and less than or equal to 4; f7 is the effective focal length of the seventh lens element L7, sag71 is the sagittal height of the object-side surface S13 of the seventh lens element L7 at the maximum effective aperture, and sag72 is the sagittal height of the image-side surface S14 of the seventh lens element L7 at the maximum effective aperture. The seventh lens L7 is the lens closest to the imaging surface S17, and the magnitude of the angle of deflection of the light rays will affect the imaging quality. The bending force and the surface shape of the seventh lens L7 can be reasonably controlled under the condition of possessing the bending force and the surface shape design, namely, the object side surface S13 and the image side surface S14 of the seventh lens L7 are controlled to be at the sagittal height of the maximum effective caliber when the seventh lens L7 has enough bending force, which is beneficial to effectively restricting the surface shape of the seventh lens L7, ensuring that the marginal view field light has enough deflection angle when passing through the seventh lens L7 and ensuring that the incident angle when the light is incident to the imaging surface S17 is smaller, thereby ensuring that the optical system 10 has larger relative illumination and further being beneficial to improving the imaging quality of the optical system 10. In some embodiments, the embodiment satisfied by the optical system 10 may be specifically 2.182, 2.364, 2.545, 2.727, 2.909, 3.100, 3.273, 3.455, 3.636, or 3.818. When the ratio is lower than the lower limit of the relation, i.e. f 7/(SAG71+SAG72) < 2, the sagittal height of the object-side surface S13 and the image-side surface S14 of the seventh lens L7 at the maximum effective aperture is too large, which causes the surface shape of the seventh lens L7 to be too distorted, which is not beneficial to the molding and assembly of the seventh lens L7 and is also inconvenient for the miniaturized design of the optical system 10; when the relation upper limit is higher than the relation upper limit, i.e. f 7/(sab71+sab72) > 4, the sagittal height of the object-side surface S13 and the image-side surface S14 of the seventh lens element L7 at the maximum effective aperture is too small, resulting in too gentle surface shape of the seventh lens element L7, which is unfavorable for deflecting fringe field light, and is inconvenient for the optical system 10 to obtain sufficient relative illuminance, resulting in reduced imaging quality.
Furthermore, in some embodiments, the optical system 10 also satisfies at least one of the following relationships, and may possess the corresponding technical effects when either relationship is satisfied:
(sd 72-sd 52)/(sd 51-sd 31) less than or equal to 1.8 and less than or equal to 3; sd72 is half of the maximum effective aperture of the image-side surface S14 of the seventh lens element L7, sd52 is half of the maximum effective aperture of the image-side surface S10 of the fifth lens element L5, sd51 is half of the maximum effective aperture of the object-side surface S9 of the fifth lens element L5, and sd31 is half of the maximum effective aperture of the object-side surface S5 of the third lens element L3. The above conditions are satisfied, that is, the ratio of the maximum effective aperture difference between the image side surface S14 of the seventh lens element L7 and the image side surface S10 of the fifth lens element L5 to the maximum effective aperture difference between the object side surface S9 of the fifth lens element L5 and the object side surface S5 of the third lens element L3 is controlled within a reasonable range, which is favorable for reducing the deflection angle of the marginal field light at the edge of each lens element, so that the light can be smoothly transmitted at the edge of each lens element, ensuring the marginal field to have excellent imaging quality, and is favorable for uniformly distributing the maximum effective aperture of each lens element in the optical system 10, reducing the aperture gradient difference of each lens element, facilitating the compact miniaturization of the optical system 10 and improving the assembly stability between the lens elements. In some embodiments, the embodiments satisfied by the optical system 10 may be, in particular, 1.909, 2.018, 2.127, 2.236, 2.345, 2.455, 2.564, 2.673, 2.782, or 2.891.
R51/r52 is more than or equal to 1 and less than or equal to 3; r51 is a radius of curvature of the object side surface S9 of the fifth lens element L5 at the optical axis 101, and r52 is a radius of curvature of the image side surface S10 of the fifth lens element L5 at the optical axis 101. The object-side surface S9 and the image-side surface S10 of the fifth lens element L5 have enough bending degrees of freedom to facilitate smooth transmission of light, and to better correct aberrations such as astigmatism and curvature of field of the optical system 10. In some embodiments, the embodiments satisfied by the optical system 10 may be specifically 1.182, 1.364, 1.545, 1.727, 1.909, 2.100, 2.273, 2.455, 2.636, or 2.818. When the ratio is lower than the lower limit of the relation, namely r51/r52 is less than 1, the bending difference between the object side surface S9 and the image side surface S10 of the fifth lens L5 is too small, light rays cannot be effectively transmitted in the lens, and marginal field aberration is easy to generate and is not beneficial to aberration correction; when the upper limit of the relation is higher than the upper limit of r51/r52 > 2.5, the image side surface S10 of the fifth lens element L5 has insufficient bending freedom, the object side surface S9 is excessively bent, the bending difference between the object side surface S9 and the image side surface S10 of the fifth lens element L5 is excessively large, which results in excessively large deflection angle of the marginal field light rays, which is also liable to generate marginal field aberration, and which is also unfavorable for the processing and molding of the fifth lens element L5.
f/EPD is less than or equal to 1.6; f is the effective focal length of the optical system 10, and EPD is the entrance pupil diameter of the optical system 10. The above conditional expression is satisfied, so that the optical system 10 has a larger clear aperture, thereby having a higher light flux, being beneficial to improving the brightness of the image plane of the optical system 10 and improving the imaging definition, thereby improving the photosensitivity of the image sensor, improving the imaging effect of the optical system 10 when working in dark environment, in addition, the higher light flux is beneficial to increasing the light beam of the edge view field, reducing the aberration of the edge view field and inhibiting the dark angle phenomenon. In some embodiments, the embodiments satisfied by the optical system 10 may be specifically 1.055, 1.110, 1.164, 1.218, 1.273, 1.327, 1.382, 1.436, 1.490, or 1.545.
TTL/ImgH is less than or equal to 1.42; TTL is a distance between the object side surface S1 of the first lens L1 and the imaging surface S17 of the optical system 10 on the optical axis 101, and Imgh is half of an image height corresponding to a maximum field angle of the optical system 10. By reasonably configuring the ratio of the relational expression, the total optical length of the optical system 10 can be effectively controlled, and the assembly sensitivity of the optical system 10 is reduced; meanwhile, the optical system 10 is advantageous to balance between miniaturization and large image surface, so that the optical system 10 has a small size and a large enough image surface S17 to match with the image sensor with higher pixels, and further more details of the object can be shot. In some embodiments, the embodiment satisfied by the optical system 10 may be specifically 1.038, 1.056, 1.115, 1.153, 1.190, 1.229, 1.267, 1.305, 1.135, or 1.382.
R12/f1 is more than or equal to 0.5 and less than or equal to 1.8; r12 is a radius of curvature of the image side surface S2 of the first lens element L1 at the optical axis 101, and f1 is an effective focal length of the first lens element L1. The bending force of the first lens L1 can be controlled within a reasonable range by meeting the above conditional expression, so that the first lens L1 contributes to the contribution of a proper positive bending force to the whole optical system 10, can effectively converge incident light rays with a large angle to enter the optical system 10, is convenient for realizing a large aperture characteristic, and also preliminarily shortens the total optical length of the optical system 10; at the same time, the curvature change of the image side surface S2 of the first lens L1 is reasonably controlled, so that the aberration of the first lens L1, which is difficult to correct, can be prevented, and the head size of the optical system 10 can be effectively reduced, so that the optical system 10 has a small head. In some embodiments, the embodiments satisfied by the optical system 10 may be specifically 0.618, 0.736, 0.855, 0.973, 1.100, 1.210, 1.327, 1.445, 1.564, or 1.682. When the ratio is lower than the lower limit of the relation, namely r12/f1 is less than or equal to 0.5, the image side surface S2 of the first lens L1 is too bent, so that the forming of the first lens L1 is not facilitated; when the relation upper limit is higher than r12/f1 > 2, the image side surface S2 of the first lens element L1 is too gentle, which is detrimental to aberration correction of the lens groups (i.e., the second lens element L2 to the seventh lens element L7) behind the optical system 10. In addition, the first lens L1 closest to the object side is made of glass, and the influence of the environmental temperature change on the optical system 10 can be effectively reduced by utilizing the temperature-eliminating and floating effect of the glass material of the first lens L1, so that the better and more stable imaging quality is maintained.
F/f6 is more than or equal to 1.2 and less than or equal to 1.5; f is the effective focal length of the optical system 10, and f6 is the effective focal length of the sixth lens L6. By configuring the bending force of the sixth lens L6 to be within a reasonable range, that is, when the above-mentioned relational expression is satisfied, the sixth lens L6 can provide a proper positive bending force, and spherical aberration generated by the front lens group (that is, the first lens L1 to the fifth lens L5) can be effectively corrected, so that the imaging resolution of the optical system 10 can be improved; in addition, the positive bending force can also reasonably deflect the light rays incident at a large angle, which is beneficial to the size compression of the sixth lens L6 on the whole optical system 10, thereby promoting the miniaturization characteristic of the optical system 10. In some embodiments, the embodiments satisfied by the optical system 10 may be specifically 1.227, 1.255, 1.282, 1.310, 1.336, 1.364, 1.390, 1.418, 1.445, or 1.473.
(r21+r22)/ct 2 is more than or equal to 30 and less than or equal to 60; r21 is a radius of curvature of the object side surface S3 of the second lens element L2 at the optical axis 101, r22 is a radius of curvature of the image side surface S4 of the second lens element L2 at the optical axis 101, and ct2 is a thickness of the second lens element L2 on the optical axis 101. By controlling the ratio of the above relation to be in a reasonable range, the radii of curvature of the object side surface S3 and the image side surface S4 of the second lens L2 are matched, which is favorable for correcting the off-axis aberration of the optical system 10 and balancing the on-axis aberration of the optical system 10, the optical sensitivity of the optical system 10 can be reduced, and thus, better imaging quality is ensured, and in addition, the reasonable surface curvature and lens thickness are favorable for the processing and forming of the second lens L2. In some embodiments, the embodiments satisfied by the optical system 10 may be, in particular, 32.727, 35.455, 38.182, 40.910, 43.636, 46.364, 49.100, 51.818, 54.545, or 57.273. When the ratio is higher than the upper limit of the relation, namely (r21+r22)/ct 2 is more than 60, the center thickness of the second lens L2 is too small, and the lens surface shape is too curved, so that the production stability of the second lens L2 is reduced, and the forming and the assembly of the second lens L2 are not facilitated; when the ratio is lower than the lower limit of the relation, i.e., (r21+r22)/ct 2 < 30, the center thickness of the second lens L2 is too large, which affects the total optical length of the optical system 10 and is also unfavorable for aberration correction and improvement of the imaging quality of the optical system 10.
F is less than or equal to 5.1mm, tan (HFOV) is less than or equal to 5.4mm; f is the effective focal length of the optical system 10 and the HFOV is half the maximum field angle of the optical system 10. By satisfying the above conditional expression, the effective focal length and the maximum field angle of the optical system 10 can be constrained to be kept within a reasonable range, which is favorable for the optical system 10 to obtain a larger imaging surface S17, and the pixels for taking pictures are improved, and the optical system 10 has a large viewing angle on the basis of having a large imaging surface, so that a large range of light rays can be converged, and the large aperture characteristic can be conveniently realized. In some embodiments, the embodiments satisfied by the optical system 10 may be, in particular, 5.127mm, 5.155mm, 5.182mm, 5.210mm, 5.236mm, 5.264mm, 5.290mm, 5.318mm, 5.34mm, or 5.373mm.
1.2 is less than or equal to (ct1+ct2)/(ct3+ct4) is less than or equal to 1.5; ct1 is the thickness of the first lens element L1 on the optical axis 101, ct2 is the thickness of the second lens element L2 on the optical axis 101, ct3 is the thickness of the third lens element L3 on the optical axis 101, and ct4 is the thickness of the fourth lens element L4 on the optical axis 101. The above conditional expression is satisfied, by restricting the ratio of the sum of the central thicknesses of the first lens L1 and the second lens L2 to the sum of the central thicknesses of the third lens L3 and the fourth lens L4, the thickness relationship between the first lens L1 and the fourth lens L4 can be reasonably configured, and the lens surfaces can be reasonably configured, so that the bending force distribution between the first lens L1 and the fourth lens L4 can be controlled, the field bending contribution of each field of view in the optical system 10 can be controlled within a reasonable range, and the field bending generated by the rear lens group (i.e., the fifth lens L5 to the seventh lens L7) can be balanced, thereby improving the imaging resolution of the optical system 10; in addition, tolerance sensitivity of the first lens L1 to the fourth lens L4 can be reduced, the lens assembly yield can be improved, and a miniaturized design of the optical system 10 can be realized. In some embodiments, the embodiments satisfied by the optical system 10 may be specifically 1.227, 1.255, 1.282, 1.309, 1.336, 1.364, 1.391, 1.418, 1.445, or 1.473.
The reference wavelength of the effective focal length in each relational condition is 555nm, the effective focal length at least refers to the value of the corresponding lens at the paraxial region 101, and the bending force of the lens at least refers to the situation at the paraxial region 101. The above relational conditions and the technical effects thereof are directed to the optical system 10 having the lens design described above. If the lens design (lens number, bending force configuration, surface configuration, etc.) of the optical system 10 cannot be ensured, it is difficult to ensure that the optical system 10 still has the corresponding technical effects when satisfying these relationships, and even significant degradation of the imaging performance may occur.
In some embodiments, at least one lens of the optical system 10 has an aspherical surface profile, i.e., when at least one side surface (object side or image side) of the lens is aspherical, the lens may be said to have an aspherical surface profile. In one embodiment, both the object side and the image side of each lens can be designed to be aspheric. The aspheric design can help the optical system 10 to more effectively eliminate aberrations and improve imaging quality. In some embodiments, at least one lens in the optical system 10 may also have a spherical surface shape, and the design of the spherical surface shape may reduce the difficulty of manufacturing the lens and reduce the manufacturing cost. In some embodiments, to achieve the desired combination of manufacturing cost, manufacturing difficulty, imaging quality, assembly difficulty, etc., the design of each lens surface in the optical system 10 may be composed of a combination of aspheric and spherical surface types.
The surface type calculation of the aspherical surface can refer to an aspherical surface formula:
where Z is the distance from the corresponding point on the aspheric surface to the tangential plane of the surface at the optical axis 101, r is the distance from the corresponding point on the aspheric surface to the optical axis 101, c is the curvature of the aspheric surface at the optical axis 101, k is the conic coefficient, ai is the higher order term coefficient corresponding to the i-th order higher order term in the aspheric surface formula.
It should further be noted that when a certain lens surface is aspherical, there may be a point of inflection on the lens surface, where a change in the type of surface will occur in the radial direction, e.g. one lens surface is convex at the paraxial region 101 and concave near the maximum effective caliber. Specifically, in some embodiments, at least one inflection point is disposed in each of the object-side surface S13 and the image-side surface S14 of the seventh lens element L7, and the surface-type designs of the object-side surface S13 and the image-side surface S14 of the seventh lens element L7 at the paraxial region 101 are combined, so that good correction of curvature of field and distortion aberration of the fringe field in the large-viewing-angle system can be achieved, and the imaging quality is improved.
In some embodiments, at least one lens of the optical system 10 is made of Plastic (PC), which may be polycarbonate, gum, or the like. In some embodiments, the material of at least one lens in the optical system 10 is Glass (GL). The lens with plastic material can reduce the production cost of the optical system 10, while the lens with glass material can withstand higher or lower temperature and has excellent optical effect and better stability. In some embodiments, lenses of different materials may be disposed in the optical system 10, i.e. a combination of glass lenses and plastic lenses may be used, but the specific configuration relationship may be determined according to practical requirements, which is not meant to be exhaustive.
In some embodiments, the optical system 10 further includes an aperture stop STO, which may also be a field stop, where the aperture stop STO is used to control the light entering amount and the depth of field of the optical system 10, and also can achieve good interception of the non-effective light to improve the imaging quality of the optical system 10, and may be disposed between the object side of the optical system 10 and the object side S1 of the first lens L1. It will be appreciated that in other embodiments, the stop STO may be disposed between two adjacent lenses, for example, between the second lens L2 and the third lens L3, and the arrangement is adjusted according to the actual situation, which is not particularly limited in this embodiment. The aperture stop STO may also be formed by a holder that holds the lens.
The optical system 10 of the present application is illustrated by the following more specific examples:
first embodiment
Referring to fig. 1, in the first embodiment, an optical system 10 includes, in order from an object side to an image side along an optical axis 101, an aperture stop STO, a first lens L1 having a positive bending force, a second lens L2 having a negative bending force, a third lens L3 having a negative bending force, a fourth lens L4 having a positive bending force, a fifth lens L5 having a negative bending force, a sixth lens L6 having a positive bending force, and a seventh lens L7 having a negative bending force. The lens surfaces of the optical system 10 are as follows:
The object side surface S1 of the first lens element L1 is convex at the paraxial region 101, and the image side surface S2 is concave at the paraxial region 101; the object side surface S1 is concave at the position near the maximum effective caliber, and the image side surface S2 is convex at the position near the maximum effective caliber.
The object side surface S3 of the second lens element L2 is convex at the paraxial region 101, and the image side surface S4 is concave at the paraxial region 101; the object side surface S3 is convex at the position near the maximum effective caliber, and the image side surface S4 is concave at the position near the maximum effective caliber.
The object side surface S5 of the third lens element L3 is convex at the paraxial region 101, and the image side surface S6 is concave at the paraxial region 101; the object side surface S5 is convex at the position near the maximum effective caliber, and the image side surface S6 is concave at the position near the maximum effective caliber.
The fourth lens element L4 has a convex object-side surface S7 at a paraxial region 101 and a concave image-side surface S8 at the paraxial region 101; the object side surface S7 is convex at the position near the maximum effective caliber, and the image side surface S8 is convex at the position near the maximum effective caliber.
The object side surface S9 of the fifth lens element L5 is convex at the paraxial region 101, and the image side surface S10 is concave at the paraxial region 101; the object side surface S9 is concave at the position near the maximum effective caliber, and the image side surface S10 is convex at the position near the maximum effective caliber.
The object side surface S11 of the sixth lens element L6 is convex at the paraxial region 101, and the image side surface S12 is concave at the paraxial region 101; the object side surface S11 is concave at the position near the maximum effective caliber, and the image side surface S12 is convex at the position near the maximum effective caliber.
The object-side surface S13 of the seventh lens element L7 is convex at the paraxial region 101, and the image-side surface S14 is concave at the paraxial region 101; the object side surface S13 is concave at the position near the maximum effective caliber, and the image side surface S14 is convex at the position near the maximum effective caliber.
In the first embodiment, each of the first lens element L1 to the seventh lens element L7 has an aspheric surface, and the object-side surface S13 and the image-side surface S14 of the seventh lens element L7 have inflection points, and each of the first lens element L1 to the seventh lens element L7 is made of Plastic (PC). The optical system 10 further includes a filter 110, the filter 110 being either part of the optical system 10 or removable from the optical system 10, but the total optical length TTL of the optical system 10 remains unchanged when the filter 110 is removed; in the embodiment, the filter 110 is an infrared cut-off filter, and the infrared cut-off filter is disposed between the image side surface S14 of the seventh lens L7 and the imaging surface S17 of the optical system 10, so as to filter out light rays in an invisible band, such as infrared light, and only allow visible light to pass through, so as to obtain a better image effect; it is understood that the optical filter 110 can also filter out light rays of other wavebands, such as visible light, and only let infrared light pass through, and the optical system 10 can be used as an infrared optical lens, i.e. the optical system 10 can also image in dim environments and other special application scenarios and can obtain better image effect.
The lens parameters of the optical system 10 in the first embodiment are presented in table 1 below. The elements from the object side to the image side of the optical system 10 are sequentially arranged in the order from top to bottom of table 1, with the aperture stop characterizing the aperture stop STO. The radius Y in table 1 is the radius of curvature of the corresponding surface of the lens at the optical axis 101. In table 1, the surface with the surface number S1 represents the object side surface of the first lens element L1, the surface with the surface number S2 represents the image side surface of the first lens element L1, and so on. The absolute value of the first value of the lens in the "thickness" parameter row is the thickness of the lens on the optical axis 101, and the absolute value of the second value is the distance from the image side of the lens to the subsequent optical surface (the object side of the subsequent lens or the aperture plane) on the optical axis 101, wherein the thickness parameter of the aperture represents the distance from the aperture plane to the object side of the adjacent lens on the optical axis 101. The refractive index and Abbe number of each lens in the table are 587.6nm, the reference wavelength of focal length (effective focal length) is 555nm, and the numerical units of Y radius, thickness and focal length (effective focal length) are millimeter (mm). The parameter data and lens surface type structure used for relational computation in the following embodiments are based on the data in the lens parameter table in the corresponding embodiments.
TABLE 1
As shown in table 1, the effective focal length f of the optical system 10 in the first embodiment is 5.944mm, the f-number FNO is 1.494, the total optical length TTL is 7.500mm, the total optical length TTL in the following embodiments is the sum of the thickness values corresponding to the surface numbers S1 to S17, the maximum field angle FOV of the optical system 10 is 82.690 °, and the optical system 10 of this embodiment has a large field angle.
Table 2 below presents the aspherical coefficients of the corresponding lens surfaces in table 1, where K is a conic coefficient and Ai is a coefficient corresponding to the i-th order higher order term in the aspherical surface type formula.
TABLE 2
In the first embodiment, the optical system 10 satisfies the following relationships:
f7/(sab71+sab72) = 2.854; f7 is the effective focal length of the seventh lens element L7, sag71 is the sagittal height of the object-side surface S13 of the seventh lens element L7 at the maximum effective aperture, and sag72 is the sagittal height of the image-side surface S14 of the seventh lens element L7 at the maximum effective aperture. The seventh lens L7 acts as the lens closest to the imaging surface S17, and the angle of deflection of the light rays will affect the imaging quality. The bending force and the surface shape of the seventh lens L7 are reasonably controlled, namely, when the seventh lens L7 has enough bending force, proper bending force can be achieved, the sagittal height of the object side surface S13 and the image side surface S14 of the seventh lens L7 at the position of the maximum effective caliber is controlled, the surface shape of the seventh lens L7 is effectively restrained, enough deflection angles of marginal view field rays are ensured when the marginal view field rays pass through the seventh lens L7, and the incidence angle of the rays when the rays are incident to the imaging surface S17 is ensured to be smaller, so that the optical system 10 is ensured to have larger relative illuminance, and the imaging quality of the optical system 10 is further improved.
(sd 72-sd 52)/(sd 51-sd 31) =1.885; sd72 is half of the maximum effective aperture of the image-side surface S14 of the seventh lens element L7, sd52 is half of the maximum effective aperture of the image-side surface S10 of the fifth lens element L5, sd51 is half of the maximum effective aperture of the object-side surface S9 of the fifth lens element L5, and sd31 is half of the maximum effective aperture of the object-side surface S5 of the third lens element L3. The ratio of the maximum effective aperture difference between the image side surface S14 of the seventh lens element L7 and the image side surface S10 of the fifth lens element L5 to the maximum effective aperture difference between the object side surface S9 of the fifth lens element L5 and the object side surface S5 of the third lens element L3 is controlled within a reasonable range, so that on one hand, the deflection angle of the marginal view field light at the edge of each lens element is reduced, the light can be smoothly transmitted at the edge of each lens element, the marginal view field has excellent imaging quality, on the other hand, the maximum effective aperture of each lens element is uniformly distributed in the optical system 10, the aperture gradient difference of each lens element is reduced, the compact miniaturization of the optical system 10 is facilitated, and the assembly stability between the lens elements is improved.
r51/r52= 2.569; r51 is a radius of curvature of the object side surface S9 of the fifth lens element L5 at the optical axis 101, and r52 is a radius of curvature of the image side surface S10 of the fifth lens element L5 at the optical axis 101. The object-side surface S9 and the image-side surface S10 of the fifth lens element L5 have enough bending degrees of freedom, which facilitates smooth transmission of light rays and better correction of aberrations such as astigmatism and curvature of field of the optical system 10.
f/epd=1.494; f is the effective focal length of the optical system 10, and EPD is the entrance pupil diameter of the optical system 10. The optical system 10 can have larger clear aperture, thereby having higher light flux, being beneficial to improving the brightness of an image plane of the optical system 10 and improving the imaging definition, thereby improving the photosensitivity of the image sensor, improving the imaging effect of the optical system 10 when working in dark environment, and being beneficial to increasing the light beam of an edge view field, reducing the aberration of the edge view field and inhibiting the dark angle phenomenon.
TTL/imgh=1.410; TTL is a distance between the object side surface S1 of the first lens L1 and the imaging surface S17 of the optical system 10 on the optical axis 101, and Imgh is half of an image height corresponding to a maximum field angle of the optical system 10. The total optical length of the optical system 10 can be effectively controlled, and the assembly sensitivity of the optical system 10 is reduced; meanwhile, the optical system 10 is advantageous to balance between miniaturization and large image surface, so that the optical system 10 has a small size and a large enough image surface S17 to match with the image sensor with higher pixels, and further more details of the object can be shot.
r12/f1=1.343; r12 is a radius of curvature of the image side surface S2 of the first lens element L1 at the optical axis 101, and f1 is an effective focal length of the first lens element L1. The bending force of the first lens L1 can be controlled within a reasonable range, so that the first lens L1 contributes to the contribution of proper positive bending force to the whole optical system 10, can effectively converge incident light rays with a large angle to enter the optical system 10, is convenient for realizing large aperture characteristics, and shortens the total optical length of the optical system 10; meanwhile, the curvature change of the image side surface S2 of the first lens L1 is reasonably controlled, so that the first lens L1 can be prevented from generating aberration which is difficult to correct, and the head size of the optical system 10 can be effectively reduced, so that the optical system 10 has a small head.
ff6=1.280; f6 is the effective focal length of the sixth lens L6. By configuring the bending force of the sixth lens L6 to be within a reasonable range, the sixth lens L6 can provide a proper positive bending force, so that spherical aberration generated by the front lens group (i.e., the first lens L1 to the fifth lens L5) can be effectively corrected, and the imaging resolution of the optical system 10 can be improved; in addition, the positive bending force can also reasonably deflect the light rays incident at a large angle, which is beneficial to the size compression of the sixth lens L6 on the whole optical system 10, thereby promoting the miniaturization characteristic of the optical system 10.
(r21+r22)/ct2= 47.532; r21 and r22 are radii of curvature of the object-side surface S3 and the image-side surface S4 of the second lens element L2 at the optical axis 101, respectively, and ct2 is a thickness of the second lens element L2 on the optical axis 101. In this way, the radii of curvature of the object-side surface S3 and the image-side surface S4 of the second lens L2 can be matched, which is favorable for correcting the off-axis aberration of the optical system 10 and balancing the on-axis aberration of the optical system 10, so as to reduce the optical sensitivity of the optical system 10, thereby ensuring better imaging quality, and in addition, the reasonable surface curvature and lens thickness are also favorable for the processing and forming of the second lens L2.
f tan (HFOV) =5.230 mm; the HFOV is one half of the maximum field angle of the optical system 10. The effective focal length and the maximum field angle of the optical system 10 can be restrained within a reasonable range, the optical system 10 can obtain a larger imaging surface S17, the pixels for shooting pictures are improved, and the optical system 10 has a large viewing angle on the basis of having a large imaging surface, so that a large range of light rays can be converged, and the large aperture characteristic can be realized conveniently.
(ct1+ct2)/(ct3+ct4) =1.411; ct1, ct3, and ct4 are thicknesses of the first lens L1, the third lens L3, and the fourth lens L4, respectively, on the optical axis 101. By restricting the ratio of the sum of the central thicknesses of the first lens L1 and the second lens L2 to the sum of the central thicknesses of the third lens L3 and the fourth lens L4, the thickness relationship between the first lens L1 and the fourth lens L4 can be reasonably configured, and the lens surfaces can be reasonably configured, so that the bending force distribution between the first lens L1 and the fourth lens L4 can be controlled, the field curvature contribution of each view field in the optical system 10 can be controlled within a reasonable range, and the field curvature generated by the rear lens group (namely the fifth lens L5 to the seventh lens L7) can be balanced, thereby improving the imaging resolution of the optical system 10; in addition, tolerance sensitivity of the first lens L1 to the fourth lens L4 can be reduced, the lens assembly yield can be improved, and a miniaturized design of the optical system 10 can be realized.
Fig. 2 includes a longitudinal spherical aberration diagram, an astigmatism diagram, and a distortion diagram of the optical system 10 in the first embodiment. Wherein the reference wavelength of the astigmatic and aberrational maps is 555nm. The longitudinal spherical aberration diagram (Longitudinal Spherical Aberration) shows the focus deviation of light rays with different wavelengths after passing through the lens. The ordinate of the longitudinal spherical aberration diagram represents the normalized pupil coordinates (Normalized Pupil Coordinator) from the pupil center to the pupil edge, and the abscissa represents the distance (in mm) from the imaging surface S17 to the intersection of the light ray and the optical axis. As can be seen from the longitudinal spherical aberration diagram, the focus deviation degree of the light beams with different wavelengths in the first embodiment tends to be consistent, the maximum focus deviation of each reference wavelength is controlled within ±0.05mm, and for a large aperture system, diffuse spots or halos in an imaging picture are effectively suppressed. Fig. 2 also includes a field curvature astigmatism graph (Astigmatic Field Curves) of the optical system 10, where the S-curve represents the sagittal field curvature at 555nm and the T-curve represents the meridional field curvature at 555nm. As can be seen from the figure, the field curvature of the optical system 10 is small, the maximum field curvature is controlled within ±0.10mm, the image surface curvature degree is effectively suppressed for the large aperture system, the sagittal field curvature and meridional field curvature under each field tend to be consistent, and the astigmatism of each field is better controlled, so that the center to the edge of the field of the optical system 10 has clear imaging. Further, as can be seen from the distortion map, the degree of distortion of the optical system 10 having a large aperture characteristic is also well controlled.
Second embodiment
Referring to fig. 3, in the second embodiment, the optical system 10 includes, in order from the object side to the image side along the optical axis 101, an aperture stop STO, a first lens L1 having a positive bending force, a second lens L2 having a negative bending force, a third lens L3 having a positive bending force, a fourth lens L4 having a negative bending force, a fifth lens L5 having a negative bending force, a sixth lens L6 having a positive bending force, and a seventh lens L7 having a negative bending force. In the second embodiment, the surface type of each lens differs from that in the first embodiment in that: the object-side surface S7 of the fourth lens element L4 is concave at the paraxial region 101, and the image-side surface S8 is concave at the position of near the maximum effective aperture. The object side surface S13 of the seventh lens element L7 is convex at a position near the maximum effective aperture. The parameters of each lens of the optical system 10 in this embodiment are shown in tables 3 and 4, wherein the names and parameters of each element are defined in the first embodiment, and are not described herein.
TABLE 3 Table 3
TABLE 4 Table 4
As can be seen from the aberration diagrams in fig. 4, the longitudinal spherical aberration, curvature of field, astigmatism and distortion of the optical system 10 having the wide-angle characteristic are well controlled, and the optical system 10 of this embodiment can have good imaging quality.
Third embodiment
Referring to fig. 5, in the third embodiment, the optical system 10 includes, in order from the object side to the image side along the optical axis 101, an aperture stop STO, a first lens L1 having a positive bending force, a second lens L2 having a negative bending force, a third lens L3 having a negative bending force, a fourth lens L4 having a positive bending force, a fifth lens L5 having a negative bending force, a sixth lens L6 having a positive bending force, and a seventh lens L7 having a negative bending force. In the third embodiment, the surface type of each lens differs from that in the first embodiment in that: the image-side surface S8 of the fourth lens element L4 is convex at a paraxial region 101, and the image-side surface S8 is concave at a position near the maximum effective aperture. The lens parameters of the optical system 10 in this embodiment are shown in tables 5 and 6, wherein the definition of the names and parameters of the elements can be obtained in the first embodiment, and the details are omitted here.
TABLE 5
TABLE 6
As can be seen from the aberration diagrams in fig. 6, the longitudinal spherical aberration, curvature of field, astigmatism and distortion of the optical system 10 having the wide-angle characteristic are well controlled, and the optical system 10 of this embodiment can have good imaging quality.
Fourth embodiment
Referring to fig. 7, in the fourth embodiment, the optical system 10 includes, in order from the object side to the image side along the optical axis 101, an aperture stop STO, a first lens L1 having a positive bending force, a second lens L2 having a negative bending force, a third lens L3 having a negative bending force, a fourth lens L4 having a positive bending force, a fifth lens L5 having a negative bending force, a sixth lens L6 having a positive bending force, and a seventh lens L7 having a negative bending force. In the fourth embodiment, the surface type of each lens differs from that in the first embodiment in that: the image-side surface S4 of the second lens element L2 is convex at a position near the maximum effective aperture. The object-side surface S5 of the third lens element L3 is concave at the paraxial region 101, and the object-side surface S5 is concave at the position of near the maximum effective aperture. The image-side surface S8 of the fourth lens element L4 is concave at a position near the maximum effective aperture. The object side surface S9 of the fifth lens element L5 is convex at a position near the maximum effective aperture. The object-side surface S11 of the sixth lens element L6 is convex at a position near the maximum effective aperture, and the image-side surface S12 is concave at a position near the maximum effective aperture. The lens parameters of the optical system 10 in this embodiment are given in tables 7 and 8, wherein the definition of the names and parameters of the elements can be obtained in the first embodiment, and the details are omitted here.
TABLE 7
TABLE 8
As can be seen from the aberration diagrams in fig. 8, the longitudinal spherical aberration, curvature of field, astigmatism and distortion of the optical system 10 having the wide-angle characteristic are well controlled, and the optical system 10 of this embodiment can have good imaging quality.
Fifth embodiment
Referring to fig. 9, in the fifth embodiment, the optical system 10 includes, in order from the object side to the image side along the optical axis 101, an aperture stop STO, a first lens L1 having a positive bending force, a second lens L2 having a positive bending force, a third lens L3 having a negative bending force, a fourth lens L4 having a positive bending force, a fifth lens L5 having a negative bending force, a sixth lens L6 having a positive bending force, and a seventh lens L7 having a negative bending force. In the fifth embodiment, the surface type of each lens differs from that in the first embodiment in that: the object-side surface S5 of the third lens element L3 is concave at a paraxial region 101, and the image-side surface S6 is convex at a region near the maximum effective aperture. The image-side surface S8 of the fourth lens element L4 is concave at a position near the maximum effective aperture. The object-side surface S9 of the fifth lens element L5 is convex at a position near the maximum effective aperture, and the image-side surface S10 is concave at a position near the maximum effective aperture. The object side surface S11 of the sixth lens element L6 is convex at a position near the maximum effective aperture. The lens parameters of the optical system 10 in this embodiment are given in table 9 and table 10, wherein the definition of the names and parameters of the elements can be obtained in the first embodiment, and the details are not repeated here.
TABLE 9
Table 10
| Face number | K | A4 | A6 | A8 | A10 | A12 | A14 |
| S1 | -7.059E+00 | 7.769E-01 | -1.118E+00 | 2.528E+00 | -6.034E+00 | 1.277E+01 | -2.004E+01 |
| S2 | 0.000E+00 | -1.280E-01 | -1.387E-02 | 9.882E-02 | -1.449E-01 | 5.720E-02 | 0.000E+00 |
| S3 | 5.465E-01 | -1.901E-01 | 1.494E-01 | -7.520E-01 | 3.991E+00 | -1.049E+01 | 1.614E+01 |
| S4 | -4.050E+00 | -4.578E-02 | 5.452E-02 | -2.356E-01 | 1.364E+00 | -3.427E+00 | 4.931E+00 |
| S5 | 0.000E+00 | -2.303E-01 | 5.607E-01 | -3.651E+00 | 1.337E+01 | -3.237E+01 | 5.045E+01 |
| S6 | 0.000E+00 | -4.117E-01 | 1.121E+00 | -4.023E+00 | 9.199E+00 | -1.364E+01 | 1.202E+01 |
| S7 | 2.609E+01 | -5.873E-01 | 1.846E+00 | -5.863E+00 | 1.498E+01 | -2.665E+01 | 2.883E+01 |
| S8 | -9.800E+01 | -7.026E-01 | 1.119E+00 | -6.479E+00 | 2.339E+01 | -5.654E+01 | 9.183E+01 |
| S9 | 0.000E+00 | -6.854E-01 | 3.226E+00 | -1.732E+01 | 5.042E+01 | -1.045E+02 | 1.162E+02 |
| S10 | 2.147E+00 | -8.944E+00 | 3.402E+01 | -9.351E+01 | 2.066E+02 | -4.554E+02 | 8.268E+02 |
| S11 | -1.000E+00 | -6.332E+00 | 2.874E+01 | -2.144E+02 | 1.075E+03 | -3.538E+03 | 7.619E+03 |
| S12 | 0.000E+00 | 1.241E+01 | -4.719E+01 | -6.709E+02 | 9.587E+03 | -6.456E+04 | 2.812E+05 |
| S13 | 0.000E+00 | -3.688E+01 | 2.966E+02 | -2.520E+03 | 1.963E+04 | -1.158E+05 | 4.916E+05 |
| S14 | -3.696E+00 | -3.867E+01 | 4.136E+02 | -3.725E+03 | 2.549E+04 | -1.274E+05 | 4.605E+05 |
| Face number | A16 | A18 | A20 | A22 | A24 | A26 | A28 |
| S1 | 2.045E+01 | -1.197E+01 | 2.991E+00 | 0.000E+00 | 0.000E+00 | 0.000E+00 | 0.000E+00 |
| S2 | 0.000E+00 | 0.000E+00 | 0.000E+00 | 0.000E+00 | 0.000E+00 | 0.000E+00 | 0.000E+00 |
| S3 | -1.463E+01 | 7.261E+00 | -1.494E+00 | 0.000E+00 | 0.000E+00 | 0.000E+00 | 0.000E+00 |
| S4 | -4.197E+00 | 1.957E+00 | -3.720E-01 | 0.000E+00 | 0.000E+00 | 0.000E+00 | 0.000E+00 |
| S5 | -4.867E+01 | 2.644E+01 | -6.161E+00 | 0.000E+00 | 0.000E+00 | 0.000E+00 | 0.000E+00 |
| S6 | -5.376E+00 | 9.215E-01 | 0.000E+00 | 0.000E+00 | 0.000E+00 | 0.000E+00 | 0.000E+00 |
| S7 | -1.680E+01 | 4.295E+00 | -2.274E-01 | 0.000E+00 | 0.000E+00 | 0.000E+00 | 0.000E+00 |
| S8 | -9.385E+01 | 5.327E+01 | -1.261E+01 | 0.000E+00 | 0.000E+00 | 0.000E+00 | 0.000E+00 |
| S9 | 1.362E+00 | -1.506E+02 | 1.462E+02 | -4.507E+01 | 0.000E+00 | 0.000E+00 | 0.000E+00 |
| S10 | -9.351E+02 | 5.592E+02 | -1.353E+02 | 0.000E+00 | 0.000E+00 | 0.000E+00 | 0.000E+00 |
| S11 | -1.103E+04 | 1.270E+04 | -1.767E+04 | 2.893E+04 | -3.576E+04 | 2.722E+04 | -1.137E+04 |
| S12 | -8.575E+05 | 1.883E+06 | -2.993E+06 | 3.409E+06 | -2.710E+06 | 1.424E+06 | -4.443E+05 |
| S13 | -1.492E+06 | 3.243E+06 | -5.048E+06 | 5.577E+06 | -4.266E+06 | 2.149E+06 | -6.416E+05 |
| S14 | -1.210E+06 | 2.324E+06 | -3.259E+06 | 3.305E+06 | -2.359E+06 | 1.125E+06 | -3.219E+05 |
As can be seen from the aberration diagrams in fig. 10, the optical system 10 having the wide-angle characteristic has well controlled longitudinal spherical aberration, curvature of field, astigmatism and distortion, and the optical system 10 of this embodiment can have good imaging quality.
Sixth embodiment
Referring to fig. 11, in the sixth embodiment, the optical system 10 includes, in order from the object side to the image side along the optical axis 101, an aperture stop STO, a first lens L1 having a positive bending force, a second lens L2 having a negative bending force, a third lens L3 having a positive bending force, a fourth lens L4 having a negative bending force, a fifth lens L5 having a positive bending force, a sixth lens L6 having a positive bending force, and a seventh lens L7 having a negative bending force. In the sixth embodiment, the surface type of each lens differs from that in the first embodiment in that: the image-side surface S6 of the third lens element L3 is convex at a paraxial region 101, and the object-side surface S5 is concave at a position near the maximum effective aperture. The object-side surface S7 of the fourth lens element L4 is concave at the paraxial region 101, and the image-side surface S8 is concave at the position of near the maximum effective aperture. The object side surface S9 of the fifth lens element L5 is convex at a position near the maximum effective aperture. The object side surface S11 of the sixth lens element L6 has a concave surface near the maximum effective aperture, and the image side surface S12 has a concave surface near the maximum effective aperture. The lens parameters of the optical system 10 in this embodiment are given in table 11 and table 12, wherein the definition of the names and parameters of the elements can be obtained in the first embodiment, and the details are not repeated here.
TABLE 11
Table 12
| Face number | K | A4 | A6 | A8 | A10 | A12 | A14 |
| S1 | -6.783E+00 | 7.075E-01 | -9.423E-01 | 1.979E+00 | -4.228E+00 | 7.882E+00 | -1.088E+01 |
| S2 | 0.000E+00 | -1.282E-01 | 8.964E-02 | -1.434E-02 | -8.277E-02 | 4.138E-02 | 0.000E+00 |
| S3 | 5.921E+00 | -2.450E-01 | 3.486E-01 | -5.170E-01 | 1.966E+00 | -5.332E+00 | 8.445E+00 |
| S4 | -3.226E+00 | -8.840E-02 | 1.791E-01 | -3.262E-01 | 1.357E+00 | -3.672E+00 | 5.874E+00 |
| S5 | 0.000E+00 | -1.323E-01 | 1.381E-01 | -1.804E+00 | 7.104E+00 | -1.700E+01 | 2.520E+01 |
| S6 | 0.000E+00 | -8.978E-02 | -1.834E-02 | -1.305E+00 | 5.369E+00 | -1.096E+01 | 1.197E+01 |
| S7 | -8.599E+01 | -2.565E-01 | 7.256E-01 | -5.942E+00 | 3.346E+01 | -9.768E+01 | 1.587E+02 |
| S8 | -7.023E+01 | -1.399E+00 | 6.989E+00 | -3.149E+01 | 8.460E+01 | -1.479E+02 | 1.757E+02 |
| S9 | 0.000E+00 | -3.182E+00 | 1.972E+01 | -8.912E+01 | 2.846E+02 | -7.022E+02 | 1.280E+03 |
| S10 | 1.924E+00 | -1.100E+01 | 4.763E+01 | -1.217E+02 | 1.555E+02 | -6.521E+01 | -2.783E+01 |
| S11 | -1.000E+00 | -5.124E+00 | 4.434E+00 | 9.093E+01 | -1.186E+03 | 8.192E+03 | -3.869E+04 |
| S12 | 0.000E+00 | 9.138E+00 | -5.448E+01 | 5.398E+01 | 1.260E+03 | -1.079E+04 | 4.749E+04 |
| S13 | 0.000E+00 | -3.555E+01 | 2.765E+02 | -2.255E+03 | 1.746E+04 | -1.035E+05 | 4.369E+05 |
| S14 | -3.528E+00 | -3.987E+01 | 4.227E+02 | -3.761E+03 | 2.540E+04 | -1.251E+05 | 4.425E+05 |
| Face number | A16 | A18 | A20 | A22 | A24 | A26 | A28 |
| S1 | 9.836E+00 | -5.119E+00 | 1.138E+00 | 0.000E+00 | 0.000E+00 | 0.000E+00 | 0.000E+00 |
| S2 | 0.000E+00 | 0.000E+00 | 0.000E+00 | 0.000E+00 | 0.000E+00 | 0.000E+00 | 0.000E+00 |
| S3 | -7.638E+00 | 3.687E+00 | -7.166E-01 | 0.000E+00 | 0.000E+00 | 0.000E+00 | 0.000E+00 |
| S4 | -5.547E+00 | 2.872E+00 | -6.257E-01 | 0.000E+00 | 0.000E+00 | 0.000E+00 | 0.000E+00 |
| S5 | -2.281E+01 | 1.160E+01 | -2.534E+00 | 0.000E+00 | 0.000E+00 | 0.000E+00 | 0.000E+00 |
| S6 | -6.622E+00 | 1.508E+00 | 0.000E+00 | 0.000E+00 | 0.000E+00 | 0.000E+00 | 0.000E+00 |
| S7 | -1.465E+02 | 7.216E+01 | -1.477E+01 | 0.000E+00 | 0.000E+00 | 0.000E+00 | 0.000E+00 |
| S8 | -1.410E+02 | 6.904E+01 | -1.513E+01 | 0.000E+00 | 0.000E+00 | 0.000E+00 | 0.000E+00 |
| S9 | -1.605E+03 | 1.275E+03 | -5.687E+02 | 1.074E+02 | 0.000E+00 | 0.000E+00 | 0.000E+00 |
| S10 | -1.239E+00 | 4.128E+01 | -1.890E+01 | 0.000E+00 | 0.000E+00 | 0.000E+00 | 0.000E+00 |
| S11 | 1.289E+05 | -3.037E+05 | 5.059E+05 | -5.912E+05 | 4.741E+05 | -2.486E+05 | 7.687E+04 |
| S12 | -1.333E+05 | 2.526E+05 | -3.263E+05 | 2.824E+05 | -1.547E+05 | 4.661E+04 | -4.510E+03 |
| S13 | -1.300E+06 | 2.742E+06 | -4.116E+06 | 4.365E+06 | -3.196E+06 | 1.538E+06 | -4.378E+05 |
| S14 | -1.123E+06 | 2.046E+06 | -2.667E+06 | 2.456E+06 | -1.550E+06 | 6.339E+05 | -1.497E+05 |
As can be seen from the aberration diagrams in fig. 12, the longitudinal spherical aberration, curvature of field, astigmatism and distortion of the optical system 10 having the wide-angle characteristic are well controlled, and the optical system 10 of this embodiment can have good imaging quality.
Seventh embodiment
Referring to fig. 13, in the seventh embodiment, the optical system 10 includes, in order from the object side to the image side along the optical axis 101, an aperture stop STO, a first lens L1 having a positive bending force, a second lens L2 having a negative bending force, a third lens L3 having a negative bending force, a fourth lens L4 having a positive bending force, a fifth lens L5 having a negative bending force, a sixth lens L6 having a positive bending force, and a seventh lens L7 having a negative bending force. In the seventh embodiment, the surface type of each lens differs from that in the first embodiment in that: the image-side surface S4 of the second lens element L2 is convex at a position near the maximum effective aperture. The image-side surface S8 of the fourth lens element L4 is convex at a paraxial region 101, and the image-side surface S8 is concave at a position near the maximum effective aperture. The object side surface S9 of the fifth lens element L5 is convex at a position near the maximum effective aperture. The image-side surface S12 of the sixth lens element L6 is convex at the paraxial region 101, and the image-side surface S12 is concave at the position near the maximum effective aperture. The object-side surface S13 of the seventh lens element L7 is concave at the paraxial region 101, the object-side surface S13 is convex at the position near the maximum effective aperture, and the image-side surface S14 is concave at the position near the maximum effective aperture. The lens parameters of the optical system 10 in this embodiment are given in tables 13 and 14, wherein the definition of the names and parameters of the elements can be obtained in the first embodiment, and the details are omitted here.
TABLE 13
TABLE 14
As can be seen from the aberration diagrams in fig. 14, the longitudinal spherical aberration, curvature of field, astigmatism and distortion of the optical system 10 having the wide-angle characteristic are well controlled, and the optical system 10 of this embodiment can have good imaging quality.
Referring to table 15, table 15 is a summary of the ratios of the relationships in the first embodiment to the seventh embodiment of the present application.
TABLE 15
The optical system 10 in the above embodiments can compress the total length to achieve a miniaturized design while maintaining good imaging quality, and can also have a large imaging range, compared to a general optical system.
Referring to fig. 15, an embodiment of the present application further provides an image capturing module 20, where the image capturing module 20 includes an optical system 10 and an image sensor 210, and the image sensor 210 is disposed on an image side of the optical system 10, and the two may be fixed by a bracket. The image sensor 210 may be a CCD sensor (Charge Coupled Device ) or a CMOS sensor (Complementary Metal Oxide Semiconductor, complementary metal oxide semiconductor). Generally, the imaging surface S17 of the optical system 10 overlaps the photosensitive surface of the image sensor 210 at the time of assembly. By adopting the optical system 10 described above, the image pickup module 20 can have good imaging quality while maintaining a compact design.
Referring to fig. 16, some embodiments of the present application also provide an electronic device 30. The electronic device 30 includes a fixing member 310, and the camera module 20 is mounted on the fixing member 310, where the fixing member 310 may be a display screen, a circuit board, a middle frame, a rear cover, and the like. The electronic device 30 may be, but is not limited to, a smart phone, a smart watch, smart glasses, an electronic book reader, a tablet computer, a PDA (Personal Digital Assistant ), etc. The camera module 20 can provide good camera quality for the electronic device 30, and simultaneously keep a small occupied volume, so that the obstruction to the miniaturized design of the device can be reduced.
In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the device or element being referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present invention.
Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present invention, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.
In the present invention, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; the device can be mechanically connected, electrically connected and communicated; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.
In the description of the present specification, a description referring to terms "one embodiment," "some embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, the different embodiments or examples described in this specification and the features of the different embodiments or examples may be combined and combined by those skilled in the art without contradiction.
While embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that: many changes, modifications, substitutions and variations may be made to the embodiments without departing from the spirit and principles of the invention, the scope of which is defined by the claims and their equivalents.
Claims (11)
1. An optical system, characterized in that the number of lenses having a bending force is seven, and sequentially comprises, from an object side to an image side along an optical axis:
a first lens element with positive refractive power having a convex object-side surface at a paraxial region and a concave image-side surface at a paraxial region;
a second lens element with a refractive power having a convex object-side surface at a paraxial region and a concave image-side surface at a paraxial region;
a third lens having a bending force;
a fourth lens having a bending force;
a fifth lens element with a convex object-side surface at a paraxial region and a concave image-side surface at a paraxial region;
a sixth lens element with positive refractive power having a convex object-side surface at a paraxial region;
a seventh lens element with negative refractive power having a concave image-side surface at a paraxial region, wherein at least one inflection point is disposed on each of the object-side surface and the image-side surface of the seventh lens element
The optical system satisfies the relationship:
2≤f7/(sag71+sag72)≤4；1.8≤(sd72-sd52)/(sd51-sd31)≤3；
f7 is the effective focal length of the seventh lens element, sag71 is the sagittal height of the object-side surface of the seventh lens element at the maximum effective aperture, sag72 is the sagittal height of the image-side surface of the seventh lens element at the maximum effective aperture,
sd72 is half of the maximum effective aperture of the seventh lens image-side surface, sd52 is half of the maximum effective aperture of the fifth lens image-side surface, sd51 is half of the maximum effective aperture of the fifth lens object-side surface, and sd31 is half of the maximum effective aperture of the third lens object-side surface.
2. The optical system of claim 1, wherein the optical system satisfies the relationship:
1≤r51/r52≤3；
r51 is a radius of curvature of the object side surface of the fifth lens element at the optical axis, and r52 is a radius of curvature of the image side surface of the fifth lens element at the optical axis.
3. The optical system of claim 1, wherein the optical system satisfies the relationship:
f/EPD≤1.6；
f is the effective focal length of the optical system, EPD is the entrance pupil diameter of the optical system.
4. The optical system of claim 1, wherein the optical system satisfies the relationship:
TTL/ImgH≤1.42；
TTL is the distance between the object side surface of the first lens and the imaging surface of the optical system on the optical axis, and Imgh is half of the image height corresponding to the maximum field angle of the optical system.
5. The optical system of claim 1, wherein the optical system satisfies the relationship:
0.5≤r12/f1≤1.8；
r12 is a radius of curvature of the image side surface of the first lens element at the optical axis, and f1 is an effective focal length of the first lens element.
6. The optical system of claim 1, wherein the optical system satisfies the relationship:
1.2≤f/f6≤1.5；
f is the effective focal length of the optical system, and f6 is the effective focal length of the sixth lens.
7. The optical system of claim 1, wherein the optical system satisfies the relationship:
30≤(r21+r22)/ct2≤60；
r21 is a radius of curvature of the object side surface of the second lens element at the optical axis, r22 is a radius of curvature of the image side surface of the second lens element at the optical axis, and ct2 is a thickness of the second lens element on the optical axis.
8. The optical system of claim 1, wherein the optical system satisfies the relationship:
5.1mm≤f*tan(HFOV)≤5.4mm；
f is the effective focal length of the optical system and the HFOV is half the maximum field angle of the optical system.
9. The optical system of claim 1, wherein the optical system satisfies the relationship:
1.2≤(ct1+ct2)/(ct3+ct4)≤1.5；
ct1 is the thickness of the first lens element on the optical axis, ct2 is the thickness of the second lens element on the optical axis, ct3 is the thickness of the third lens element on the optical axis, and ct4 is the thickness of the fourth lens element on the optical axis.
10. An imaging module comprising an image sensor and the optical system of any one of claims 1 to 9, the image sensor being disposed on an image side of the optical system.
11. An electronic device, comprising a fixing member and the camera module of claim 10, wherein the camera module is disposed on the fixing member.
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| CN112612119A (en) * | 2021-01-07 | 2021-04-06 | 浙江舜宇光学有限公司 | Optical imaging lens |
| CN113189752A (en) * | 2021-06-04 | 2021-07-30 | 浙江舜宇光学有限公司 | Optical imaging lens |
| CN113376810A (en) * | 2021-06-29 | 2021-09-10 | 江西晶超光学有限公司 | Optical system, image capturing module and electronic equipment |
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2021
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN211826689U (en) * | 2020-02-28 | 2020-10-30 | 南昌欧菲精密光学制品有限公司 | Optical system, lens module and electronic equipment |
| CN112612119A (en) * | 2021-01-07 | 2021-04-06 | 浙江舜宇光学有限公司 | Optical imaging lens |
| CN113189752A (en) * | 2021-06-04 | 2021-07-30 | 浙江舜宇光学有限公司 | Optical imaging lens |
| CN113376810A (en) * | 2021-06-29 | 2021-09-10 | 江西晶超光学有限公司 | Optical system, image capturing module and electronic equipment |
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