WO2022061823A1

WO2022061823A1 - Optical system, lens module and electronic device

Info

Publication number: WO2022061823A1
Application number: PCT/CN2020/118153
Authority: WO
Inventors: 党绪文; 刘彬彬; 李明; 邹海荣
Original assignee: 欧菲光集团股份有限公司; 南昌欧菲精密光学制品有限公司
Priority date: 2020-09-27
Filing date: 2020-09-27
Publication date: 2022-03-31

Abstract

An optical system, a lens module and an electronic device. The optical system sequentially comprises, from an object side to an image side in an optical axis direction, first to fifth lenses (L1, L2, L3, L4, L5) having refractive power, wherein the first lens (L1) and a fourth lens (L4) have a positive refractive power, and the fifth lens (L5) has a negative refractive power; paraxial regions of object side faces (S1, S3, S5, S7) of the first to fourth lenses (L1, L2, L3, L4) and an image side face (S8) of the fourth lens (L4) are convex faces, and paraxial regions of image side faces (S2, S4, S6) of the first to third lenses (L1, L2, L3) are concave faces; and an object side face (S9) and an image side face (S10) of the fifth lens (L5) are aspheric faces, at least one inflection point is arranged on at least one of the object side face (S9) and the image side face (S10), and the optical system meets the conditional expression: 0.2 ≤ IMGH/OBJH ≤ 0.8. By means of arranging the structure comprising the five lenses (L1, L2, L3, L4, L5), the refractive power of the five optical lenses (L1, L2, L3, L4, L5) and the face type of the paraxial regions are reasonably configured, and the optical system meets the relational expression, such that the optical system has a wider imaging range and a higher magnification, and is easy to miniaturize.

Description

Optical systems, lens modules and electronics

technical field

The present application belongs to the technical field of optical imaging, and in particular relates to an optical system, a lens module and an electronic device.

Background technique

By reducing the shooting distance, the macro imaging lens can make small objects into an enlarged image on the image surface, highlighting the details that are difficult to capture by the human eye, which makes the macro imaging lens play an increasingly important role in multi-camera electronic devices. At present, macro imaging lenses mostly use small-area photosensitive chips and aperture numbers exceeding 2.2. The shooting range is small and the amount of light entering is limited, which leads to unsatisfactory imaging quality. Thinner.

SUMMARY OF THE INVENTION

The purpose of the present application is to provide an optical system, a lens module and an electronic device, which can have a wider imaging range and higher magnification, and can be easily miniaturized.

To achieve the purpose of the application, the application provides the following technical solutions:

In a first aspect, the present invention provides an optical system, comprising in sequence from the object side to the image side along the optical axis direction: a first lens having a positive refractive power, and a near-optical axis region of the object side of the first lens is a convex surface, The near-optical axis region of the image side of the first lens is concave; the second lens has refractive power, the object-side near-optical axis region of the second lens is convex, and the image-side near-optical axis region of the second lens is concave; the third lens has a refractive power, the near-optical axis region of the object side of the third lens is convex, and the near-optical axis region of the image side of the third lens is concave; the fourth lens has a positive refractive power, The near-optical axis area of the object side of the fourth lens is convex, and the near-optical axis area of the image side of the fourth lens is convex; the fifth lens has a negative refractive power, and the object side and the image side of the fifth lens are convex. All are aspherical, and at least one inflection point is set on at least one of the object side and the image side; the optical system satisfies the conditional formula: 0.2≤IMGH/OBJH≤0.8; wherein, IMGH is the maximum value of the optical system The image height corresponding to half of the field of view, OBJH is the object height corresponding to half of the maximum field of view of the optical system. The size of the IMGH determines the size of the largest photosensitive chip supported by the optical system. In this embodiment, the maximum imaging circle diameter is 4.9mm, which can support more high-pixel photosensitive chips; IMGH/OBJH represents the magnification of the optical system, and the numerical value The larger the magnification, the better the magnification effect on tiny objects; when IMGH/OBJH>0.8, the object distance is extremely small, although it can bring a higher magnification, but due to the small object distance, the shooting equipment blocks the light, and the large The amplitude reduces the amount of light entering the optical system, which affects the imaging quality; when IMGH/OBJH<0.2, the magnification is small; satisfying the above relationship can make the optical system maintain sufficient light input and provide better magnification.

By setting the five-piece lens structure, the refractive power of the five-piece optical lens and the surface shape of the near-optical axis region are reasonably configured, and the optical system can satisfy the above relationship, so that the optical system has a wider imaging range and higher magnification and easy miniaturization.

In an embodiment, the optical system satisfies the conditional formula: 1.0<OBJ/TTL<3.5; wherein, OBJ is the distance from the object surface of the optical system to the object surface of the first lens on the optical axis, and TTL is the distance from the object side of the first lens to the imaging plane on the optical axis. This embodiment provides a shooting object distance of 15mm-5mm, and the shooting macro distance is small, which provides a better magnification; at the same time, the 5-piece optical system structure is set to keep the total optical length TTL within 5mm, providing good light and thin characteristics; Satisfying the above relationship, through reasonable refractive power configuration, it is easy to achieve ultra-small macro shooting, and meet the requirements of light and thin optical system and high image quality.

In an embodiment, the optical system satisfies the conditional formula: f1234/R22<1.8; wherein, f1234 is the effective combination of the first lens, the second lens, the third lens and the fourth lens The focal length, R22 is the radius of curvature of the image side of the second lens at the optical axis. The positive effective focal length f1234 of the combination of the first lens, the second lens, the third lens and the fourth lens matches the negative effective focal length of the fifth lens, and the positive and negative structures formed make the optical It is easier to reduce the system chromatic aberration, spherical aberration and focal length; the large change of R22 can cause the adaptive adjustment of the surface shapes of the first lens to the fourth lens, and provide reasonable light deflection for the optical system The state and the reasonable ratio of surface type and spacing; satisfying the above relationship is conducive to molding and assembly, and reduces the sensitivity of the optical system.

In one embodiment, the optical system satisfies the conditional formula: 39.0deg<FOV/FNO≤55.0deg; wherein, FOV is the maximum angle of view of the optical system, and FNO is the aperture number of the optical system. In the macro imaging system, the smaller the FOV, the easier it is to achieve high magnification, but at the same time, the size of the object space will be greatly reduced, which is not conducive to macro shooting; the macro imaging system is limited by the small object distance, which is more likely to generate incoming light. Insufficient and affecting image quality; satisfying the above relationship, it can provide a shooting range of over 60°, and at the same time provide a large aperture of less than 1.65, which can improve the macro shooting experience and image quality under macro and high shutter speeds. optimal magnification.

In one embodiment, the optical system satisfies the conditional formula: 6.0<BF/CT12<43.5; wherein, BF is the minimum distance in the optical axis direction from the image side of the fifth lens to the imaging surface, and AT12 is the The distance between the first lens and the second lens on the optical axis. The longer the BF, the greater the margin provided for the assembly of the photosensitive chip, which is beneficial to the design and manufacture of the lens module; the BF of this embodiment is all greater than 0.45, which can meet the actual matching requirements. In addition, the smaller CT12 enables the first lens and the second lens to form a close-contact lens group, the light deflection angle between the first lens and the second lens is small, and the field curvature and chromatic aberration are good. Improve the effect.

In an embodiment, the optical system satisfies the conditional formula: ET4/CT3≤3.2; wherein, ET4 is the position of the effective aperture of the object side of the fourth lens to the effective aperture of the image side of the fourth lens in the direction of the optical axis and CT3 is the thickness of the third lens in the optical axis direction. The change of ET4 will cause the effective diameter of the fourth lens to change accordingly, so that the light diffused by the third lens can be incident on the fifth lens at a smaller angle; if the above relationship is satisfied, the third lens The difference from the effective diameter of the fourth lens is small, which avoids the excessively large bending angle of light and limits the improvement of performance, helps to reduce the complexity of the surface shape, and is easy to form and manufacture.

In an embodiment, the optical system satisfies the conditional formula: 66.0<f3/AT23<3105.0; wherein, f3 is the effective focal length of the third lens, and CT23 is the optical distance between the second lens and the third lens. Spacing on the axis. Through the large-scale variation of the effective focal length of the third lens, in coordination with the position of the second lens, the flexibility of the optical system can be enhanced to meet the design requirements of a small head and a large aperture; The second lens and the third lens can reduce the marginal ray angle more slowly; by setting the close-contact structure, the second lens and the third lens can not introduce excessive primary aberration, which is conducive to further Control overall aberrations and improve image quality.

In one embodiment, the optical system satisfies the conditional formula: 0.5≤ET5/(CT45+CT5)<1.1; wherein, ET5 is the effective aperture from the object side of the fifth lens to the image side of the fifth lens. The aperture is the distance in the direction of the optical axis, AT45 is the distance between the fourth lens and the fifth lens on the optical axis, and CT5 is the thickness of the fifth lens in the direction of the optical axis. Satisfying the above relational formula can make the middle and edge thicknesses of the fourth lens and the fifth lens reasonable and have good manufacturability; at the same time, the surface complexity of the fourth lens and the fifth lens is reduced , the introduced primary aberration can also be well controlled, and with the reasonable distribution of the refracting force, it can meet the high image quality requirements under macro.

In a second aspect, the present invention also provides a lens module, which includes the optical system described in any one of the embodiments of the first aspect. By adding the optical system provided by the present invention to the lens module, the lens module has a wider imaging range and higher magnification, and is easy to miniaturize.

In a third aspect, the present invention also provides an electronic device, the electronic device includes a housing and the lens module described in the second aspect, wherein the lens module is arranged in the housing. By adding the lens module provided by the present invention to the electronic device, the electronic device has higher macro shooting performance and competitiveness.

Description of drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings that are used in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only These are some embodiments of the present application, and for those of ordinary skill in the art, other drawings can also be obtained from these drawings without creative effort.

1a is a schematic structural diagram of an optical system of the first embodiment;

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

2a is a schematic structural diagram of an optical system of a second embodiment;

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

3a is a schematic structural diagram of an optical system of a third embodiment;

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

4a is a schematic structural diagram of an optical system of a fourth embodiment;

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

Fig. 5a is the structural schematic diagram of the optical system of the fifth embodiment;

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

6a is a schematic structural diagram of an optical system according to a sixth embodiment;

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

7a is a schematic structural diagram of an optical system according to a seventh embodiment;

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

detailed description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

The optical system provided by the embodiments of the present application includes a first lens, a second lens, a third lens, a fourth lens, and a fifth lens in sequence from the object side to the image side along the optical axis direction. In the first lens to the fifth lens, any two adjacent lenses may have an air space between them.

Specifically, the specific shapes and structures of the five lenses are as follows: the first lens has a positive refractive power, the near-optical axis region and the near-circumferential region of the object side of the first lens are both convex surfaces, and the image side of the first lens is convex. The near-optical axis area is concave; the second lens has refractive power, the near-optical axis area on the object side of the second lens is convex, and the near-optical axis area on the image side of the second lens is concave; the third lens, has Refractive power, the object side near-optical axis area of the third lens is convex, and the image side near-optical axis area of the third lens; The axial area is a convex surface, and the near-optical axis area of the image side of the fourth lens is convex; the fifth lens has a negative refractive power, and the object side and the image side of the fifth lens are both aspherical, and the object side and At least one inflection point is set on at least one surface of the image side surface; the optical system satisfies the conditional formula: 0.2≤IMGH/OBJH≤0.8; wherein, IMGH is the image height corresponding to half of the maximum field angle of the optical system, and OBJH is the optical system The object height corresponding to half of the maximum field of view of the system. The size of IMGH determines the size of the largest photosensitive chip supported by the optical system. In this embodiment, the maximum imaging circle diameter is 4.9mm, which can support more high-pixel photosensitive chips; IMGH/OBJH represents the magnification of the optical system. The magnification effect of small objects is better; when IMGH/OBJH>0.8, the object distance is extremely small, although it can bring a higher magnification, but due to the small object distance, the shooting equipment blocks the light, which greatly reduces the The amount of light entering the optical system affects the imaging quality; when IMGH/OBJH < 0.2, the magnification is small; satisfying the above relationship can make the optical system maintain a sufficient amount of light and provide a better magnification.

The optical system further includes a diaphragm, and the diaphragm can be arranged at any position between the object plane and the fifth lens and on the object side or the image side of any lens, such as between the first lens and the second lens. In this embodiment, the diaphragm is arranged on the object side of the first lens.

By setting the five-piece lens structure, the refractive power of the five-piece optical lens and the surface shape of the near-optical axis region are reasonably configured, and the optical system can satisfy the above relationship, so that the optical system has a wider imaging range and higher magnification magnification and easy miniaturization.

An infrared cut-off filter can also be set between the fifth lens and the imaging surface, which is used to pass through the visible light band and cut off the infrared light band, so as to avoid the phenomenon of false color or ripple caused by the interference of light waves in the non-working band, and at the same time, it can improve the effective Resolution and color reproduction.

In one embodiment, the optical system satisfies: the near-circumferential region of the object side of the first lens is convex; the near-circumferential region of the image side of the third lens is concave; and the near-circumferential region of the image side of the fifth lens is convex. By reasonably configuring the surface shapes of the first lens, the third lens and the fifth lens in the near-circumferential regions, it is beneficial to expand the imaging range and magnification of the optical system.

In one embodiment, the optical system satisfies the conditional formula: 1.0<OBJ/TTL<3.5; wherein, OBJ is the distance on the optical axis from the object plane of the optical system to the object plane of the first lens, and TTL is the object plane of the first lens. The distance from the side to the imaging plane on the optical axis. This embodiment provides a shooting object distance of 15mm-5mm, and the shooting macro distance is small, which provides a better magnification; at the same time, the 5-piece optical system structure is set to keep the total optical length TTL within 5mm, providing good light and thin characteristics; Satisfying the above relationship, through reasonable refractive power configuration, it is easy to achieve ultra-small macro shooting, and meet the requirements of light and thin optical system and high image quality.

In one embodiment, the optical system satisfies the conditional formula: f1234/R22<1.8; where f1234 is the combined effective focal length of the first lens, the second lens, the third lens and the fourth lens, and R22 is the image side of the second lens The radius of curvature at the optical axis. The positive effective focal length f1234 of the combination of the first lens, the second lens, the third lens and the fourth lens cooperates with the negative effective focal length of the fifth lens to form a positive and negative structure that makes it easier to reduce the chromatic aberration, spherical aberration and focal length of the optical system ; The large change of R22 can cause the adaptive adjustment of each surface type of the first lens to the fourth lens, providing a reasonable light deflection state and a reasonable ratio of surface type and spacing for the optical system; satisfying the above relationship is conducive to Molded assembly to reduce the sensitivity of the optical system.

In one embodiment, the optical system satisfies the conditional formula: 39.0deg<FOV/FNO≤55.0deg; wherein, FOV is the maximum angle of view of the optical system, and FNO is the aperture number of the optical system. In the macro imaging system, the smaller the FOV, the easier it is to achieve high magnification, but at the same time, the size of the object space will be greatly reduced, which is not conducive to macro shooting; the macro imaging system is limited by the small object distance, which is more prone to insufficient light input. The situation that affects the image quality; satisfying the above relationship, it can provide a shooting range of over 60°, and at the same time provide a large aperture of less than 1.65, which can improve the macro shooting experience and imaging quality under macro and high shutter speeds. magnification.

In one embodiment, the optical system satisfies the conditional formula: 6.0<BF/CT12<43.5; wherein, BF is the minimum distance in the optical axis direction from the image side of the fifth lens to the imaging surface, and AT12 is the distance between the first lens and the first lens. The distance between the two lenses on the optical axis. The longer the BF, the greater the margin provided for the assembly of the photosensitive chip, which is beneficial to the design and manufacture of the lens module; the BF of this embodiment is all greater than 0.45, which can meet the actual matching requirements. In addition, the smaller AT12 makes the first lens and the second lens form a close-contact lens group, and the light deflection angle between the first lens and the second lens is small, which has a good effect on improving the field curvature and chromatic aberration.

In one embodiment, the optical system satisfies the conditional formula: ET4/CT3≤3.2; wherein, ET4 is the distance from the effective aperture of the object side of the fourth lens to the effective aperture of the image side of the fourth lens in the direction of the optical axis, and CT3 is: The thickness of the third lens in the direction of the optical axis. The change of ET4 will cause the effective diameter of the fourth lens to change accordingly, so that the light diffused by the third lens can be incident on the fifth lens at a smaller angle; satisfying the above relationship, the effective diameters of the third lens and the fourth lens The difference is small, avoiding the excessive bending angle of the light and limiting the performance improvement, which helps to reduce the complexity of the surface shape and is easy to form and manufacture.

In one embodiment, the optical system satisfies the conditional formula: 66.0<f3/CT23<3105.0; where f3 is the effective focal length of the third lens, and AT23 is the distance between the second lens and the third lens on the optical axis. Through the large-scale change of the effective focal length of the third lens, in coordination with the position of the second lens, the flexibility of the optical system can be enhanced to meet the design requirements of small head and large aperture; satisfying the above relationship, the second lens and the third lens can make The edge light angle is reduced more slowly; by setting the close-contact structure, the second lens and the third lens can not introduce too large primary aberration, which is beneficial to further control the overall aberration and improve the imaging quality.

In one embodiment, the optical system satisfies the conditional formula: 0.5≤ET5/(CT45+CT5)<1.1; wherein, ET5 is the effective aperture on the object side of the fifth lens to the effective aperture on the image side of the fifth lens in the direction of the optical axis The distance above, AT45 is the distance between the fourth lens and the fifth lens on the optical axis, and CT5 is the thickness of the fifth lens in the direction of the optical axis. Satisfying the above relationship can make the thickness and edge thickness of the fourth lens and the fifth lens reasonable, and have good manufacturability; at the same time, the surface complexity of the fourth lens and the fifth lens is reduced, and the introduced primary aberration can also be reduced. With good control and reasonable distribution of inflection force, it can meet the needs of high image quality under macro.

An embodiment of the present invention provides a lens module. The lens module includes a lens barrel, a photosensitive element, and the optical system provided by the embodiment of the present invention. The first lens to the fifth lens of the optical system are installed in the lens barrel, and the electronic photosensitive element is installed in the lens barrel. The photosensitive surface of the element is located on the imaging surface of the optical system. The light incident on the object on the photosensitive surface of the electronic photosensitive element through the first lens to the fifth lens can be converted into an electrical signal of the image. The electronic photosensitive element can be CMOS or charge-coupled. Device (Charge-coupled Device, CCD). The lens module may be an independent lens of a digital camera, or an imaging module integrated on electronic devices such as smart phones and tablet computers. By adding the optical system provided by the present invention to the lens module, the lens module has the characteristics of wider imaging range, higher imaging quality and smaller size during macro shooting.

The embodiment of the present invention provides an electronic device, the electronic device includes a housing and the lens module provided by the embodiment of the present invention, and the lens module is arranged in the housing. The electronic device may be a smart phone, a personal digital assistant (PDA), a tablet computer, a smart watch, a drone, an electronic book reader, a driving recorder, a wearable device, and the like. By adding the lens module provided by the present invention to the electronic device, the electronic device has higher macro shooting performance and competitiveness.

first embodiment

Please refer to FIG. 1a and FIG. 1b. The optical system of this embodiment includes sequentially from the object side to the image side along the optical axis direction:

The first lens L1 has a positive refractive power, the object side S1 of the first lens L1 near the optical axis area and the near circumference area are convex surfaces, and the image side S2 of the first lens L1 The near optical axis area and the near circumference area are both concave surfaces;

The second lens L2 has refractive power, and the object side S3 of the second lens L2 near the optical axis area and the near circumference area are convex surfaces, and the image side S4 near the optical axis area and the near circumference area of the second lens L2 are both concave surfaces;

The 3rd lens L3 has refractive power, and the object side surface S5 of the 3rd lens L3 is a convex surface near the optical axis area, and the near-circumferential area is a concave surface, and the image side S6 of the 3rd lens L3 The near-optical axis area and the near-circumferential area are all concave surfaces;

The fourth lens L4 has a positive refractive power, and the object side S7 of the fourth lens L4 near the optical axis area and the near circumference area are convex surfaces; the image side S8 of the fourth lens L4 is convex in the near optical axis area, and the near circumference area is both. concave;

The fifth lens L5 has negative refractive power, the object side S9 of the fifth lens L5 is concave in the near-optical axis area and the near-circumferential area, the image side S10 of the fifth lens is convex in the near-optical axis area and the near-circumferential area, and the first Both the object side and the image side of the penta lens are aspherical, and at least one inflection point is set on at least one of the object side and the image side.

The materials of the first lens L1 to the fifth lens L5 are all plastic.

In addition, the optical system also includes a diaphragm STO, an infrared cut filter IR, and an imaging surface IMG. The diaphragm STO is disposed on the object side of the first lens L1 for controlling the amount of incoming light. In other embodiments, the stop STO may also be set at any position between the object plane and the fifth lens. The infrared cut filter IR is arranged between the image side S10 of the fifth lens L5 and the imaging surface IMG, which includes the object side S11 and the image side S12, and the infrared cut filter IR is used to filter out infrared rays, so that the incident imaging The light of the surface IMG is visible light, and the wavelength of visible light is 380nm-780nm. The material of the infrared cut-off filter is glass (Glass), and can be coated on the glass. The effective pixel area of the electronic photosensitive element is located on the imaging plane IMG.

Table 1a shows a table of characteristics of the optical system of the present embodiment, wherein each data is obtained using visible light with a wavelength of 587 nm, and the units of Y radius, thickness and effective focal length are all millimeters (mm).

Table 1a

Among them, f is the effective focal length of the optical system, FNO is the aperture number of the optical system, FOV is the maximum field of view of the optical system, and TTL is the distance on the optical axis from the object side S1 of the first lens L1 to the imaging surface IMG.

In this embodiment, the object side surface and the image side surface of any one of the first lens L1 to the fifth lens L5 are aspherical, and the surface x of each aspherical lens can be defined by but not limited to the following aspherical formula:

Among them, x is the distance vector height of the aspheric surface from the vertex of the aspheric surface when the height is h along the optical axis; c is the paraxial curvature of the aspheric surface, c=1/R (that is, the paraxial curvature c is the above table The reciprocal of the Y radius R in 1a); k is the conic coefficient; Ai is the correction coefficient of the i-th order of the aspheric surface. Table 1b gives the higher order coefficients A4, A6, A8, A10, A12, A14, A16, A18 and A20 that can be used for each of the aspheric mirror surfaces S1-S12 in the first embodiment.

Table 1b

FIG. 1b shows longitudinal spherical aberration curves, astigmatism curves and distortion curves of the optical system of the first embodiment. Among them, the longitudinal spherical aberration curve is drawn with the focus value as the abscissa, and the longitudinal spherical aberration value is drawn on the ordinate. The longitudinal spherical aberration curve represents the deviation of the focus point of light of different wavelengths after passing through each lens of the optical system; the astigmatism curve is based on the focus value. is the abscissa, the image height is drawn as the ordinate, and the astigmatism curve represents the curvature of the meridional imaging plane and the sagittal imaging plane; the distortion curve is drawn with the percentage of distortion as the abscissa, and the image height is the ordinate, and the distortion curve represents different views. Distortion value corresponding to the field angle. It can be seen from FIG. 1b that the optical system provided in the first embodiment can achieve good imaging quality.

Second Embodiment

Please refer to FIG. 2a and FIG. 2b. The optical system of this embodiment includes sequentially from the object side to the image side along the optical axis direction:

The second lens L2 has refractive power, the object side S3 of the second lens L2 near the optical axis area and the near-circumferential area are convex surfaces, the image side S4 of the second lens L2 The near-optical axis area is a concave surface, and the near-circumferential area is a convex surface;

The third lens L3 has refractive power, the object side S5 of the third lens L3 is convex in the near-optical axis area, the near-circumferential area is concave, and the image side S6 of the third lens L3 The near-optical axis area and the near-circumferential area are both concave ;

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

The fifth lens L5 has negative refractive power, the object side S9 of the fifth lens L5 is concave in the near-optical axis area and the near-circumferential area, the image side S10 of the fifth lens L5 is concave in the near-optical axis area, and the near-circumferential area is convex. .

Other structures of the second embodiment are the same as those of the first embodiment, which can be referred to.

Table 2a shows a table of characteristics of the optical system of the present embodiment, wherein each data is obtained using visible light with a wavelength of 587 nm, and the units of Y radius, thickness and effective focal length are all millimeters (mm).

Table 2a

Wherein, the meanings of the parameters in Table 2a are the same as the meanings of the parameters in the first embodiment.

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

Table 2b

Fig. 2b shows the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the optical system of the second embodiment, wherein the longitudinal spherical aberration curve is drawn with the focus value on the abscissa and the longitudinal spherical aberration value on the ordinate, and the longitudinal spherical aberration The difference curve represents the deviation of the focal point of light of different wavelengths after passing through each lens of the optical system; the astigmatism curve is drawn with the focus value as the abscissa and the image height as the ordinate, and the astigmatism curve represents the curvature of the meridional imaging plane and the sagittal imaging plane. Bending; the distortion curve is drawn with the percentage of distortion as the abscissa and the image height as the ordinate, and the distortion curve represents the distortion magnitude corresponding to different field angles. It can be seen from FIG. 2b that the optical system provided in the second embodiment can achieve good imaging quality.

Third Embodiment

Please refer to FIG. 3a and FIG. 3b. The optical system of this embodiment includes sequentially from the object side to the image side along the optical axis direction:

The first lens L1 has a positive refractive power, the object side S1 of the first lens L1 near the optical axis area and the near circumference area are convex surfaces, and the image side S2 of the first lens L1 The near optical axis area and the near circumference area are concave surfaces;

The second lens L2 has refractive power. The object side S3 of the second lens L2 has a convex surface near the optical axis, and the near circumferential region is concave. The image side S4 of the second lens L2 has a concave near optical axis, and the near circumferential region is is convex;

The third lens L3 has refractive power. The object side S5 of the third lens L3 has a convex surface near the optical axis, and the near circumferential region is concave. ;

The fourth lens L4 has a positive refractive power, and the object side S7 of the fourth lens L4 is a convex surface near the optical axis area, and the near circumferential area is a concave surface, and the image side S8 of the fourth lens L4 The near optical axis area and the near circumference area are both. convex;

The fifth lens L5 has a negative refractive power, and the object side S9 of the fifth lens L5 is a convex surface near the optical axis, and the near circumference area is a concave surface, and the image side S10 near the optical axis area of the fifth lens L5 is a concave surface, and the near circumference area is a concave surface. Convex.

Other structures of the third embodiment are the same as those of the first embodiment, which can be referred to.

Table 3a shows a table of characteristics of the optical system of this embodiment, wherein each data is obtained using visible light with a wavelength of 587 nm, and the units of Y radius, thickness and effective focal length are all millimeters (mm).

Table 3a

Wherein, the meanings of the parameters in Table 3a are the same as the meanings of the parameters in the first embodiment.

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

Table 3b

Fig. 3b shows the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the optical system of the third embodiment, wherein the longitudinal spherical aberration curve is drawn with the focus value on the abscissa and the longitudinal spherical aberration value on the ordinate, and the longitudinal spherical aberration value is drawn on the ordinate. The difference curve represents the deviation of the focal point of light of different wavelengths after passing through each lens of the optical system; the astigmatic curve is drawn with the focus value as the abscissa and the image height as the ordinate, and the astigmatism curve represents the curvature of the meridional imaging plane and the sagittal imaging plane. Bending; the distortion curve is drawn with the percentage of distortion as the abscissa and the image height as the ordinate, and the distortion curve represents the distortion magnitude corresponding to different field angles. It can be seen from FIG. 3b that the optical system provided in the third embodiment can achieve good imaging quality.

Fourth Embodiment

Referring to FIG. 4a and FIG. 4b, the optical system of the present embodiment includes sequentially from the object side to the image side along the optical axis direction:

The first lens L1 has a positive refractive power, the object side S1 of the first lens L1 is convex in the near-optical axis area and the near-circumferential area, the image side S2 of the first lens L1 is concave in the near-optical axis area, and the near-circumferential area is convex. ;

The second lens L2 has refractive power, and the object side surface S3 of the second lens L2 is a convex surface near the optical axis area, and the near-circumferential area is a concave surface, and the image side S4 of the second lens L2 The near-optical axis area and the near-circumferential area are both concave surfaces;

The third lens L3 has refractive power, and the object side S5 of the third lens L3 near the circumference area and the near optical axis area are convex surfaces, and the image side S6 near the optical axis area and the near circumference area of the third lens L3 are both concave surfaces;

The fourth lens L4 has a positive refractive power, the object side S7 of the fourth lens L4 is convex in the near-optical axis area and the near-circumferential area, and the image side S8 of the fourth lens L4 is also convex in the near-optical axis area and the near-circumferential area. ;

The fifth lens L5 has a negative refractive power, the object side S9 of the fifth lens L5 is a convex surface near the optical axis, and the near circumference area is a concave surface, and the image side S10 of the fifth lens L5 is a concave near the optical axis area, and the near circumference area is Convex.

Other structures of the fourth embodiment are the same as those of the first embodiment, and can be referred to.

Table 4a shows a table of characteristics of the optical system of the present embodiment, wherein each data is obtained using visible light with a wavelength of 587 nm, and the units of Y radius, thickness and effective focal length are all millimeters (mm).

Table 4a

Wherein, the meanings of the parameters in Table 4a are the same as the meanings of the parameters in the first embodiment.

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

Table 4b

Fig. 4b shows the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the optical system of the fourth embodiment, wherein the longitudinal spherical aberration curve is drawn with the focus value on the abscissa and the longitudinal spherical aberration value on the ordinate, and the longitudinal spherical aberration value is drawn on the ordinate. The difference curve represents the deviation of the focal point of light of different wavelengths after passing through each lens of the optical system; the astigmatism curve is drawn with the focus value as the abscissa and the image height as the ordinate, and the astigmatism curve represents the curvature of the meridional imaging plane and the sagittal imaging plane. Bending; the distortion curve is drawn with the percentage of distortion as the abscissa and the image height as the ordinate, and the distortion curve represents the distortion magnitude corresponding to different field angles. It can be seen from FIG. 4b that the optical system provided in the fourth embodiment can achieve good imaging quality.

Fifth Embodiment

Please refer to FIG. 5a and FIG. 5b , the optical system of this embodiment includes sequentially from the object side to the image side along the optical axis direction:

The first lens L1 has a positive refractive power, the near-optical axis region and the near-circumferential region of the object side S1 of the first lens L1 are convex surfaces, the image side S2 of the first lens L1 is concave in the near-optical axis region, and the near-circumferential region is convex. ;

The second lens L2 has refractive power. The object side S3 of the second lens L2 has a convex surface near the optical axis, and the near circumferential region is concave. The image side S4 of the second lens L2 has a concave near optical axis, and the near circumferential region is convex;

The third lens L3 has refractive power, and the object side S5 of the third lens L3 is a convex surface near the optical axis, and the near-circumferential region is a concave surface, and the image side S6 and the near-circumferential region of the third lens L3 are both concave;

The fourth lens L4 has a positive refractive power, the object side S7 of the fourth lens L4 is a convex surface near the optical axis, and the near-circumferential area is a concave surface, and the image side S8 of the fourth lens L4 is a convex surface near the optical axis, and the near-circumferential area is convex. is concave;

The fifth lens L5 has a negative refractive power, and the object side S9 of the fifth lens L5 has a convex surface near the optical axis, and the near-circumferential region is a concave surface. .

The other structures of the fifth embodiment are the same as those of the first embodiment, which can be referred to.

Table 5a is a table showing the characteristics of the optical system of the present embodiment, wherein each data is obtained using visible light with a wavelength of 587 nm, and the units of Y radius, thickness and effective focal length are all millimeters (mm).

Table 5a

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

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

Table 5b

Fig. 5b shows the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the optical system of the fifth embodiment, wherein the longitudinal spherical aberration curve is drawn with the focus value on the abscissa and the longitudinal spherical aberration value on the ordinate, and the longitudinal spherical aberration value is drawn on the ordinate. The difference curve represents the deviation of the focal point of light of different wavelengths after passing through each lens of the optical system; the astigmatism curve is drawn with the focus value as the abscissa and the image height as the ordinate, and the astigmatism curve represents the curvature of the meridional imaging plane and the sagittal imaging plane. Bending; the distortion curve is drawn with the percentage of distortion as the abscissa and the image height as the ordinate, and the distortion curve represents the distortion magnitude corresponding to different field angles. It can be seen from FIG. 5b that the optical system provided in the fifth embodiment can achieve good imaging quality.

Sixth Embodiment

Please refer to FIG. 6a and FIG. 6b. The optical system of this embodiment, from the object side to the image side along the optical axis direction, sequentially includes:

The third lens L3 has refractive power, the object side S5 of the third lens L3 is a convex surface near the optical axis, and the near circumferential region is a concave surface, and the image side S6 of the third lens L3 is a concave surface near the near optical axis and near the circumference. ;

The fourth lens L4 has a positive refractive power, the object side surface S7 of the fourth lens L4 is a convex surface near the optical axis, and the near circumference area is a concave surface, and the image side S8 of the fourth lens L4 is a convex surface near the optical axis area and the near circumference area. ;

The fifth lens L5 has a negative refractive power, the object side S9 of the fifth lens L5 is a convex surface near the near-optical axis area, and the near-circumferential area is a concave surface, and the image side S10 of the fifth lens is a concave area near the optical axis, and the near-circumferential area is a concave surface. Convex.

The other structures of the sixth embodiment are the same as those of the first embodiment, which can be referred to.

Table 6a shows a table of characteristics of the optical system of this embodiment, wherein each data is obtained using visible light with a wavelength of 587.6 nm, and the units of Y radius, thickness and effective focal length are all millimeters (mm).

Table 6a

Wherein, the meanings of the parameters in Table 6a are the same as the meanings of the parameters in the first embodiment.

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

Table 6b

Fig. 6b shows the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the optical system of the sixth embodiment, wherein the longitudinal spherical aberration curve is drawn with the focus value on the abscissa and the longitudinal spherical aberration value on the ordinate, and the longitudinal spherical aberration value is drawn on the ordinate. The difference curve represents the deviation of the focal point of light of different wavelengths after passing through each lens of the optical system; the astigmatic curve is drawn with the focus value as the abscissa and the image height as the ordinate, and the astigmatism curve represents the curvature of the meridional imaging plane and the sagittal imaging plane. Bending; the distortion curve is drawn with the percentage of distortion as the abscissa and the image height as the ordinate, and the distortion curve represents the distortion magnitude corresponding to different field angles. It can be seen from FIG. 6b that the optical system provided in the sixth embodiment can achieve good imaging quality.

Seventh Embodiment

Please refer to FIG. 7a and FIG. 7b. The optical system of this embodiment, from the object side to the image side along the optical axis direction, sequentially includes:

The second lens L2 has refractive power, and the object side surface S3 of the second lens L2 is a convex surface near the optical axis area, and the near circumference is a concave surface, and the image side S4 of the second lens L2 is a concave surface near the optical axis area, and the near-circumferential area is a convex surface;

The third lens L3 has refractive power. The object side S5 of the third lens L3 has a convex surface near the optical axis, and the near circumference is concave. The image side S6 of the third lens L3 has a concave surface near the optical axis and the near circumference.

The fourth lens L4 has a positive refractive power, the object side surface S7 of the fourth lens L4 is convex in the near-optical axis area and the near-circumferential area, and the near-optical axis area of the image side S8 of the fourth lens L4 is convex, and the near-circumferential area is a concave surface ;

The fifth lens L5 has a negative refractive power, the object side S9 of the fifth lens L5 is concave in the near-optical axis area, and the near circumference is convex, and the image side S10 of the fifth lens L5 is concave in the near-optical axis area, and the near circumference area is convex.

The other structures of the seventh embodiment are the same as those of the first embodiment, which can be referred to.

Table 7a shows a table of characteristics of the optical system of this embodiment, wherein each data is obtained using visible light with a wavelength of 587 nm, and the units of Y radius, thickness and effective focal length are all millimeters (mm).

Table 7a

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

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

Table 7b

Fig. 7b shows the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the optical system of the seventh embodiment, wherein the longitudinal spherical aberration curve is drawn with the focus value on the abscissa and the longitudinal spherical aberration value on the ordinate. The difference curve represents the deviation of the focal point of light of different wavelengths after passing through each lens of the optical system; the astigmatic curve is drawn with the focus value as the abscissa and the image height as the ordinate, and the astigmatism curve represents the curvature of the meridional imaging plane and the sagittal imaging plane. Bending; the distortion curve is drawn with the percentage of distortion as the abscissa and the image height as the ordinate, and the distortion curve represents the distortion magnitude corresponding to different field angles. According to Fig. 7b, it can be seen that the optical system provided in the seventh embodiment can achieve good imaging quality.

Table 8 shows OIMGH/OBJH, OBJ/TTL, f1234/R22, FOV/FNO, BF/AT12, ET4/CT3, f3/AT23, ET5/(AT45 in the optical systems of the first to seventh embodiments +CT5) value.

Table 8

It can be seen from Table 8 that the optical systems of the first to seventh embodiments all satisfy the following conditional expressions: 0.2≤IMGH/OBJH≤0.8, 1.0<OBJ/TTL<3.5, f1234/R22<1.8, 39.0deg<FOV/ FNO≤55.0deg, 6.0＜BF/AT12＜43.5, ET4/CT3≤3.2, 66.0＜f3/AT23＜3105.0, 0.5≤ET5/(AT45+CT5)＜1.1.

What is disclosed above is only a preferred embodiment of the present application, and of course, it cannot limit the scope of the right of the present application. Those of ordinary skill in the art can understand all or part of the process of implementing the above-mentioned embodiment, and the right to The equivalent changes required are still within the scope of the application.

Claims

An optical system, characterized in that, from the object side to the image side along the optical axis direction, it comprises:

The first lens has a positive refractive power, the near-optical axis region of the object side of the first lens is a convex surface, and the near-optical axis region of the image side of the first lens is a concave surface;

The second lens has a refractive power, the near-optical axis region of the object side of the second lens is a convex surface, and the near-optical axis region of the image side of the second lens is a concave surface;

The third lens has a refractive power, the object-side near-optical axis region of the third lens is convex, and the image-side near-optical axis region of the third lens is concave;

The fourth lens has a positive refractive power, the object-side near-optical axis region of the fourth lens is convex, and the image-side near-optical axis region of the fourth lens is convex;

The fifth lens has a negative refractive power, the object side and the image side of the fifth lens are both aspherical, and at least one of the object side and the image side is provided with at least one inflection point;

The optical system satisfies the conditional formula: 0.2≤IMGH/OBJH≤0.8;

Wherein, IMGH is the image height corresponding to half of the maximum viewing angle of the optical system, and OBJH is the object height corresponding to half the maximum viewing angle of the optical system.
The optical system of claim 1, wherein the optical system satisfies the conditional expression:

1.0<OBJ/TTL<3.5;

OBJ is the distance from the object surface of the optical system to the object surface of the first lens on the optical axis, and TTL is the distance from the object surface of the first lens to the imaging surface on the optical axis.
The optical system of claim 1, wherein the optical system satisfies the conditional expression:

f1234/R22<1.8;

Wherein, f1234 is the combined effective focal length of the first lens, the second lens, the third lens and the fourth lens, and R22 is the radius of curvature of the image side of the second lens at the optical axis.
The optical system of claim 1, wherein the optical system satisfies the conditional expression:

39.0deg＜FOV/FNO≤55.0deg;

Wherein, FOV is the maximum angle of view of the optical system, and FNO is the aperture number of the optical system.
The optical system of claim 1, wherein the optical system satisfies the conditional expression:

6.0<BF/AT12<43.5;

Wherein, BF is the minimum distance from the image side of the fifth lens to the imaging surface in the direction of the optical axis, and AT12 is the distance between the first lens and the second lens on the optical axis.
The optical system of claim 1, wherein the optical system satisfies the conditional expression:

ET4/CT3≤3.2;

Wherein, ET4 is the distance from the effective aperture on the object side of the fourth lens to the effective aperture on the image side of the fourth lens in the direction of the optical axis, and CT3 is the thickness of the third lens in the direction of the optical axis.
The optical system of claim 1, wherein the optical system satisfies the conditional expression:

66.0＜f3/AT23＜3105.0;

Wherein, f3 is the effective focal length of the third lens, and AT23 is the distance between the second lens and the third lens on the optical axis.
The optical system of claim 1, wherein the optical system satisfies the conditional expression:

0.5≤ET5/(AT45+CT5)＜1.1;

Wherein, ET5 is the distance from the effective aperture of the object side of the fifth lens to the effective aperture of the image side of the fifth lens in the direction of the optical axis, and AT45 is the distance between the fourth lens and the fifth lens on the optical axis and CT5 is the thickness of the fifth lens in the optical axis direction.
A lens module, characterized in that it comprises a lens barrel, a photosensitive element and the optical system according to any one of claims 1 to 8, wherein the first lens to the fifth lens of the optical system are mounted on In the lens barrel, the photosensitive element is arranged on the image side of the optical system.
An electronic device, comprising a housing and a lens module according to claim 9, wherein the lens module is arranged in the housing.