Optical systems, camera modules and electronic devices

Abstract

The present invention provides an optical system, a camera module and an electronic device. The optical system includes, from the object side to the image side in the direction of the first optical axis, a first lens having positive refractive power, a convex surface at the object side near the axis, and a flat surface at the image side near the axis; a prism for folding the light path so that the light path is turned from the first optical axis to the second optical axis, and the first optical axis intersects with the second optical axis; from the object side to the image side in the direction of the second optical axis, the optical system includes, from the object side to the image side in the direction of the second optical axis, a second lens having positive refractive power, a convex surface at the object side near the axis, and a convex surface at the image side near the axis; a third lens having refractive power, a concave surface at the object side near the axis; a fourth lens having refractive power; a fifth lens having refractive power; a sixth lens having negative refractive power, a convex surface at the object side near the axis, and a concave surface at the image side near the axis; and a seventh lens having negative refractive power. The surface shape and refractive power of each lens are reasonably configured so that the structure can be miniaturized while satisfying a good telephoto effect.

Description

Technical Field

[0001] The present invention belongs to the technical field of optical imaging, and in particular relates to an optical system, a camera module and an electronic device. Background Art

[0002] The manufacturing technology of electronic products such as smartphones and tablets is constantly developing, and the lens, as one of the important basic parts of image data acquisition, is also undergoing diversified development. With the market's demand for high-quality imaging, the lens needs to have a good telephoto effect. However, the traditional telephoto lens is too long to meet the requirements of miniaturization.

[0003] Therefore, periscope lenses came into being, and how to make periscope lenses have good telephoto effects while meeting the requirements of miniaturization is a technical problem that needs to be solved urgently. Summary of the invention

[0004] The purpose of this application is to provide an optical system, a camera module and an electronic device to solve the above-mentioned technical problems.

[0005] To achieve the purpose of this application, this application provides the following technical solutions:

[0006] In the first aspect, the present application provides an optical system, which includes, from the object side to the image side along the first optical axis direction: a first lens having positive refractive power, wherein the object side surface of the first lens is convex at the near-axis position, and the image side surface of the first lens is flat at the near-axis position; a prism for folding the light path so that the light path is turned from the first optical axis to the second optical axis, and the first optical axis intersects with the second optical axis; and from the object side to the image side along the second optical axis direction: a second lens having positive refractive power, wherein the object side surface of the second lens is convex at the near-axis position, and the image side surface of the second lens is convex at the near-axis position; a third lens having refractive power, wherein the object side surface of the third lens is concave at the near-axis position; a fourth lens having refractive power; a fifth lens having refractive power; a sixth lens having negative refractive power, wherein the object side surface of the sixth lens is convex at the near-axis position, and the image side surface of the sixth lens is concave at the near-axis position; and a seventh lens having negative refractive power. By reasonably configuring the surface shape and refractive power of each lens from the first lens to the seventh lens, the optical system described in the present application can achieve a small structure while achieving a good telephoto effect.

[0007] In one embodiment, at least one surface of at least one of the first lens to the seventh lens is an aspherical surface. In this structure, the optical system can achieve a good telephoto effect while achieving a compact structure.

[0008] In one embodiment, the optical system satisfies the conditional formula: 1.6 < TTL / (ImgH*2) < 2.5; 11° < HFOV < 16°; 0.6 < DL / TTL < 0.8; where TTL is the distance from the object side surface of the second lens to the imaging surface of the optical system on the second optical axis, ImgH is half of the diagonal length of the effective imaging area of the optical system on the imaging surface, HFOV is half of the maximum field of view angle of the optical system, and DL is the distance between the object side surface of the second lens and the image side surface of the seventh lens on the second optical axis. When the optical system satisfies the above conditional formula, that is, a reasonable structural layout is performed on the second lens to the seventh lens, so that the ratio of the lens height to the imaging surface is within a small range, thereby miniaturizing the optical system. On the basis of achieving miniaturization, the space of the lens part is reduced, which is beneficial to the layout of the module structure end.

[0009] In one embodiment, the optical system satisfies the conditional formula: 0.9 < TTL / f < 1.2; where TTL is the distance from the object side surface of the second lens to the imaging surface of the optical system on the second optical axis, and f is the effective focal length of the optical system. When the optical system satisfies the above conditional formula, a lower lens height can be provided within the range of HFOV < 16°, making it easier for the optical system to be implanted into portable devices. At the same time, the use of aspherical surfaces makes the ratio of TTL to f within a small numerical range. Under the condition of achieving telephoto photography, it is beneficial for the optical system to balance aberrations such as chromatic aberration and spherical aberration and obtain good imaging quality.

[0010] In one embodiment, the optical system satisfies the conditional formula: EFY(L2~L7) > 10mm; where EFY(L2~L7) is the focal length of the rear lens group composed of the second lens to the seventh lens. When the optical system satisfies the above conditional formula, that is, by reasonably configuring the optical power of the first lens and the rear lens group, the light rays entering through the first lens can be effectively balanced, corrected for the generated aberrations and the effective convergence of marginal rays by the rear lens group, so that while ensuring the compactness and miniaturization of the optical system, the optical system has a good telephoto effect.

[0011] In one embodiment, the optical system satisfies the conditional formula: T56 / T67<0.25; wherein T56 is the distance between the image side surface of the fifth lens and the object side surface of the sixth lens on the second optical axis, and T67 is the distance between the image side surface of the sixth lens and the object side surface of the seventh lens on the second optical axis. When the optical system satisfies the above conditional formula, that is, by reasonably configuring the positional relationship between the fifth lens and the sixth lens, and between the sixth lens and the seventh lens, the length dimension of the optical system can be effectively compressed, the change in direction of light after entering the optical system can be slowed down, and the intensity of stray light can be reduced.

[0012] In one embodiment, the optical system satisfies the conditional formula: |f2 / f1|<0.3; wherein f1 is the effective focal length of the first lens, and f2 is the effective focal length of the second lens. When the optical system satisfies the above conditional formula, that is, by reasonably configuring the size and refractive power of the first lens and the second lens, the large spherical aberration generated by the front lens group can be balanced, the overall resolution of the optical system can be improved, and the refractive power configuration of the rear end of the optical system can be controlled to strengthen the peripheral aberration correction of the optical system. At the same time, it is also conducive to size compression, so that the optical system can be miniaturized.

[0013] In one embodiment, the optical system satisfies the conditional formula: |V2-V4|>30; wherein V2 is the Abbe number of the second lens, and V4 is the Abbe number of the fourth lens. When the optical system satisfies the above conditional formula, that is, the Abbe numbers of the second lens and the fourth lens are reasonably configured, it is beneficial to the chromatic aberration correction and performance guarantee of the optical system.

[0014] In a second aspect, the present application further provides a camera module, comprising a lens barrel, an electronic photosensitive element, and the optical system in any embodiment of the first aspect, wherein the first lens to the seventh lens and the prism of the optical system are installed in the lens barrel, and the electronic photosensitive element is arranged on the image side of the optical system, and is used to convert the light signal of the object incident on the electronic photosensitive element through the first lens, the prism, and the second lens to the seventh lens into an electrical signal of the image. By installing the above optical system in the camera module, the camera module can achieve a small structure while achieving a good telephoto effect.

[0015] In a third aspect, the present application further provides an electronic device, comprising a housing and the camera module according to the second aspect, wherein the camera module is disposed in the housing. By arranging the camera module according to the second aspect in the electronic device, the electronic device can achieve a small structure while achieving a good telephoto effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1a is a schematic structural diagram of the optical system of the first embodiment;

[0018] Figure 1b 7 are the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the first embodiment;

[0019] Figure 2a is a schematic structural diagram of an optical system of a second embodiment;

[0020] Figure 2b 7 are the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the second embodiment;

[0021] Figure 3a is a schematic structural diagram of an optical system of a third embodiment;

[0022] Figure 3b 7 are the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the third embodiment;

[0023] Figure 4a is a schematic structural diagram of an optical system of a fourth embodiment;

[0024] Figure 4b 7 are the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the fourth embodiment;

[0025] Figure 5a is a schematic structural diagram of an optical system of a fifth embodiment;

[0026] Figure 5b 7 are the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the fifth embodiment;

[0027] Figure 6a is a schematic structural diagram of an optical system of a sixth embodiment;

[0028] Figure 6b 1 and 2 are the longitudinal spherical aberration curve, astigmatism curve, and distortion curve of the sixth embodiment.

[0029] Figure 7a is a schematic structural diagram of an optical system of a seventh embodiment;

[0030] Figure 7b 7 are the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the seventh embodiment; DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] The embodiment of the present application provides a camera module, which includes a lens barrel, an electronic photosensitive element and an optical system provided by an embodiment of the present invention, wherein the first lens to the seventh lens and a prism of the optical system are installed in the lens barrel, and the electronic photosensitive element is arranged on the image side of the optical system, and is used to convert the light signal of the object incident on the electronic photosensitive element through the first lens, the prism and the second lens to the seventh lens into an electrical signal of an image. The electronic photosensitive element can be a complementary metal oxide semiconductor (CMOS) or a charge coupled device (CCD). The camera module can be an independent lens of a digital camera, or an imaging module integrated in an electronic device such as a smart phone. By installing the first lens to the seventh lens and the prism of the optical system in the camera module, and rationally configuring the surface shape and refractive power of each lens of the first lens to the seventh lens, the camera module provided by the embodiment of the present application can achieve structural miniaturization while satisfying a good telephoto effect.

[0033] An embodiment of the present application provides an electronic device, which includes a housing and a camera module provided in an embodiment of the present application. The camera module and the electronic photosensitive element are arranged in the housing. The electronic device can be a smart phone, a personal digital assistant (PDA), a tablet computer, a smart watch, a drone, an e-book reader, a driving recorder, a wearable device, etc. By setting the camera module provided in an embodiment of the present application in an electronic device, the electronic device can achieve a miniaturized structure while satisfying a good telephoto effect.

[0034] The embodiment of the present application provides an optical system, which includes a first lens and a prism in sequence from the object side to the image side along the first optical axis direction, the prism is used to fold the light path so that the light path is turned from the first optical axis ① to the second optical axis ②, the first optical axis ① intersects with the second optical axis ②, and the optical system includes a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens in sequence from the object side to the image side along the second optical axis ② direction. Among the first lens to the seventh lens, any two adjacent lenses may have an air gap between them.

[0035] Specifically, the specific shapes and structures of the seven lenses are as follows:

[0036] The first lens has a positive refractive power. The paraxial part of the object side surface of the first lens is convex, and the paraxial part of the image side surface of the first lens is flat. The second lens has a positive refractive power. The paraxial part of the object side surface of the second lens is convex, and the paraxial part of the image side surface of the second lens is convex. The third lens has a refractive power. The paraxial part of the object side surface of the third lens is concave. The fourth lens has a refractive power. The fifth lens has a refractive power. The sixth lens has a negative refractive power. The paraxial part of the object side surface of the sixth lens is convex, and the paraxial part of the image side surface of the sixth lens is concave. The seventh lens has a negative refractive power. By reasonably configuring the surface shapes and refractive powers of the first lens to the seventh lens, the optical system of the present application can achieve miniaturization of the structure while satisfying a good telephoto effect.

[0037] In one embodiment, at least one surface of at least one of the first lens to the seventh lens is an aspherical surface. With this structure, the optical system can achieve miniaturization of the structure while satisfying a good telephoto effect.

[0038] In one embodiment, the optical system satisfies the conditional expressions: 1.6 < TTL / (ImgH*2) < 2.5; 11° < HFOV < 16°; 0.6 < DL / TTL < 0.8; where TTL is the distance from the object side surface of the second lens to the imaging surface of the optical system on the second optical axis ②, ImgH is half of the diagonal length of the effective imaging area of the optical system on the imaging surface, HFOV is half of the maximum field of view angle of the optical system, and DL is the distance between the object side surface of the second lens and the image side surface of the seventh lens on the second optical axis ②. When the optical system satisfies the above conditional expressions, that is, a reasonable structural layout is carried out for the second lens to the seventh lens, so that the ratio of the lens height to the imaging surface is in a small range, thereby making the optical system miniaturized. On the basis of achieving miniaturization, the space of the lens part is reduced, which is beneficial to the layout of the module structure end.

[0039] In one embodiment, the optical system satisfies the conditional expression: 0.9 < TTL / f < 1.2; where TTL is the distance from the object side surface of the second lens to the imaging surface of the optical system on the second optical axis ②, and f is the effective focal length of the optical system. When the optical system satisfies the above conditional expression, a lower lens height can be provided within the range of HFOV < 16°, making it easier for the optical system to be implanted in portable devices. At the same time, the use of aspherical surfaces enables the ratio of TTL to f to be within a small numerical range. Under the conditions of achieving telephoto photography, it is beneficial for the optical system to balance aberrations such as chromatic aberration and spherical aberration and obtain good imaging quality.

[0040] In one embodiment, the optical system satisfies the conditional formula: EFY(L2-L7)>10mm; wherein EFY(L2-L7) is the focal length of the rear lens group composed of the second lens to the seventh lens. When the optical system satisfies the above conditional formula, that is, by reasonably configuring the focal length of the first lens and the rear lens group, the light entering through the first lens is effectively balanced and corrected by the rear lens group, and the aberrations generated and the marginal light are effectively converged, the optical system can have a good telephoto effect while ensuring the compactness and miniaturization of the optical system.

[0041] In one embodiment, the optical system satisfies the conditional formula: T56 / T67<0.25; wherein T56 is the distance between the image side surface of the fifth lens and the object side surface of the sixth lens on the second optical axis ②, and T67 is the distance between the image side surface of the sixth lens and the object side surface of the seventh lens on the second optical axis ②. When the optical system satisfies the above conditional formula, that is, by reasonably configuring the positional relationship between the fifth lens and the sixth lens, and between the sixth lens and the seventh lens, the length dimension of the optical system can be effectively compressed, the change in direction of light after entering the optical system can be slowed down, and the intensity of stray light can be reduced.

[0042] In one embodiment, the optical system satisfies the conditional formula: |f2 / f1|<0.3; wherein f1 is the effective focal length of the first lens, and f2 is the effective focal length of the second lens. When the optical system satisfies the above conditional formula, that is, by reasonably configuring the size and refractive power of the first lens and the second lens, the large spherical aberration generated by the front lens group can be balanced, the overall resolution of the optical system can be improved, and the refractive power configuration of the rear end of the optical system can be controlled to strengthen the peripheral aberration correction of the optical system. At the same time, it is also conducive to size compression, so that the optical system can be miniaturized.

[0043] In one embodiment, the optical system satisfies the conditional formula: |V2-V4|>30; wherein V2 is the Abbe number of the second lens, and V4 is the Abbe number of the fourth lens. When the optical system satisfies the above conditional formula, that is, the Abbe numbers of the second lens and the fourth lens are reasonably configured, it is beneficial to the chromatic aberration correction and performance guarantee of the optical system.

[0044] First embodiment,

[0045] Please refer to Figure 1a and Figure 1b The optical system of this embodiment includes, in order from the object side to the image side along the optical axis:

[0046] The first lens L1 has positive refractive power, the object side surface S1 of the first lens L1 is convex at the near axis and near the circumference, and the image side surface S2 of the first lens L1 is flat at the near axis and near the circumference;

[0047] Prism Lp, used to fold the light path;

[0048] The second lens L2 has positive refractive power, the object side surface S3 of the second lens L2 is convex at the near axis and near the circumference, and the image side surface S4 of the second lens L2 is convex at the near axis and near the circumference;

[0049] The third lens L3 has negative refractive power, the object side surface S5 of the third lens L3 is concave at the near axis and near the circumference, the image side surface S6 of the third lens L3 is convex at the near axis, and the image side surface S6 is concave near the circumference;

[0050] The fourth lens L4 has a positive refractive power. The object side surface S7 of the fourth lens L4 is concave near the axis, and the object side surface S7 is convex near the circumference. The image side surface S8 of the fourth lens L4 is convex near the axis, and the image side surface S8 is concave near the circumference.

[0051] The fifth lens L5 has negative refractive power, the object side surface S9 of the fifth lens L5 is convex at the near axis and near the circumference, and the image side surface S10 of the fifth lens L5 is concave at the near axis and near the circumference;

[0052] The sixth lens L6 has negative refractive power, the object side surface S11 of the sixth lens L6 is convex at the near axis and near the circumference, and the image side surface S12 of the sixth lens L6 is concave at the near axis and near the circumference;

[0053] The seventh lens L7 has negative refractive power. The object side surface S13 of the seventh lens L7 is convex near the axis, and the object side surface S13 is concave near the circumference. The image side surface S14 of the seventh lens L7 is concave near the axis, and the image side surface S14 is convex near the circumference.

[0054] Among the first lens L1 to the seventh lens L7, at least one lens is made of a first plastic material, and at least one lens is made of a second plastic material, wherein the first plastic material and the second plastic material have different optical properties.

[0055] In addition, the optical system also includes an aperture STO, an infrared filter L8 and an imaging surface S17. The aperture STO is arranged on the side of the second lens L2 away from the third lens L3, and is used to control the amount of light entering. In other embodiments, the aperture STO can also be arranged between two adjacent lenses, or on other lenses. The infrared filter L8 is arranged on the image side of the seventh lens L7, which includes an object side surface S15 and an image side surface S16. The infrared filter L8 is used to filter out infrared light so that the light incident on the imaging surface S17 is visible light, and the wavelength of visible light is 380nm-780nm. The material of the infrared filter L8 is glass, and a film can be coated on the glass. S17 is the imaging surface of the optical system, and the area mapped on the effective pixel area of ​​the electronic photosensitive element is the effective imaging area. It can be understood that the imaging surface overlaps with the electronic photosensitive element but does not coincide. In a specific embodiment, the imaging surface in the mobile phone is the circumscribed circle of the effective pixel area.

[0056] Table 1a shows a table of the characteristics of the optical system of this embodiment, wherein the focal length data is obtained using light with a wavelength of 555nm, the refractive index and dispersion coefficient data are obtained using light with a wavelength of 587.56nm, and the units of the curvature radius and thickness are both millimeters (mm).

[0057] Table 1a

[0058]

[0059]

[0060] Wherein, f is the effective focal length of the optical system, FNO is the aperture number of the optical system, FOV is the field of view of the optical system, TTL is the distance from the object side of the second lens to the imaging plane of the optical system on the second optical axis ②, ImgH is half of the diagonal length of the effective imaging area of ​​the optical system on the imaging plane, and DL is the distance between the object side of the second lens and the image side of the seventh lens on the second optical axis ②.

[0061] In this embodiment, at least one surface of at least one of the first lens L1 to the seventh lens L7 is an aspherical surface, and the surface shape x of each aspherical lens can be defined by but not limited to the following aspherical surface formula:

[0062]

[0063] Wherein, x is the distance vector height from the vertex of the aspheric surface when the aspheric surface is at a height of h along the optical axis; c is the paraxial curvature of the aspheric surface, c=1 / R (i.e., the paraxial curvature c is the reciprocal of the Y radius R in the above Table 1a); k is the cone coefficient; Ai is the correction coefficient of the i-th order of the aspheric surface. Table 1b shows the high-order coefficients A4, A6, A8, A10, A12, A14, A16, A18 and A20 that can be used for each aspheric mirror surface S1-S16 in the first embodiment.

[0064] Table 1b

[0065]

[0066] Figure 1b The longitudinal spherical aberration curve, astigmatism curve and distortion curve of the optical system of the first embodiment are shown. The longitudinal spherical aberration curve indicates the deviation of the focal point of light of different wavelengths after passing through each lens of the optical system; the astigmatism curve indicates the meridional image curvature and sagittal image curvature; and the distortion curve indicates the distortion magnitude value corresponding to different field angles. Figure 1b It can be seen that the optical system provided in the first embodiment can achieve good imaging quality.

[0067] Second embodiment

[0068] Please refer to Figure 2a and Figure 2b The optical system of this embodiment includes, in order from the object side to the image side along the optical axis:

[0069] The first lens L1 has positive refractive power, the object side surface S1 of the first lens L1 is convex at the near axis and near the circumference, and the image side surface S2 of the first lens L1 is flat at the near axis and near the circumference;

[0070] Prism Lp, used to fold the light path;

[0071] The second lens L2 has positive refractive power, the object side surface S3 of the second lens L2 is convex at the near axis and near the circumference, and the image side surface S4 of the second lens L2 is convex at the near axis and near the circumference;

[0072] The third lens L3 has negative refractive power, the object side surface S5 of the third lens L3 is concave at the near axis and near the circumference, and the image side surface S6 of the third lens L3 is convex at the near axis and near the circumference;

[0073] The fourth lens L4 has negative refractive power, the object side surface S7 of the fourth lens L4 is convex at the near axis and near the circumference, and the image side surface S8 of the fourth lens L4 is concave at the near axis and near the circumference;

[0074] The fifth lens L5 has negative refractive power, the object side surface S9 of the fifth lens L5 is convex at the near axis and near the circumference, and the image side surface S10 of the fifth lens L5 is concave at the near axis and near the circumference;

[0075] The sixth lens L6 has negative refractive power, the object side surface S11 of the sixth lens L6 is convex at the near axis and near the circumference, and the image side surface S12 of the sixth lens L6 is concave at the near axis and near the circumference;

[0076] The seventh lens L7 has negative refractive power. The object side surface S13 of the seventh lens L7 is convex near the axis, and the object side surface S13 is concave near the circumference. The image side surface S14 of the seventh lens L7 is concave near the axis, and the image side surface S14 is convex near the circumference.

[0077] The other structures of the second embodiment are the same as those of the first embodiment, and can be used as a reference.

[0078] Table 2a shows a table of the characteristics of the optical system of this embodiment, wherein the focal length data is obtained using light with a wavelength of 555 nm, the refractive index and dispersion coefficient data are obtained using light with a wavelength of 587.56 nm, and the units of the curvature radius and thickness are both millimeters (mm).

[0079] Table 2a

[0080]

[0081]

[0082] The meanings of the parameters in Table 2a are the same as those in the first embodiment.

[0083] Table 2b gives the coefficients of the higher-order terms that can be used for each aspherical mirror surface in the second embodiment, wherein each aspherical surface shape can be defined by the formula given in the first embodiment.

[0084] Table 2b

[0085]

[0086] Figure 2b The longitudinal spherical aberration curve, astigmatism curve and distortion curve of the optical system of the second embodiment are shown. Figure 2b It can be seen that the optical system provided in the second embodiment can achieve good imaging quality.

[0087] Third embodiment

[0088] Please refer to Figure 3a and Figure 3b The optical system of this embodiment includes, in order from the object side to the image side along the optical axis:

[0089] The first lens L1 has positive refractive power, the object side surface S1 of the first lens L1 is convex at the near axis and near the circumference, and the image side surface S2 of the first lens L1 is flat at the near axis and near the circumference;

[0090] Prism Lp, used to fold the light path;

[0091] The second lens L2 has positive refractive power, the object side surface S3 of the second lens L2 is convex at the near axis and near the circumference, and the image side surface S4 of the second lens L2 is convex at the near axis and near the circumference;

[0092] The third lens L3 has negative refractive power, the object side surface S5 of the third lens L3 is concave at the near axis and near the circumference, and the image side surface S6 of the third lens L3 is convex at the near axis and near the circumference;

[0093] The fourth lens L4 has a positive refractive power, the object side surface S7 of the fourth lens L4 is convex at the near axis and near the circumference, and the image side surface S8 of the fourth lens L4 is concave at the near axis and near the circumference;

[0094] The fifth lens L5 has negative refractive power, the object side surface S9 of the fifth lens L5 is convex at the near axis and near the circumference, and the image side surface S10 of the fifth lens L5 is concave at the near axis and near the circumference;

[0095] The sixth lens L6 has a positive refractive power, the object side surface S11 of the sixth lens L6 is convex at the near axis and near the circumference, and the image side surface S12 of the sixth lens L6 is concave at the near axis and near the circumference;

[0096] The seventh lens L7 has negative refractive power. The object side surface S13 of the seventh lens L7 is concave at the near axis and near the circumference. The image side surface S14 of the seventh lens L7 is convex at the near axis and near the circumference.

[0097] The other structures of the third embodiment are the same as those of the first embodiment, and can be used as a reference.

[0098] Table 3a shows a table of the characteristics of the optical system of this embodiment, wherein the focal length data is obtained using light with a wavelength of 555 nm, the refractive index and dispersion coefficient data are obtained using light with a wavelength of 587.56 nm, and the units of the curvature radius and thickness are both millimeters (mm).

[0099] Table 3a

[0100]

[0101]

[0102] The meanings of the parameters in Table 3a are the same as those in the first embodiment.

[0103] Table 3b gives the coefficients of the higher-order terms that can be used for each aspherical mirror surface in the third embodiment, wherein each aspherical surface shape can be defined by the formula given in the first embodiment.

[0104] Table 3b

[0105]

[0106]

[0107] Figure 3b The longitudinal spherical aberration curve, astigmatism curve and distortion curve of the optical system of the third embodiment are shown. Figure 3b It can be seen that the optical system provided in the third embodiment can achieve good imaging quality.

[0108] Fourth embodiment

[0109] Please refer to Figure 4a and Figure 4b The optical system of this embodiment includes, in order from the object side to the image side along the optical axis:

[0110] The first lens L1 has positive refractive power, the object side surface S1 of the first lens L1 is convex at the near axis and near the circumference, and the image side surface S2 of the first lens L1 is flat at the near axis and near the circumference;

[0111] Prism Lp, used to fold the light path;

[0112] The second lens L2 has positive refractive power, the object side surface S3 of the second lens L2 is convex at the near axis and near the circumference, and the image side surface S4 of the second lens L2 is convex at the near axis and near the circumference;

[0113] The third lens L3 has positive refractive power, the object side surface S5 of the third lens L3 is concave at the near axis and near the circumference, and the image side surface S6 of the third lens L3 is convex at the near axis and near the circumference;

[0114] The fourth lens L4 has a negative refractive power. The object side surface S7 of the fourth lens L4 is concave at the near axis and near the circumference. The image side surface S8 of the fourth lens L4 is convex at the near axis, and the image side surface S8 is concave at the near circumference.

[0115] The fifth lens L5 has a positive refractive power. The object side surface S9 of the fifth lens L5 is concave near the axis, and the object side surface S9 is convex near the circumference. The image side surface S10 of the fifth lens L5 is convex near the axis, and the image side surface S10 is concave near the circumference.

[0116] The sixth lens L6 has negative refractive power, the object side surface S11 of the sixth lens L6 is convex at the near axis and near the circumference, and the image side surface S12 of the sixth lens L6 is concave at the near axis and near the circumference;

[0117] The seventh lens L7 has negative refractive power. The object side surface S13 of the seventh lens L7 is convex near the axis, and the object side surface S13 is concave near the circumference. The image side surface S14 of the seventh lens L7 is concave near the axis, and the image side surface S14 is convex near the circumference.

[0118] The other structures of the fourth embodiment are the same as those of the first embodiment, and can be referred to herein.

[0119] Table 4a shows a table of the characteristics of the optical system of this embodiment, wherein the focal length data is obtained using light with a wavelength of 555 nm, the refractive index and dispersion coefficient data are obtained using light with a wavelength of 587.56 nm, and the units of the curvature radius and thickness are both millimeters (mm).

[0120] Table 4a

[0121]

[0122] The meanings of the parameters in Table 4a are the same as those in the first embodiment.

[0123] Table 4b gives the coefficients of the higher-order terms that can be used for each aspherical mirror surface in the fourth embodiment, wherein each aspherical surface shape can be defined by the formula given in the first embodiment.

[0124] Table 4b

[0125]

[0126]

[0127] Figure 4b The longitudinal spherical aberration curve, astigmatism curve and distortion curve of the optical system of the fourth embodiment are shown. Figure 4b It can be seen that the optical system provided in the fourth embodiment can achieve good imaging quality.

[0128] Fifth embodiment

[0129] Please refer to Figure 5a and Figure 5b The optical system of this embodiment includes, in order from the object side to the image side along the optical axis:

[0130] The first lens L1 has positive refractive power, the object side surface S1 of the first lens L1 is convex at the near axis and near the circumference, and the image side surface S2 of the first lens L1 is flat at the near axis and near the circumference;

[0131] Prism Lp, used to fold the light path;

[0132] The second lens L2 has positive refractive power, the object side surface S3 of the second lens L2 is convex at the near axis and near the circumference, and the image side surface S4 of the second lens L2 is convex at the near axis and near the circumference;

[0133] The third lens L3 has negative refractive power, the object side surface S5 of the third lens L3 is concave at the near axis and near the circumference, the image side surface S6 of the third lens L3 is convex at the near axis, and the image side surface S6 is concave near the circumference;

[0134] The fourth lens L4 has a positive refractive power. The object side surface S7 of the fourth lens L4 is concave near the axis, and the object side surface S7 is convex near the circumference. The image side surface S8 of the fourth lens L4 is convex near the axis, and the image side surface S8 is concave near the circumference.

[0135] The fifth lens L5 has a negative refractive power. The object side surface S9 of the fifth lens L5 is concave near the axis, and the object side surface S9 is convex near the circumference. The image side surface S10 of the fifth lens L5 is convex near the axis, and the image side surface S10 is concave near the circumference.

[0136] The sixth lens L6 has negative refractive power, the object side surface S11 of the sixth lens L6 is convex at the near axis and near the circumference, and the image side surface S12 of the sixth lens L6 is concave at the near axis and near the circumference;

[0137] The seventh lens L7 has negative refractive power. The object side surface S13 of the seventh lens L7 is convex near the axis, and the object side surface S13 is concave near the circumference. The image side surface S14 of the seventh lens L7 is concave near the axis, and the image side surface S14 is convex near the circumference.

[0138] The other structures of the fifth embodiment are the same as those of the first embodiment, and can be referred to herein.

[0139] Table 5a shows a table of the characteristics of the optical system of this embodiment, wherein the focal length data is obtained using light with a wavelength of 555 nm, the refractive index and dispersion coefficient data are obtained using light with a wavelength of 587.56 nm, and the units of the curvature radius and thickness are both millimeters (mm).

[0140] Table 5a

[0141]

[0142]

[0143] The meanings of the parameters in Table 5a are the same as those in the first embodiment.

[0144] Table 5b gives the coefficients of the higher-order terms that can be used for each aspherical mirror surface in the fifth embodiment, wherein each aspherical surface shape can be defined by the formula given in the first embodiment.

[0145] Table 5b

[0146]

[0147] Figure 5b The longitudinal spherical aberration curve, astigmatism curve and distortion curve of the optical system of the fifth embodiment are shown. Figure 5b It can be seen that the optical system provided in the fifth embodiment can achieve good imaging quality.

[0148] Sixth embodiment

[0149] Please refer to Figure 6a and Figure 6b The optical system of this embodiment includes, in order from the object side to the image side along the optical axis:

[0150] The first lens L1 has positive refractive power, the object side surface S1 of the first lens L1 is convex at the near axis and near the circumference, and the image side surface S2 of the first lens L1 is flat at the near axis and near the circumference;

[0151] Prism Lp, used to fold the light path;

[0152] The second lens L2 has positive refractive power, the object side surface S3 of the second lens L2 is convex at the near axis and near the circumference, and the image side surface S4 of the second lens L2 is convex at the near axis and near the circumference;

[0153] The third lens L3 has negative refractive power, the object side surface S5 of the third lens L3 is concave at the near axis and near the circumference, the image side surface S6 of the third lens L3 is convex at the near axis, and the image side surface S6 is concave near the circumference;

[0154] The fourth lens L4 has negative refractive power, the object side surface S7 of the fourth lens L4 is convex at the near axis and near the circumference, and the image side surface S8 of the fourth lens L4 is concave at the near axis and near the circumference;

[0155] The fifth lens L5 has a positive refractive power. The object side surface S9 of the fifth lens L5 is convex at the near axis and near the circumference. The image side surface S10 of the fifth lens L5 is convex at the near axis, and the image side surface S10 is concave at the near circumference.

[0156] The sixth lens L6 has negative refractive power, the object side surface S11 of the sixth lens L6 is convex at the near axis and near the circumference, and the image side surface S12 of the sixth lens L6 is concave at the near axis and near the circumference;

[0157] The seventh lens L7 has negative refractive power. The object side surface S13 of the seventh lens L7 is concave at the near axis and near the circumference. The image side surface S14 of the seventh lens L7 is concave at the near axis, and the image side surface S14 is convex near the circumference.

[0158] The other structures of the sixth embodiment are the same as those of the first embodiment, and can be referred to herein.

[0159] Table 6a shows a table of the characteristics of the optical system of this embodiment, wherein the focal length data is obtained using light with a wavelength of 555nm, the refractive index and dispersion coefficient data are obtained using light with a wavelength of 587.56nm, and the units of the curvature radius and thickness are both millimeters (mm).

[0160] Table 6a

[0161]

[0162]

[0163] The meanings of the parameters in Table 6a are the same as those in the first embodiment.

[0164] Table 6b gives the coefficients of the higher-order terms that can be used for each aspherical mirror surface in the sixth embodiment, wherein each aspherical surface shape can be defined by the formula given in the first embodiment.

[0165] Table 6b

[0166]

[0167] Figure 6b The longitudinal spherical aberration curve, astigmatism curve and distortion curve of the optical system of the sixth embodiment are shown. Figure 6b It can be seen that the optical system provided in the sixth embodiment can achieve good imaging quality.

[0168] Seventh embodiment

[0169] Please refer to Figure 7a and Figure 7b The optical system of this embodiment includes, in order from the object side to the image side along the optical axis:

[0170] The first lens L1 has positive refractive power, the object side surface S1 of the first lens L1 is convex at the near axis and near the circumference, and the image side surface S2 of the first lens L1 is flat at the near axis and near the circumference;

[0171] Prism Lp, used to fold the light path;

[0172] The second lens L2 has positive refractive power, the object side surface S3 of the second lens L2 is convex at the near axis and near the circumference, and the image side surface S4 of the second lens L2 is convex at the near axis and near the circumference;

[0173] The third lens L3 has negative refractive power, the object side surface S5 of the third lens L3 is concave at the near axis and near the circumference, and the image side surface S6 of the third lens L3 is concave at the near axis and near the circumference;

[0174] The fourth lens L4 has negative refractive power, the object side surface S7 of the fourth lens L4 is convex at the near axis and near the circumference, and the image side surface S8 of the fourth lens L4 is concave at the near axis and near the circumference;

[0175] The fifth lens L5 has positive refractive power, the object side surface S9 of the fifth lens L5 is convex at the near axis and near the circumference, and the image side surface S10 of the fifth lens L5 is concave at the near axis and near the circumference;

[0176] The sixth lens L6 has negative refractive power, the object side surface S11 of the sixth lens L6 is convex at the near axis and near the circumference, and the image side surface S12 of the sixth lens L6 is concave at the near axis and near the circumference;

[0177] The seventh lens L7 has negative refractive power. The object side surface S13 of the seventh lens L7 is concave at the near axis and near the circumference. The image side surface S14 of the seventh lens L7 is convex at the near axis and near the circumference.

[0178] The other structures of the seventh embodiment are the same as those of the first embodiment, and can be referred to herein.

[0179] Table 7a shows a table of the characteristics of the optical system of this embodiment, wherein the focal length data is obtained using light with a wavelength of 555nm, the refractive index and dispersion coefficient data are obtained using light with a wavelength of 587.56nm, and the units of the curvature radius and thickness are both millimeters (mm).

[0180] Table 7a

[0181]

[0182]

[0183] The meanings of the parameters in Table 7a are the same as those in the first embodiment.

[0184] Table 7b gives the coefficients of the higher-order terms that can be used for each aspherical mirror surface in the seventh embodiment, wherein each aspherical surface shape can be defined by the formula given in the first embodiment.

[0185] Table 7b

[0186]

[0187]

[0188] Figure 7b The longitudinal spherical aberration curve, astigmatism curve and distortion curve of the optical system of the seventh embodiment are shown. Figure 7b It can be seen that the optical system provided in the seventh embodiment can achieve good imaging quality.

[0189] Table 8 shows the values ​​of TTL / (ImgH*2), HFOV, DL / TTL, TTL / f, EFY(L2~L7), T56 / T67, |f2 / f1|, and |V2-V4| of the optical systems of the first to seventh embodiments.

[0190] Table 8

[0191] TTL / (ImgH*2) HFOV(°) DL / TTL TTL / f First embodiment 1.990456714 13.3 0.659246575 0.947283049 Second embodiment 2.010906612 13.3 0.674576271 0.962479608 Third embodiment 2.060327198 13.1 0.675765095 0.971084337 Fourth embodiment 1.954669393 15.2 0.721011334 1.071962617 Fifth embodiment 2.099522836 12.6 0.666396104 0.955779674 Sixth embodiment 2.109747785 12.6 0.684975767 0.961926962 Seventh embodiment 1.862644853 15 0.719121683 1.002752294 EFY(L2~L7)(mm) T56 / T67 |f2 / f1| |V2-V4| First embodiment 15.74 0.140785592 0.089818061 34.61 Second embodiment 15.52 0.18738194 0.085389998 34.61 Third embodiment 15.14 0.186302972 0.078322455 34.61 Fourth embodiment 12.36 0.138018458 0.072255703 34.61 Fifth embodiment 12.6 0.090736713 0.091149281 34.61 Sixth embodiment 16.47 0.089362322 0.09386172 34.61 Seventh embodiment 13.08 0.099603401 0.097745095 34.61

[0192] It can be seen from Table 8 that each embodiment satisfies the following conditional formula: 1.6 <TTL / (ImgH*2)<2.5、11°<HFOV<16°、0.6<DL / TTL<0.8、0.9<TTL / f<1.2、EFY(L2~L7)> 10mm, T56 / T67<0.25, |f2 / f1|<0.3, |V2-V4|>30.

[0193] The technical features of the above embodiments may be arbitrarily combined. To make the description concise, all possible combinations of the technical features in the above embodiments are not described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0194] The above embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present invention. It should be pointed out that, for those of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the attached claims.

Claims

1. An optical system, characterized in that: There are a total of seven lenses with refractive power, which successively include from the object side to the image side along the first optical axis direction: The first lens, which has a positive refractive power. The paraxial part of the object side surface of the first lens is convex, and the paraxial part of the image side surface of the first lens is flat. A prism, which is used to deflect the optical path so that the optical path turns from the first optical axis to the second optical axis, and the first optical axis intersects with the second optical axis. It successively includes from the object side to the image side along the second optical axis direction: The second lens, which has a positive refractive power. The paraxial part of the object side surface of the second lens is convex, and the paraxial part of the image side surface of the second lens is convex. The third lens, which has a refractive power. The paraxial part of the object side surface of the third lens is concave. The fourth lens, which has a refractive power. The fifth lens, which has a refractive power. The sixth lens, which has a negative refractive power. The paraxial part of the object side surface of the sixth lens is convex, and the paraxial part of the image side surface of the sixth lens is concave. The seventh lens, which has a negative refractive power. At least one surface of at least one of the first lens to the seventh lens is an aspherical surface, and the optical system satisfies the conditional formula: 11° < HFOV < 16°; where, HFOV is half of the maximum field of view angle of the optical system.

2. The optical system according to claim 1, characterized in that The optical system satisfies the conditional formula: 1.6 < TTL / (ImgH * 2) < 2.5; Where, TTL is the distance from the object side surface of the second lens to the imaging surface of the optical system on the second optical axis, and ImgH is half of the diagonal length of the effective imaging area on the imaging surface of the optical system.

3. The optical system according to claim 1, characterized in that The optical system satisfies the conditional formula: 0.6 < DL / TTL < 0.8; Where, TTL is the distance from the object side surface of the second lens to the imaging surface of the optical system on the second optical axis, and DL is the distance between the object side surface of the second lens and the image side surface of the seventh lens on the second optical axis.

4. The optical system according to claim 1, characterized in that The optical system satisfies the conditional formula: 0.9 < TTL / f < 1.2; Where, TTL is the distance from the object side surface of the second lens to the imaging surface of the optical system on the second optical axis, and f is the effective focal length of the optical system.

5. The optical system according to claim 1, characterized in that The optical system satisfies the conditional formula: EFY(L2~L7) > 10mm; Where, EFY(L2~L7) is the focal length of the rear lens group composed of the second lens to the seventh lens.

6. The optical system according to claim 1, characterized in that The optical system satisfies the conditional formula: T56 / T67 < 0.25; Where, T56 is the interval distance between the image side surface of the fifth lens and the object side surface of the sixth lens on the second optical axis, and T67 is the interval distance between the image side surface of the sixth lens and the object side surface of the seventh lens on the second optical axis.

7. The optical system according to claim 1, characterized in that The optical system satisfies the conditional formula: |f2 / f1| < 0.3; Where, f1 is the effective focal length of the first lens, and f2 is the effective focal length of the second lens.

8. The optical system according to claim 1, characterized in that The optical system satisfies the conditional formula: |V2 - V4| > 30; Where, V2 is the Abbe number of the second lens, and V4 is the Abbe number of the fourth lens.

9. A camera module, characterized in that: The optical system comprises a lens barrel, an electronic photosensitive element and the optical system as claimed in any one of claims 1 to 8, wherein the first lens to the seventh lens and the prism of the optical system are installed in the lens barrel, and the electronic photosensitive element is arranged on the image side of the optical system for converting the light signal of an object that passes through the first lens, the prism and the second lens to the seventh lens and is incident on the electronic photosensitive element into an electrical signal of an image.

10. An electronic device, characterized in that: It comprises a shell and the camera module as claimed in claim 9, wherein the camera module is arranged in the shell.

Images