Optical lens and mobile terminal

Abstract

The application discloses an optical lens, which comprises, along an optical axis, from an object plane to an imaging plane, in sequence: a diaphragm; a first lens with positive focal power, the object side of which is a convex surface, and the image side of which is a convex surface near the optical axis; a second lens with negative focal power, the object side of which is a convex surface, and the image side of which is a concave surface; a third lens with focal power, the object side of which is a convex surface, and the image side of which is a concave surface; and a flat glass or a reflecting element. The application also discloses a mobile terminal comprising the optical lens and an image sensor, which is arranged on the imaging plane of the optical lens, and is used for receiving an optical signal output by the optical lens and forming an electrical signal corresponding to the optical signal. The optical lens and the mobile terminal provided by the application have good optical performance, and at least have the advantages of long focal length, short total length and high resolution quality.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of imaging lens, in particular to an optical lens and a mobile terminal. BACKGROUND

[0002] In recent years, with the pursuit of the imaging quality of portable electronic products, multi-camera has become a standard configuration of mobile phone products. In order to improve the imaging quality of long-distance objects, most flagship mobile phones of mobile phone manufacturers are equipped with a long-focus optical lens to clearly enlarge the scene when shooting long-distance, thereby improving the quality of mobile phone shooting.

[0003] In the existing multi-camera portable electronic products, most of the conventional long-focus lenses and wide-angle lenses are combined and used to make the zoom ratio reach 3-5 times. However, compared with the traditional zoom lens, the optical zoom ratio is still small, which is difficult to meet the increasing demand of customers for high-definition imaging of portable electronic products. SUMMARY

[0004] Therefore, the purpose of the present application is to provide an optical lens and a mobile terminal, which at least have the advantages of long focal length, short total length and high resolution quality.

[0005] The present application achieves the above-mentioned application purposes through the following technical solutions.

[0006] In a first aspect, the present application provides an optical lens, which comprises, in order from the object side to the image plane along the optical axis: a stop; a first lens with positive refractive power, the object side of which is a convex surface, and the image side of which is a convex surface near the optical axis; a second lens with negative refractive power, the object side of which is a convex surface, and the image side of which is a concave surface; and a third lens with refractive power, the object side of which is a convex surface, and the image side of which is a concave surface; the optical lens satisfies the following conditional expression: -5.0 < R12 / R11 < 0; wherein R12 represents the curvature radius of the image side of the first lens, and R11 represents the curvature radius of the object side of the first lens.

[0007] In a second aspect, the present application provides an optical lens, comprising, in order from an object side to an image plane along an optical axis, an aperture stop, a first lens with positive refractive power, the object side of which is convex, and the image side of which is convex near the optical axis, a second lens with negative refractive power, the object side of which is convex, and the image side of which is concave, a third lens with refractive power, the object side of which is convex, and the image side of which is concave, and a reflective element comprising a plurality of reflective surfaces, the optical lens satisfying the following conditional expressions: 0<CT23 / (CT2+CT3)<0.3, and 6<CT1 / (CT12+CT23)<20; wherein CT1 represents the center thickness of the first lens, CT2 represents the center thickness of the second lens, CT3 represents the center thickness of the third lens, CT12 represents the air gap of the first lens and the second lens on the optical axis, and CT23 represents the air gap of the second lens and the third lens on the optical axis.

[0008] In a third aspect, the present application provides a mobile terminal comprising an image sensor and an optical lens, the image sensor being arranged at an image plane of the optical lens, and being configured to receive a light signal output by the optical lens and form an electrical signal corresponding to the light signal.

[0009] Compared with the prior art, the optical lens and the mobile terminal provided by the present application have the beneficial effects that: by reasonably allocating the thickness and refractive power of the three lenses and reasonably controlling the surface shape of each lens, the optical lens has the characteristics of long focal length, short total length, and high resolution quality. BRIEF DESCRIPTION OF DRAWINGS

[0010] Figure 1 FIG. 1 is a structural schematic diagram of an optical lens provided in a first subembodiment of the present application.

[0011] Figure 2 FIG. 2 is a relative luminance curve of the optical lens in the first subembodiment of the present application.

[0012] Figure 3 FIG. 3 is an optical distortion curve of the optical lens in the first subembodiment of the present application.

[0013] Figure 4 FIG. 4 is a field curvature curve of the optical lens in the first subembodiment of the present application.

[0014] Figure 5 FIG. 5 is a structural schematic diagram of an optical lens provided in a second subembodiment of the present application.

[0015] Figure 6 FIG. 6 is a relative luminance curve of the optical lens in the second subembodiment of the present application.

[0016] Figure 7 FIG. 7 is an optical distortion curve of the optical lens in the second subembodiment of the present application.

[0017] Figure 8 A field curvature curve diagram of the optical lens in sub-embodiment 2 of the present application.

[0018] Figure 9 A structural schematic diagram of the optical lens provided in sub-embodiment 3 of the present application.

[0019] Figure 10 A relative luminance curve diagram of the optical lens in sub-embodiment 3 of the present application.

[0020] Figure 11 An optical distortion curve diagram of the optical lens in sub-embodiment 3 of the present application.

[0021] Figure 12 A field curvature curve diagram of the optical lens in sub-embodiment 3 of the present application.

[0022] Figure 13 A structural schematic diagram of the optical lens provided in sub-embodiment 4 of the present application.

[0023] Figure 14 A structural schematic diagram of the optical lens provided in sub-embodiment 5 of the present application.

[0024] Figure 15 A structural schematic diagram of the optical lens provided in sub-embodiment 6 of the present application.

[0025] Figure 16 A structural schematic diagram of the mobile terminal provided in the third embodiment of the present application. DETAILED DESCRIPTION

[0026] In order to facilitate the understanding of the present application, the present application will be described more fully below with reference to the accompanying drawings. The accompanying drawings show several embodiments of the present application. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs. The terminology used in the description of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application. Throughout this document, the same reference numerals refer to the same elements.

[0028] First Embodiment

[0029] The present application provides an optical lens, which comprises, in sequence along an optical axis from an object side to an image plane, a diaphragm, a first lens, a second lens, a third lens, and a flat glass.

[0030] The first lens has positive focal power, the object side of the first lens is convex, and the image side of the first lens is convex at the near optical axis; the second lens has negative focal power, the object side of the second lens is convex, and the image side of the second lens is concave; the third lens has positive or negative focal power, the object side of the third lens is convex, and the image side of the third lens is concave; and the first lens to the third lens are all aspherical lenses.

[0031] In some embodiments, the curvature radius R12 of the image side of the first lens and the curvature radius R11 of the object side of the first lens satisfy the condition formula: -5.0 < R12 / R11 < 0. The present application adopts three aspherical lenses, and through specific surface shape matching and reasonable focal power distribution, the condition formula is satisfied, and by reasonably controlling the curvature radius of the first lens, the effective focal length of the optical lens is increased, so that the optical lens has the characteristics of long focal length, short total length and high resolution. Further, the curvature radius R12 of the image side of the first lens and the curvature radius R11 of the object side of the first lens can satisfy: -3.0 < R12 / R11 < -1.5.

[0032] In some embodiments, the air gap CT23 of the second lens and the third lens on the optical axis and the sum of the central thickness CT2 of the second lens and the central thickness CT3 of the third lens satisfy the condition formula: 0 < CT23 / (CT2+CT3) < 0.3; and the central thickness CT1 of the first lens and the sum of the air gap CT12 of the first lens and the second lens on the optical axis and the air gap CT23 of the second lens and the third lens on the optical axis satisfy the condition formula: 6 < CT1 / (CT12+CT23) < 20. By reasonably controlling the relationship between the air gap of the second lens and the third lens on the optical axis and the sum of the central thicknesses of the second lens and the third lens, and reasonably controlling the relationship between the central thickness of the first lens and the sum of the air gaps of the first lens to the third lens on the optical axis, the length of the first lens to the third lens on the optical axis is reduced, the volume of the lens barrel is reduced, and the balance between the miniaturization and the long focal length of the lens is achieved. Further, the air gap CT23 of the second lens and the third lens on the optical axis and the sum of the central thickness CT2 of the second lens and the central thickness CT3 of the third lens can satisfy: 0 < CT23 / (CT2+CT3) < 0.2; and the central thickness CT1 of the first lens and the sum of the air gap CT12 of the first lens and the second lens on the optical axis and the air gap CT23 of the second lens and the third lens on the optical axis can satisfy: 9 < CT1 / (CT12+CT23) < 15.

[0033] In some embodiments, the effective focal length f2 of the second lens and the effective focal length f of the optical lens satisfy the condition formula: -1.0 < f2 / f < -0.4. By reasonably controlling the focal length of the second lens, the spherical aberration of the central field of view of the optical lens is corrected, and the imaging quality of the optical lens is improved.

[0034] In some embodiments, the curvature radius R21 of the object side of the second lens and the curvature radius R32 of the image side of the third lens satisfy the condition formula: 1.1 < R21 / R32 < 1.6; the curvature radius R22 of the image side of the second lens and the curvature radius R31 of the object side of the third lens satisfy the condition formula: 0.7 < R22 / R31 < 0.9. By reasonably controlling the surface shape of the second lens and the third lens, the field curvature of the optical lens is corrected, and the imaging quality of the optical lens is improved.

[0035] In some embodiments, the distance FFL of the image side of the third lens to the imaging surface on the optical axis and the total optical length TTL of the optical lens satisfy the condition formula: 0.90 < FFL / TTL < 0.92. By reasonably controlling the relationship between the optical back focal length and the total optical length of the optical lens, the height of the overall module is shortened.

[0036] In some embodiments, the curvature radius R12 of the image side of the first lens and the curvature radius R21 of the object side of the second lens satisfy the condition formula: -4.0 < R12 / R21 < -2.0. By reasonably controlling the relationship between the curvature radii of the image side of the first lens and the object side of the second lens, the coma of the off-axis field of view of the optical lens is corrected, and the imaging quality of the optical lens is improved.

[0037] In some embodiments, the central thickness CT4 of the flat glass on the optical axis and the distance FFL of the image side of the third lens to the imaging surface on the optical axis satisfy the condition formula: 0.65 < CT4 / FFL < 0.90. By reasonably controlling the proportion of the flat glass in the optical back focal length, the thickness of the flat glass is increased, which provides conditions for subsequent use of the reflecting element to shorten the height of the overall module, reduces the risk of interference between the mechanism and the reflecting element, and is beneficial to the mechanism design of the product.

[0038] In some embodiments, the optical power φ1 of the first lens and the sum of the optical power φ2 of the second lens and the optical power φ3 of the third lens satisfy the condition formula: -1.5 < φ1 / (φ2+φ3) < -1.0. By reasonably controlling the relationship between the optical powers of the first lens, the second lens, and the third lens, the effective focal length of the optical lens is increased.

[0039] In some embodiments, the center thickness CT1 of the first lens and the total track length TTL of the optical lens satisfy the condition formula: 0.05 < CT1 / TTL < 0.07. By reasonably controlling the relationship between the center thickness of the first lens and the total track length, the total length of the optical lens is reduced, and the miniaturization of the lens is realized.

[0040] In some embodiments, the refractive power φ21 of the object side surface of the second lens, the curvature radius R21 of the object side surface of the second lens, the refractive power φ31 of the object side surface of the third lens, and the curvature radius R31 of the object side surface of the third lens satisfy the condition formula: 0.4 < φ21×R21×φ31×R31 < 0.5. By reasonably controlling the surface shape of the second lens and the third lens, the aberration of the optical lens is corrected, and the imaging quality of the optical lens is improved.

[0041] In some embodiments, the sag SAG21 of the object side surface of the second lens and the sag SAG12 of the image side surface of the first lens satisfy the condition formula: 12 < SAG21 / SAG12 < 65; the sag SAG21 of the object side surface of the second lens and the sag SAG32 of the image side surface of the third lens satisfy the condition formula: 0.7 < SAG21 / SAG32 < 1.5. By reasonably controlling the relationship between the sag of the object side surface of the second lens and the sags of the image side surfaces of the first lens and the third lens, the distribution of the first lens, the second lens, and the third lens is made more compact, the total length of the optical lens is reduced, and the miniaturization of the optical lens is realized.

[0042] In some embodiments, the sag SAG31 of the object side surface of the third lens, the sag SAG32 of the image side surface of the third lens, and the center thickness CT3 of the third lens satisfy the condition formula: -1.5 < (SAG31-SAG32) / CT3 < -0.5; the sag SAG22 of the image side surface of the second lens, the sag SAG31 of the object side surface of the third lens, and the air separation CT23 of the second lens and the third lens on the optical axis satisfy the condition formula: 0.5 < (SAG22-SAG31) / CT23 < 1.0. By reasonably controlling the relationship between the sag of the third lens and the center thickness of the third lens, and the relationship between the sags of the image side surface of the second lens and the object side surface of the third lens and the air separation of the second lens and the third lens on the optical axis, the aberration of different fields of view is corrected, and the imaging quality of the optical lens is improved.

[0043] In various embodiments of the present application, when the lens adopts an aspheric lens, the surface shape of the aspheric lens satisfies the following equation:

[0044] ;

[0045] Where z is the distance from the aspheric surface vertex to the height h along the optical axis, c is the paraxial curvature of the surface, k is the conic coefficient, A 2i is the 2i-order aspheric surface coefficient.

[0046] The present invention is further illustrated below with reference to several embodiments. In each embodiment, the thickness, radius of curvature, and material selection of each lens in the optical lens vary; for details, please refer to the parameter tables of each embodiment. The following embodiments are merely preferred embodiments of the present invention, but the present invention is not limited thereto. Any other changes, substitutions, combinations, or simplifications that do not deviate from the novelties of the present invention shall be considered equivalent replacements and are included within the scope of protection of the present invention.

[0047] Sub-Example 1

[0048] See also Figure 1 , shown is a schematic structural diagram of the optical lens 100 provided in sub-embodiment 1 of the present invention. The optical lens 100 includes, along the optical axis from the object side to the imaging surface S9, an aperture ST, a first lens L1, a second lens L2, a third lens L3 and a flat glass G1.

[0049] Specifically, the first lens L1 has positive refractive power, with its object-side surface S1 being convex, and its image-side surface S2 being convex near the optical axis. The second lens L2 has negative refractive power, with its object-side surface S3 being convex, and its image-side surface S4 being concave. The third lens L3 has positive refractive power, with its object-side surface S5 being convex, and its image-side surface S6 being concave. The object-side surface S7 and the image-side surface S8 of the flat glass G1 are all aspherical lenses.

[0050] Table 1 shows the parameters of each lens in the optical lens 100 provided in Sub-Example 1 of the present invention.

[0051] Table 1

[0052]

[0053] The aspheric surface coefficients of each lens of the optical lens 100 in this embodiment are shown in Table 2.

[0054] Table 2

[0055]

[0056] In this embodiment, the structure diagram, relative illumination curve diagram, optical distortion curve diagram and field curvature curve diagram of the optical lens 100 are respectively as shown in FIG. Figure 1 、Figure 2 、 Figure 3 and Figure 4 .

[0057] Figure 2 The relative illumination curve of the optical lens 100 in the embodiment is shown, which represents the relative illumination values at different fields of view. It can be seen from the figure that the relative illumination values of the fields of view are controlled to be above 95%, which indicates that the relative illumination of the optical lens 100 is good.

[0058] Figure 3 The optical distortion curve of the optical lens 100 in the embodiment is shown, which represents the distortion at different fields of view on the imaging surface. It can be seen from the figure that the optical distortion is controlled to be within ±0.1%, which indicates that the optical distortion of the optical lens 100 is well corrected.

[0059] Figure 4 The field curvature curve of the optical lens 100 in the embodiment is shown, which represents the field curvature at different fields of view on the imaging surface. It can be seen from the figure that the field curvature is controlled to be within ±0.1mm, which indicates that the field curvature of the optical lens 100 is well corrected.

[0060] Sub-embodiment 2

[0061] Referring to Figure 5 , which is a structural schematic diagram of the optical lens 200 provided in the sub-embodiment 2 of the present application. The optical lens 200 in the embodiment is generally the same as that in the sub-embodiment 1, except that the optical power of the third lens is negative, and other differences are shown in Table 3 and Table 4.

[0062] The related parameters of each lens in the optical lens 200 provided in the sub-embodiment 2 of the present application are shown in Table 3.

[0063] Table 3

[0064]

[0065] The aspheric surface type coefficients of each lens of the optical lens 200 in the embodiment are shown in Table 4.

[0066] Table 4

[0067]

[0068] In the embodiment, the structural diagram, the relative illumination curve diagram, the optical distortion curve diagram and the field curvature curve diagram of the optical lens 200 are respectively shown in Figure 5 、 Figure 6 、 Figure 7 and Figure 8As shown in the figures, the relative luminance is controlled to be above 95%, indicating that the optical lens 200 has good relative luminance; the optical distortion is controlled to be within ±0.1%, indicating that the distortion of the optical lens 200 is well corrected; and the field curvature is controlled to be within ±0.05mm, indicating that the field curvature of each field of view of the optical lens 200 is well corrected.

[0069] Sub-embodiment 3

[0070] As shown in Figure 9 , which is a structural schematic diagram of an optical lens 300 provided in the sub-embodiment 3 of the present application, the optical lens 300 in the present embodiment is generally the same as that in the sub-embodiment 1, except that the optical power of the third lens is negative, and other differences are shown in Table 5 and Table 6.

[0071] The related parameters of each lens in the optical lens 300 provided in the sub-embodiment 3 of the present application are shown in Table 5.

[0072] Table 5

[0073]

[0074] The aspheric surface profile coefficients of each lens of the optical lens 300 in the present embodiment are shown in Table 6.

[0075] Table 6

[0076]

[0077] In the present embodiment, the structural diagram, the relative luminance curve, the optical distortion curve and the field curvature curve of the optical lens 300 are shown in Figure 9 , Figure 10 , Figure 11 and Figure 12 respectively. As can be seen from the figures, the relative luminance is controlled to be above 95%, indicating that the optical lens 300 has good relative luminance; the optical distortion is controlled to be within ±0.1%, indicating that the distortion of the optical lens 300 is well corrected; and the field curvature is controlled to be within ±0.1mm, indicating that the field curvature of each field of view of the optical lens 300 is well corrected.

[0078] Second Embodiment

[0079] The total optical length (TTL) of the optical lens provided in the first embodiment of the present application is all more than 30mm (for details, please refer to sub-embodiments 1 to 3), which is far more than the thickness of a portable electronic device, and when used in a portable electronic device such as a mobile phone, the flat glass in the first embodiment can be replaced by a reflective element such as a prism, and the height of the lens is shortened by using the prism to be embedded in the mobile phone, so as to meet the demand of light and thin electronic products.

[0080] Therefore, the application further provides an optical lens, which comprises, in sequence from the object side to the imaging surface along the optical axis, an aperture stop, a first lens, a second lens, a third lens, and a reflecting element.

[0081] The first lens has positive focal power, the object side surface of the first lens is convex, and the image side surface of the first lens is convex near the optical axis; the second lens has negative focal power, the object side surface of the second lens is convex, and the image side surface of the second lens is concave; the third lens has positive or negative focal power, the object side surface of the third lens is convex, and the image side surface of the third lens is concave; the reflecting element is a prism and comprises a first reflecting surface, a second reflecting surface, a third reflecting surface, and a fourth reflecting surface, the first reflecting surface is configured to reflect light emitted from the third lens to the imaging surface via the first reflecting surface, the second reflecting surface, the third reflecting surface, and the fourth reflecting surface in sequence; and the first lens to the third lens are all aspherical lenses.

[0082] In some embodiments, the air separation CT23 of the second lens and the third lens on the optical axis and the sum of the central thickness CT2 of the second lens and the central thickness CT3 of the third lens satisfy the condition formula: 0<CT23 / (CT2+CT3)<0.3; and the central thickness CT1 of the first lens and the sum of the air separation CT12 of the first lens and the second lens on the optical axis and the air separation CT23 of the second lens and the third lens on the optical axis satisfy the condition formula: 6<CT1 / (CT12+CT23)<20. Satisfying the above condition formula, by reasonably controlling the relationship between the air separation of the second lens and the third lens on the optical axis and the sum of the central thicknesses of the second lens and the third lens, and reasonably controlling the relationship between the central thickness of the first lens and the sum of the air separations of the first lens to the third lens on the optical axis, the length of the first lens to the third lens on the optical axis is reduced, the volume of the lens barrel is reduced, and the balance between the miniaturization and the long focal length of the lens is achieved. Further, the air separation CT23 of the second lens and the third lens on the optical axis and the sum of the central thickness CT2 of the second lens and the central thickness CT3 of the third lens can satisfy: 0<CT23 / (CT2+CT3)<0.2; and the central thickness CT1 of the first lens and the sum of the air separation CT12 of the first lens and the second lens on the optical axis and the air separation CT23 of the second lens and the third lens on the optical axis can satisfy: 9<CT1 / (CT12+CT23)<15.

[0083] In some embodiments, the radius of curvature R12 of the image side surface of the first lens and the radius of curvature R11 of the object side surface of the first lens satisfy the condition formula: -5.0 < R12 / R11 < 0. By reasonably controlling the radii of curvature of the object side surface and the image side surface of the first lens, the effective focal length of the optical lens is increased, and the balance between the miniaturization and the long focal length of the lens is achieved. Further, the radius of curvature R12 of the image side surface of the first lens and the radius of curvature R11 of the object side surface of the first lens can satisfy: -3.0 < R12 / R11 < -1.5.

[0084] In some embodiments, the effective focal length f2 of the second lens and the effective focal length f of the optical lens satisfy the condition formula: -1.0 < f2 / f < -0.4. By reasonably controlling the focal length of the second lens, the spherical aberration of the central field of view of the optical lens is corrected, and the imaging quality of the optical lens is improved.

[0085] In some embodiments, the refractive power φ21 of the object side surface of the second lens, the radius of curvature R21 of the object side surface of the second lens, the refractive power φ31 of the object side surface of the third lens, and the radius of curvature R31 of the object side surface of the third lens satisfy the condition formula: 0.4 < φ21×R21×φ31×R31 < 0.5. By reasonably controlling the surface shape of the second lens and the third lens, the aberration of the optical lens is corrected, and the imaging quality of the optical lens is improved.

[0086] In some embodiments, the thickness DP of the reflective element in the direction of the center axis of the lens group and the central thickness DT4 of the reflective element on the optical axis satisfy the condition formula: 0.15 < DP / DT4 < 0.30. By reasonably controlling the thickness of the reflective element, the overall height of the module is reduced, and the miniaturization of the system is achieved.

[0087] In some embodiments, the refractive index Nd4 of the reflective element satisfies the condition formula: 1.62 < Nd4 < 2.0. By reasonably selecting a material with a larger refractive index, total reflection of light in the reflective element (i.e., the prism) is achieved.

[0088] In some embodiments, the radius of curvature R21 of the object side surface of the second lens and the radius of curvature R32 of the image side surface of the third lens satisfy the condition formula: 1.1 < R21 / R32 < 1.6; and the radius of curvature R22 of the image side surface of the second lens and the radius of curvature R31 of the object side surface of the third lens satisfy the condition formula: 0.7 < R22 / R31 < 0.9. By reasonably controlling the surface shape of the second lens and the third lens, the curvature of field of the optical lens is corrected, and the imaging quality of the optical lens is improved.

[0089] In some embodiments, the first lens image-side surface has a radius of curvature R12, and the second lens object-side surface has a radius of curvature R21, and the ratio of R12 to R21 satisfies the condition formula: -4.0 < R12 / R21 < -2.0. Satisfying the above condition formula, by reasonably controlling the relationship between the radii of curvature of the first lens image-side surface and the second lens object-side surface, the coma of the optical lens is corrected, and the imaging quality of the optical lens is improved.

[0090] In some embodiments, the first lens has a focal power φ1, the second lens has a focal power φ2, and the third lens has a focal power φ3, and the ratio of φ1 to the sum of φ2 and φ3 satisfies the condition formula: -1.5 < φ1 / (φ2+φ3) < -1.0. Satisfying the above condition formula, by reasonably controlling the relationship between the focal powers of the first lens, the second lens, and the third lens, the effective focal length of the optical lens is increased.

[0091] In some embodiments, the second lens object-side surface has a sag SAG21, the first lens image-side surface has a sag SAG12, and the ratio of SAG21 to SAG12 satisfies the condition formula: 12 < SAG21 / SAG12 < 65; the second lens object-side surface has a sag SAG21, the third lens image-side surface has a sag SAG32, and the ratio of SAG21 to SAG32 satisfies the condition formula: 0.7 < SAG21 / SAG32 < 1.5. Satisfying the above condition formula, by reasonably controlling the relationship between the sag of the second lens object-side surface and the sags of the first lens image-side surface and the third lens image-side surface, the distribution of the first lens, the second lens, and the third lens is made more compact, the total length of the optical lens is reduced, and the miniaturization of the optical lens is realized.

[0092] In some embodiments, the third lens object-side surface has a sag SAG31, the third lens image-side surface has a sag SAG32, and the central thickness CT3 of the third lens satisfies the condition formula: -1.5 < (SAG31-SAG32) / CT3 < -0.5; the second lens image-side surface has a sag SAG22, the third lens object-side surface has a sag SAG31, and the air separation CT23 of the second lens and the third lens on the optical axis satisfies the condition formula: 0.5 < (SAG22-SAG31) / CT23 < 1.0. Satisfying the above condition formula, by reasonably controlling the relationship between the sag of the third lens and the central thickness of the third lens, and reasonably controlling the relationship between the sags of the second lens image-side surface and the third lens object-side surface and the air separation of the second lens and the third lens on the optical axis, the aberrations of different fields are corrected, and the imaging quality of the optical lens is improved.

[0093] The application is further described in the following embodiments.

[0094] Sub-embodiment 4

[0095] Please refer to Figure 13An optical lens 400 is provided for the fourth sub-embodiment of the present application, which comprises, in order from the object side to the image plane S13 along the optical axis, a diaphragm ST, a lens group L, and a prism P.

[0096] The lens group L can be the same as the lens group in the first embodiment (e.g., the first sub-embodiment), that is, the first lens L1, the second lens L2, and the third lens L3 have the same structure as the first embodiment.

[0097] The prism P is arranged at the exit of the lens group L, which forms the exit light rays after four reflections of the light rays, and the exit light rays are parallel to the incident light rays entering the prism P. Specifically, the prism P can be a quadrangular prism with parallelogram-shaped upper and lower bases, or other similar shapes; meanwhile, the acute angles of the parallelogram can be any acute angle. If the prism P is a quadrangular prism, the prism P comprises an incident surface S7, a first reflecting surface S8, a second reflecting surface S9, a third reflecting surface S10, a fourth reflecting surface S11, and an exit surface S12. The incident surface S7 and the second reflecting surface S9 are coplanar and partially overlap; the third reflecting surface S10 and the exit surface S12 are coplanar and partially overlap; the first reflecting surface S8, the second reflecting surface S9, the third reflecting surface S10, and the fourth reflecting surface S11 form a parallelogram. In this sub-embodiment, the angle between the first reflecting surface S8 and the incident surface S7 is 30 degrees, and the angle between the fourth reflecting surface S11 and the exit surface S12 is also 30 degrees. Therefore, the light rays exiting from the lens group L enter the incident surface S7 of the prism P, and after four reflections of the first reflecting surface S8, the second reflecting surface S9, the third reflecting surface S10, and the fourth reflecting surface S11, the exit light rays are formed and exit from the exit surface S12, that is, the directions of the light rays entering the prism P are changed four times and then the light rays are emitted to the image plane S13 in the same direction. Therefore, the optical path of the optical lens 400 is reflected multiple times in the prism P, effectively reducing the thickness of the optical lens in the center axis direction of the lens group.

[0098] In particular, the optical lens 400 satisfies the condition: D1+D2+D3+D4+D5= DT4; wherein D1 represents the path length of the light rays from the incident surface S7 to the first reflecting surface S8, D2 represents the path length of the light rays from the first reflecting surface S8 to the second reflecting surface S9, D3 represents the path length of the light rays from the second reflecting surface S9 to the third reflecting surface S10, D4 represents the path length of the light rays from the third reflecting surface S10 to the fourth reflecting surface S11, D5 represents the path length of the light rays from the fourth reflecting surface S11 to the exit surface S12, and DT4 represents the center thickness of the reflecting element on the optical axis, which can be equivalent to the center thickness CT4 of the flat glass G1 in any of the above sub-embodiments. In other words, the path length of the light rays of the optical lens in the first embodiment is equal to the path length of the light rays of the optical lens 400 in the fourth sub-embodiment.

[0099] The optical lens 400 provided by the fourth sub-embodiment of the present application has the related parameters of each lens and prism as shown in Table 7 (the lens group adopts the first sub-embodiment).

[0100] Table 7

[0101]

[0102] The aspheric surface coefficients of each lens of the optical lens 400 in the present embodiment are shown in Table 2.

[0103] The fifth sub-embodiment

[0104] Referring to Figure 14 The optical lens 500 provided by the fifth sub-embodiment of the present application is generally the same as the fourth sub-embodiment, except that the included angle between the first reflecting surface S8 and the incident surface S7 is 32.5 degrees, and other differences are shown in Table 8.

[0105] The optical lens 500 provided by the fifth sub-embodiment of the present application has the related parameters of each lens as shown in Table 8 (the lens group adopts the second sub-embodiment).

[0106] Table 8

[0107]

[0108] The aspheric surface coefficients of each lens of the optical lens 500 in the present embodiment are shown in Table 4.

[0109] The sixth sub-embodiment

[0110] Referring to Figure 15 The optical lens 600 provided by the sixth sub-embodiment of the present application is generally the same as the fourth sub-embodiment, except that the included angle between the first reflecting surface S8 and the incident surface S7 is 27.5 degrees, and other differences are shown in Table 9.

[0111] The optical lens 600 provided by the sixth sub-embodiment of the present application has the related parameters of each lens as shown in Table 9 (the lens group adopts the third sub-embodiment).

[0112] Table 9

[0113]

[0114] The aspheric surface coefficients of each lens of the optical lens 600 in the present embodiment are shown in Table 6.

[0115] Table 10 is the optical characteristics corresponding to the above six sub-embodiments, mainly including effective focal length f, F# of optical lens, optical total length TTL, maximum field of view angle FOV and image height IH corresponding to FOV, and the numerical value corresponding to each of the above condition expressions.

[0116] Table 10

[0117]

[0118] In summary, the optical lens provided by the present application adopts three aspheric lenses with specific optical power, and through specific surface shape matching and reasonable optical power distribution, the effective focal length f of the optical lens reaches 26.7mm or more, and the 35mm equivalent focal length can reach 195mm or more; at the same time, the three lenses are arranged compactly, the total length of the optical lens is reduced, and the optical lens has the advantages of long focal length, short total length and high resolution quality.

[0119] Third embodiment

[0120] Please refer to Figure 16 The embodiment of the present application provides a mobile terminal 700, which comprises the optical lens (for example, the optical lens 400) in any of the above sub-embodiments and an image sensor S. Wherein, the image sensor S is arranged at the imaging surface of the optical lens 400, for receiving the optical signal output by the optical lens 400 and forming the electrical signal corresponding to the optical signal. The image sensor S can be a CMOS (Complementary Metal Oxide Semiconductor) image sensor, and can also be a CCD (Charge Coupled Device) image sensor.

[0121] The optical total length TTL of the optical lens provided by the sub-embodiment 1 to the sub-embodiment 3 of the present application reaches 33mm or more, which is far more than the thickness required by the portable electronic device, and the sub-embodiment 4 to the sub-embodiment 6 can reduce the thickness of the optical lens in the center axis direction of the lens group to 12mm-18mm through the prism multiple reflection light path, so as to meet the miniaturization requirement of the mobile terminal 700.

[0122] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "example", "specific example" or "some examples" means that the specific features, structures, materials or characteristics described in combination with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily mean the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0123] The above embodiments only express several implementation manners of the present application, which are described in a more specific and detailed manner, but cannot be understood as a limitation on the scope of the present application. It should be noted that, for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present application, which all belong to the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the appended claims.

Claims

1. An optical lens, comprising three lenses, characterized in that: Along the optical axis from the object side to the imaging surface, it includes: Aperture; a first lens having positive refractive power, wherein the object-side surface of the first lens is convex, and the image-side surface of the first lens is convex near the optical axis; a second lens having negative optical power, wherein the object-side surface of the second lens is convex and the image-side surface of the second lens is concave; a third lens having optical power, wherein the object-side surface of the third lens is convex and the image-side surface of the third lens is concave; The optical lens satisfies the following conditional formula: -5.0 <R12 / R11<0; Wherein, R12 represents the curvature radius of the image side surface of the first lens, and R11 represents the curvature radius of the object side surface of the first lens; -4.0 <R12 / R21<-2.0; Wherein, R12 represents the curvature radius of the image side surface of the first lens, and R21 represents the curvature radius of the object side surface of the second lens.

2. The optical lens according to claim 1, wherein: The optical lens satisfies the following conditional formula: 0 <CT23 / (CT2+CT3)<0.3; 6 <CT1 / (CT12+CT23)<20; Wherein, CT1 represents the center thickness of the first lens, CT2 represents the center thickness of the second lens, CT3 represents the center thickness of the third lens, CT12 represents the air gap between the first lens and the second lens on the optical axis, and CT23 represents the air gap between the second lens and the third lens on the optical axis.

3. The optical lens according to claim 1, wherein: The optical lens satisfies the following conditional formula: -1.0 <f2 / f<-0.4; Wherein, f2 represents the effective focal length of the second lens, and f represents the effective focal length of the optical lens.

4. The optical lens according to claim 1, wherein: The optical lens satisfies the following conditional formula: 1.1 <R21 / R32<1.6; 0.7 <R22 / R31<0.9; Among them, R21 represents the curvature radius of the object side of the second lens, R32 represents the curvature radius of the image side of the third lens, R22 represents the curvature radius of the image side of the second lens, and R31 represents the curvature radius of the object side of the third lens.

5. The optical lens according to claim 1, wherein: The optical lens satisfies the following conditional formula: 0.90 <FFL / TTL<0.92; Wherein, FFL represents the distance from the image side surface of the third lens to the imaging surface on the optical axis, and TTL represents the total optical length of the optical lens.

6. The optical lens according to claim 1, wherein: It also includes a flat glass disposed between the third lens and the imaging surface, and the optical lens satisfies the following conditional formula: 0.65 <CT4 / FFL<0.90; Wherein, CT4 represents the center thickness of the flat glass on the optical axis, and FFL represents the distance from the image side surface of the third lens to the imaging surface on the optical axis.

7. An optical lens, comprising three lenses, characterized in that: Along the optical axis from the object side to the imaging surface, it includes: Aperture; a first lens having positive refractive power, wherein the object-side surface of the first lens is convex, and the image-side surface of the first lens is convex near the optical axis; a second lens having negative optical power, wherein the object-side surface of the second lens is convex and the image-side surface of the second lens is concave; a third lens having optical power, wherein the object-side surface of the third lens is convex and the image-side surface of the third lens is concave; a reflective element comprising a plurality of reflective surfaces; The optical lens satisfies the following conditional formula: 0 <CT23 / (CT2+CT3)<0.3; 6 <CT1 / (CT12+CT23)<20; Wherein, CT1 represents the center thickness of the first lens, CT2 represents the center thickness of the second lens, CT3 represents the center thickness of the third lens, CT12 represents the air gap between the first lens and the second lens on the optical axis, and CT23 represents the air gap between the second lens and the third lens on the optical axis.

8. The optical lens according to claim 7, wherein: The optical lens satisfies the following conditional formula: -5.0 <R12 / R11<0; Wherein, R12 represents the curvature radius of the image side surface of the first lens, and R11 represents the curvature radius of the object side surface of the first lens.

9. The optical lens according to claim 7, wherein: The optical lens satisfies the following conditional formula: -1.0 <f2 / f<-0.4; Wherein, f2 represents the effective focal length of the second lens, and f represents the effective focal length of the optical lens.

10. The optical lens according to claim 7, wherein: The optical lens satisfies the following conditional formula: 0.4<φ21×R21×φ31×R31<0.5; Wherein, φ21 represents the optical power of the second lens objective side, R21 represents the curvature radius of the second lens objective side, φ31 represents the optical power of the third lens objective side, and R31 represents the curvature radius of the third lens objective side.

11. The optical lens according to claim 7, wherein: The optical lens satisfies the following conditional formula: 0.15 <DP / DT4<0.30; Wherein, DP represents the thickness of the reflective element in the direction of the central axis of the lens group, and DT4 represents the center thickness of the reflective element on the optical axis.

12. The optical lens according to claim 7, wherein: The reflective element is configured as a prism and includes a first reflective surface, a second reflective surface, a third reflective surface and a fourth reflective surface. The first reflective surface is configured to reflect the light emitted from the third lens to the imaging surface via the first reflective surface, the second reflective surface, the third reflective surface and the fourth reflective surface in sequence.

13. A mobile terminal, characterized in that: It comprises an image sensor and the optical lens according to any one of claims 1 to 12, wherein the image sensor is arranged on the imaging surface of the optical lens and is used to receive the light signal output by the optical lens and form an electrical signal corresponding to the light signal.

Images