Optical lens

Abstract

The invention provides an optical lens, which consists of two lenses with focal power and two refraction and reflection elements, and sequentially comprises a first lens with positive focal power, a second lens with negative focal power, a third lens with positive focal power, a fourth lens with negative focal power, a fifth lens with negative focal power and a sixth lens with negative focal power from an object side to an imaging surface along a light transmission direction, the image side surface of the second lens is a concave surface; the first refraction and reflection element comprises a first light incident plane, a first reflection plane, a second reflection plane, a third reflection plane, a fourth reflection plane and a first light emergent plane which are all planes; the second refraction and reflection element comprises a second light incident plane, a fifth reflection plane, a sixth reflection plane, a seventh reflection plane, an eighth reflection plane and a second light emergent plane which are all planes; the first refraction and reflection element and the second refraction and reflection element are respectively provided with a plurality of optical axes and are subjected to multiple times of light path turning. The optical lens provided by the invention can realize the excellent effect of periscopic long-focus shooting, and has one or more advantages of super long focus, short total length, miniaturization, low sensitivity, high imaging quality and the like.

Description

TECHNICAL FIELD

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

[0002] With the rapid development of social technology, people's requirements for cameras are getting higher and higher in order to meet different shooting scenes, especially photography enthusiasts, the demand for long focal length lenses is particularly obvious. Most long focal length lenses on the market are either too long in total length or too large in size, or have insufficient focal length, resulting in poor telephoto effect. SUMMARY

[0003] In view of the above problems, the purpose of the present application is to provide an optical lens which can realize miniaturization, long focal length and has the characteristics of excellent imaging quality.

[0004] The technical scheme adopted by the present application is: An optical lens composed of two lenses with optical power and two catadioptric elements, comprising in order from the object side to the imaging surface along the light transmission direction: a first lens with positive optical power, the object side surface of which is a convex surface; a second lens with negative optical power, the image side surface of which is a concave surface; a first catadioptric element comprising a first light incident surface, a first reflection surface, a second reflection surface, a third reflection surface, a fourth reflection surface and a first light exit surface, all of which are planes, wherein the first light incident surface and the second reflection surface are substantially the same plane; the third reflection surface and the first light exit surface are substantially the same plane; a second catadioptric element comprising a second light incident surface, a fifth reflection surface, a sixth reflection surface, a seventh reflection surface, an eighth reflection surface and a second light exit surface, all of which are planes, wherein the second light incident surface and the sixth reflection surface are substantially the same plane; the seventh reflection surface and the second light exit surface are substantially the same plane; the cross sections of the first catadioptric element and the second catadioptric element are parallelograms; The first catadioptric element has a first optical axis, a second optical axis, a third optical axis, a fourth optical axis and a fifth optical axis; the light path passes through the first lens and the second lens along the first optical axis into the first catadioptric element, passes through the first light incident surface to the first reflecting surface, is reflected to the second reflecting surface, is totally reflected to the third reflecting surface, is totally reflected to the fourth reflecting surface, and is reflected to the first light exit surface to exit; the first reflecting surface turns the light path from the first optical axis to the second optical axis, the second reflecting surface turns the light path from the second optical axis to the third optical axis, the third reflecting surface turns the third optical axis to the fourth optical axis, and the fourth reflecting surface turns the fourth optical axis to the fifth optical axis; The second catadioptric element has a sixth optical axis, a seventh optical axis, an eighth optical axis, a ninth optical axis and a tenth optical axis; the light path passes through the second light incident surface to the fifth reflecting surface along the sixth optical axis, is reflected to the sixth reflecting surface, is totally reflected to the seventh reflecting surface, is totally reflected to the eighth reflecting surface, and is reflected to the second light exit surface to the imaging surface; the fifth reflecting surface turns the light path from the sixth optical axis to the seventh optical axis, the sixth reflecting surface turns the light path from the seventh optical axis to the eighth optical axis, the seventh reflecting surface turns the eighth optical axis to the ninth optical axis, and the eighth reflecting surface turns the ninth optical axis to the tenth optical axis; the tenth optical axis is perpendicular to the imaging surface; the first optical axis and the tenth optical axis are in the same direction; the fifth optical axis and the sixth optical axis are in the same direction; Wherein, the real image height IH corresponding to the maximum field angle of the optical lens and the effective focal length f of the optical lens satisfy: 9 < (43.27 / IHxf) / 24 < 19.

[0005] Compared with the prior art, the optical lens provided by the application can realize excellent long-focus shooting effect through the arrangement of two lenses and two catadioptric elements. Since the light path is turned multiple times in the catadioptric element, the volume of the folded optical system is greatly compressed. The optical lens has one or more advantages of super long focus, short total length, miniaturization, low sensitivity, high imaging quality and the like, and greatly improves the user experience. BRIEF DESCRIPTION OF DRAWINGS

[0006] The above and / or additional aspects and advantages of the application will become apparent and be readily understood from the following description, taken in connection with the accompanying drawings, in which: Figure 1 FIG. 1 is a structural schematic diagram of an optical lens provided in Embodiment 1 of the application.

[0007] Figure 2 is a schematic view of a prism structure and a schematic view of an optical path.

[0008] Figure 3 is a F-Tan(Theta) distortion curve of the optical lens in the embodiment 1 of the present application.

[0009] Figure 4 is a curve of field curvature of the optical lens in the embodiment 1 of the present application.

[0010] Figure 5 is a curve of the transverse chromatic aberration of the optical lens in the embodiment 1 of the present application.

[0011] Figure 6 is a schematic view of a structure of the optical lens provided in the embodiment 2 of the present application.

[0012] Figure 7 is a F-Tan(Theta) distortion curve of the optical lens in the embodiment 2 of the present application.

[0013] Figure 8 is a curve of field curvature of the optical lens in the embodiment 2 of the present application.

[0014] Figure 9 is a curve of the transverse chromatic aberration of the optical lens in the embodiment 2 of the present application.

[0015] Figure 10 is a schematic view of a structure of the optical lens provided in the embodiment 3 of the present application.

[0016] Figure 11 is a F-Tan(Theta) distortion curve of the optical lens in the embodiment 3 of the present application.

[0017] Figure 12 is a curve of field curvature of the optical lens in the embodiment 3 of the present application.

[0018] Figure 13 is a curve of the transverse chromatic aberration of the optical lens in the embodiment 3 of the present application.

[0019] Figure 14 is a schematic view of a structure of the optical lens provided in the embodiment 4 of the present application.

[0020] Figure 15 is a F-Tan(Theta) distortion curve of the optical lens in the embodiment 4 of the present application.

[0021] Figure 16 is a curve of field curvature of the optical lens in the embodiment 4 of the present application.

[0022] Figure 17 is a curve of the transverse chromatic aberration of the optical lens in the embodiment 4 of the present application.

[0023] The following detailed description will further explain the present application with reference to the above mentioned drawings. DETAILED DESCRIPTION

[0024] For a better understanding of the present application, various aspects of the present application will be described in greater detail below with reference to the drawings. It is to be noted that these detailed descriptions are merely descriptive of embodiments of the present application and are not intended in any way to limit the scope of the present application. Throughout the specification, like drawing reference numerals refer to like elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0025] It is to be noted that the expressions first, second, third, etc. are used in this specification only to distinguish one feature from another feature, and do not indicate any limitation on the features. Thus, the first lens discussed below can also be referred to as a second lens or a third lens without departing from the teachings of the present application.

[0026] In the drawings, the thickness, size, and shape of the lenses have been slightly exaggerated for the sake of explanation. Specifically, the shape of the spherical or aspherical surface shown in the drawings is shown by way of example. That is, the shape of the spherical or aspherical surface is not limited to the shape of the spherical or aspherical surface shown in the drawings. The drawings are merely examples and are not drawn to scale.

[0027] In this specification, the paraxial region refers to a region near the optical axis. If a lens surface is convex and the position of the convex surface is not specified, it means that the lens surface is convex at least in the paraxial region. If a lens surface is concave and the position of the concave surface is not specified, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the object is referred to as the object side surface of the lens, and the surface of each lens closest to the image plane is referred to as the image side surface of the lens.

[0028] It is also to be understood that the use of the terms "including", "including having", "having", "containing", and / or "containing having", when used in this specification, indicate the presence of the stated features, elements and / or components but do not preclude the presence or addition of one or more other features, elements, components, and / or groups thereof. In addition, when the expression such as "at least one of" appears after the list of the features, it modifies the entire list of features and not the individual elements of the list. Furthermore, when describing embodiments of the present application, the use of "may" indicates that one or more embodiments of the present application. Also, the expression "exemplary" is intended to mean example or illustrative.

[0029] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0030] It should be noted that the embodiments and features of the embodiments in the present application can be combined with each other without conflict. The present application will be described in detail below with reference to the drawings and in combination with the embodiments.

[0031] The optical lens provided by the embodiment of the present application is composed of two lenses with optical power and two catadioptric elements, and sequentially includes a first lens, a second lens, a first catadioptric element and a second catadioptric element from the object side to the imaging surface along the light transmission direction.

[0032] The first lens can have positive optical power, the object side surface thereof is a convex surface, and the image side surface thereof can be a concave surface or a convex surface; the second lens can have negative optical power, the object side surface thereof can be a concave surface or a convex surface, and the image side surface thereof is a concave surface.

[0033] The first catadioptric element includes a first light incident surface, a first reflection surface, a second reflection surface, a third reflection surface, a fourth reflection surface and a first light exit surface, and all are planes, wherein the first light incident surface and the second reflection surface are substantially the same plane; the third reflection surface and the first light exit surface are substantially the same plane.

[0034] The second catadioptric element includes a second light incident surface, a fifth reflection surface, a sixth reflection surface, a seventh reflection surface, an eighth reflection surface and a second light exit surface, and all are planes, wherein the second light incident surface and the sixth reflection surface are substantially the same plane; the seventh reflection surface and the second light exit surface are substantially the same plane. The first catadioptric element and the second catadioptric element can be prisms with a parallelogram cross section.

[0035] The first catadioptric element has a first optical axis, a second optical axis, a third optical axis, a fourth optical axis and a fifth optical axis. The light path passes through the first lens and the second lens along the first optical axis into the first catadioptric element, passes through the first light incident surface to the first reflection surface, is reflected to the second reflection surface, is totally reflected to the third reflection surface, is totally reflected to the fourth reflection surface, and is reflected to the first light exit surface to exit into the second catadioptric element; the first reflection surface turns the light path from the first optical axis to the second optical axis, the second reflection surface turns the light path from the second optical axis to the third optical axis, the third reflection surface turns the third optical axis to the fourth optical axis, and the fourth reflection surface turns the fourth optical axis to the fifth optical axis.

[0036] The second catadioptric element has a sixth optical axis, a seventh optical axis, an eighth optical axis, a ninth optical axis and a tenth optical axis; the light path passes through the second light incident surface to the fifth reflecting surface along the sixth optical axis, is reflected to the sixth reflecting surface, is totally reflected to the seventh reflecting surface, is totally reflected to the eighth reflecting surface, and is emitted to the imaging surface from the second light exit surface; the fifth reflecting surface bends the light path from the sixth optical axis to the seventh optical axis, the sixth reflecting surface bends the light path from the seventh optical axis to the eighth optical axis, the seventh reflecting surface bends the eighth optical axis to the ninth optical axis, and the eighth reflecting surface bends the ninth optical axis to the tenth optical axis; the tenth optical axis is perpendicular to the imaging surface; the first optical axis and the tenth optical axis are in the same direction; and the fifth optical axis and the sixth optical axis are in the same direction.

[0037] The light path is bent four times in the first catadioptric element and the second catadioptric element, the first optical axis and the tenth optical axis are in the same direction and are coaxial, the first two lenses and the chip are coaxial, which helps to improve the manufacturing yield. The fifth optical axis and the sixth optical axis are in the same direction and are coaxial. The first reflecting surface, the fourth reflecting surface, the fifth reflecting surface and the eighth reflecting surface have a reflecting coating (film) or are mirror surfaces. By arranging the catadioptric elements, the light path can be bent multiple times inside the catadioptric elements, greatly increasing the propagation distance of the light, making the spatial configuration more flexible, and being conducive to compressing the volume of the folded optical system and achieving super-long focal imaging effect.

[0038] In some embodiments, the optical lens can further include a diaphragm, which can be located between the object side and the first lens. It can be understood that the diaphragm is used to limit the amount of light to change the brightness of the imaging.

[0039] In some embodiments, the maximum field of view angle of the optical lens corresponds to a real image height IH, and the effective focal length f of the optical lens satisfies: 9 < (43.27 / IH x f) / 24 < 19. The above condition is an optical magnification calculation formula, and the optical lens can achieve a high magnification super-long focal shooting effect of 9X~19X, which not only has a super-long focal length, but also can well meet the demand of periscopic long focal shooting. More specifically, 9.71 < (43.27 / IH x f) / 24 < 17.21.

[0040] In some embodiments, the long side D1 of the first catadioptric element, the height H1 of the first catadioptric element, and the angle θ1 between the first light-incident surface and the first reflecting surface satisfy -1.6 < D1 - 2 x H1 / tan(θ1) < 2.2; the long side D2 of the second catadioptric element, the height H2 of the second catadioptric element, and the angle θ2 between the second light-incident surface and the fifth reflecting surface satisfy -1.6 < D2 - 2 x H2 / tan(θ2) < 2.2. θ1 and θ2 can be understood as the angles between the long side and the short side of the first catadioptric element and the second catadioptric element. Satisfying the above conditions and reasonably setting the shape of the first catadioptric element and the second catadioptric element can effectively limit the size of the first catadioptric element and the second catadioptric element, so that the first catadioptric element and the second catadioptric element have a smaller height and a larger long side, thereby reducing the volume of the optical lens while increasing the optical path in the catadioptric element. More specifically, -1.55 < D1 - 2 x H1 / tan(θ1) < 2.02; -1.55 < D2 - 2 x H2 / tan(θ2) < 2.02.

[0041] In some embodiments, the maximum angle of incidence CRA at the maximum image height of the optical lens satisfies 3° < CRA < 7°; the long side D1 of the first catadioptric element, the height H1 of the first catadioptric element, and the angle θ1 between the first light-incident surface and the first reflecting surface respectively satisfy 10 mm < D1 < 16 mm; 2.8 mm < H1 < 3.8 mm; 23° < θ1 < 33°; the long side D2 of the second catadioptric element, the height H2 of the second catadioptric element, and the angle θ2 between the second light-incident surface and the fifth reflecting surface respectively satisfy 10 mm < D2 < 16 mm; 2.8 mm < H2 < 3.8 mm; 23° < θ2 < 33°. Satisfying the above conditions and reasonably limiting the size of the first catadioptric element and the second catadioptric element is conducive to the miniaturization of the optical lens. More specifically, 3.6° < CRA < 6.46°; 10.8 mm < D1 < 15.1 mm; 2.89 mm < H1 < 3.76 mm; 24° < θ1 < 31°; 10.8 mm < D2 < 15.1 mm; 2.89 mm < H2 < 3.76 mm; 24° < θ2 < 31°.

[0042] In some embodiments, the angle θ1 between the first light-incident surface and the first reflecting surface is equal to the angle θ2 between the second light-incident surface and the fifth reflecting surface; the height H1 of the first catadioptric element is equal to the height H2 of the second catadioptric element.

[0043] In some embodiments, the distance L from the object side surface of the first lens to the imaging surface in the first optical axis direction and the effective focal length f of the optical lens satisfy: 0.27 < L / f < 0.37; the distance L from the object side surface of the first lens to the imaging surface in the first optical axis direction and the real image height IH corresponding to the maximum field angle of the optical lens satisfy: 1.6 < L / IH < 3.2. Satisfying the above conditions, the thicknesses of the first lens, the second lens and the catadioptric element can be effectively compressed while satisfying the long focal design and the large image surface of the optical lens, satisfying the product demand of thin and light. More specifically, 0.29 < L / f < 0.35; 1.79 < L / IH < 2.97.

[0044] In some embodiments, the real image height IH corresponding to the maximum field angle of the optical lens and the effective focal length f of the optical lens satisfy: 0.08 < IH / f < 0.2. Satisfying the above conditions, it is helpful to realize a large image surface and improve the imaging quality of the lens. More specifically, 0.09 < IH / f < 0.2.

[0045] In some embodiments, the distance L from the object side surface of the first lens to the imaging surface in the first optical axis direction and the total optical length TTL of the optical lens satisfy: 0.22 < L / TTL < 0.3. It can be understood that TTL is the sum of the geometric distances from the object side surface of the first lens to the imaging surface in all optical axes. Satisfying the above conditions, the thicknesses of the first lens, the second lens and the catadioptric element can be effectively compressed, satisfying the product demand of thin and light. More specifically, 0.24 < L / TTL < 0.29.

[0046] In some embodiments, the distance L from the object side surface of the first lens to the imaging surface in the first optical axis direction, the real image height IH corresponding to the maximum field angle of the optical lens and the maximum field angle FOV of the optical lens satisfy: 115 < 180°xL / (IH / 2) / (FOV / 2) < 390. Satisfying the above range, it is beneficial to balance the relationship among the length, the image height and the field angle of the optical lens. More specifically, 124.67 < 180°xL / (IH / 2) / (FOV / 2) < 355.4.

[0047] In some embodiments, the half light entrance radius d1 of the object side surface of the first lens, the real image height IH corresponding to the maximum field angle of the optical lens and the maximum field angle FOV of the optical lens satisfy: 15 < d1 / (IH / 2) / tan(FOV / 2) < 43. Satisfying the above range, it is beneficial to have a small front end while satisfying the optical lens with a large field angle and a large image surface, which is conducive to the miniaturization of the optical lens. More specifically, 15.79 < d1 / (IH / 2) / tan(FOV / 2) < 41.16.

[0048] In some embodiments, the focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: 0.08 < f1 / f < 0.45; the radius of curvature R1 of the object side surface of the first lens and the effective focal length f of the optical lens satisfy: 0.14 < R1 / f < 0.28. Satisfying the above conditions, as the first positive lens and the convex object side surface, the first lens can converge incident light and construct a long-focus optical path, while providing a basis for subsequent negative lens optical path compression.

[0049] In some embodiments, the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: -0.65 < f2 / f < -0.05; the radius of curvature R4 of the image side surface of the second lens and the effective focal length f of the optical lens satisfy: 0.03 < R4 / f < 0.1. Satisfying the above range, the second lens adopts a negative lens, which can diverge light, lengthen the equivalent focal length but shorten the physical optical path length, while compensating for the aberration of the front group positive lens. More specifically, -0.6 < f2 / f < -0.06; 0.04 < R4 / f < 0.09.

[0050] In some embodiments, the center thickness CT1 of the first lens, the center thickness CT2 of the second lens, and the distance L in the first optical axis direction from the object side surface of the first lens to the imaging surface satisfy: 0.14 < (CT1+CT2) / L < 0.2; the center thickness CT1 of the first lens, the spacing CT12 of the first lens and the second lens in the first optical axis direction, the center thickness CT2 of the second lens, and the total optical length TTL of the optical lens satisfy: 0.03 < (CT1+CT12+CT2) / TTL < 0.07. Satisfying the above conditions, the size proportion of the first lens and the second lens is reasonably set to meet the product demand of miniaturization of the optical lens. More specifically, 0.15 < (CT1+CT2) / L < 0.19; 0.03 < (CT1+CT12+CT2) / TTL < 0.07.

[0051] In some embodiments, the maximum field of view FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 0.6° < FOV / Fno < 1.5°. Satisfying the above range, the relationship between the maximum field of view and the aperture value is balanced, and the lens is more compact, suitable for periscopic structure (such as mobile phone long-focus lens), and still maintains small volume after optical path folding. More specifically, 0.66° < FOV / Fno < 1.42°.

[0052] In some embodiments, the real image height IH corresponding to the maximum field of view of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 0.9 < IH / EPD < 1.5. Satisfying the above range, the field of view and the luminous flux are balanced, and the imaging quality of the lens is improved. More specifically, 0.93 < IH / EPD < 1.4.

[0053] In some embodiments, the effective focal length f of the optical lens, the maximum field of view FOV of the optical lens, and the real image height IH corresponding to the maximum field of view FOV of the optical lens satisfy: 0.99 < (IH / 2) / (f*tan(FOV / 2)) < 1.02. Satisfying the above range, the lens has a smaller distortion value and can provide a high-definition imaging effect.

[0054] In some embodiments, the focal length f1 of the first lens and the focal length f2 of the second lens satisfy: -1.5 < f1 / f2 < -0.7. Satisfying the above range, a positive-negative focal power combination is formed, which can improve the temperature drift stability of the lens, reduce sensitivity, help to reduce the influence of environmental temperature on the lens group, and also meet the compactness requirement of the lens. More specifically, -1.35 < f1 / f2 < -0.73.

[0055] In some embodiments, the real image height IH corresponding to the maximum field of view of the optical lens and the effective focal length f of the optical lens satisfy: 200 < 43.27 / IHxf < 450. The above condition is an equivalent focal length calculation formula, and satisfying the above condition indicates that the optical lens has a longer equivalent focal length. More specifically, 233.29 < 43.27 / IHxf < 412.79.

[0056] In some embodiments, the object side half light entrance diameter d1 of the first lens and the real image height IH corresponding to the maximum field of view of the optical lens satisfy: 0.7 < d1 / (IH / 2) < 1.1. Satisfying the above condition balances the relationship between the front end diameter and the image height of the optical lens. More specifically, 0.72 < d1 / (IH / 2) < 1.09.

[0057] In some embodiments, the optical lens satisfies the condition formula: 27mm < f < 44mm, 3.5mm < EPD < 4.7mm, 8.5mm < L < 13mm, 30mm < TTL < 52mm, 7 < Fno < 9.5, 4mm < IH < 6.5mm, 5° < FOV < 11°; wherein f represents an effective focal length of the optical lens, EPD represents an entrance pupil diameter of the optical lens, L represents a distance from an object side of the first lens to an imaging surface in a first optical axis direction; TTL represents an optical total length of the optical lens, Fno represents an aperture value of the optical lens, IH represents a real image height corresponding to a maximum field of view angle of the optical lens, and FOV represents a maximum field of view angle of the optical lens. By satisfying the above condition, the optical lens provided by the embodiments of the present application at least has the characteristics of super-telephoto, short total length, miniaturization and the like. More specifically, 29.76mm < f < 40.27mm, 3.69mm < EPD < 4.51mm, 8.98mm < L < 12.51mm, 31.88mm < TTL < 50.01mm, 7.5 < Fno < 8.96, 4.21mm < IH < 6.11mm, 5.99° < FOV < 10.61°.

[0058] In some embodiments, the material of the lenses and catadioptric elements in the optical lens provided by the present application can be glass or plastic. When the material of the lenses and catadioptric elements is plastic, the production cost can be effectively reduced. When the material of the lenses and catadioptric elements is glass, the geometric chromatic aberration of the optical system can be effectively corrected by the low dispersion characteristic of the glass itself. The first catadioptric element and the second catadioptric element in the optical lens provided by the present application can adopt glass material; the first lens and the second lens can adopt plastic material, which not only makes the lens have excellent imaging performance, but also makes the structure of the lens more compact, and can better realize the balance between miniaturization and high image quality of the lens.

[0059] In some embodiments, the first lens and the second lens can adopt spherical lenses or aspherical lenses. Compared with the spherical structure, the aspherical structure can effectively reduce the aberration of the optical system, thereby reducing the number of lenses and the size of the lenses, and better realizing the miniaturization of the lens. More specifically, the first lens and the second lens of the present application can both adopt aspherical lenses, which can effectively reduce the aberration of the optical lens, thereby reducing the number of lenses and the size of the lenses, and better realizing the miniaturization of the lens.

[0060] In various embodiments of the present application, when the lenses adopt aspherical lenses, the shape of each aspherical surface of the optical lens satisfies the following equation: ; Wherein, z is the distance of the curved surface and the curved surface vertex in the direction of the optical axis, h is the distance of the optical axis to the curved surface, c is the curvature of the curved surface vertex, K is the quadratic curved surface coefficient, B, C, D, E, F are the fourth order, sixth order, eighth order, tenth order, and twelfth order curved surface coefficients respectively.

[0061] The application will be further described in the following embodiments. In each embodiment, the thickness, the radius of curvature, and the material selection of each lens in the optical lens are different, and the specific differences can be referred to the parameter table of each embodiment. The following embodiments are merely the preferred embodiments of the application, but the embodiments of the application are not limited to the following embodiments only, and any change, substitution, combination, or simplification made without departing from the innovative points of the application should be regarded as equivalent replacement, and should be included in the protection scope of the application.

[0062] Embodiment 1 Please refer to Figure 1 and Figure 2 , Figure 1 the structure schematic diagram of the optical lens 100 provided in Embodiment 1 of the application, Figure 2 the prism structure schematic diagram and the optical path schematic diagram. The optical lens sequentially comprises a stop ST, a first lens L1, a second lens L2, a first catadioptric element Pr1, and a second catadioptric element Pr2 from the object side to the imaging surface along the light transmission direction.

[0063] The first lens L1 has positive focal power, the object side surface S1 thereof is a convex surface, and the image side surface S2 thereof is a concave surface; The second lens L2 has negative focal power, the object side surface S3 thereof is a convex surface, and the image side surface S4 thereof is a concave surface; The first catadioptric element Pr1 comprises a first light incident surface S5, a first reflection surface S6, a second reflection surface S7, a third reflection surface S8, a fourth reflection surface S9, and a first light exit surface S10, and all are planes, wherein the first light incident surface S5 and the second reflection surface S7 are substantially the same plane; the third reflection surface S8 and the first light exit surface S10 are substantially the same plane.

[0064] The second catadioptric element Pr2 comprises a second light incident surface S11, a fifth reflection surface S12, a sixth reflection surface S13, a seventh reflection surface S14, an eighth reflection surface S15, and a second light exit surface S16, and all are planes, wherein the second light incident surface S11 and the sixth reflection surface S13 are substantially the same plane; the seventh reflection surface S14 and the second light exit surface S16 are substantially the same plane.

[0065] The cross section of the first catadioptric element Pr1 and the second catadioptric element Pr2 is parallelogram; and the angle θ1 between the first light incident surface S5 and the first reflection surface S6 is 30°; the angle θ2 between the second light incident surface S11 and the fifth reflection surface S12 is 30°. The height H1 of the first catadioptric element Pr1 is 3.75 mm; the height H2 of the second catadioptric element Pr2 is 3.75 mm. The long side D1 of the first catadioptric element Pr1 is 15 mm; the long side D2 of the second catadioptric element Pr2 is 13.8 mm.

[0066] The first catadioptric element Pr1 has a first optical axis OA1, a second optical axis OA2, a third optical axis OA3, a fourth optical axis OA4, and a fifth optical axis OA5. The light path enters the first catadioptric element Pr1 through the first lens L1 and the second lens L2 along the first optical axis OA1, passes through the first light incident surface S5 to the first reflection surface S6, is reflected to the second reflection surface S7, is totally reflected to the third reflection surface S8, is totally reflected to the fourth reflection surface S9, is reflected to the first light exit surface S10, and enters the second catadioptric element Pr2. The first reflection surface S6 turns the light path from the first optical axis OA1 to the second optical axis OA2, the second reflection surface S7 turns the light path from the second optical axis OA2 to the third optical axis OA3, the third reflection surface S8 turns the third optical axis OA3 to the fourth optical axis OA4, and the fourth reflection surface S9 turns the fourth optical axis OA4 to the fifth optical axis OA5.

[0067] The second catadioptric element Pr2 has a sixth optical axis OA6, a seventh optical axis OA7, an eighth optical axis OA8, a ninth optical axis OA9, and a tenth optical axis OA10. The light path passes through the second light incident surface S11 to the fifth reflection surface S12 along the sixth optical axis OA6, is reflected to the sixth reflection surface S13, is totally reflected to the seventh reflection surface S14, is totally reflected to the eighth reflection surface S15, is reflected to the second light exit surface S16, and exits to the imaging surface. The fifth reflection surface S12 turns the light path from the sixth optical axis OA6 to the seventh optical axis OA7, the sixth reflection surface S13 turns the light path from the seventh optical axis OA7 to the eighth optical axis OA8, the seventh reflection surface S14 turns the eighth optical axis OA8 to the ninth optical axis OA9, and the eighth reflection surface S15 turns the ninth optical axis OA9 to the tenth optical axis OA10 (the tenth optical axis OA10 is perpendicular to the imaging surface).

[0068] The light path turns four times in the first catadioptric element Pr1 and the second catadioptric element Pr2, respectively, and the first optical axis OA1 and the tenth optical axis OA10 are in the same direction; the fifth optical axis OA5 and the sixth optical axis OA6 are in the same direction. The first reflection surface S6, the fourth reflection surface S9, the fifth reflection surface S12, and the eighth reflection surface S15 have a reflective coating (plating) or are mirror surfaces.

[0069] The first lens L1 and the second lens L2 are plastic aspherical lenses. The first catadioptric element Pr1 and the second catadioptric element Pr2 can be made of glass.

[0070] The related parameters of the lenses in the optical lens 100 in Example 1 are shown in Table 1-1.

[0071] Table 1-1 The surface parameters of the aspherical lenses in the optical lens 100 in Example 1 are shown in Table 1-2.

[0072] Table 1-2 In this embodiment, the F-Tan(Theta) distortion curve, the field curvature curve, and the axial chromatic aberration curve of the optical lens 100 are shown in FIGS. Figure 3 , Figure 4 , Figure 5

[0073] Figure 3 The distortion curve of Example 1 is shown, which represents the distortion of light rays of different wavelengths at different image heights on the imaging plane, the horizontal axis represents the distortion value (unit: %), and the vertical axis represents the half field angle (unit: °). As can be seen from the figure, the distortion of the optical lens is controlled within -0.02%~0, which shows that the optical lens 100 can well correct the distortion.

[0074] Figure 4 The field curvature curve of Example 1 is shown, which represents the field curvature of light rays on the meridional image plane and the sagittal image plane, the horizontal axis represents the offset (unit: mm), and the vertical axis represents the half field angle (unit: °). As can be seen from the figure, the field curvature of the meridional image plane and the sagittal image plane is controlled within 0~0.05mm, which shows that the optical lens 100 can well correct the field curvature.

[0075] Figure 5 The axial chromatic aberration curve of Example 1 is shown, which represents the axial chromatic aberration of each wavelength relative to the central wavelength (0.555μm) at different image heights on the imaging plane, the horizontal axis represents the axial chromatic aberration value of each wavelength relative to the central wavelength (unit: μm), and the vertical axis represents the normalized field angle. As can be seen from the figure, the axial chromatic aberration of the longest wavelength and the shortest wavelength is controlled within -1μm~2μm, which shows that the optical lens 100 can well correct the chromatic aberration.

[0076] Example 2 Please refer to Figure 6 ​, as shown is a structural schematic view of the optical lens 200 provided in the embodiment 2 of the present application, the embodiment is basically same as the embodiment 1, the turning and transmission path of the light are also basically same, the main difference lies in that the optical parameters such as the radius of curvature of each lens surface and the lens thickness are different. Wherein, the angle θ1 between the first light incidence surface S5 and the first reflection surface S6 is 30°; the angle θ2 between the second light incidence surface S11 and the fifth reflection surface S12 is 30°. The height H1 of the first catadioptric element Pr1 is 3.75 mm; the height H2 of the second catadioptric element Pr2 is 3.75 mm. The long side D1 of the first catadioptric element Pr1 is 15 mm; the long side D2 of the second catadioptric element Pr2 is 15 mm.

[0077] The related parameters of each lens in the optical lens 200 in the embodiment 2 are shown in table 2-1.

[0078] Table 2-1 The surface type parameters of the aspheric lens of the optical lens 200 in the embodiment 2 are shown in table 2-2.

[0079] Table 2-2 In the embodiment, the F-Tan(Theta) distortion curve, the field curvature curve and the axial chromatic aberration curve of the optical lens 200 are respectively shown in Figure 7 、 Figure 8 、 Figure 9 .

[0080] It can be seen from Figure 7 that the distortion of the optical lens is controlled within 0~0.02%, which shows that the optical lens 200 can well correct the distortion.

[0081] It can be seen from Figure 8 that the field curvature of the meridional image surface and the sagittal image surface is controlled within ±0.02 mm, which shows that the optical lens 200 can well correct the field curvature.

[0082] It can be seen from Figure 9 that the axial chromatic aberration of the longest wavelength and the shortest wavelength is controlled within ±1 μm, which shows that the optical lens 200 can better correct the chromatic aberration.

[0083] Embodiment 3 Please refer to Figure 10, which is a structural schematic view of the optical lens 300 provided in Embodiment 3 of the present application. Compared with Embodiment 1, the present embodiment is substantially the same, and the turning and transmission path of the light rays are also substantially the same. The main difference lies in that the image side S2 of the first lens L1 is a convex surface; the optical parameters such as the curvature radius and the thickness of each lens surface are different. Among them, the included angle θ1 between the first light incident surface S5 and the first reflecting surface S6 is 30°; the included angle θ2 between the second light incident surface S11 and the fifth reflecting surface S12 is 30°. The height H1 of the first catadioptric element Pr1 is 3.75 mm; the height H2 of the second catadioptric element Pr2 is 3.75 mm. The long side D1 of the first catadioptric element Pr1 is 15 mm; the long side D2 of the second catadioptric element Pr2 is 13.8 mm.

[0084] The related parameters of each lens in the optical lens 300 in Embodiment 3 are shown in Table 3-1.

[0085] Table 3-1 The surface type parameters of the aspheric lens of the optical lens 300 in Embodiment 3 are shown in Table 3-2.

[0086] Table 3-2 In the present embodiment, the F-Tan(Theta) distortion curve, the field curvature curve and the axial chromatic aberration curve of the optical lens 300 are shown in Figure 11 、 Figure 12 、 Figure 13 respectively.

[0087] As can be seen from Figure 11 , the distortion of the optical lens is controlled within-0.05%~0, which indicates that the optical lens 300 can well correct the distortion.

[0088] As can be seen from Figure 12 , the field curvature of the meridional image surface and the sagittal image surface is controlled within-0.02 mm~0.06 mm, which indicates that the optical lens 300 can well correct the field curvature.

[0089] As can be seen from Figure 13 , the axial chromatic aberration of the longest wavelength and the shortest wavelength is controlled within ±2 μm, which indicates that the optical lens 300 can well correct the chromatic aberration.

[0090] Embodiment 4 Please refer to Figure 14, which is a structural schematic view of the optical lens 400 provided in Embodiment 4 of the present application. Compared with Embodiment 1, the present embodiment is substantially the same, and the turning and transmission path of the light rays are also substantially the same. The main difference lies in that: the image side S2 of the first lens L1 is a convex surface; the object side S3 of the second lens L2 is a concave surface; and the optical parameters such as the curvature radius and the lens thickness of each lens surface are different. Among them, the angle θ1 between the first light incident surface S5 and the first reflecting surface S6 is 25°; the angle θ2 between the second light incident surface S11 and the fifth reflecting surface S12 is 25°. The height H1 of the first catadioptric element Pr1 is 2.9 mm; the height H2 of the second catadioptric element Pr2 is 2.9 mm. The long side D1 of the first catadioptric element Pr1 is 10.9 mm; the long side D2 of the second catadioptric element Pr2 is 10.9 mm.

[0091] The related parameters of each lens in the optical lens 400 in Embodiment 4 are shown in Table 4-1.

[0092] Table 4-1 The surface type parameters of the aspherical lens of the optical lens 400 in Embodiment 4 are shown in Table 4-2.

[0093] Table 4-2 In the present embodiment, the F-Tan(Theta) distortion curve, the field curvature curve, and the axial chromatic aberration curve of the optical lens 400 are shown in Figure 15 , Figure 16 , Figure 17 respectively.

[0094] As can be seen from Figure 15 , the distortion of the optical lens is controlled within 0~0.4%, which indicates that the optical lens 400 can well correct the distortion.

[0095] As can be seen from Figure 16 , the field curvature of the meridional image surface and the sagittal image surface is controlled within ±0.3 mm, which indicates that the optical lens 400 can well correct the field curvature.

[0096] As can be seen from Figure 17 , the axial chromatic aberration of the longest wavelength and the shortest wavelength is controlled within ±5 μm, which indicates that the optical lens 400 can well correct the chromatic aberration.

[0097] Please refer to Table 5 for the optical characteristics of the above-mentioned embodiments, including the effective focal length f of the optical lens, the total track length TTL (the sum of the geometric distances on all optical axes from the object side of the first lens to the imaging surface), the aperture value Fno, the real image height IH corresponding to the maximum field of view angle, the chief ray angle of incidence CRA at the maximum image height, the maximum field of view angle FOV, the distance L from the object side of the first lens to the imaging surface in the first optical axis direction, and the numerical values corresponding to each conditional expression in the embodiments.

[0098] Table 5 In summary of the above embodiments, the optical lens provided by the present application can achieve excellent long-focus shooting effect through the arrangement of two lenses and two catadioptric elements, and the optical zoom can reach 9.7-17.2. Since the light path is folded multiple times in the catadioptric element, the volume of the folded optical system is greatly compressed, the volume of the optical lens is greatly reduced while achieving good long-focus shooting effect (which can be placed vertically in a mobile phone), and the miniaturization of the lens is better achieved, so that the optical lens has one or more advantages of super-long focus, short total length, miniaturization, low sensitivity, high imaging quality, etc., greatly improving the user experience.

[0099] 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 connection 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 refer to 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.

[0100] The above-described embodiments only express several implementation manners of the present application, which are described in a more specific and detailed manner, but should not be understood as a limitation on the scope of the present application. It should be noted that for those skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are all within 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, characterized in that, It consists of two lenses with optical power and two catadioptric elements, and along the light transmission direction from the object side to the imaging plane, it includes the following components in sequence: A first lens with positive optical power has a convex object-side surface. A second lens with negative optical power has a concave image-side surface; The first reflective element includes a first light incident surface, a first reflecting surface, a second reflecting surface, a third reflecting surface, a fourth reflecting surface, and a first light exiting surface, all of which are planar. Specifically, the first light incident surface and the second reflecting surface are on the same plane, and the third reflecting surface and the first light exiting surface are on the same plane. The second reflective element includes a second light incident surface, a fifth reflecting surface, a sixth reflecting surface, a seventh reflecting surface, an eighth reflecting surface, and a second light exiting surface, all of which are planar. Specifically, the second light incident surface and the sixth reflecting surface are on the same plane; the seventh reflecting surface and the second light exiting surface are on the same plane; and the cross-sections of both the first reflective element and the second reflective element are parallelograms. The first refracting element has a first optical axis, a second optical axis, a third optical axis, a fourth optical axis, and a fifth optical axis. The light path enters the first refracting element along the first optical axis, passes through the first lens and the second lens, passes through the first light incident surface to the first reflective surface, is reflected to the second reflective surface, is then totally reflected to the third reflective surface, is then totally reflected to the fourth reflective surface, and is then reflected to the first light exiting surface before exiting and entering the second refracting element. The first reflective surface deflects the light path from the first optical axis to the second optical axis, the second reflective surface deflects the light path from the second optical axis to the third optical axis, the third reflective surface deflects the third optical axis to the fourth optical axis, and the fourth reflective surface deflects the fourth optical axis to the fifth optical axis. The second reflective element has a sixth optical axis, a seventh optical axis, an eighth optical axis, a ninth optical axis, and a tenth optical axis; the optical path passes along the sixth optical axis through the second ray incident surface to the fifth reflecting surface, is reflected back to the sixth reflecting surface, is then totally reflected back to the seventh reflecting surface, is then totally reflected back to the eighth reflecting surface, and is then reflected back to the second ray exiting surface and exits to the imaging surface; the fifth reflecting surface deflects the optical path from the sixth optical axis to the seventh optical axis, the sixth reflecting surface deflects the optical path from the seventh optical axis to the eighth optical axis, the seventh reflecting surface deflects the eighth optical axis to the ninth optical axis, and the eighth reflecting surface deflects the ninth optical axis to the tenth optical axis; the tenth optical axis is perpendicular to the imaging surface; the first optical axis and the tenth optical axis are in the same direction; the fifth optical axis and the sixth optical axis are in the same direction; Wherein, the true image height IH corresponding to the maximum field of view of the optical lens and the effective focal length f of the optical lens satisfy: 9 < (43.27 / IH×f) / 24 < 19.

2. The optical lens according to claim 1, characterized in that, The long side D1 of the first reflective element, the height H1 of the first reflective element, and the angle θ1 between the first light incident surface and the first reflecting surface satisfy: -1.6 < D1 - 2 × H1 / tan(θ1) < 2.2; the long side D2 of the second reflective element, the height H2 of the second reflective element, and the angle θ2 between the second light incident surface and the fifth reflecting surface satisfy: -1.6 < D2 - 2 × H2 / tan(θ2) < 2.

2.

3. The optical lens according to claim 2, characterized in that, The maximum image height incident angle CRA of the optical lens satisfies: 3° < CRA < 7°; the long side D1 of the first catadioptric element, the height H1 of the first catadioptric element, and the angle θ1 between the first light incident surface and the first reflecting surface satisfy: 10mm < D1 < 16mm; 2.8mm < H1 < 3.8mm; 23° < θ1 < 33°; the long side D2 of the second catadioptric element, the height H2 of the second catadioptric element, and the angle θ2 between the second light incident surface and the fifth reflecting surface satisfy: 10mm < D2 < 16mm; 2.8mm < H2 < 3.8mm; 23° < θ2 < 33°.

4. The optical lens according to claim 3, characterized in that, The angle θ1 between the first light incident surface and the first reflecting surface is equal to the angle θ2 between the second light incident surface and the fifth reflecting surface; the height H1 of the first reflective element is equal to the height H2 of the second reflective element.

5. The optical lens according to claim 1, characterized in that, The distance L from the object side of the first lens to the imaging surface in the first optical axis direction and the effective focal length f of the optical lens satisfy: 0.27 < L / f < 0.37; the distance L from the object side of the first lens to the imaging surface in the first optical axis direction and the true image height IH corresponding to the maximum field of view of the optical lens satisfy: 1.6 < L / IH < 3.

2.

6. The optical lens according to claim 1, characterized in that, The true image height IH corresponding to the maximum field of view of the optical lens and the effective focal length f of the optical lens satisfy: 0.08 < IH / f < 0.2; the distance L from the object side of the first lens to the imaging surface in the first optical axis direction and the total optical length TTL of the optical lens satisfy: 0.22 < L / TTL < 0.

3.

7. The optical lens according to claim 1, characterized in that, The distance L from the object side of the first lens to the imaging surface in the direction of the first optical axis, the true image height IH corresponding to the maximum field of view of the optical lens, and the maximum field of view FOV of the optical lens satisfy: 115 < 180° × L / (IH / 2) / (FOV / 2) < 390°; the half-aperture d1 of the object side of the first lens, the true image height IH corresponding to the maximum field of view of the optical lens, and the maximum field of view FOV of the optical lens satisfy: 15 < d1 / (IH / 2) / tan(FOV / 2) < 43°.

8. The optical lens according to claim 1, characterized in that, The focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: 0.08 < f1 / f < 0.45; the radius of curvature R1 of the object side surface of the first lens and the effective focal length f of the optical lens satisfy: 0.14 < R1 / f < 0.

28.

9. The optical lens according to claim 1, characterized in that, The focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: -0.65 < f2 / f < -0.05; the radius of curvature R4 of the image side surface of the second lens and the effective focal length f of the optical lens satisfy: 0.03 < R4 / f < 0.

1.

10. The optical lens according to claim 1, characterized in that, The center thickness CT1 of the first lens, the center thickness CT2 of the second lens, and the distance L from the object side of the first lens to the imaging surface in the first optical axis direction satisfy: 0.14 < (CT1 + CT2) / L < 0.2; the center thickness CT1 of the first lens, the distance CT12 between the first lens and the second lens in the first optical axis direction, the center thickness CT2 of the second lens, and the total optical length TTL of the optical lens satisfy: 0.03 < (CT1 + CT12 + CT2) / TTL < 0.07.

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