Optical lens

Abstract

The present invention provides an optical lens, which sequentially includes, from the object side to the imaging surface: a reflective element, the reflective element including an incident surface, a reflective surface, and an exit surface; the reflective surface of the reflective element forms an angle of 45° with the optical axes of the incident surface and the exit surface of the reflective element respectively; a first lens with positive optical power, the object side surface of which is convex; a second lens with negative optical power; a third lens with positive optical power; a fourth lens with negative optical power, the object side surface of which is concave and the image side surface of which is convex; a fifth lens with positive optical power, the object side surface of which is convex and the image side surface of which is concave; the first lens is formed by a trimmed lens forming process, and the minimum optical aperture D1min of the first lens and the maximum optical aperture D1max of the first lens satisfy: 0.92 < D1min / D1max < 0.98. The optical lens of the present invention adopts a combination of a reflective element and multiple lenses, effectively compresses the optical aperture of the lenses, and has the characteristics of miniaturization and thinness.

Description

Technical Field

[0001] The present invention relates to the technical field of imaging lenses, and particularly to an optical lens. Background Art

[0002] Telephoto cameras can meet the needs of consumers to shoot specific targets, but the overall optical length of traditional telephoto cameras is too large to meet the design requirements of thin and light smartphones.

[0003] In order to endow mobile phone photography with more powerful telephoto characteristics, the periscope mobile phone lens has been a hot topic since its birth and has become a standard feature of some imaging flagship mobile phones. In order to pursue higher quality and more stable telephoto performance, the optical system needs to have a larger aperture and light throughput. However, after the optical path of the periscope telephoto lens is turned by reflecting components such as prisms, the size of the lens aperture is limited by the thickness of the mobile phone and cannot be increased, which hinders the development of telephoto lenses with large apertures, large fields of view, and high-quality imaging. Summary of the Invention

[0004] Aiming at the above problems, the purpose of the present invention is to provide an optical lens with excellent imaging quality.

[0005] The technical solution adopted by the present invention is as follows:

[0006] An optical lens is composed of one reflecting element and five lenses, and sequentially includes from the object side to the imaging surface:

[0007] A reflecting element, the reflecting element includes an incident surface, a reflecting surface, and an exit surface; the reflecting surface of the reflecting element forms an angle of 45° with the optical axes of the incident surface and the exit surface of the reflecting element respectively;

[0008] A first lens with positive optical power, the object side surface of which is convex;

[0009] A second lens with negative optical power;

[0010] A third lens with positive optical power;

[0011] A fourth lens with negative optical power, the object side surface of which is concave and the image side surface of which is convex;

[0012] A fifth lens with positive optical power, the object side surface of which is convex and the image side surface of which is concave;

[0013] Wherein, the first lens adopts a trimmed lens forming process, and the minimum optical aperture D1min of the first lens and the maximum optical aperture D1max of the first lens satisfy: 0.92 < D1min / D1max < 0.98.

[0014] Further preferably, the distance TTL from the object side surface of the first lens to the imaging surface on the optical axis and the distance TL from the object side surface of the first lens to the image side surface of the fifth lens on the optical axis satisfy: 0.32 < TL / TTL < 0.5.

[0015] Further preferably, the effective optical aperture DM1 of the first lens, the effective optical aperture DM2 of the second lens, the effective optical aperture DM3 of the third lens, the effective optical aperture DM4 of the fourth lens, and the effective optical aperture DM5 of the fifth lens satisfy: DM1 > DM2 > DM3 > DM4 > DM5; the effective optical aperture DM5 of the fifth lens satisfies: 5.15 mm < DM5 < 5.3 mm.

[0016] Further preferably, the effective optical aperture DM1 of the first lens and the effective optical aperture DM5 of the fifth lens satisfy: 1.2 < DM1 / DM5 < 1.55; the effective optical aperture DM5 of the fifth lens and the true image height IH corresponding to the maximum field of view angle of the optical lens satisfy: 0.45 < DM5 / IH < 0.55.

[0017] Further preferably, the back focal length BFL of the optical lens and the distance TTL from the object side surface of the first lens to the imaging surface on the optical axis satisfy: 0.5 < BFL / TTL < 0.65.

[0018] Further preferably, the effective focal length f of the optical lens and the combined focal length f12 of the first lens and the second lens satisfy: 1.3 < f12 / f < 2.5; the effective focal length f of the optical lens and the combined focal length f345 of the third lens, the fourth lens, and the fifth lens satisfy: 1.2 < f345 / f < 2.3.

[0019] Further preferably, the focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: 0.58 < f1 / f < 0.7; the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: -1.2 < f2 / f < -0.5.

[0020] Further preferably, the focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: 0.5 < f3 / f < 3.3.

[0021] Further preferably, the focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy: -3.2 < f4 / f < -0.5; the radius of curvature R7 of the object side surface of the fourth lens and the radius of curvature R8 of the image side surface of the fourth lens satisfy: 0.2 < R7 / R8 < 1.

[0022] More preferably, the focal length f5 of the fifth lens and the effective focal length f of the optical lens satisfy: 0.9 < f5 / f < 2.3; the radius of curvature R9 of the object side surface of the fifth lens and the radius of curvature R10 of the image side surface of the fifth lens satisfy: 0.3 < R9 / R10 < 0.8.

[0023] Compared with the prior art, when the object-side light beam of the optical lens of the present invention passes through the reflection element, it is reflected on the reflection surface of the reflection element, causing the optical axis to turn 90°. Then it passes through the first lens, the second lens, the third lens, the fourth lens and the fifth lens in sequence, and finally undergoes the filtering process of the filter to complete the image acquisition on the photosensitive chip; and because the first lens adopts the lens slicing process, while ensuring that the lens has a large light-gathering aperture, the lateral size of the lens is minimized to the greatest extent, so as to better realize the periscope imaging effect of the large aperture and large field of view of the lens, and it can also meet the development trend of the ultra-thinning of portable electronic devices such as mobile phones. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The above and / or additional aspects and advantages of the present invention will become obvious and easy to understand from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0025] Figure 1 It is a cross-sectional schematic view of the trimmed lens of the first lens provided by the embodiment of the present invention.

[0026] Figure 2 It is a schematic structural view of the optical lens in Embodiment 1 of the present invention.

[0027] Figure 3 It is an axial aberration curve graph of the optical lens in Embodiment 1 of the present invention.

[0028] Figure 4 It is a longitudinal chromatic aberration curve graph of the optical lens in Embodiment 1 of the present invention.

[0029] Figure 5 It is a distortion curve graph of the optical lens in Embodiment 1 of the present invention.

[0030] Figure 6 It is a schematic structural view of the optical lens in Embodiment 2 of the present invention.

[0031] Figure 7 It is an axial aberration curve graph of the optical lens in Embodiment 2 of the present invention.

[0032] Figure 8 It is a longitudinal chromatic aberration curve graph of the optical lens in Embodiment 2 of the present invention.

[0033] Figure 9 It is a distortion curve graph of the optical lens in Embodiment 2 of the present invention.

[0034] Figure 10 This is a schematic structural diagram of the optical lens in Embodiment 3 of the present invention.

[0035] Figure 11 This is the axial aberration curve graph of the optical lens in Embodiment 3 of the present invention.

[0036] Figure 12 This is the longitudinal chromatic aberration curve graph of the optical lens in Embodiment 3 of the present invention.

[0037] Figure 13 This is the distortion curve graph of the optical lens in Embodiment 3 of the present invention.

[0038] The following specific embodiments will further illustrate the present invention in conjunction with the above-mentioned drawings. Specific Embodiments

[0039] To better understand the present application, more detailed descriptions of various aspects of the present application will be made with reference to the accompanying drawings. It should be understood that these detailed descriptions are only descriptions of the embodiments of the present application and do not limit the scope of the present application in any way. Throughout the specification, the same reference numerals refer to the same elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0040] It should be noted that in this specification, the expressions such as first, second, third, etc. are only used to distinguish one feature from another feature and do not represent any limitation on the feature. Therefore, without departing from the teachings of the present invention, the first lens discussed below may also be referred to as the second lens or the third lens.

[0041] In the drawings, for the sake of convenience of illustration, the thickness, size, and shape of the lens have been slightly exaggerated. Specifically, the spherical or aspherical shapes shown in the drawings are shown by way of example. That is, the spherical or aspherical shapes are not limited to the spherical or aspherical shapes shown in the drawings. The drawings are only for illustration and are not drawn strictly to scale.

[0042] In this article, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the position of the convex surface is not defined, it means that the lens surface is convex at least in the paraxial region; if the lens surface is concave and the position of the concave surface is not defined, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the object to be photographed is called the object side surface of the lens, and the surface of each lens closest to the imaging surface is called the image side surface of the lens.

[0043] It should also be understood that the terms "comprise", "comprises", "include", "includes", "have", "has", "contain" and / or "contains", when used in this specification, denote 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 combinations thereof. Further, when an expression such as "at least one of..." appears after a list of listed features, it modifies the entire list of listed features rather than individual elements in the list. Further, when describing embodiments of the present application, the use of "may" means "one or more embodiments of the present application". Also, the term "exemplary" is intended to refer to an example or illustration.

[0044] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It should also be understood that terms (such as those defined in a common dictionary) should be interpreted as having a meaning 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.

[0045] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments may be combined with each other. The present application will be described in detail below with reference to the drawings and in conjunction with the embodiments.

[0046] The optical lens provided by the embodiment of the present invention is composed of one reflecting element and five lenses, and sequentially includes from the object side to the imaging surface: a reflecting element, a first lens, a second lens, a third lens, a fourth lens and a fifth lens. The reflecting element of the present invention is used to deflect light, and by changing the angle of the light, the direction of the incident light is perpendicular to the arrangement direction of the multiple lenses, reducing the overall thickness of the optical system and achieving the effect of a periscope long focal length of the lens.

[0047] Specifically, the reflecting element includes an incident surface, a reflecting surface and an exit surface, and its incident surface, reflecting surface and exit surface may all be flat surfaces. The reflecting surface of the reflecting element forms an angle of 45° with the optical axes of the incident surface and the exit surface of the reflecting element respectively. The reflecting element may adopt a right-angled triangular prism, and the prism may be made of glass or plastic.

[0048] In some embodiments, the first lens may have a positive optical power, its object side surface is a convex surface, and its image side surface may be a concave surface or a convex surface. The second lens may have a negative optical power, its object side surface may be a concave surface or a convex surface, and its image side surface may be a concave surface or a convex surface. The third lens may have a positive optical power, its object side surface may be a concave surface or a convex surface, and its image side surface may be a concave surface or a convex surface. The fourth lens may have a negative optical power, its object side surface is a concave surface, and its image side surface is a convex surface. The fifth lens may have a positive optical power, its object side surface is a convex surface, and its image side surface is a concave surface.

[0049] In some embodiments, the optical lens may further include a diaphragm, which may be located between the first lens and the second lens. It can be understood that the diaphragm is used to limit the amount of incident light to change the brightness of the imaging. The optical lens of the present invention adopts a structure with the diaphragm placed at the rear, and the diaphragm is arranged behind the first lens, which can enable the lens to have a large aperture while effectively reducing the diameter of the subsequent optical lenses; in addition, it is also beneficial to avoid structural problems such as side light leakage caused by the cutting edge of the first lens in front of the diaphragm.

[0050] In some embodiments, the optical lens may further include a filter, which may be disposed between the fifth lens and the imaging surface. The filter is used to filter out interfering light to prevent the interfering light from reaching the imaging surface of the optical lens and affecting normal imaging.

[0051] When the object-side light beam of the optical lens of the present invention passes through the reflecting element, it is reflected on the reflecting surface of the prism, causing the optical axis to turn by 90°. Then it passes through the first lens, the second lens, the third lens, the fourth lens and the fifth lens in sequence, and finally undergoes the filtering process of the filter to complete image acquisition on the photosensitive chip (imaging surface).

[0052] In some embodiments, the first lens is formed by a trimmed lens molding process, and the minimum optical diameter D1min of the first lens and the maximum optical diameter D1max of the first lens satisfy: 0.92 < D1min / D1max < 0.98. More specifically, 6 mm < D1min < D1max < 8 mm. Generally speaking, the effective diameter of the first lens (close to the prism) is the largest in the system, and the amount of incident light of the optical system is largely determined by the diameter of the first lens. The shape of a conventional optical lens in the direction perpendicular to the optical axis is circular. In order to increase the amount of incident light of the periscope lens, the first lens is injection molded by a trimmed lens molding process, so that the lateral dimension of the first lens is trimmed to a certain extent, effectively reducing the lateral dimension of the lens in the mobile phone lens module. While ensuring that the lens has a large light passing diameter, the lateral dimension of the lens is minimized to the greatest extent, so as to better achieve the periscope imaging effect of the optical lens with a large aperture, a large diaphragm and a large field of view, and can also meet the development trend of the ultra-thinning of portable electronic devices such as mobile phones.

[0053] It should be noted that after the periscope optical lens of the present invention turns the optical path through the reflecting element (prism), the lens lies horizontally inside the mobile phone, so the lens diameter is limited by the thickness of the mobile phone itself. The lens of the first lens of the present invention will be trimmed in the thickness direction of the mobile phone and can remain unchanged in the other direction perpendicular to it. The first lens is formed by a trimmed lens, which can effectively increase the amount of incident light and increase the aperture value of the system. More specifically, the trimmed lens of the first lens of the present invention is injection molded by a mold.

[0054] In an embodiment of the present invention, the first lens is a plastic lens, and the edge-cut lens forming process is adopted. The refractive index of the material of the first lens is between 1.5 and 1.6, and the Abbe number is between 50 and 60. By controlling the range of the refractive index and Abbe number of the first lens, the stress influence of the lens material in product manufacturing can be reduced, the process difficulty of slicing the lens can be lowered, and the stability of the injection molding of the edge-cut lens and the product yield can be improved. At the same time, the refractive index of the materials of the second lens, the third lens, the fourth lens, and the fifth lens provided by the present invention is between 1.5 and 1.7. By reasonably matching the materials selected for the lenses, the periscope telephoto lens has the ability to correct the purple fringing effect, effectively suppressing the influence of the purple fringing aperture caused by purple light in actual telephoto shooting (see the aberration curve with a wavelength of 435 nm in the performance curve graph).

[0055] In some embodiments, the distance TTL from the object side of the first lens to the imaging surface on the optical axis and the distance TL from the object side of the first lens to the image side of the fifth lens on the optical axis satisfy: 0.32 < TL / TTL < 0.5. Satisfying the above conditions can make the structure of the lens group relatively compact, making the lens have the characteristics of being thin and light, while improving the anti-shake and focusing capabilities of the telephoto lens.

[0056] In some embodiments, the effective optical aperture DM1 of the first lens, the effective optical aperture DM2 of the second lens, and the effective optical aperture DM5 of the fifth lens satisfy: DM1 > DM2 > DM5; the effective optical aperture DM5 of the fifth lens satisfies: 5.15 mm < DM5 < 5.3 mm. Satisfying the above conditions indicates that from the first lens to the fifth lens, the optical aperture decreases in sequence. Such a structural configuration is beneficial to reducing the influence of lens tolerances in lens assembly, thereby improving the accuracy and yield.

[0057] In some embodiments, the effective optical aperture DM1 of the first lens and the effective optical aperture DM5 of the fifth lens satisfy: 1.2 < DM1 / DM5 < 1.55; the effective optical aperture DM5 of the fifth lens and the true image height IH corresponding to the maximum field of view angle of the optical lens satisfy: 0.45 < DM5 / IH < 0.55. Satisfying the above conditions can make the lens have the characteristics of being thin and light and having a large image plane, facilitating the horizontal placement of the lens group inside the mobile phone, being beneficial to improving the limitation problem brought by the external structure of the lens barrel, and thus improving the adaptability of the lens to the module motor.

[0058] In some embodiments, the back focal length BFL of the optical lens and the effective focal length f of the optical lens satisfy: 0.52 < BFL / f < 0.7; the back focal length BFL of the optical lens and the distance TTL from the object side surface of the first lens to the imaging surface on the optical axis satisfy: 0.5 < BFL / TTL < 0.65. Satisfying the above conditions can make the lens have a larger back focus, ensure the compatibility between the lens and the fuselage, better realize the telephoto performance of the lens, and achieve a more compact structure and balanced telephoto performance of the lens.

[0059] In some embodiments, the effective focal length f of the optical lens and the combined focal length f12 of the first lens and the second lens satisfy: 1.3 < f12 / f < 2.5. Satisfying the above conditions is beneficial to reducing the spherical aberration and field curvature generated by the front lens of the optical lens and improving the imaging quality of the optical lens by reasonably distributing the combined focal length of the first two lenses.

[0060] In some embodiments, the effective focal length f of the optical lens and the combined focal length f345 of the third lens, the fourth lens, and the fifth lens satisfy: 1.2 < f345 / f < 2.3. Satisfying the above conditions is beneficial to balancing the distortion and astigmatism generated by the front lens of the optical lens and improving the imaging quality of the optical lens by reasonably distributing the combined focal length of the last three lenses.

[0061] In some embodiments, the focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: 0.58 < f1 / f < 0.7. Satisfying the above conditions can make the first lens have a larger positive refractive power, which is beneficial to collecting light at large angles, reducing the height of the light incident on the first lens, and facilitating the miniaturization of the lens.

[0062] In some embodiments, the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: -1.2 < f2 / f < -0.5. Satisfying the above conditions can effectively diverge the light trend emerging from the first lens, make the light transition smoothly to the rear, reduce the difficulty of aberration correction; at the same time, it can also make the light emerging from the first lens have a larger light receiving surface when entering the rear optical system, achieve a larger light input, and is beneficial to increasing the relative illuminance of the captured image.

[0063] In some embodiments, the focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: 0.5 < f3 / f < 3.3. Satisfying the above conditions is beneficial to the reasonable convergence of light, enabling the diverging light to smoothly enter the rear optical system and better realizing the high-quality imaging of the lens.

[0064] In some embodiments, the focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy: -3.2 < f4 / f < -0.5; the radius of curvature R7 of the object side surface of the fourth lens and the radius of curvature R8 of the image side surface of the fourth lens satisfy: 0.2 < R7 / R8 < 1. Satisfying the above conditions is beneficial to the smooth transition of light, balancing the aberration of the optical lens, and improving the imaging quality of the optical lens.

[0065] In some embodiments, the focal length f5 of the fifth lens and the effective focal length f of the optical lens satisfy: 0.9 < f5 / f < 2.3; the radius of curvature R9 of the object side surface of the fifth lens and the radius of curvature R10 of the image side surface of the fifth lens satisfy: 0.3 < R9 / R10 < 0.8. Satisfying the above conditions can effectively converge light, making the light converge on the imaging surface more smoothly, which is beneficial for the optical system to obtain a stable high-quality imaging effect with a large image surface.

[0066] In some embodiments, the distance TTL on the optical axis from the object side surface of the first lens to the imaging surface and the effective focal length f of the optical lens satisfy: 1 < TTL / f < 1.2; the distance TTL on the optical axis from the object side surface of the first lens to the imaging surface and the true image height IH corresponding to the maximum field of view angle of the optical lens satisfy: 1.5 < TTL / IH < 1.85. Satisfying the above conditions ensures that the lens has a large image surface while having a small overall length, can match a larger-sized imaging chip to achieve high-definition imaging, and preferably realizes the balance between the small overall length and the large image surface of the lens.

[0067] In some embodiments, the true image height IH corresponding to the maximum field of view angle of the optical lens and the effective focal length f of the optical lens satisfy: 0.6 < IH / f < 0.7. Satisfying the above conditions can not only achieve the long focal length characteristic of the lens to meet the local shooting requirements, but also achieve the large image surface characteristic of the lens, can carry a larger-sized chip, and realize the high-definition imaging of the lens.

[0068] In some embodiments, the central thickness CT1 of the first lens and the central thickness CT5 of the fifth lens satisfy: 2.8 < CT1 / CT5 < 4.5. Satisfying the above conditions can control the ratio of the central thicknesses of the first and last lenses, which is beneficial to reducing the deflection angle of the incident light on the first lens and reducing the sensitivity of the first lens in the entire optical lens; at the same time, it helps the optical lens to correct chromatic aberration and spherical aberration, reduce the amount of aberration introduced, and is beneficial to improving the imaging quality of the optical lens.

[0069] In some embodiments, the combined focal length f12 of the first lens and the second lens and the combined focal length f345 of the third lens, the fourth lens, and the fifth lens satisfy: 0.6 < f12 / f345 < 2. Meeting the above conditions, by reasonably setting the proportion of the combined focal lengths of the front and rear lens groups, on the one hand, it is beneficial to the convergence of light, enabling the light entering the system from the front end to smoothly enter the rear optical system, making the overall light path more gentle. On the other hand, it is beneficial to optimizing aberrations and improving the overall resolution of the lens.

[0070] In some embodiments, the entrance pupil diameter EPD of the optical lens and the f-number Fno of the optical lens satisfy: 2.3 mm < EPD / Fno < 3.3 mm; the true image height IH corresponding to the maximum field of view angle of the optical lens and the f-number Fno of the optical lens satisfy: 4 mm < IH / Fno < 5 mm. Meeting the above conditions, by controlling the light passing aperture, f-number, and image height of the lens, while ensuring that the optical lens has a large image plane, it can have a larger light passing amount, which is beneficial to the realization of optical image stabilization technology in the periscope telephoto module and improves the imaging quality of the optical lens. In addition, achieving a balance between the f-number and the light passing aperture is beneficial to the realization of the structural process of the trimmed lens, and can effectively avoid excessive trimming and ineffective trimming.

[0071] In the embodiments of the present invention, the designed wavelength range of the optical lens is 435 nm - 650 nm, and the optical lens satisfies the following conditional expressions: 14.5 mm < f < 17 mm; 35° < FOV < 38°; 15 mm < TTL < 20 mm; 2.2 < Fno < 2.55; 10 mm < IH < 11.5 mm. In the above conditional expressions, f represents the effective focal length of the optical lens, FOV represents the maximum field of view angle of the optical lens, TTL represents the distance from the object side surface of the first lens to the imaging surface on the optical axis, Fno represents the f-number of the optical lens, and IH represents the true image height corresponding to the maximum field of view angle of the optical lens. Meeting the above range, the optical lens has at least one or more advantages such as long focal length, large field of view angle, large aperture, and large image plane. At the same time, it realizes the optimization of aberrations of short-wavelength light, improves the influence of purple fringing phenomenon during lens shooting, and improves the imaging quality.

[0072] In some embodiments, the lens material in the optical lens provided by the present invention can be glass or plastic. When the lens material is plastic, the production cost can be effectively reduced. When the lens material is glass, the geometric chromatic aberration of the optical system can be effectively corrected by the low dispersion characteristic of the glass itself. The optical lens provided by the present invention can adopt an all-plastic lens structure, which not only enables the lens to have excellent imaging performance, but also makes the structure of the lens relatively compact, and can better achieve the balance between the miniaturization of the lens and high image quality.

[0073] In some embodiments, the first lens, the second lens, the third lens, the fourth lens, and the fifth lens may be 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, the second lens, the third lens, the fourth lens, and the fifth lens of the present invention can all 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.

[0074] To enable the system to have better optical performance, multiple aspherical lenses are used in the lens. The shapes of the aspherical surfaces of the optical lens satisfy the following equation:

[0075] ;

[0076] where z is the distance between the curved surface and the vertex of the curved surface in the optical axis direction, h is the distance from the optical axis to the curved surface, c is the curvature of the vertex of the curved surface, K is the conic coefficient, and B, C, D, E, F, G, H, I, J are the second-order, fourth-order, sixth-order, eighth-order, tenth-order, twelfth-order, fourteenth-order, sixteenth-order, eighteenth-order, and twentieth-order surface coefficients respectively.

[0077] The present invention will be further described below with multiple embodiments. In each embodiment, the thickness, radius of curvature, and material selection of each lens in the optical lens are somewhat different. For specific differences, refer to the parameter tables of each embodiment. The following embodiments are only the preferred embodiments of the present invention, but the embodiments of the present invention are not limited only by the following embodiments. Any changes, substitutions, combinations, or simplifications made without departing from the innovative points of the present invention should be regarded as equivalent replacement methods and are included in the protection scope of the present invention.

[0078] Embodiment 1

[0079] Please refer to Figure 2 , Figure 2 which is a schematic structural diagram of the optical lens 100 provided in Embodiment 1 of the present invention. The optical lens 100 sequentially includes, from the light propagation direction (from the object side to the imaging surface S15): a reflection element Pr, a first lens L1, a diaphragm ST, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, and a filter G1. There may be an air gap between any two adjacent lenses.

[0080] The reflective element Pr adopts the design of a catadioptric prism, specifically a right-angled triangular prism, including an incident surface S1, a reflective surface R0, and an exit surface S2; the incident surface S1, the reflective surface R0, and the exit surface S2 are all flat surfaces. The reflective surface of the prism forms a 45° angle with the optical axes of the incident surface and the exit surface of the prism respectively. It can be understood that the incident surface S1 faces the object side, and the exit surface S2 faces the first lens L1.

[0081] The first lens L1 has a positive optical power, its object side surface S3 is a convex surface, and its image side surface S4 is a concave surface near the optical axis;

[0082] The second lens L2 has a negative optical power, its object side surface S5 is a concave surface, and its image side surface S6 is a convex surface;

[0083] The third lens L3 has a positive optical power, its object side surface S7 is a concave surface, and its image side surface S8 is a convex surface;

[0084] The fourth lens L4 has a negative optical power, its object side surface S9 is a concave surface, and its image side surface S10 is a convex surface;

[0085] The fifth lens L5 has a positive optical power, its object side surface S11 is a convex surface, and its image side surface S12 is a concave surface;

[0086] The object side surface S13 and the image side surface S14 of the filter G1 are both flat surfaces;

[0087] The imaging surface S15 is a flat surface.

[0088] Among them, the reflective element Pr can be made of glass or plastic, and the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, and the fifth lens L5 are all plastic aspherical lenses.

[0089] Specifically, the first lens L1 is a trimmed plastic lens, which is directly injection-molded through a trimming process. Therefore, it is possible to further compress the aperture of the lens in the thickness direction of the mobile phone, so that an optical lens with a large light transmission and a large field of view can be well adapted to the conventional module assembly of the mobile phone lens, providing greater possibilities for realizing a telephoto lens module with a large aperture, a large image surface, and a small volume.

[0090] Specifically, Figure 1 is a schematic cross-sectional view of the trimmed shape of the first lens provided in the embodiment of the present invention. In order to clearly show the effect of the trimmed lens of the first lens L1, two dotted lines are drawn along the optical axis direction in Figure 2 in a single direction of the first lens L1 (any direction perpendicular to the optical axis direction). The outside of the dotted line represents the part removed by the sliced lens. More specifically, the trimming amount of the first lens L1 in a single direction in Embodiment 1 is 0.22 mm on one side.

[0091] The relevant parameters of each lens in the optical lens 100 in Embodiment 1 are shown in Table 1-1.

[0092] Table 1-1

[0093]

[0094] The surface shape parameters of the aspherical lens of the optical lens 100 in Embodiment 1 are shown in Table 1-2.

[0095] Table 1-2

[0096]

[0097] In this embodiment, the axial aberration curve graph, the lateral chromatic aberration curve graph, and the distortion curve graph of the optical lens 100 are respectively as Figure 3 , Figure 4 , Figure 5 shown.

[0098] Figure 3 shows the axial aberration curve graph of Embodiment 1, which represents the aberration on the optical axis at the imaging plane for each wavelength. The horizontal axis represents the axial aberration value (unit: mm), and the vertical axis represents the normalized pupil radius. It can be seen from the figure that the offset of the axial aberration is controlled within ±0.05 mm, indicating that the optical lens 100 can correct the axial aberration well.

[0099] Figure 4 shows the lateral chromatic aberration curve graph of Embodiment 1, which represents the chromatic aberration at different image heights on the imaging plane for each wavelength relative to the central wavelength (550 nm). The horizontal axis represents the chromatic aberration value of each wavelength relative to the central wavelength (unit: μm), and the vertical axis represents the normalized field angle. It can be seen from the figure that the chromatic aberration between the longest wavelength and the shortest wavelength is controlled within ±2 μm, indicating that the optical lens 100 can correct the chromatic aberration extremely well.

[0100] Figure 5 shows the distortion curve graph of Embodiment 1, which represents the distortion of light rays with different wavelengths at different image heights on the imaging plane. The horizontal axis represents the distortion value (unit: %), and the vertical axis represents the image height (unit: mm). It can be seen from the figure that the distortion of the optical lens is controlled within ±0.5%, indicating that the optical lens 100 can correct the distortion well.

[0101] Embodiment 2

[0102] Please refer to Figure 6, which shows a schematic structural diagram of the optical lens 200 provided in Embodiment 2 of the present invention. Compared with Embodiment 1, the main differences are as follows: the object side S5 of the second lens L2 is a convex surface, and the image side S6 of the second lens L2 is a concave surface; the object side S7 of the third lens L3 is a convex surface near the optical axis, and the image side S8 of the third lens L3 is a concave surface near the optical axis; the optical parameters such as the curvature radius, lens thickness, and lens material selection of each lens surface are different. In Embodiment 2, the trimming amount of the first lens L1 in a single direction is 0.14 mm on one side.

[0103] The relevant parameters of each lens in the optical lens 200 in Embodiment 2 are shown in Table 2-1.

[0104] Table 2-1

[0105]

[0106] The surface type parameters of the aspherical lenses of the optical lens 200 in Embodiment 2 are shown in Table 2-2.

[0107] Table 2-2

[0108]

[0109] In this embodiment, the axial aberration curve graph, lateral chromatic aberration curve graph, and distortion curve graph of the optical lens 200 are respectively as Figure 7 , Figure 8 , Figure 9 shown.

[0110] From Figure 7 , it can be seen that the offset of the axial aberration is controlled within ±0.05 mm, indicating that the optical lens 200 can correct the axial aberration well.

[0111] From Figure 8 , it can be seen that the chromatic aberration between the longest wavelength and the shortest wavelength is controlled within ±3 μm, indicating that the optical lens 200 can correct the chromatic aberration extremely well.

[0112] From Figure 9 , it can be seen that the distortion of the optical lens is controlled within ±1.5%, indicating that the optical lens 200 can correct the distortion well.

[0113] Embodiment 3

[0114] Please refer to Figure 10, which shows the structural schematic diagram of the optical lens 300 provided in Embodiment 3 of the present invention. Compared with Embodiment 1, the main differences are as follows: The image side S4 of the first lens L1 is convex near the optical axis; the object side S5 of the second lens L2 is convex, and the image side S6 of the second lens L2 is concave; the optical parameters such as the curvature radius of each lens surface, the lens thickness, and the lens material selection are different. In Embodiment 3, the trimming amount of the first lens L1 in a single direction is 0.15 mm on one side.

[0115] The relevant parameters of each lens in the optical lens 300 in Embodiment 3 are shown in Table 3-1.

[0116] Table 3-1

[0117]

[0118] The surface type parameters of the aspherical lens of the optical lens 300 in Embodiment 3 are shown in Table 3-2.

[0119] Table 3-2

[0120]

[0121] In this embodiment, the axial aberration curve graph, the lateral chromatic aberration curve graph, and the distortion curve graph of the optical lens 300 are respectively as Figure 11 , Figure 12 , Figure 13 shown.

[0122] From Figure 11 it can be seen that the offset of the axial aberration is controlled within ±0.05 mm, indicating that the optical lens 300 can correct the axial aberration well.

[0123] From Figure 12 it can be seen that the chromatic aberration between the longest wavelength and the shortest wavelength is controlled within ±2 μm, indicating that the optical lens 300 can correct the chromatic aberration extremely well.

[0124] From Figure 13 it can be seen that the distortion of the optical lens is controlled within ±1%, indicating that the optical lens 300 can correct the distortion well.

[0125] Please refer to Table 4 for the optical characteristics corresponding to the above embodiments, including the effective focal length f of the optical lens, the distance TTL from the object side of the first lens to the imaging surface on the optical axis, BFL represents the back focal length of the optical lens, the aperture value Fno, the true image height IH corresponding to the maximum field of view angle of the optical lens, the maximum field of view angle FOV, and the numerical values corresponding to each conditional formula in each embodiment.

[0126] Table 4

[0127]

[0128] In combination with the above embodiments, when the object-side light beam of the optical lens of the present invention passes through the reflection element, reflection occurs on the reflection surface of the reflection element, causing the optical axis to turn by 90°. Then, it sequentially passes through the first lens, the second lens, the third lens, the fourth lens, and the fifth lens, and finally undergoes the filtering process of the filter to complete image acquisition on the photosensitive chip. Moreover, since the first lens adopts the lens slicing process, while ensuring a large light-gathering aperture of the lens, the lateral size of the lens is minimized to the greatest extent, thereby better realizing the periscope imaging effect with a large aperture and a large field of view of the lens, and also meeting the development trend of ultra-thinness of portable electronic devices such as mobile phones. In addition, by reasonably matching the materials selected for the lenses and the reflection element, the periscope telephoto lens has the ability to correct the purple fringing effect, effectively suppressing the influence of the purple fringing aperture caused by purple light in actual telephoto shooting.

[0129] In the description of this specification, the description with reference to terms such as "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 invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0130] The above-described embodiments merely represent several implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patent of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the appended claims.

Claims

1. An optical lens, characterized in that, It is composed of one reflecting element and five lenses, and successively includes from the object side to the imaging surface: A reflecting element, the reflecting element includes an incident surface, a reflecting surface and an exit surface; the reflecting surface of the reflecting element forms an angle of 45° with the optical axes of the incident surface and the exit surface of the reflecting element respectively; A first lens with a positive optical power, the object side surface of which is convex; A second lens with a negative optical power; A third lens with a positive optical power; A fourth lens with a negative optical power, the object side surface of which is concave and the image side surface of which is convex; A fifth lens with a positive optical power, the object side surface of which is convex and the image side surface of which is concave; Wherein, the first lens adopts a trimming lens forming process, and the minimum optical aperture D1min of the first lens and the maximum optical aperture D1max of the first lens satisfy: 0.92 < D1min / D1max < 0.98; the effective optical aperture DM1 of the first lens, the effective optical aperture DM2 of the second lens and the effective optical aperture DM5 of the fifth lens satisfy: DM1 > DM2 > DM5; the effective optical aperture DM5 of the fifth lens satisfies: 5.15mm < DM5 < 5.3mm.

2. The optical lens according to claim 1, characterized in that, The distance TTL on the optical axis from the object side surface of the first lens to the imaging surface and the distance TL on the optical axis from the object side surface of the first lens to the image side surface of the fifth lens satisfy: 0.32 < TL / TTL < 0.

5.

3. The optical lens according to claim 1, wherein The effective optical aperture DM1 of the first lens and the effective optical aperture DM5 of the fifth lens satisfy: 1.2 < DM1 / DM5 < 1.55; the effective optical aperture DM5 of the fifth lens and the true image height IH corresponding to the maximum field of view angle of the optical lens satisfy: 0.45 < DM5 / IH < 0.

55.

4. The optical lens according to claim 1, characterized in that, The back focal length BFL of the optical lens and the distance TTL on the optical axis from the object side surface of the first lens to the imaging surface satisfy: 0.5 < BFL / TTL < 0.

65.

5. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the combined focal length f12 of the first lens and the second lens satisfy: 1.3 < f12 / f < 2.5; the effective focal length f of the optical lens and the combined focal length f345 of the third lens, the fourth lens and the fifth lens satisfy: 1.2 < f345 / f < 2.

3.

6. The optical lens according to claim 1, wherein The focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: 0.58 < f1 / f < 0.7; the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: -1.2 < f2 / f < -0.

5.

7. The optical lens according to claim 1, characterized in that, The focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: 0.5 < f3 / f < 3.

3.

8. The optical lens according to claim 1, characterized in that, The focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy: -3.2 < f4 / f < -0.5; the curvature radius R7 of the object side surface of the fourth lens and the curvature radius R8 of the image side surface of the fourth lens satisfy: 0.2 < R7 / R8 < 1.

9. The optical lens according to claim 1, characterized in that, The focal length f5 of the fifth lens and the effective focal length f of the optical lens satisfy: 0.9 < f5 / f < 2.3; the curvature radius R9 of the object side of the fifth lens and the curvature radius R10 of the image side of the fifth lens satisfy: 0.3 < R9 / R10 < 0.8.

Images