Optical lens

Abstract

The invention provides an optical lens, and the optical lens sequentially comprises a reflecting element from an object side to an imaging surface, and the reflecting element comprises an incident surface, a reflecting surface and an emergent surface; an included angle of 45 degrees is respectively formed between the reflecting surface of the reflecting element and the optical axis of the incident surface and the optical axis of the emergent surface of the reflecting element; the first lens has positive focal power, and the object side surface of the first lens is a convex surface; the second lens has negative focal power; the third lens has positive focal power; the object side surface of the fourth lens is a concave surface, and the image side surface of the fourth lens is a convex surface; the object side surface of the fifth lens is a convex surface, and the image side surface of the fifth lens is a concave surface; 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 meet the following conditions: 0.92 lt; d < 1 > min / D < 1 > maxt; and 0.98%. According to the optical lens, the reflection element and the plurality of lenses are combined and matched, the optical aperture of the lenses is effectively compressed, and the optical lens has the characteristics of miniaturization, lightness and thinness.

Description

Technical Field

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

[0002] Telephoto cameras can meet consumers' needs for photographing specific targets, but the total optical length of traditional telephoto cameras is too large and does not meet the requirements of lightweight design of smartphones.

[0003] In order to give mobile photography a more powerful telephoto feature, periscope mobile phone lenses have been a hot topic since their birth and have become standard for some flagship imaging 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 reflective parts such as prisms, the size of the lens aperture cannot be increased due to the thickness of the mobile phone, which has hindered the development of telephoto lenses with large apertures, large fields of view, and high-quality imaging. Summary of the invention

[0004] In view of the above problems, an object of the present invention is to provide an optical lens having the advantage of excellent imaging quality.

[0005] The technical solution adopted by the present invention is: An optical lens, consisting of a reflective element and five lenses, including, from the object side to the imaging surface: A reflective element, the reflective element comprising 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 having positive optical power, whose object side surface is convex; a second lens having negative optical power; a third lens having positive refractive power; a fourth lens having negative optical power, whose object side surface is concave and whose image side surface is convex; a fifth lens having positive refractive power, whose object-side surface is convex and whose image-side surface is concave; The first lens is formed by a trimming lens molding 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。

[0006] 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。

[0007] 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.

[0008] 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.

[0009] 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.

[0010] 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.

[0011] 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.

[0012] 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.

[0013] 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 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.

[0014] Further 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 curvature radius R9 of the object side surface of the fifth lens and the curvature radius R10 of the image side surface of the fifth lens satisfy: 0.3 < R9 / R10 < 0.8.

[0015] Compared with the prior art, when the object light beam of the optical lens of the present invention passes through the reflective element, it is reflected on the reflective surface of the reflective element, so that the optical axis turns 90°, and then passes through the first lens, the second lens, the third lens, the fourth lens and the fifth lens in sequence, and finally is filtered by 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 aperture, the lateral size of the lens is minimized to the greatest extent, thereby better realizing the periscope imaging effect of the lens with a large aperture and a large field of view, and can also meet the development trend of ultra-thin portable electronic devices such as mobile phones. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which: Figure 1 A schematic cross-sectional view of a cut edge lens of a first lens provided in an embodiment of the present invention.

[0017] Figure 2 Schematic diagram of the structure of the optical lens in Example 1 of the present invention.

[0018] Figure 3 Graph showing the axial aberration of the optical lens in Example 1 of the present invention.

[0019] Figure 4 Graph showing the magnification chromatic aberration of the optical lens in Example 1 of the present invention.

[0020] Figure 5 4 is a distortion curve diagram of the optical lens in Example 1 of the present invention.

[0021] Figure 6 Schematic diagram of the structure of the optical lens in Example 2 of the present invention.

[0022] Figure 7 Graph showing the axial aberration of the optical lens in Embodiment 2 of the present invention.

[0023] Figure 8 Graph showing the magnification chromatic aberration of the optical lens in Example 2 of the present invention.

[0024] Fig. 9 4 is a distortion curve diagram of the optical lens in Example 2 of the present invention.

[0025] Fig.10 Schematic diagram of the structure of the optical lens in Example 3 of the present invention.

[0026] Fig.11 Graph showing the axial aberration of the optical lens in Embodiment 3 of the present invention.

[0027] Fig.12Graph showing the magnification chromatic aberration of the optical lens in Example 3 of the present invention.

[0028] Fig.13 3 is a distortion curve diagram of the optical lens in Example 3 of the present invention.

[0029] The following specific implementation manner will further illustrate the present invention in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0030] In order to better understand the present application, a more detailed description will be made of various aspects of the present application 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 are not intended to 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.

[0031] It should be noted that in this specification, the expressions of first, second, third, etc. are only used to distinguish one feature from another feature, and do not represent any limitation on the features. Therefore, without departing from the teaching of the present invention, the first lens discussed below may also be referred to as the second lens or the third lens.

[0032] In the drawings, the thickness, size and shape of the lenses have been slightly exaggerated for ease of explanation. Specifically, the shapes of the spherical or aspherical surfaces shown in the drawings are shown by way of example. That is, the shapes of the spherical or aspherical surfaces are not limited to the shapes of the spherical or aspherical surfaces shown in the drawings. The drawings are only examples and are not drawn strictly to scale.

[0033] 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 is called the object side of the lens, and the surface of each lens closest to the imaging plane is called the image side of the lens.

[0034] It should also be understood that the terms "comprises", "including", "having", "includes" and / or "comprising", when used in this specification, indicate the presence of the stated features, elements and / or components, but do not exclude the presence or addition of one or more other features, elements, components and / or combinations thereof. In addition, when expressions such as "at least one of..." appear after a list of listed features, they modify the entire listed features rather than modifying the individual elements in the list. In addition, when describing embodiments of the present application, "may" is used to mean "one or more embodiments of the present application". And, the term "exemplary" is intended to refer to an example or illustration.

[0035] Unless otherwise defined, all terms (including technical terms and scientific terms) used in this article have the same meaning as commonly understood by ordinary technicians in the field to which this application belongs. It should also be understood that terms (such as terms defined in commonly used dictionaries) should be interpreted as having the same meaning as their meaning in the context of the relevant technology, and will not be interpreted in an idealized or overly formal sense unless explicitly defined in this article.

[0036] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0037] The optical lens provided by the embodiment of the present invention is composed of a reflective element and five lenses, and includes, from the object side to the imaging surface, a reflective element, a first lens, a second lens, a third lens, a fourth lens and a fifth lens. The reflective element of the present invention is used to deflect light, and by changing the angle of light, the direction of the incident light is perpendicular to the arrangement direction of the multiple lenses, thereby reducing the overall thickness of the optical system and achieving the effect of a periscope-type long focal length lens.

[0038] Specifically, the reflective element includes an incident surface, a reflective surface and an exit surface, and the incident surface, the reflective surface and the exit surface can all be planes. 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. The reflective element can be a right-angle triangular prism, and the prism can be made of glass or plastic.

[0039] In some embodiments, the first lens may have positive optical power, its object side surface is convex, and its image side surface may be concave or convex. The second lens may have negative optical power, its object side surface may be concave or convex, and its image side surface may be concave or convex. The third lens may have positive optical power, its object side surface may be concave or convex, and its image side surface may be concave or convex. The fourth lens may have negative optical power, its object side surface is concave, and its image side surface is convex. The fifth lens may have positive optical power, its object side surface is convex, and its image side surface is concave.

[0040] In some embodiments, the optical lens may further include an aperture, and the aperture may be located between the first lens and the second lens. It is understandable that the aperture is used to limit the amount of light entering to change the brightness of the image. The optical lens of the present invention adopts a post-aperture structure, and the aperture is arranged after the first lens, so that the lens has a large aperture while effectively compressing the aperture size of the subsequent optical lens; in addition, it is also helpful to avoid structural problems such as side light leakage caused by cutting edges of the first lens before the aperture.

[0041] 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 and prevent the interfering light from reaching the imaging surface of the optical lens and affecting normal imaging.

[0042] 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, after passing through the filtering process of the filter, it reaches the photosensitive chip (imaging surface) to complete image acquisition.

[0043] In some embodiments, 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. More specifically, 6mm < D1min < D1max < 8mm. Generally speaking, the effective aperture of the first lens (close to the prism) is the largest in the system, and the light input amount of the optical system is largely determined by the aperture size 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 light input amount of the periscope lens, the first lens is injection molded by a trimmed lens forming process, so that the lateral dimension of the first lens is trimmed to a certain extent, effectively compressing the lateral dimension of the lens in the mobile phone lens module, and minimizing the lateral dimension of the lens to the greatest extent while ensuring that the lens has a large light passing aperture, so as to better achieve the periscope imaging effect of the optical lens with a large aperture, a large aperture, and a large field of view, and also meet the development trend of the ultra-thinning of portable electronic devices such as mobile phones.

[0044] 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 aperture is limited by the thickness of the mobile phone itself. And 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 light input amount 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.

[0045] In the 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 ranges of the refractive index and the 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 can have the ability to correct the purple fringing effect, and effectively suppress 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).

[0046] 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, and while making the lens have the characteristics of being thin and light, improve the anti-shake and focusing capabilities of the telephoto lens.

[0047] 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.

[0048] 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 surface, facilitate lying the lens group horizontally inside the mobile phone, and is beneficial to improving the limitation problems brought by the external structure of the lens barrel, thereby improving the adaptability of the lens to the module motor.

[0049] 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 of the first lens to the imaging surface on the optical axis satisfy: 0.5 < BFL / TTL < 0.65. Meeting the above conditions can make the lens have a larger back focus, ensure the compatibility between the lens and the camera body, and better achieve the telephoto performance of the lens, realizing a more compact lens structure and balanced telephoto performance.

[0050] 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. Meeting the above conditions is conducive to reducing the spherical aberration and field curvature generated by the front lens of the optical lens by reasonably distributing the combined focal length of the first two lenses, and improving the imaging quality of the optical lens.

[0051] 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. Meeting the above conditions is conducive to balancing the distortion and astigmatism generated by the front lens of the optical lens by reasonably distributing the combined focal length of the last three lenses, and improving the imaging quality of the optical lens.

[0052] 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. Meeting the above conditions can make the first lens have a large positive refractive power, which is conducive to collecting light at large angles, while reducing the height of the light incident on the first lens, facilitating the miniaturization of the lens.

[0053] 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. Meeting the above conditions can effectively diverge the light trend emerging from the first lens, enabling the light to smoothly transition to the rear, reducing 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, achieving a larger light input, which is conducive to increasing the relative illumination of the captured image.

[0054] 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. Meeting the above conditions is conducive to the reasonable convergence of light, enabling the diverging light to smoothly enter the rear optical system, and better achieving high-quality imaging of the lens.

[0055] 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. Meeting 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.

[0056] 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. Meeting 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.

[0057] 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. Meeting the above conditions ensures that the lens has a large image surface while having a small total length, can match a larger-sized imaging chip to achieve high-definition imaging, and preferably realizes the balance between the small total length and the large image surface of the lens.

[0058] 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. Meeting the above conditions can both achieve the telephoto characteristics of the lens to meet the local shooting requirements and achieve the large-image-surface characteristics of the lens, be able to carry a larger-sized chip, and realize the high-definition imaging of the lens.

[0059] 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. Meeting 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 correct chromatic aberration and spherical aberration, reduce the amount of aberration introduced, and is beneficial to improving the imaging quality of the optical lens.

[0060] 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 optical path more gentle. On the other hand, it is beneficial to optimizing aberrations and improving the overall resolution of the lens.

[0061] 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, it is possible to have a larger light passing amount while ensuring that the optical lens has a large image plane, 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 edge-cutting lens in terms of structural process, and can effectively avoid excessive edge cutting and ineffective edge cutting.

[0062] 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 telephoto, 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.

[0063] 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.

[0064] 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 spherical structures, aspherical structures can effectively reduce the aberration of the optical system, thereby reducing the number of lenses and the size of lenses, and better miniaturizing the lens. More specifically, the first lens, the second lens, the third lens, the fourth lens, and the fifth lens of the present invention may all be aspherical lenses, which can effectively reduce the aberration of the optical lens, thereby reducing the number of lenses and the size of lenses, and better miniaturizing the lens.

[0065] In order to make the system have better optical performance, multiple aspherical lenses are used in the lens, and the shape of each aspherical surface of the optical lens satisfies the following equation: ; Among them, z is the distance between the surface and the vertex of the surface in the direction of the optical axis, h is the distance from the optical axis to the surface, c is the curvature of the surface vertex, K is the quadratic surface coefficient, B, C, D, E, F, G, H, I, and 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.

[0066] The present invention is further described below in multiple embodiments. In each embodiment, the thickness, radius of curvature, and material selection of each lens in the optical lens are different. For specific differences, please refer to the parameter table of each embodiment. The following embodiments are only preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the following embodiments. Any other changes, substitutions, combinations or simplifications that do not deviate 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.

[0067] Example 1 See also Figure 2 , Figure 2 Schematic diagram of the structure of the optical lens 100 provided in Embodiment 1 of the present invention. The optical lens 100 includes, in order from the light propagation direction (from the object side to the imaging surface S15), a reflective element Pr, a first lens L1, a stop ST, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5 and a filter G1, and there may be an air gap between any two adjacent lenses.

[0068] The reflective element Pr adopts a folding prism design, which can be a right-angle triangular prism, including an incident surface S1, a reflection surface R0 and an exit surface S2; the incident surface S1, the reflection surface R0 and the exit surface S2 are all planes. The reflection surface of the prism forms an angle of 45° 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.

[0069] The first lens L1 has positive refractive power, its object side surface S3 is convex, and its image side surface S4 is concave at the near optical axis; The second lens L2 has negative refractive power, its object-side surface S5 is concave, and its image-side surface S6 is convex; The third lens L3 has positive refractive power, its object-side surface S7 is concave, and its image-side surface S8 is convex; The fourth lens L4 has negative refractive power, its object-side surface S9 is concave, and its image-side surface S10 is convex; The fifth lens L5 has positive refractive power, its object-side surface S11 is convex, and its image-side surface S12 is concave; The object side surface S13 and the image side surface S14 of the filter G1 are both planes; The imaging surface S15 is a plane.

[0070] The reflective element Pr may 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.

[0071] Specifically, the first lens L1 is a trimmed plastic lens, which is directly injection molded through a trimming process. Therefore, the diameter of the lens can be further compressed in the thickness direction of the mobile phone, so that the optical lens with large light flux and large field of view can be well adapted to the conventional module assembly of the mobile phone lens, providing greater possibilities for realizing a large aperture, large image surface, and small-volume telephoto lens module.

[0072] Specifically, Figure 1 FIG. 1 is a schematic cross-sectional view of the cut edge shape of the first lens provided in an embodiment of the present invention. In order to clearly reflect the effect of the cut edge lens of the first lens L1, Figure 2 Two dotted lines are drawn along the optical axis in a single direction (in any direction perpendicular to the optical axis) of the first lens L1 in Example 1, and the outer side of the dotted lines represents the portion removed by the slicing lens. More specifically, the trimming amount of the first lens L1 in a single direction in Example 1 is 0.22 mm on one side.

[0073] The relevant parameters of each lens in the optical lens 100 in Example 1 are shown in Table 1-1.

[0074] Table 1-1 The surface parameters of the aspheric lens of the optical lens 100 in Example 1 are shown in Table 1-2.

[0075] Table 1-2 In this embodiment, the axial aberration curve, the magnification chromatic aberration curve, and the distortion curve of the optical lens 100 are respectively as follows: Figure 3 , Figure 4 , Figure 5 shown.

[0076] Figure 3 The axial aberration curve of Example 1 is shown, which represents the aberration of each wavelength on the optical axis at the imaging plane, the horizontal axis represents the axial aberration value (unit: mm), and the vertical axis represents the normalized pupil radius. As can be seen from the figure, the offset of the axial aberration is controlled within ±0.05mm, indicating that the optical lens 100 can better correct the axial aberration.

[0077] Figure 4 The magnification chromatic aberration curve of Example 1 is shown, which represents the chromatic aberration of each wavelength relative to the central wavelength (550nm) at different image heights on the imaging surface, 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 of the longest wavelength and the shortest wavelength is controlled within ±2μm, indicating that the optical lens 100 can correct chromatic aberration very well.

[0078] Figure 5 The distortion curve of Example 1 is shown, which represents the distortion of light of different wavelengths at different image heights on the imaging surface, with the horizontal axis representing the distortion value (unit: %) and the vertical axis representing 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.

[0079] Example 2 See also Figure 6 , which is a schematic diagram of the structure of the optical lens 200 provided in Example 2 of the present invention. Compared with Example 1, the main differences of this embodiment are: the object side surface S5 of the second lens L2 is convex, and the image side surface S6 of the second lens L2 is concave; the object side surface S7 of the third lens L3 is convex at the near optical axis, and the image side surface S8 of the third lens L3 is concave at the near optical axis; the optical parameters such as the curvature radius, lens thickness, and lens material selection of each lens surface are different. The trimming amount of the first lens L1 in a single direction in Example 2 is 0.14mm on one side.

[0080] The relevant parameters of each lens in the optical lens 200 in Example 2 are shown in Table 2-1.

[0081] Table 2-1 The surface parameters of the aspheric lens of the optical lens 200 in Example 2 are shown in Table 2-2.

[0082] Table 2-2 In this embodiment, the axial aberration curve, the magnification chromatic aberration curve, and the distortion curve of the optical lens 200 are respectively as follows: Figure 7 , Figure 8 , Fig. 9 shown.

[0083] 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.

[0084] 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 chromatic aberration very well.

[0085] from Fig. 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.

[0086] Example 3 See also Fig.10 , which is a schematic diagram of the structure of the optical lens 300 provided in Example 3 of the present invention. Compared with Example 1, the main differences of this embodiment are: the image side surface S4 of the first lens L1 is convex at the near optical axis; the object side surface S5 of the second lens L2 is convex, and the image side surface S6 of the second lens L2 is concave; the optical parameters such as the curvature radius, lens thickness, and lens material of each lens surface are different. In Example 3, the trimming amount of the first lens L1 in a single direction is 0.15mm on one side.

[0087] The relevant parameters of each lens in the optical lens 300 in Example 3 are shown in Table 3-1.

[0088] Table 3-1 The surface parameters of the aspheric lens of the optical lens 300 in Example 3 are shown in Table 3-2.

[0089] Table 3-2 In this embodiment, the axial aberration curve, the magnification chromatic aberration curve, and the distortion curve of the optical lens 300 are respectively as follows: Fig.11 , Fig.12 , Fig.13 shown.

[0090] from Fig.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.

[0091] from Fig.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 chromatic aberration very well.

[0092] from Fig.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.

[0093] Please refer to Table 4, which shows 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 plane on the optical axis, BFL representing the back focal length of the optical lens, the aperture value Fno, the real image height IH corresponding to the maximum field of view of the optical lens, the maximum field of view FOV, and the numerical value corresponding to each conditional expression in each embodiment.

[0094] Table 4 In summary of the above embodiments, when the object light beam of the optical lens of the present invention passes through the reflective element, it is reflected on the reflective surface of the reflective element, so that the optical axis turns 90°, and then passes through the first lens, the second lens, the third lens, the fourth lens and the fifth lens in sequence, and finally passes through the filter processing 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 aperture, the lateral size of the lens is minimized to the greatest extent, so as to better achieve the periscope imaging effect of the lens with a large aperture and a large field of view, and can also meet the development trend of ultra-thin portable electronic devices such as mobile phones. In addition, by reasonably matching the materials selected for the lens and the reflective element, the periscope telephoto lens also has the ability to correct the purple fringing effect, effectively suppressing the purple fringing aperture effect caused by purple light in actual telephoto shooting.

[0095] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0096] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which 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 attached claims.

Claims

1. An optical lens, characterized in that: It consists of one reflecting element and five lenses, and successively includes from the object side to the imaging plane: The 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; The first lens with positive optical power, its object side is convex; The second lens with negative optical power; The third lens with positive optical power; The fourth lens with negative optical power, its object side is concave and its image side is convex; The fifth lens with positive optical power, its object side is convex and its image side is concave; 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.

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

5.

3. The optical lens according to claim 1, characterized in that: 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.

4. The optical lens according to claim 1, characterized in that: 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.

5. 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 of the first lens to the imaging plane satisfy: 0.5 < BFL / TTL < 0.

65.

6. 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.

7. 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: 0.58 < 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.

8. 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.

9. 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 of the fourth lens and the curvature radius R8 of the image side of the fourth lens satisfy: 0.2 < R7 / R8 < 1.

10. 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 radius of curvature R9 of the object side of the fifth lens and the radius of curvature R10 of the image side of the fifth lens satisfy: 0.3 < R9 / R10 < 0.8.

Images