Optical lens

Abstract

The application provides an optical lens which is composed of four lenses and a reflecting element, and sequentially comprises, from an object side to an imaging surface along a light propagation direction, a first lens with positive focal power, the object side of which is a convex surface and the image side of which is a concave surface; a second lens with negative focal power, the image side of which is a concave surface; a third lens with positive focal power, the image side of which is a convex surface; a fourth lens with negative focal power; and a reflecting element which is a prism, the prism comprising an incident surface, a reflecting surface and an exit surface which are all flat, light rays entering the prism from the incident surface along an optical axis, being reflected by the reflecting surface and exiting from the exit surface to the imaging surface, and the reflecting surface and the optical axes of the incident surface and the exit surface forming an included angle of 45 degrees respectively. The optical lens of the application adopts the combination of multiple lenses and a reflecting element, realizes the effect of a periscopic long focus, and has the characteristics of miniaturization and lightness.

Description

TECHNICAL FIELD

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

[0002] Long-focus cameras can meet the needs of consumers to shoot specific targets, but the total length of the traditional long-focus camera is too large, which does not meet the design requirements of the thin and light smart phone.

[0003] In order to give the mobile phone photography stronger telephoto long-focus characteristics, the periscopic mobile phone lens has been a hot topic since its inception and has become a standard configuration of some image flagship phones. The existing periscopic long-focus lens usually uses a right-angle prism or other catadioptric elements to turn the light path at the light inlet and then enter the optical system. This conventional periscopic scheme has many disadvantages and shortcomings, which is not conducive to the optimization of aberration and the adjustment of different architectures of the whole machine. SUMMARY

[0004] In view of the above problems, the purpose of the present application is to provide an optical lens with the advantages of excellent imaging quality.

[0005] The technical scheme adopted by the present application is:

[0006] An optical lens composed of four lenses and one reflecting element, including from the object side to the imaging surface in the order of:

[0007] The first lens with positive refractive power, the object side of which is convex, and the image side of which is concave;

[0008] The second lens with negative refractive power, the image side of which is concave;

[0009] The third lens with positive refractive power, the image side of which is convex;

[0010] The fourth lens with negative refractive power;

[0011] The reflecting element, which is a prism, includes an incident surface, a reflecting surface and an exit surface, all of which are flat. Light rays enter the prism along the optical axis from the incident surface, are reflected by the reflecting surface, and exit from the exit surface to the imaging surface. The reflecting surface and the optical axis of the incident surface and the optical axis of the exit surface form an included angle of 45°.

[0012] Wherein, the focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: 0.46 < f3 / f < 1.52.

[0013] Further preferably, the distance TTL from the object side surface of the first lens to the imaging surface on the optical axis and the effective focal length f of the optical lens satisfy: 1.1 < TTL / f < 1.15.

[0014] Further preferably, the focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: 0.5 < f1 / f < 0.76.

[0015] Further preferably, the real 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: 0.62 < IH / f < 0.64.

[0016] Further preferably, the distance TTL of the object side surface of the first lens to the imaging surface on the optical axis, the real image height IH corresponding to the maximum field of view angle of the optical lens and the maximum field of view angle FOV of the optical lens satisfy: 0.05 / ° < TTL / IH / FOV < 0.055 / °.

[0017] Further preferably, the radius of curvature R1 of the object side surface of the first lens and the radius of curvature R2 of the image side surface of the first lens satisfy: 0.07 < R1 / R2 < 0.36.

[0018] Further preferably, the sum ∑CT of the central thicknesses of the first lens and the reflecting element along the optical axis respectively and the distance TTL of the object side surface of the first lens to the imaging surface on the optical axis satisfy: 0.5 < ∑CT / TTL < 0.54.

[0019] Further preferably, the effective focal length f of the optical lens, the maximum field of view angle FOV of the optical lens and the real image height IH corresponding to the maximum field of view angle of the optical lens satisfy: 53° < (f x FOV) / IH < 56°.

[0020] Further preferably, the maximum field of view angle FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 13° < FOV / Fno < 14°.

[0021] Further preferably, the half light passing radius DM11 of the object side surface of the first lens and the half light passing radius DM42 of the image side surface of the fourth lens satisfy: 1.3 < DM11 / DM42 < 1.5.

[0022] Compared with the prior art, the object side beam of the optical lens of the present application passes through the first lens, the second lens, the third lens, the fourth lens and then the reflecting element, is reflected on the reflecting surface of the reflecting element, so that the optical axis is turned by 90°, and finally passes through the filtering treatment of the filter to achieve image collection on the photosensitive chip. The rear placement of the reflecting element facilitates the adjustment of the overall architecture. The long focal length, large image surface and periscopic imaging effect of the lens are better achieved, and the development trend of the ultra-thin portable electronic device such as a mobile phone is also met. BRIEF DESCRIPTION OF DRAWINGS

[0023] The above and / or additional aspects and advantages of the present application will become apparent and more readily appreciated from the following description, taken in conjunction with the following drawings of which:

[0024] Figure 1 The structure schematic diagram of the optical lens in the embodiment 1 of the present application.

[0025] Figure 2 The field curvature curve diagram of the optical lens in the embodiment 1 of the present application.

[0026] Figure 3 The distortion curve diagram of the optical lens in the embodiment 1 of the present application.

[0027] Figure 4 The axial aberration curve diagram of the optical lens in the embodiment 1 of the present application.

[0028] Figure 5 The lateral chromatic aberration curve diagram of the optical lens in the embodiment 1 of the present application.

[0029] Figure 6 The structure schematic diagram of the optical lens in the embodiment 2 of the present application.

[0030] Figure 7 The field curvature curve diagram of the optical lens in the embodiment 2 of the present application.

[0031] Figure 8 The distortion curve diagram of the optical lens in the embodiment 2 of the present application.

[0032] Figure 9 The axial aberration curve diagram of the optical lens in the embodiment 2 of the present application.

[0033] Figure 10 The lateral chromatic aberration curve diagram of the optical lens in the embodiment 2 of the present application.

[0034] Figure 11 The structure schematic diagram of the optical lens in the embodiment 3 of the present application.

[0035] Figure 12 The field curvature curve diagram of the optical lens in the embodiment 3 of the present application.

[0036] Figure 13 The distortion curve diagram of the optical lens in the embodiment 3 of the present application.

[0037] Figure 14 The axial aberration curve diagram of the optical lens in the embodiment 3 of the present application.

[0038] Figure 15 The lateral chromatic aberration curve diagram of the optical lens in the embodiment 3 of the present application.

[0039] Figure 16A structure diagram of an optical lens in Embodiment 4 of the present application.

[0040] Figure 17 A field curvature curve of the optical lens in Embodiment 4 of the present application.

[0041] Figure 18 A distortion curve of the optical lens in Embodiment 4 of the present application.

[0042] Figure 19 An axial aberration curve of the optical lens in Embodiment 4 of the present application.

[0043] Figure 20 A lateral chromatic aberration curve of the optical lens in Embodiment 4 of the present application.

[0044] The following detailed description will further describe the present application with reference to the above-mentioned drawings. DETAILED DESCRIPTION

[0045] For a better understanding of the present application, various aspects of the present application will be described in more detail below with reference to the accompanying drawings. It is to be noted that these detailed descriptions are only descriptions of embodiments of the present application and do not limit the scope of the present application in any way. Throughout the specification, like reference numerals refer to like elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0046] It should be noted that, in the present specification, the expressions first, second, third and the like are used only to distinguish one feature from another feature, and do not indicate any limitation on the features. Thus, the first lens discussed below can also be referred to as a second lens or a third lens without departing from the teachings of the present application.

[0047] In the drawings, the thickness, size, and shape of the lenses have been slightly exaggerated for ease of explanation. Specifically, the shape of the spherical or aspherical surface shown in the drawings is shown by way of example. That is, the shape of the spherical or aspherical surface is not limited to the shape of the spherical or aspherical surface shown in the drawings. The drawings are merely examples and are not drawn to scale.

[0048] In this context, the paraxial region refers to a region near the optical axis. If a lens surface is convex and the position of the convex surface is not specified, it means that the lens surface is convex at least in the paraxial region. If a lens surface is concave and the position of the concave surface is not specified, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the object is referred to as the object side surface of the lens, and the surface of each lens closest to the image plane is referred to as the image side surface of the lens.

[0049] It should also be understood that the words "comprise," "comprising," "include," "including," and / or "has," "having," when used in this specification, specify the presence of stated features, elements, and / or components, but do not preclude the presence or addition of one or more other features, elements, components, and / or groups thereof. Furthermore, when describing the embodiments of the present application, the word "may" is used to mean "one or more embodiments of the present application." Also, the word "example" is used to mean "serving as an example, instance, or illustration."

[0050] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an overly literal or overly formal sense unless expressly so defined herein.

[0051] It should be noted that the embodiments and features of the embodiments in the present application can be combined with each other without conflict. The present application will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments.

[0052] The optical lens provided by the embodiment of the present application is composed of four lenses and one reflecting element, and sequentially includes a first lens, a second lens, a third lens, a fourth lens and a reflecting element from the object side to the imaging surface along the light propagation direction. The reflecting element of the present application is used to fold the light, and by changing the angle of the light, the lens module can be arranged horizontally (such as the thickness direction of the mobile phone). The structure of the prism behind the lens is conducive to adjusting different architectures of the whole machine, reducing the overall thickness of the optical system, realizing the effect of the periscope long focal length of the lens, and is also conducive to the optimization of the aberration of the optical system.

[0053] In some embodiments, the first lens can have a positive focal power, the object side surface of which is convex, and the image side surface of which is concave. The second lens can have a negative focal power, the object side surface of which can be concave or convex, and the image side surface of which is concave. The third lens can have a positive focal power, the object side surface of which can be concave or convex, and the image side surface of which is convex. The fourth lens can have a negative focal power, the object side surface of which can be concave or convex, and the image side surface of which can be concave or convex.

[0054] Specifically, the reflecting element can be a prism, the prism including an incident plane, a reflecting plane and an exit plane, all of which are planes, light rays enter the prism from the incident plane along an optical axis, are reflected by the reflecting plane, and exit from the exit plane to an imaging plane; the reflecting plane of the reflecting element forms a 45° angle with the optical axis of the incident plane and the exit plane of the reflecting element, and the angle between the incident plane and the exit plane is 90°. The prism can be a right-angled triangular prism made of plastic.

[0055] In some embodiments, the optical lens can further include a diaphragm, which can be located between the object side and the first lens or between the first lens and the second lens. It can be understood that the diaphragm is used to limit the amount of light to change the brightness of the imaging.

[0056] In some embodiments, the optical lens can further include a filter, which can be disposed between the reflecting element and the imaging plane. The filter is used to filter out interference light to prevent interference light from reaching the imaging plane of the optical lens and affecting normal imaging.

[0057] The object beam of the optical lens of the present application sequentially passes through the first lens, the second lens, the third lens, the fourth lens, and is reflected on the reflecting plane of the prism when passing through the reflecting element, so that the optical axis is turned by 90°, and finally the light is filtered by the filter to complete image acquisition on the photosensitive chip (imaging plane).

[0058] In some embodiments, the focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: 0.46 < f3 / f < 1.52. Satisfying the above range, the third lens adopts a positive lens, which can re-converge the divergent light rays, compensate for the diverging effect of the negative lens, avoid excessive diffusion of the light path leading to uneven brightness of the image plane, and correct residual monochromatic aberrations such as spherical aberration and coma.

[0059] In some embodiments, the distance TTL (i.e. the propagation path length of light along the optical axis from the object side surface of the first lens to the imaging plane) from the object side surface of the first lens to the imaging plane on the optical axis and the effective focal length f of the optical lens satisfy: 1.1 < TTL / f < 1.15. Satisfying the above range, on the premise of realizing a long-focus lens, the total length of the lens is shortened by realizing a periscope structure through the prism, which is beneficial to the miniaturization of the optical lens.

[0060] In some embodiments, the focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: 0.5 < f1 / f < 0.76. Satisfying the above range, as the first positive lens, the incident light rays are converged, the long-focus light path is constructed, and the basis for subsequent light path compression of the negative lens is provided.

[0061] In some embodiments, the real 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: 0.62<IH / f<0.64. Satisfying the above range can make the lens have a longer focal length and a larger imaging surface.

[0062] In some embodiments, the distance TTL on the optical axis from the object side surface of the first lens to the imaging surface, the real image height IH corresponding to the maximum field of view angle of the optical lens, and the maximum field of view angle FOV of the optical lens satisfy: 0.05 / °<TTL / IH / FOV<0.055 / °. Satisfying the above range can help balance the relationship among the total length, the image height, and the field of view angle of the optical lens.

[0063] In some embodiments, the radius of curvature R1 of the object side surface of the first lens and the radius of curvature R2 of the image side surface of the first lens satisfy: 0.07<R1 / R2<0.36. Satisfying the above range can make the incident light rays converge to a greater extent, and more light rays enter the system, which helps improve the light intake of the lens.

[0064] In some embodiments, the sum ∑CT of the central thicknesses of the first lens and the reflecting element along the optical axis and the distance TTL on the optical axis from the object side surface of the first lens to the imaging surface satisfy: 0.5<∑CT / TTL<0.54. Satisfying the above range can effectively compress the total length of the lens, while helping the structural design and production process of the lens. It can be understood that the central thickness of the reflecting element along the optical axis is the propagation path length of the incident surface to the exit surface along the optical axis, that is, the sum of the distance from the incident surface to the reflecting surface and the distance from the reflecting surface to the exit surface.

[0065] In some embodiments, the effective focal length f of the optical lens, the maximum field of view angle FOV of the optical lens, and the real image height IH corresponding to the maximum field of view angle of the optical lens satisfy: 53°<(f×FOV) / IH<56°. Satisfying the above range can make the optical lens have good optical performance by reasonably limiting the relationship among the focal length, the field of view angle, and the image height of the optical lens, and can well capture the details of the subject.

[0066] In some embodiments, the maximum field of view angle FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 13°<FOV / Fno<14°. Satisfying the above range can make the lens improve the light flux through a large aperture, and make the lens more compact, which is suitable for a periscope structure (such as a mobile phone long-focus lens), and the folded light path still maintains a small volume.

[0067] In some embodiments, the object-side half-aperture radius DM11 of the first lens and the image-side half-aperture radius DM42 of the fourth lens satisfy: 1.3 < DM11 / DM42 < 1.5. By satisfying the above range, by reasonably setting the focal length and aperture relationship of the first and last lenses, the area of the light entering the image plane is increased while ensuring that as much light as possible enters the system, thereby achieving high relative illumination and large image plane imaging of the lens.

[0068] In some embodiments, the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: -2.8 < f2 / f < -0.4. By satisfying the above range, the second lens adopts a negative lens, which can diverge light, extend the equivalent focal length but shorten the physical light path length, and at the same time compensate for the aberration of the positive lens in the front group.

[0069] In some embodiments, the focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy: -40 < f4 / f < -0.7. By satisfying the above range, the fourth lens can correct field curvature, balance chromatic aberration, and form complementary dispersion in combination with the first three lenses, and adapt to the sensor image plane.

[0070] In some embodiments, the object-side curvature radius R7 of the fourth lens and the image-side curvature radius R8 of the fourth lens satisfy: -0.1 < R7 / R8 < 1.5. By satisfying the above range, it is beneficial to moderate the degree of deflection of light passing through the lens, and the aberration can be well reduced.

[0071] In some embodiments, the object-side curvature radius R1 of the first lens and the image-side curvature radius R2 of the first lens satisfy: -2.2 < (R1+R2) / (R1-R2) < -1.1. By satisfying the above range, the curvature radii of the object-side surface and the image-side surface of the first lens at the near optical axis are reasonably controlled, thereby being beneficial to control the shape of the first lens, correct the aberration generated by itself, and improve the imaging quality.

[0072] In some embodiments, the object-side curvature radius R1 of the first lens and the effective focal length f of the optical lens satisfy: 0.25 < R1 / f < 0.3. By satisfying the above range, the direction of light can be controlled, spherical aberration can be reduced, coma can be corrected, light utilization can be increased, and stability can be improved.

[0073] In some embodiments, the focal length f1 of the first lens and the focal length f2 of the second lens satisfy: -1.25 < f1 / f2 < -0.2; the focal length f2 of the second lens and the focal length f3 of the third lens satisfy: -1.8 < f2 / f3 < -0.5; the focal length f3 of the third lens and the focal length f4 of the fourth lens satisfy: -1.6 < f3 / f4 < 0; and the focal length f1 of the first lens and the focal length f4 of the fourth lens satisfy: -0.8 < f1 / f4 < 0. Satisfying the above ranges, a positive-negative focal length combination is formed, which can improve the temperature drift stability of the lens, help to reduce the influence of the environment temperature on the lens group, and meet the compactness requirement of the lens.

[0074] In some embodiments, the distance CT12 between the first lens and the second lens on the optical axis, the distance CT23 between the second lens and the third lens on the optical axis, the distance CT34 between the third lens and the fourth lens on the optical axis, and the distance TTL from the object side surface of the first lens to the imaging surface on the optical axis satisfy: 0.06 < (CT12+CT23+CT34) / TTL < 0.09. Satisfying the above condition, the total length of the lens is compressed by reducing the distance between the first lens, the second lens, the third lens and the fourth lens.

[0075] In some embodiments, the real image height IH corresponding to the maximum field of view angle of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 1.5 < IH / EPD < 1.7. Satisfying the above range, the field of view and the light flux are balanced, and the imaging quality of the lens is improved.

[0076] In some embodiments, the effective focal length f of the optical lens, the maximum field of view angle FOV of the optical lens, and the real image height IH corresponding to the maximum field of view angle of the optical lens satisfy: 0.97 < (2xfxtan(FOV / 2)) / IH < 0.98. Satisfying the above range, the lens has a small distortion value and can provide a high-definition imaging effect.

[0077] In the embodiments of the present application, the optical lens satisfies the following conditional expressions: 11.5 mm < TTL < 12.5 mm; 10.5 mm < f < 11 mm; 34° < FOV < 35°; 6.7 mm < IH < 6.9 mm; and 2.4 < Fno < 2.7. In the conditional expressions, TTL represents the distance from the object side surface of the first lens to the imaging surface on the optical axis (i.e., the propagation path length of the light along the optical axis from the object side surface of the first lens to the imaging surface), f represents the effective focal length of the optical lens, FOV represents the maximum field of view angle of the optical lens, IH represents the real image height corresponding to the maximum field of view angle of the optical lens, and Fno represents the aperture value of the optical lens. Satisfying the above ranges, the optical lens has one or more advantages such as telephoto, miniaturization, large image surface, etc.

[0078] In some embodiments, the material of the four lenses in the optical lens provided by the present application can be glass or plastic. When the material of the lenses is plastic, the production cost can be effectively reduced. When the material of the lenses is glass, the geometric chromatic aberration of the optical system can be effectively corrected by the low dispersion characteristics of the glass. The optical lens provided by the present application can adopt a full-plastic lens structure, which not only has excellent imaging performance, but also has a compact structure, and can better achieve the balance between miniaturization and high image quality.

[0079] In some embodiments, the first lens, the second lens, the third lens and the fourth lens can adopt a spherical lens or an aspherical lens. 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 achieving the miniaturization of the lens. More specifically, the first lens, the second lens, the third lens and the fourth lens of the present application can all adopt an aspherical lens, which can effectively reduce the aberration of the optical lens, thereby reducing the number of lenses and the size of the lenses, and better achieving the miniaturization of the lens.

[0080] In order to make the system have better optical performance, a plurality of aspherical lenses are used in the lens, and the shape of each aspherical surface of the optical lens satisfies the following equation:

[0081] ;

[0082] Wherein, z is the distance of the curved surface and the vertex of the curved surface in the direction of the optical axis, 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 quadratic surface coefficient, B, C, D, E, F, G and H are the fourth-order, sixth-order, eighth-order, tenth-order, twelfth-order, fourteenth-order and sixteenth-order curved surface coefficients, respectively.

[0083] The present application will be further described in the following embodiments. In each embodiment, the thickness, the radius of curvature and the material selection of each lens in the optical lens are different, and the specific differences can be referred to the parameter table of each embodiment. The following embodiments are only preferred embodiments of the present application, but the embodiments of the present application are not limited to the following embodiments, and any changes, substitutions, combinations or simplifications made without departing from the innovative points of the present application should be regarded as equivalent replacement methods, and are included in the protection scope of the present application.

[0084] Embodiment 1

[0085] Please refer to Figure 1 , Figure 1A structural schematic diagram of the optical lens 100 provided in Embodiment 1 of the present application. The optical lens 100 comprises, in sequence from the light propagation direction (from the object side to the imaging surface S13), a diaphragm ST, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a reflecting element L5 and a filter G1, and there can be an air gap between any two adjacent lenses.

[0086] The first lens L1 has positive focal power, the object side S1 thereof is a convex surface, and the image side S2 thereof is a concave surface;

[0087] The second lens L2 has negative focal power, the object side S3 thereof is a convex surface, and the image side S4 thereof is a concave surface;

[0088] The third lens L3 has positive focal power, the object side S5 thereof is a concave surface at the near optical axis, and the image side S6 thereof is a convex surface;

[0089] The fourth lens L4 has negative focal power, the object side S7 thereof is a convex surface, and the image side S8 thereof is a concave surface;

[0090] The reflecting element L5 is a prism, specifically a right-angled triangular prism, comprising an incident surface S9, a reflecting surface R0 and an exit surface S10; the incident surface S9, the reflecting surface R0 and the exit surface S10 are all planes. The reflecting surface of the prism forms a 45° angle with the optical axis of the incident surface and the exit surface of the prism. It can be understood that the incident surface S9 faces the object side, and the exit surface S10 faces the imaging surface. Light rays enter the prism from the incident surface, are reflected by the reflecting surface, exit the prism from the exit surface to the imaging surface, and the angle between the incident surface and the exit surface is 90°.

[0091] The object side S11 and the image side S12 of the filter G1 are both planes;

[0092] The imaging surface S13 is a plane.

[0093] The reflecting element L5 can be made of plastic, and the first lens L1, the second lens L2, the third lens L3 and the fourth lens L4 are all plastic aspherical lenses.

[0094] The related parameters of the lenses in the optical lens 100 in Embodiment 1 are shown in Table 1-1.

[0095] Table 1-1

[0096]

[0097] The surface type parameters of the aspherical lenses of the optical lens 100 in Embodiment 1 are shown in Table 1-2.

[0098] Table 1-2

[0099]

[0100] In the present embodiment, the field curvature curve, the distortion curve, the axial aberration curve and the transverse aberration curve of the optical lens 100 are shown in FIGS. 1-4, respectively. Figure 2 Figure 3 Figure 4 Figure 5

[0101] Figure 2 The field curvature curve of Example 1 is shown, which represents the curvature of light rays of different wavelengths on the meridional image surface and the sagittal image surface, the horizontal axis represents the offset (unit: mm), and the vertical axis represents the half field angle (unit: °). It can be seen from the figure that the field curvature of the meridional image surface and the sagittal image surface is controlled within -0.1mm~0, which shows that the optical lens 100 can well correct the field curvature.

[0102] Figure 3 The distortion curve of Example 1 is shown, which represents the distortion of light rays at different image heights on the imaging surface, the horizontal axis represents the distortion value (unit: %), and the vertical axis represents the half field angle (unit: °). It can be seen from the figure that the distortion of the optical lens is controlled within 0~2%, which shows that the optical lens 100 can well correct the distortion.

[0103] Figure 4 The axial aberration curve of Example 1 is shown, which represents the aberration of each wavelength on the optical axis at the imaging surface, 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 ±0.06mm, which shows that the optical lens 100 can better correct the axial aberration.

[0104] Figure 5 The transverse aberration curve of Example 1 is shown, which represents the chromatic aberration of each wavelength relative to the central wavelength (555nm) 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 ±1μm, which shows that the optical lens 100 can very well correct the chromatic aberration.

[0105] Example 2

[0106] Please refer to Figure 6 , which is a structural schematic diagram of the optical lens 200 provided in Example 2 of the present application. Compared with Example 1, the main difference is that the stop ST is arranged between the first lens L1 and the second lens L2; the object side S5 of the third lens L3 is a convex surface; the object side S7 of the fourth lens L4 is a concave surface; the image side S8 of the fourth lens L4 is a convex surface at the near optical axis; the optical parameters such as the curvature radius of each lens surface, the lens thickness, and the lens material selection are different.

[0107] ​​​​The related parameters of each lens in the optical lens 200 in Embodiment 2 are shown in Table 2-1.

[0108] Table 2-1

[0109]

[0110] The surface type parameters of the aspherical lenses of the optical lens 200 in Embodiment 2 are shown in Table 2-2.

[0111] Table 2-2

[0112]

[0113] In this embodiment, the field curvature curve, the distortion curve, the axial aberration curve and the transverse aberration curve of the optical lens 200 are shown in Figure 7 、 Figure 8 、 Figure 9 、 Figure 10 respectively.

[0114] As can be seen from Figure 7 , the field curvature of the meridional image surface and the sagittal image surface is controlled within-0.1mm~0.05mm, which indicates that the optical lens 200 can well correct the field curvature.

[0115] As can be seen from Figure 8 , the distortion of the optical lens is controlled within 0~3%, which indicates that the optical lens 200 can well correct the distortion.

[0116] As can be seen from Figure 9 , the offset of the axial aberration is controlled within-0.1mm~0.08mm, which indicates that the optical lens 200 can well correct the axial aberration.

[0117] As can be seen from Figure 10 , the chromatic aberration of the longest wavelength and the shortest wavelength is controlled within-3μm~2μm, which indicates that the optical lens 200 can well correct the chromatic aberration.

[0118] Embodiment 3

[0119] Please refer to Figure 11 , which is a structural schematic diagram of the optical lens 300 provided in Embodiment 3 of the present application. Compared with Embodiment 1, the main difference is that the object side S3 of the second lens L2 is a concave surface at the near optical axis; the optical parameters such as the curvature radius of each lens surface, the lens thickness and the lens material selection are different.

[0120] The related parameters of each lens in the optical lens 300 in Embodiment 3 are shown in Table 3-1.

[0121] Table 3-1

[0122]

[0123] The surface profile parameters of the aspherical lens of the optical lens 300 in Example 3 are shown in Table 3-2.

[0124] Table 3-2

[0125]

[0126] In this embodiment, the field curvature curve, distortion curve, axial aberration curve, and transverse chromatic aberration curve of the optical lens 300 are respectively as follows: Figure 12 , Figure 13 , Figure 14 , Figure 15 As shown.

[0127] from Figure 12 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within -0.1mm to 0, indicating that the optical lens 300 can effectively correct the field curvature.

[0128] from Figure 13 As can be seen, the distortion of the optical lens is controlled within 0~2%, indicating that the optical lens 300 can effectively correct distortion.

[0129] from Figure 14 As can be seen, the axial aberration offset is controlled within -0.02mm to 0.1mm, indicating that the optical lens 300 can correct axial aberration well.

[0130] from Figure 15 As can be seen, the chromatic difference between the longest and shortest wavelengths is controlled within -2μm to 4μm, indicating that the optical lens 300 can correct chromatic aberration very well.

[0131] Example 4

[0132] Please see Figure 16 The figure shows a schematic diagram of the structure of the optical lens 400 provided in Embodiment 4 of the present invention. The main difference between this embodiment and Embodiment 1 is that: the aperture ST is located between the first lens L1 and the second lens L2; ​​the object side surface S5 of the third lens L3 is a plane near the optical axis; the object side surface S7 of the fourth lens L4 is a concave surface; and the optical parameters such as the radius of curvature, lens thickness, and lens material of each lens surface are different.

[0133] The relevant parameters of each lens in the optical lens 400 in Example 4 are shown in Table 4-1.

[0134] Table 4-1

[0135]

[0136] The surface profile parameters of the aspherical lens of the optical lens 400 in Example 4 are shown in Table 4-2.

[0137] Table 4-2

[0138]

[0139] In this embodiment, the field curvature curve, distortion curve, axial aberration curve, and transverse chromatic aberration curve of the optical lens 400 are respectively as follows: Figure 17 , Figure 18 , Figure 19 , Figure 20 As shown.

[0140] from Figure 17 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within -0.05mm to 0.15mm, indicating that the optical lens 400 can effectively correct the field curvature.

[0141] from Figure 18 As can be seen, the distortion of the optical lens is controlled within 0-3%, indicating that the optical lens 400 can effectively correct distortion.

[0142] from Figure 19 As can be seen, the axial aberration offset is controlled within -0.1mm to 0.1mm, indicating that the optical lens 400 can correct axial aberration well.

[0143] from Figure 20 As can be seen, the chromatic difference between the longest and shortest wavelengths is controlled within -2μm to 1μm, indicating that the optical lens 400 can correct chromatic aberration very well.

[0144] Please refer to Table 5 for the optical characteristics corresponding to each of 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 representing the back focal length of the optical lens, the aperture value Fno, the true image height IH corresponding to the maximum field of view of the optical lens, the maximum field of view FOV, and the values ​​corresponding to each conditional expression in each embodiment.

[0145] Table 5

[0146]

[0147] In summary of the above embodiments, the object side beam of the optical lens of the present application passes through the first lens, the second lens, the third lens, the fourth lens, and then the reflecting element, is reflected on the reflecting surface of the reflecting element, so that the optical axis is turned 90°, and finally passes through the filtering treatment of the optical filter to achieve image acquisition on the photosensitive chip. The rear placement of the reflecting element is convenient for adjusting the overall architecture. The periscopic imaging effect of long focal length and large image field of the lens is better achieved, and the development trend of the ultra-thin of the portable electronic device such as the mobile phone is also met.

[0148] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0149] The above described embodiments only express several implementation manners of the present application, the description is more specific and detailed, but it cannot be understood as the limitation of the patent scope of the present application. It should be noted that for ordinary skilled in the art, without departing from the concept of the present application, several modifications and improvements can be made, which belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. An optical lens characterized in that, Composed of four lenses and a reflective element, sequentially comprising from the object side to the imaging plane along the direction of light propagation: a first lens with positive refractive power, the object side surface of which is convex, and the image side surface of which is concave; a second lens with negative refractive power, the image side surface of which is concave; a third lens with positive refractive power, the image side surface of which is convex; a fourth lens with negative refractive power; a reflective element, which is a prism, the prism comprising an incident plane, a reflective plane and an exit plane, all of which are flat, light rays entering the prism from the incident plane along the optical axis, reflecting off the reflective plane, and exiting from the exit plane to the imaging plane; the reflective plane and the optical axis of the incident plane and the optical axis of the exit plane form an included angle of 45° respectively; wherein the focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: 0.46 < f3 / f < 1.52; the focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy: -40 < f4 / f < -0.7; the real image height IH corresponding to the maximum field of view angle of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 1.5 < IH / EPD < 1.

7.

2. The optical lens of claim 1, wherein, the distance TTL on the optical axis from the object side surface of the first lens to the imaging plane and the effective focal length f of the optical lens satisfy: 1.1 < TTL / f < 1.

15.

3. The optical lens of claim 1, wherein, the focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: 0.5 < f1 / f < 0.

76.

4. The optical lens of claim 1, wherein, the real 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: 0.62 < IH / f < 0.

64.

5. The optical lens of claim 1, wherein, the distance TTL on the optical axis from the object side surface of the first lens to the imaging plane, the real image height IH corresponding to the maximum field of view angle of the optical lens and the maximum field of view angle FOV of the optical lens satisfy: 0.05 / ° < TTL / IH / FOV < 0.055 / °.

6. The optical lens of claim 1, wherein, the radius of curvature R1 of the object side surface of the first lens and the radius of curvature R2 of the image side surface of the first lens satisfy: 0.07 < R1 / R2 < 0.

36.

7. The optical lens of claim 1, wherein, the sum ∑CT of the central thicknesses of the first lens to the reflective element along the optical axis and the distance TTL on the optical axis from the object side surface of the first lens to the imaging plane satisfy: 0.5 < ∑CT / TTL < 0.

54.

8. The optical lens of claim 1, wherein, the effective focal length f of the optical lens, the maximum field of view angle FOV of the optical lens and the real image height IH corresponding to the maximum field of view angle of the optical lens satisfy: 53° < (f x FOV) / IH < 56°.

9. The optical lens of claim 1, wherein, the maximum field of view angle FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 13° < FOV / Fno < 14°.

10. The optical lens of claim 1, wherein, the half diameter DM11 of the object side surface of the first lens and the half diameter DM42 of the image side surface of the fourth lens satisfy: 1.3 < DM11 / DM42 < 1.5.

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