Optical lens

Abstract

The invention provides an optical lens, which consists of four lenses and a reflecting element, and sequentially comprises a first lens with positive focal power, a second lens with negative focal power, a third lens with positive focal power, a fourth lens with negative focal power, a fifth lens with positive focal power and a sixth lens with negative focal power from an object side to an imaging surface along a light propagation direction, the image side surface of the second lens is a concave surface; the third lens has positive focal power, and the image side surface of the third lens is a convex surface; the fourth lens has negative focal power; the reflecting element is a prism, the prism comprises an incident plane, a reflecting plane and an emergent plane which are all planes, and light enters the prism from the incident plane along an optical axis, is reflected by the reflecting plane and exits from the emergent plane to an imaging plane; and an included angle of 45 degrees is respectively formed between the reflecting surface and the optical axis of the incident surface and between the reflecting surface and the optical axis of the emergent surface. According to the optical lens, the multiple lenses are combined and matched with the reflecting element, the periscopic long-focus effect is achieved, and the optical lens has the advantages of being small, light and thin.

Description

Technical Field

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

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

[0003] In order to endow mobile phone photography with more powerful telephoto characteristics, periscope mobile phone lenses have been a hot topic since their birth and have become a standard feature of some imaging flagship mobile phones. Existing periscope telephoto lenses usually use refractive and reflective elements such as right-angled prisms to deflect the light path at the light inlet and then enter the optical system. This conventional periscope scheme has great deficiencies and disadvantages, which is not conducive to the optimization of aberration and the adjustment of different architectures of the whole machine, etc. Summary of the Invention

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

[0005] The technical solution adopted by the present invention is as follows: An optical lens is composed of four lenses and one reflective element, and sequentially includes from the object side to the imaging surface along the light propagation direction: A first lens with positive optical power, whose object side is convex and whose image side is concave; A second lens with negative optical power, whose image side is concave; A third lens with positive optical power, whose image side is convex; A fourth lens with negative optical power; A reflective element, the reflective element is a prism, the prism includes an incident surface, a reflective surface and an exit surface that are all planes, light enters the prism along the optical axis from the incident surface, is reflected by the reflective surface, and exits from the exit surface to the imaging surface; the reflective surface forms an angle of 45° with the optical axes of the incident surface and the exit surface 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.

[0006] Further preferably, the distance TTL on the optical axis from the object side of the first lens to the imaging surface and the effective focal length f of the optical lens satisfy: 1.1 < TTL / f < 1.15.

[0007] 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.

[0008] Further preferably, the real image height IH corresponding to the maximum field angle of the optical lens and the effective focal length f of the optical lens satisfy: 0.62 <IH / f<0.64。

[0009] Further preferably, the distance TTL from the object side of the first lens to the imaging surface on the optical axis, the real image height IH corresponding to the maximum field of view of the optical lens and the maximum field of view FOV of the optical lens satisfy: 0.05 / ° <TTL / IH / FOV<0.055 / °。

[0010] Further preferably, the curvature radius R1 of the object side surface of the first lens and the curvature radius R2 of the image side surface of the first lens satisfy: 0.07 <R1 / R2<0.36。

[0011] Further preferably, the sum of the center thicknesses ΣCT of the first lens to the reflective element along 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: 0.5<ΣCT / TTL<0.54.

[0012] Further preferably, the effective focal length f of the optical lens, the maximum field of view FOV of the optical lens and the real image height IH corresponding to the maximum field of view of the optical lens satisfy: 53°<(f×FOV) / IH<56°.

[0013] Further preferably, the maximum field of view FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 13° <FOV / Fno<14°。

[0014] Further preferably, the object-side light transmission semi-aperture DM11 of the first lens and the image-side light transmission semi-aperture DM42 of the fourth lens satisfy: 1.3 <DM11 / DM42<1.5。

[0015] Compared with the prior art, the object light beam of the optical lens of the present invention passes through the first lens, the second lens, the third lens, the fourth lens and then the reflective element, and is reflected on the reflective surface of the reflective element, so that the optical axis turns 90 degrees, and finally passes through the filtering treatment of the filter to complete the image acquisition on the photosensitive chip. The rear placement of the reflective element facilitates the adjustment of the overall machine architecture; it can better realize the telephoto and large image surface periscope imaging effects of the lens, 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 Schematic diagram of the structure of the optical lens in Example 1 of the present invention.

[0017] Figure 2 It is the field curvature curve graph of the optical lens in Embodiment 1 of the present invention.

[0018] Figure 3 It is the distortion curve graph of the optical lens in Embodiment 1 of the present invention.

[0019] Figure 4 It is the axial aberration curve graph of the optical lens in Embodiment 1 of the present invention.

[0020] Figure 5 It is the lateral chromatic aberration curve graph of the optical lens in Embodiment 1 of the present invention.

[0021] Figure 6 It is the structural schematic diagram of the optical lens in Embodiment 2 of the present invention.

[0022] Figure 7 It is the field curvature curve graph of the optical lens in Embodiment 2 of the present invention.

[0023] Figure 8 It is the distortion curve graph of the optical lens in Embodiment 2 of the present invention.

[0024] Figure 9 It is the axial aberration curve graph of the optical lens in Embodiment 2 of the present invention.

[0025] Figure 10 It is the lateral chromatic aberration curve graph of the optical lens in Embodiment 2 of the present invention.

[0026] Figure 11 It is the structural schematic diagram of the optical lens in Embodiment 3 of the present invention.

[0027] Figure 12 It is the field curvature curve graph of the optical lens in Embodiment 3 of the present invention.

[0028] Figure 13 It is the distortion curve graph of the optical lens in Embodiment 3 of the present invention.

[0029] Figure 14 It is the axial aberration curve graph of the optical lens in Embodiment 3 of the present invention.

[0030] Figure 15 It is the lateral chromatic aberration curve graph of the optical lens in Embodiment 3 of the present invention.

[0031] Figure 16 It is the structural schematic diagram of the optical lens in Embodiment 4 of the present invention.

[0032] Figure 17 It is the field curvature curve graph of the optical lens in Embodiment 4 of the present invention.

[0033] Figure 18 It is the distortion curve graph of the optical lens in Embodiment 4 of the present invention.

[0034] Figure 19 This is the axial aberration curve graph of the optical lens in Embodiment 4 of the present invention.

[0035] Figure 20 This is the lateral chromatic aberration curve graph of the optical lens in Embodiment 4 of the present invention.

[0036] The following specific embodiments will further illustrate the present invention in conjunction with the above-mentioned drawings. Specific Embodiments

[0037] To better understand the present application, more detailed descriptions of various aspects of the present application will be made with reference to the accompanying drawings. It should be understood that these detailed descriptions are only descriptions of the embodiments of the present application and do not limit the scope of the present application in any way. Throughout the specification, the same reference numerals refer to the same elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0038] It should be noted that in this specification, the expressions such as first, second, and third are only used to distinguish one feature from another feature and do not represent any limitation on the feature. Therefore, without departing from the teachings of the present invention, the first lens discussed below may also be referred to as the second lens or the third lens.

[0039] In the drawings, for the sake of clarity, the thickness, dimensions, and shape of the lenses have been slightly exaggerated. Specifically, the spherical or aspherical shapes shown in the drawings are shown by way of example. That is, the spherical or aspherical shapes are not limited to the spherical or aspherical shapes shown in the drawings. The drawings are only examples and are not drawn to an exact scale.

[0040] In this document, 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 being photographed is called the object side surface of the lens, and the surface of each lens closest to the imaging surface is called the image side surface of the lens.

[0041] It should also be understood that the terms "comprise", "comprising", "have", "including" and / or "containing", when used in this specification, denote the presence of the stated features, elements and / or components, but do not preclude the presence or addition of one or more other features, elements, components and / or combinations thereof. In addition, when an expression such as "at least one of..." appears after a list of listed features, it modifies the entire list of listed features rather than an individual element in the list. In addition, when describing embodiments of the present application, the use of "may" means "one or more embodiments of the present application". Also, the term "exemplary" is intended to refer to an example or illustration.

[0042] 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 should also be understood that terms (such as those defined in a common dictionary) should be interpreted as having a meaning consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0043] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments may be combined with each other. The present application will be described in detail below with reference to the drawings and in combination with the embodiments.

[0044] The optical lens provided by the embodiment of the present invention 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 along the light propagation direction from the object side to the imaging surface. The reflecting element of the present invention is used to turn the light, and by changing the angle of the light, the lens module can be arranged horizontally (such as in the thickness direction of a mobile phone). The structure with the prism placed at the rear is beneficial to the whole machine to adjust different architectures, reduce the overall thickness of the optical system, achieve the effect of a telephoto long focal length of the lens, and is also beneficial to the optimization of the aberration of the optical system.

[0045] In some embodiments, the first lens may have a positive focal power, its object side is convex, and its image side is concave. The second lens may have a negative focal power, its object side may be concave or convex, and its image side is concave. The third lens may have a positive focal power, its object side may be concave or convex, and its image side is convex. The fourth lens may have a negative focal power, its object side may be concave or convex, and its image side may be concave or convex.

[0046] Specifically, the reflecting element can be a prism. The 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 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, and the angle between the incident surface and the exit surface is 90°. The prism can be a right-angled triangular prism and is made of a plastic material.

[0047] In some embodiments, the optical lens may further include a diaphragm, and the diaphragm may 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 incident light to change the brightness of the image.

[0048] In some embodiments, the optical lens may further include a filter, and the filter may be disposed between the reflecting element and the imaging surface. The filter is used to filter out interfering light to prevent the interfering light from reaching the imaging surface of the optical lens and affecting normal imaging.

[0049] When the object-side light beam of the optical lens of the present invention sequentially passes through the first lens, the second lens, the third lens, and the fourth lens, and then passes through the reflecting element, reflection occurs on the reflecting surface of the prism, causing the optical axis to turn by 90°. Finally, after passing through the filtering process of the filter, it reaches the photosensitive chip (imaging surface) to complete image acquisition.

[0050] 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 is a positive lens, which can re-converge the diverging light rays, compensate for the diverging effect of the negative lens, avoid uneven brightness of the image plane caused by excessive diffusion of the optical path, and correct residual monochromatic aberrations such as spherical aberration and coma.

[0051] In some embodiments, the distance TTL (i.e., the length of the propagation path of the light ray along the optical axis from the object side surface of the first lens to the imaging surface) 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. Satisfying the above range, on the premise of realizing a telephoto lens, a periscope structure is realized through a prism to shorten the total length of the lens, which is beneficial to the miniaturization 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: 0.5 < f1 / f < 0.76. Satisfying the above range, as the first positive lens, it converges the incident light rays, constructs a telephoto optical path, and provides a basis for the optical path compression of the subsequent negative lens.

[0053] 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: 0.62 < IH / f < 0.64. Meeting the above range can make the lens have a longer focal length and a larger imaging surface.

[0054] In some embodiments, the distance TTL on the optical axis from the object side surface of the first lens to the imaging surface, the true 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 / °. Meeting the above range is beneficial to balancing the relationship among the total length, image height, and field of view angle of the optical lens.

[0055] In some embodiments, the curvature radius R1 of the object side surface of the first lens and the curvature radius R2 of the image side surface of the first lens satisfy: 0.07 < R1 / R2 < 0.36. Meeting the above range can cause the incident light rays to converge to a greater extent and allow more light rays to enter the system, which is beneficial to improving the light input of the lens.

[0056] In some embodiments, the sum ∑CT of the central thicknesses along the optical axis from the first lens to the reflecting element 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. Meeting the above range can effectively compress the total length of the lens and is beneficial to 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 along the optical axis from the incident surface to the exit surface, 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.

[0057] 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 true image height IH corresponding to the maximum field of view angle of the optical lens satisfy: 53° < (f×FOV) / IH < 56°. Meeting the above range, by reasonably restricting the relationship among the focal length, field of view angle, and image height of the optical lens, the optical lens has good optical performance and can well capture the details of the object to be photographed.

[0058] 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°. Meeting the above range, the lens can increase the light flux through a large aperture and make the lens more compact, suitable for a periscope structure (such as a mobile phone telephoto lens), and still maintain a small volume after the optical path is folded.

[0059] In some embodiments, the clear aperture diameter DM11 of the object side of the first lens and the clear aperture diameter DM42 of the image side of the fourth lens satisfy: 1.3 < DM11 / DM42 < 1.5. Meeting the above range, by reasonably setting the focal length and aperture relationship of the first and last lenses, while ensuring that as much light as possible enters the system, the area of the light entering the image plane is increased, achieving high relative illumination of the lens and imaging on a large image plane.

[0060] 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. Meeting the above range, the second lens is a negative lens, which can diverge light, extend the equivalent focal length but shorten the physical optical path length, and at the same time compensate for the aberration of the front positive lens group.

[0061] 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. Meeting the above range, the fourth lens can correct field curvature, balance chromatic aberration, form dispersion complementarity with the first three lenses, and adapt to the sensor image plane.

[0062] In some embodiments, 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: -0.1 < R7 / R8 < 1.5. Meeting the above range is beneficial to alleviating the deflection degree of the light passing through the lens and can well reduce aberration.

[0063] In some embodiments, the curvature radius R1 of the object side of the first lens and the curvature radius R2 of the image side of the first lens satisfy: -2.2 < (R1 + R2) / (R1 - R2) < -1.1. Meeting the above range, reasonably controlling the curvature radii of the object side and image side of the first lens near the optical axis is beneficial to controlling the shape of the first lens, correcting the aberration generated by itself, and improving the imaging quality.

[0064] In some embodiments, the curvature radius R1 of the object side of the first lens and the effective focal length f of the optical lens satisfy: 0.25 < R1 / f < 0.3. Meeting the above range can control the light direction, reduce spherical aberration, correct coma aberration, increase light utilization rate, and improve stability.

[0065] 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; the focal length f1 of the first lens and the focal length f4 of the fourth lens satisfy: -0.8 < f1 / f4 < 0. Meeting the above ranges forms a positive-negative optical power combination, which can improve the temperature drift stability performance of the lens, help reduce the influence of the ambient temperature on the lens group, and also meet the compactness requirements of the lens.

[0066] 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. Meeting the above conditions, by reducing the distances between the first lens, the second lens, the third lens, and the fourth lens directly, the total length of the lens is compressed.

[0067] In some embodiments, the true 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. Meeting the above range makes the field of view and the light flux balanced and improves the imaging quality of the lens.

[0068] 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 true image height IH corresponding to the maximum field of view angle of the optical lens satisfy: 0.97 < (2×f×tan(FOV / 2)) / IH < 0.98. Meeting the above range, the lens has a small distortion value and can provide a high-definition imaging effect.

[0069] In the embodiments of the present invention, 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; 2.4 < Fno < 2.7. In the above 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 from the object side surface of the first lens to the imaging surface along the optical axis), 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 true image height corresponding to the maximum field of view angle of the optical lens, and Fno represents the aperture value of the optical lens. Meeting the above ranges, the optical lens has at least one or more advantages such as long focal length, miniaturization, and large image plane.

[0070] In some embodiments, the materials of the four lenses in the optical lens provided by the present invention can be glass or plastic. When the material of the lens is plastic, the production cost can be effectively reduced. When the material of the lens 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 enables the structure of the lens to be relatively compact, and can better achieve the balance between miniaturization and high image quality of the lens.

[0071] In some embodiments, the first lens, the second lens, the third lens, and the fourth lens can adopt spherical lenses or aspherical lenses. Compared with the spherical structure, the aspherical structure can effectively reduce the aberration of the optical system, thereby reducing the number of lenses and the size of the lenses, and better realizing the miniaturization of the lens. More specifically, the first lens, the second lens, the third lens, and the fourth lens of the present invention can all adopt aspherical lenses, which can effectively reduce the aberration of the optical lens, thereby reducing the number of lenses and the size of the lenses, and better realizing the miniaturization of the lens.

[0072] To enable the system to have better optical performance, multiple aspherical lenses are used in the lens, and the shapes of the aspherical surfaces of the optical lens satisfy the following equation: ; where z is the distance between the curved surface and the vertex of the curved surface in the optical axis direction, h is the distance from the optical axis to the curved surface, c is the curvature of the vertex of the curved surface, K is the conic coefficient, and B, C, D, E, F, G, H are the coefficients of the fourth-order, sixth-order, eighth-order, tenth-order, twelfth-order, fourteenth-order, and sixteenth-order curved surfaces respectively.

[0073] The present invention will be further described below with multiple embodiments. In each embodiment, the thickness, radius of curvature, and material selection of each lens in the optical lens are slightly different. For specific differences, please refer to the parameter tables of each embodiment. The following embodiments are only the preferred embodiments of the present invention, but the embodiments of the present invention are not limited only by the following embodiments. Any changes, substitutions, combinations, or simplifications made without departing from the innovative points of the present invention should be regarded as equivalent replacement methods and are included in the protection scope of the present invention.

[0074] Embodiment 1 Please refer to Figure 1 , Figure 1 which is a schematic structural diagram of the optical lens 100 provided in Embodiment 1 of the present invention. The optical lens 100 sequentially includes, from the light propagation direction (from the object side to the imaging surface S13): a diaphragm ST, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a reflection element L5, and a filter G1. An air gap can be provided between any two adjacent lenses.

[0075] The first lens L1 has a positive optical power. Its object side S1 is convex, and its image side S2 is concave. The second lens L2 has a negative optical power. Its object side S3 is convex, and its image side S4 is concave. The third lens L3 has a positive optical power. Its object side S5 is concave near the optical axis, and its image side S6 is convex. The fourth lens L4 has a negative optical power. Its object side S7 is convex, and its image side S8 is concave. The reflecting element L5 is a prism, specifically a right-angled triangular prism, including an incident surface S9, a reflecting surface R0, and an exit surface S10. Its incident surface S9, reflecting surface R0, and exit surface S10 are all flat surfaces. The reflecting surface of the prism forms a 45° angle with the optical axes of the incident surface and the exit surface of the prism respectively. It can be understood that the incident surface S9 faces the object side, and the exit surface S10 faces the imaging surface. Light enters the prism from the incident surface, is reflected by the reflecting surface, and exits from the exit surface to the imaging surface. The angle between the incident surface and the exit surface is 90°.

[0076] The object side S11 and the image side S12 of the filter G1 are both flat surfaces. The imaging surface S13 is a flat surface.

[0077] Among them, the reflecting element L5 can be made of plastic material, and the first lens L1, the second lens L2, the third lens L3, and the fourth lens L4 are all plastic aspherical lenses.

[0078] The relevant parameters of each lens in the optical lens 100 in Embodiment 1 are shown in Table 1-1.

[0079] Table 1-1 The surface shape parameters of the aspherical lenses of the optical lens 100 in Embodiment 1 are shown in Table 1-2.

[0080] Table 1-2 In this embodiment, the field curvature curve graph, distortion curve graph, axial aberration curve graph, and lateral chromatic aberration curve graph of the optical lens 100 are respectively as Figure 2 , Figure 3 , Figure 4 , Figure 5 shown.

[0081] Figure 2The field curvature curve of Embodiment 1 is shown, which represents the bending degree of light rays with different wavelengths in the meridional image plane and the sagittal image plane. The horizontal axis represents the offset (unit: mm), and the vertical axis represents the semi-field angle (unit: °). It can be seen from the figure that the field curvature of the meridional image plane and the sagittal image plane is controlled within -0.1 mm to 0, indicating that the optical lens 100 can well correct the field curvature.

[0082] Figure 3 The distortion curve graph of Embodiment 1 is shown, which represents the distortion of light rays at different image heights on the imaging plane. The horizontal axis represents the distortion value (unit: %), and the vertical axis represents the semi-field angle (unit: °). It can be seen from the figure that the distortion of the optical lens is controlled within 0 to 2%, indicating that the optical lens 100 can well correct the distortion.

[0083] Figure 4 The axial aberration curve graph of Embodiment 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. It can be seen from the figure that the offset of the axial aberration is controlled within ±0.06 mm, indicating that the optical lens 100 can better correct the axial aberration.

[0084] Figure 5 The lateral chromatic aberration curve graph of Embodiment 1 is shown, which represents the chromatic aberration of each wavelength relative to the central wavelength (555 nm) at different image heights on the imaging plane. The horizontal axis represents the chromatic aberration value of each wavelength relative to the central wavelength (unit: μm), and the vertical axis represents the normalized field angle. It can be seen from the figure that the chromatic aberration between the longest wavelength and the shortest wavelength is controlled within ±1 μm, indicating that the optical lens 100 can excellently correct the chromatic aberration.

[0085] Embodiment 2 Please refer to Figure 6 , which shows the structural schematic diagram of the optical lens 200 provided in Embodiment 2 of the present invention. Compared with Embodiment 1, the main differences are as follows: The aperture stop ST is arranged between the first lens L1 and the second lens L2; the object side surface S5 of the third lens L3 is a convex surface; the object side surface S7 of the fourth lens L4 is a concave surface; the image side surface S8 of the fourth lens L4 is a convex surface near the optical axis; the optical parameters such as the curvature radius, lens thickness, and lens material selection of each lens surface are different.

[0086] The relevant parameters of each lens in the optical lens 200 in Embodiment 2 are shown in Table 2-1.

[0087] Table 2-1 The surface type parameters of the aspherical lenses of the optical lens 200 in Embodiment 2 are shown in Table 2-2.

[0088] Table 2-2 In this embodiment, the field curvature curve graph, distortion curve graph, axial aberration curve graph, and lateral chromatic aberration curve graph of the optical lens 200 are respectively as follows Figure 7 , Figure 8 , Figure 9 , Figure 10 shown.

[0089] It can be seen from Figure 7 that the field curvature of the meridional image plane and the sagittal image plane is controlled within -0.1 mm to 0.05 mm, indicating that the optical lens 200 can correct the field curvature well.

[0090] It can be seen from Figure 8 that the distortion of the optical lens is controlled within 0 to 3%, indicating that the optical lens 200 can correct the distortion well.

[0091] It can be seen from Figure 9 that the offset of the axial aberration is controlled within -0.1 mm to 0.08 mm, indicating that the optical lens 200 can correct the axial aberration better.

[0092] It can be seen from Figure 10 that the chromatic aberration between the longest wavelength and the shortest wavelength is controlled within -3 μm to 2 μm, indicating that the optical lens 200 can correct the chromatic aberration excellently.

[0093] Embodiment 3 Please refer to Figure 11 , which shows the structural schematic diagram of the optical lens 300 provided in Embodiment 3 of the present invention. Compared with Embodiment 1, the main differences are as follows: the object side surface S3 of the second lens L2 is concave 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.

[0094] The relevant parameters of each lens in the optical lens 300 in Embodiment 3 are shown in Table 3-1.

[0095] Table 3-1 The aspheric lens surface type parameters of the optical lens 300 in Embodiment 3 are shown in Table 3-2.

[0096] Table 3-2 In this embodiment, the field curvature curve graph, distortion curve graph, axial aberration curve graph, and lateral chromatic aberration curve graph of the optical lens 300 are respectively as follows Figure 12 , Figure 13 , Figure 14 , Figure 15 shown.

[0097] From Figure 12 it can be seen that the field curvature of the meridional image plane and the sagittal image plane is controlled within -0.1 mm to 0, indicating that the optical lens 300 can correct the field curvature well.

[0098] From Figure 13 it can be seen that the distortion of the optical lens is controlled within 0 to 2%, indicating that the optical lens 300 can correct the distortion well.

[0099] From Figure 14 it can be seen that the offset of the axial aberration is controlled within -0.02 mm to 0.1 mm, indicating that the optical lens 300 can correct the axial aberration well.

[0100] From Figure 15 it can be seen that the chromatic aberration between the longest wavelength and the shortest wavelength is controlled within -2 μm to 4 μm, indicating that the optical lens 300 can correct the chromatic aberration excellently.

[0101] Embodiment 4 Please refer to Figure 16 , which shows a schematic structural diagram of the optical lens 400 provided in Embodiment 4 of the present invention. Compared with Embodiment 1, the main differences are as follows: the aperture stop ST is disposed 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; the optical parameters such as the curvature radius, lens thickness, and lens material selection of each lens surface are different.

[0102] The relevant parameters of each lens in the optical lens 400 in Embodiment 4 are shown in Table 4-1.

[0103] Table 4-1 The surface type parameters of the aspherical lenses of the optical lens 400 in Embodiment 4 are shown in Table 4-2.

[0104] Table 4-2 In this embodiment, the field curvature curve graph, distortion curve graph, axial aberration curve graph, and lateral chromatic aberration curve graph of the optical lens 400 are respectively as Figure 17 , Figure 18 , Figure 19 , Figure 20 shown.

[0105] From Figure 17 it can be seen that the field curvature of the meridional image plane and the sagittal image plane is controlled within -0.05 mm to 0.15 mm, indicating that the optical lens 400 can correct the field curvature well.

[0106] from Figure 18 It can be seen that the distortion of the optical lens is controlled within 0~3%, indicating that the optical lens 400 can correct the distortion well.

[0107] from Figure 19 It can be seen that the offset of the axial aberration is controlled within -0.1mm~0.1mm, which means that the optical lens 400 can correct the axial aberration well.

[0108] from Figure 20 It can be seen that the chromatic aberration between the longest wavelength and the shortest wavelength is controlled within -2μm~1μm, indicating that the optical lens 400 can correct chromatic aberration very well.

[0109] Please refer to Table 5, 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.

[0110] Table 5 In summary of the above embodiments, the object light beam of the optical lens of the present invention passes through the first lens, the second lens, the third lens, the fourth lens and then the reflective element, and is reflected on the reflective surface of the reflective element, so that the optical axis turns 90°, and finally passes through the filtering treatment of the filter to complete the image acquisition on the photosensitive chip. The rear placement of the reflective element facilitates the adjustment of the overall machine architecture; so that the telephoto and large image plane periscope imaging effects of the lens can be better achieved, and the development trend of ultra-thin portable electronic devices such as mobile phones can be met.

[0111] 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.

[0112] The above-described embodiments merely represent several implementation manners of the present invention. The description thereof is relatively specific and detailed, but it should not be construed as a limitation to the scope of the patent of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the appended claims.

Claims

1. An optical lens, characterized in that, It consists of four lenses and one reflecting element, and successively includes from the object side to the imaging surface along the light propagation direction: The first lens with positive optical power, whose object side is convex and whose image side is concave; The second lens with negative optical power, whose image side is concave; The third lens with positive optical power, whose image side is convex; The fourth lens with negative optical power; The reflecting element, which is a prism. The prism includes an incident surface, a reflecting surface and an exit surface that are all flat. Light enters the prism from the incident surface along the optical axis, is reflected by the reflecting surface, and exits from the exit surface to the imaging surface; the reflecting surface forms an angle of 45° with the optical axes of the incident surface and the exit surface 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.

2. The optical lens according to claim 1, wherein The distance TTL from the object side 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.

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

76.

4. The optical lens according to claim 1, characterized in that, 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: 0.62 < IH / f < 0.

64.

5. The optical lens according to claim 1, characterized in that, The distance TTL from the object side of the first lens to the imaging surface on the optical axis, the true 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 according to claim 1, characterized in that, The curvature radius R1 of the object side of the first lens and the curvature radius R2 of the image side of the first lens satisfy: 0.07 < R1 / R2 < 0.

36.

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

54.

8. The optical lens according to 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 true image height IH corresponding to the maximum field of view angle of the optical lens satisfy: 53° < (f×FOV) / IH < 56°.

9. The optical lens according to 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 according to claim 1, wherein The clear aperture semi-diameter DM11 of the object side of the first lens and the clear aperture semi-diameter DM42 of the image side of the fourth lens satisfy: 1.3 < DM11 / DM42 < 1.5.

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