Optical lens

Abstract

The present invention provides an optical lens comprising four lenses and a folding reflective element. The lens comprises, in order from the object side to the image side, the following components along the light transmission direction: a first lens having positive optical power, whose object-side surface is convex; a second lens having optical power, whose object-side surface is convex and whose image-side surface is concave; a third lens having negative optical power; and a fourth lens having optical power, whose object-side surface is convex. The folding reflective element comprises a light incident surface, a first reflective surface, a second reflective surface, a third reflective surface, and a light exit surface, all of which are planes, wherein the light incident surface, the second reflective surface, and the light exit surface are substantially the same plane. The optical axes of the optical lens comprise a first optical axis, a second optical axis, a third optical axis, and a fourth optical axis. The optical lens provided by the present invention can achieve excellent periscope telephoto photography effects and has one or more advantages, including miniaturization, a large image plane, a large aperture, and high-quality imaging.

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 shooting specific targets, but the total optical length of traditional telephoto cameras is too large and does not meet the lightweight design requirements of smartphones.

[0003] To empower mobile photography with more powerful telephoto and long-focus capabilities, periscope lenses have been a hot topic since their inception and have become standard equipment in some flagship imaging phones. The pursuit of higher-quality, more stable telephoto performance requires a larger optical system aperture and greater light throughput. However, after the optical path of a periscope telephoto lens deflects through reflective elements such as prisms, the lens aperture is limited by the thickness of the phone and cannot be increased, hindering the development of high-quality telephoto lenses. Summary of the Invention

[0004] In view of the above problems, the object of the present invention is to provide an optical lens that can achieve a telephoto periscope effect and has the characteristics of excellent imaging quality.

[0005] The technical solution adopted in the present invention is:

[0006] An optical lens, consisting of four lenses and a reflective element, includes the following elements in order from the object side to the imaging surface along the light transmission direction:

[0007] a first lens having positive optical power and a convex object-side surface;

[0008] a second lens having optical power, wherein the object-side surface thereof is convex and the image-side surface thereof is concave;

[0009] a third lens having negative optical power;

[0010] a fourth lens having optical power and a convex object-side surface;

[0011] A folding and reflecting element, comprising a light incident surface, a first reflecting surface, a second reflecting surface, a third reflecting surface, and a light emitting surface, all of which are planes, wherein the light incident surface, the second reflecting surface, and the light emitting surface are substantially the same plane;

[0012] The optical axis of the optical lens includes a first optical axis, a second optical axis, a third optical axis, and a fourth optical axis. The light path passes through the first lens, the second lens, the third lens, and the fourth lens along the first optical axis and enters the refractive element. The light path passes through the light incident surface to the first reflective surface, is reflected to the second reflective surface, is totally reflected to the third reflective surface, and is then reflected to the light exit surface and emitted to the imaging surface. The first reflective surface redirects the light path from the first optical axis to the second optical axis, the second reflective surface redirects the light path from the second optical axis to the third optical axis, and the third reflective surface redirects the light path from the third optical axis to the fourth optical axis. The fourth optical axis is perpendicular to the imaging surface. The first optical axis and the fourth optical axis are parallel.

[0013] 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 the following relationship: 4<((43.26 / IH)×f) / 23<5.5.

[0014] Compared to existing technologies, the optical lens provided by the present invention, through the configuration of four conventional lenses and one catadioptric element, can achieve excellent periscope-style telephoto photography, offering one or more advantages such as a large image surface, a large aperture, and high-quality imaging, significantly improving the user experience. Furthermore, because the optical path undergoes three deflections within the catadioptric element, the volume of the folded optical system is significantly compressed. While achieving excellent telephoto photography, the overall length of the optical lens is significantly reduced, effectively miniaturizing the lens and better matching the space requirements of lightweight electronic devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments with reference to the accompanying drawings, in which:

[0016] Figure 1 Schematic diagram of the structure of the optical lens in Example 1 of the present invention.

[0017] In the figure, LY is the distance perpendicular to the first optical axis between the intersection of the object-side surface of the first lens on the first optical axis and the intersection of the imaging plane on the fourth optical axis; LZ is the maximum displacement of the light path from the object-side surface of the first lens to the imaging plane parallel to the first optical axis; θ is the angle between the first optical axis and the second optical axis.

[0018] Figure 2 4 is an astigmatism curve diagram of the optical lens in Example 1 of the present invention.

[0019] Figure 3 Graph showing the magnification chromatic aberration of the optical lens in Example 1 of the present invention.

[0020] Figure 41 is an axial aberration curve diagram of the optical lens in Example 1 of the present invention.

[0021] Figure 5 Schematic diagram of the structure of the optical lens in Example 2 of the present invention.

[0022] Figure 6 Graph showing the astigmatism of the optical lens in Example 2 of the present invention.

[0023] Figure 7 2 is a graph showing the magnification chromatic aberration curve of the optical lens in Example 2 of the present invention.

[0024] Figure 8 2 is an axial aberration curve diagram of the optical lens in Example 2 of the present invention.

[0025] Figure 9 Schematic diagram of the structure of the optical lens in Example 3 of the present invention.

[0026] Figure 10 4 is an astigmatism curve diagram of the optical lens in Example 3 of the present invention.

[0027] Figure 11 Graph showing the magnification chromatic aberration of the optical lens in Example 3 of the present invention.

[0028] Figure 12 4 is an axial aberration curve diagram of the optical lens in Example 3 of the present invention.

[0029] Figure 13 Schematic diagram of the structure of the optical lens in Example 4 of the present invention.

[0030] Figure 14 4 is an astigmatism curve diagram of the optical lens in Example 4 of the present invention.

[0031] Figure 15 Graph showing the magnification chromatic aberration of the optical lens in Example 4 of the present invention.

[0032] Figure 16 4 is an axial aberration curve diagram of the optical lens in Example 4 of the present invention.

[0033] Figure 17 Schematic diagram of the structure of the optical lens in Example 5 of the present invention.

[0034] Figure 18 4 is an astigmatism curve diagram of the optical lens in Example 5 of the present invention.

[0035] Figure 19 Graph showing the magnification chromatic aberration of the optical lens in Example 5 of the present invention.

[0036] Figure 20 4 is an axial aberration curve diagram of the optical lens in Example 5 of the present invention.

[0037] Figure 21 Schematic diagram of the structure of the optical lens in Example 6 of the present invention.

[0038] Figure 22 4 is an astigmatism curve diagram of the optical lens in Example 6 of the present invention.

[0039] Figure 23 2 is a graph showing the magnification chromatic aberration curve of the optical lens in Example 6 of the present invention.

[0040] Figure 24 Graph showing the axial aberration of the optical lens in Example 6 of the present invention.

[0041] Figure 25 Schematic diagram of the structure of the optical lens in Example 7 of the present invention.

[0042] Figure 26 4 is an astigmatism curve diagram of the optical lens in Example 7 of the present invention.

[0043] Figure 27 Graph showing the magnification chromatic aberration of the optical lens in Example 7 of the present invention.

[0044] Figure 28 Graph showing the axial aberration of the optical lens in Example 7 of the present invention.

[0045] The following specific embodiments will further illustrate the present invention in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0046] For a better understanding of the present application, various aspects of the present application will be described in more detail with reference to the accompanying drawings. It should be understood that these detailed descriptions are merely descriptions of 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.

[0047] It should be noted that in this specification, the terms "first," "second," "third," etc., are used solely to distinguish one feature from another and do not limit the features. Thus, the first lens discussed below could also be referred to as the second lens or the third lens without departing from the teachings of the present invention.

[0048] In the drawings, the thickness, size, and shape of the lenses are slightly exaggerated for ease of illustration. Specifically, the shapes of the spherical and aspherical surfaces shown in the drawings are provided by way of example. That is, the shapes of the spherical and aspherical surfaces are not limited to those shown in the drawings. The drawings are for illustration only and are not drawn strictly to scale.

[0049] In this article, the paraxial region refers to the area near the optical axis. If a lens surface is convex and the location of the convex surface is undefined, it means that the lens surface is convex at least in the paraxial region. If a lens surface is concave and the location of the concave surface is undefined, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the subject is called the object-side surface of the lens, and the surface of each lens closest to the imaging plane is called the image-side surface of the lens.

[0050] 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 preclude 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 list of 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.

[0051] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by those skilled in the art to which this application belongs. It should also be understood that terms (such as those defined in commonly used dictionaries) should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology and will not be interpreted in an idealized or overly formal sense unless expressly defined as such herein.

[0052] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this 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.

[0053] The optical lens provided in an embodiment of the present invention is composed of four lenses and a folding reflective element, and includes, in order from the object side to the imaging surface along the direction of light transmission: a first lens, a second lens, a third lens, a fourth lens and a folding reflective element.

[0054] In some embodiments, the first lens may have positive focal power, its object side surface is convex, and its image side surface may be concave or convex. The second lens may have positive focal power or negative focal power, its object side surface is convex, and its image side surface is concave. The third lens may have negative focal 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 positive focal power or negative focal power, its object side surface is convex, and its image side surface may be concave or convex. The refractive element includes a light incident surface, a first reflecting surface, a second reflecting surface, a third reflecting surface, and a light exit surface, all of which are planes, wherein the light incident surface, the second reflecting surface, and the light exit surface are essentially the same plane. By setting the refractive element, the light path can be made to make multiple turns inside the refractive element, greatly increasing the propagation path of the light, making the spatial configuration more flexible, and facilitating the compression of the volume of the folded optical system to achieve a telephoto periscope imaging effect. More specifically, the refractive element can adopt a prism structure.

[0055] In the present invention, the optical axis of the optical lens includes a first optical axis, a second optical axis, a third optical axis, and a fourth optical axis. The first lens, the second lens, the third lens, and the fourth lens may be located on the first optical axis. The light path passes through the first lens, the second lens, the third lens, and the fourth lens along the first optical axis and enters the refractive element. The light path passes through the light incident surface to the first reflective surface, is reflected to the second reflective surface, is then totally reflected to the third reflective surface, and is then reflected to the light exit surface and emitted to the imaging surface. The first reflective surface redirects the light path from the first optical axis to the second optical axis, the second reflective surface redirects the light path from the second optical axis to the third optical axis, and the third reflective surface redirects the light path from the third optical axis to the fourth optical axis.

[0056] Please refer to Figure 1 As shown, the light path makes three turns in the refracting element, wherein total reflection of the light occurs on the second reflective surface. Reflection occurs on the first reflective surface and the third reflective surface. It can be understood that the first reflective surface and the third reflective surface have a reflective coating or are mirror surfaces. At the same time, the positional relationship of the surfaces where the first, second, and third reflective surfaces are located is determined by the angle between the optical axes, and the angle between the optical axes can be set according to the space requirements and the requirements of the refracting light path. Specifically, the first optical axis and the fourth optical axis are parallel, the fourth optical axis is perpendicular to the imaging plane, the angle between the third optical axis and the fourth optical axis is the same as the angle between the first optical axis and the second optical axis; the angle between the second optical axis and the third optical axis is twice the angle between the first optical axis and the second optical axis; the first optical axis can be perpendicular to the light incident surface of the refracting element.

[0057] In some embodiments, the optical lens may further include an aperture, which may be located between the object side and the first lens. It is understood that the aperture is used to limit the amount of light entering to change the brightness of the image.

[0058] In some embodiments, the optical lens may further include a filter, which is disposed between the refractive and reflective element 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.

[0059] In some embodiments, the true image height IH corresponding to the maximum field angle of the optical lens and the effective focal length f of the optical lens satisfy: 4 < ((43.26 / IH) × f) / 23 < 5.5. The above conditional formula is a magnification calculation formula. Meeting the above conditions indicates that the optical lens can achieve a high magnification ultra-long focal length shooting effect of 4X to 6X. It not only has an ultra-large imaging target surface but also has an ultra-long focal length, and can well meet the requirements of periscope telephoto shooting.

[0060] In some embodiments, the distance LY perpendicular to the first optical axis between the intersection point of the object side surface of the first lens on the first optical axis and the intersection point of the imaging surface on the fourth optical axis and the maximum displacement amount LZ parallel to the first optical axis of the light path traveling from the object side surface of the first lens to the imaging surface satisfy: 0.7 < LY / LZ < 0.95. Figure 1 The schematic diagrams of LY and LZ are shown. It can also be obtained from the figure that the values of LY and LZ directly determine the size of the optical lens in the height and thickness directions of the electronic device on which it is mounted. Meeting the above conditions, by controlling the ratio relationship of the lens in the LY and LZ directions, the ratio of the folding optical lens in the height and thickness directions can be adjusted, which helps to control the shape size ratio of the folding optical lens to better match the space configuration requirements of the thin and light electronic device.

[0061] In some embodiments, the distance LY perpendicular to the first optical axis between the intersection point of the object side surface of the first lens on the first optical axis and the intersection point of the imaging surface on the fourth optical axis and the total distance TTL passed along the first optical axis, the second optical axis, the third optical axis and the fourth optical axis from the object side surface of the first lens to the imaging surface satisfy: 0.33 < LY / TTL < 0.45; the maximum displacement amount LZ parallel to the first optical axis of the light path traveling from the object side surface of the first lens to the imaging surface and the total distance TTL passed along the first optical axis, the second optical axis, the third optical axis and the fourth optical axis from the object side surface of the first lens to the imaging surface satisfy: 0.42 < LZ / TTL < 0.52. Meeting the above conditions, by controlling the optical path of the optical path refractive and reflective element (prism) and reasonably setting the angle between the reflecting surface and the incident surface in the refractive and reflective element, not only can the LZ direction not be too large, but the size of LY can also be controlled, achieving the balance between the LY and LZ directions, which is beneficial to the miniaturization of the lens module to better match the space configuration requirements of the thin and light electronic device.

[0062] In some embodiments, the angle θ between the first optical axis and the second optical axis satisfies: 56° < θ < 66°. Further, the angle θ between the first optical axis and the second optical axis satisfies: 58° < θ < 63°. By satisfying the above conditions and reasonably setting the angle between the first and second optical axes, total internal reflection can occur on the second reflecting surface after the light ray is incident on the first reflecting surface of the refractive-reflective element and then reaches the second reflecting surface. At the same time, the refractive-reflective element has good processability and the volume of the refractive-reflective element is reduced. The angle between the first and second optical axes can be determined according to the spatial configuration and the refractive index of the material of the selected refractive-reflective element. When this angle is determined, the angles of the planes where the respective surfaces of the refractive-reflective element (such as the light incident surface, the first, second, and third reflecting surfaces, and the light exit surface) are located are immediately determined and can be set according to requirements in practical applications. Specifically, if the angles between the first and second optical axes and between the third and fourth optical axes are both θ, then the angle between the second and third optical axes is 2θ; since the light ray is reflected on the first and third reflecting surfaces and total internal reflection occurs on the second reflecting surface, it can be further obtained that the angle between the plane where the first reflecting surface is located and the plane where the second reflecting surface is located is θ / 2, the angle between the plane where the second reflecting surface is located and the plane where the third reflecting surface is located is also θ / 2, and the angle between the plane where the first reflecting surface is located and the plane where the third reflecting surface is located is (180° - θ). It should be noted that on the basis of not affecting the reflection of the light rays in the marginal field of view, the prism angle formed by the first and third reflecting surfaces and the plane where the second reflecting surface is located in the refractive-reflective element can be cut, or the prism angle formed by the first and third reflecting surfaces can be cut. There is no light refraction in the cut prism angle, which will not affect the overall light ray turning effect, but can minimize the size of the refractive-reflective element, thereby reducing the overall size of the optical lens.

[0063] In some embodiments, the effective aperture DM11 of the first lens and the true image height IH corresponding to the maximum field angle of the optical lens satisfy: 0.9 < DM11 / IH < 1.1. By satisfying the above conditions, the lens can have a larger light incident aperture, ensuring a larger light flux of the lens, facilitating the realization of the large aperture performance, and at the same time can match a larger imaging target surface to achieve high-pixel imaging of the lens.

[0064] In some embodiments, the focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: 0.35 < f1 / f < 3.3. By satisfying the above conditions and setting the first lens to have a large positive refractive power, the first lens can converge as many incident light rays as possible, and while compressing the total length of the optical lens, it will not introduce overly serious aberrations.

[0065] In some embodiments, the edge thickness ET1 of the first lens and the central thickness CT1 of the first lens satisfy: 0.32 < ET1 / CT1 < 0.55. Meeting the above conditions, by adjusting the edge thickness ratio of the first lens, it helps to achieve a balance between reducing manufacturing difficulty and reducing stray light within the lens.

[0066] In some embodiments, the focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: -8.5 < f3 / f < -0.3. Meeting the above conditions, the incident light can be diverged to a certain extent, causing the peripheral light and the central light to turn upwards and reach a higher imaging position.

[0067] In some embodiments, the focal length f1 of the first lens and the combined focal length f234 of the second, third, and fourth lenses satisfy: -1 < f1 / f234 < -0.1. Meeting the above conditions, by reasonably setting the combined focal length relationship of the front and rear lens groups, on the one hand, it is beneficial to control the height of the incident light entering the system and achieve large target surface imaging of the lens, and on the other hand, it can reduce the exit angle of the chief ray, making the lens have a smaller CRA, which is beneficial to improving the matching degree between the lens and the ultra-long focal length SENESOR (imaging chip) and improving imaging clarity.

[0068] In some embodiments, the focal length f1 of the first lens and the focal length f3 of the third lens satisfy: -2 < f1 / f3 < -0.1. Meeting the above conditions, the incident light can be diverged to a certain extent, thereby effectively increasing the height of the light entering the imaging surface and better achieving large target surface imaging of the lens.

[0069] In some embodiments, the true image height IH corresponding to the maximum field angle of the optical lens and the F-number Fno of the optical lens satisfy: 3.2 mm < IH / Fno < 4.2 mm. Meeting the above conditions, by controlling the image height and F-number of the lens, while ensuring that the lens has a large image surface, it has a larger light transmission amount, which is beneficial to the implementation of optical anti-shake technology in the periscope telephoto module and improves the imaging quality of the optical lens.

[0070] In some embodiments, the thickness LG of the catadioptric element equivalent to a flat glass satisfies: 18 mm < LG < 22 mm. LG is the sum of the lengths of the first, second, third, and fourth optical axes within the catadioptric element. And the thickness LG of the catadioptric element equivalent to a flat glass and the distance TTL from the object side surface of the first lens to the imaging surface along the first, second, third, and fourth optical axes satisfy: 0.6 < LG / TTL < 0.7. Meeting the above conditions, by reasonably planning the propagation path length of the folded light path in the catadioptric element, while meeting the long focal length design of the optical lens, it can effectively compress the occupied space of the catadioptric element and meet the product requirements of being thin and light.

[0071] In some embodiments, the combined focal length f234 of the second lens, the third lens, and the fourth lens and the effective focal length f of the optical lens satisfy: -7 < f234 / f < 2. Meeting the above conditions, by reasonably setting the proportion of the combined focal length of the latter three lenses, it is beneficial to control the height of the incident light entering the catadioptric element, beneficial to reducing the volume of the catadioptric element, and further achieving the thinning and lightening of the lens. Preferably, -7 < f234 / f < -0.5.

[0072] In some embodiments, the refractive index Nd5 of the catadioptric element satisfies: 1.5 < Nd5 < 1.85. Meeting the above conditions, by setting the catadioptric element to have an appropriate refractive index, there can be a sufficient difference in the refractive index values between the catadioptric element and air, so as to adjust the critical angle to ensure total internal reflection of light on the second reflection surface of the catadioptric element.

[0073] In some embodiments, the back focal length BFL of the optical lens and the effective focal length f of the optical lens satisfy: 0.03 < BFL / f < 0.13. Meeting the above conditions, the lens can have an appropriate back focus, ensuring the compatibility between the lens and the body while making the structure of the lens more compact.

[0074] In some embodiments, the curvature radius R3 of the object side surface of the second lens and the curvature radius R4 of the image side surface of the second lens satisfy: 0.2 < R3 / R4 < 1.5. Meeting the above conditions, by reasonably setting the surface shape of the second lens, it helps to adjust the optical path to improve the image quality.

[0075] In some embodiments, the curvature radius R1 of the object side surface of the first lens and the effective focal length f of the optical lens satisfy: 0.2 < R1 / f < 0.7. Meeting the above conditions, by reasonably setting the surface shape of the first lens, the optical path control ability of the light incident surface of the first lens can be strengthened, achieving a greater degree of convergence of the incident light and reducing the difficulty of subsequent aberration correction.

[0076] In some embodiments, the distance TL on the first optical axis from the object side surface of the first lens to the incident surface of the catadioptric element and the thickness LG of the catadioptric element equivalent to a flat glass satisfy: 0.35 < TL / LG < 0.5. LG is the sum of the lengths of the first, second, third, and fourth optical axes in the catadioptric element. Meeting the above conditions, by setting a smaller lens group length and a longer folded optical path length, it is beneficial to the folding of the optical path of the optical lens and better achieves the thinning and lightening of the lens.

[0077] In some embodiments, the principal ray angle of incidence CRA at the maximum image height of the optical lens satisfies: 14.5° < CRA < 18°. Meeting the above conditions, the optical lens can have a smaller CRA (not greater than 18°), and a smaller CRA is beneficial to improving the matching degree between the lens and the ultra-long focal length SENSOR (imaging chip) and improving the imaging clarity.

[0078] In some embodiments, the distance LY perpendicular to the first optical axis between the intersection point of the object side surface of the first lens on the first optical axis and the intersection point of the imaging surface on the fourth optical axis satisfies: 10 mm < LY < 13.5 mm. LY is the linear distance in the perpendicular direction between the first optical axis and the fourth optical axis. The parameters LY and LZ can be referred to the markings in the schematic diagram. Figure 1 Controlling the value of the optical lens in the LY direction within a certain range is beneficial to the spatial arrangement of the SENSOR and is also beneficial to the miniaturization of the lens volume.

[0079] In some embodiments, the maximum displacement amount LZ of the optical path traveling from the object side surface of the first lens to the imaging surface parallel to the first optical axis satisfies: 13 mm < LZ < 15 mm. Meeting the above conditions can adjust the length of the folded optical system in the first optical axis direction, that is, reduce the size of the lens in the thickness direction of the electronic device on which it is mounted, which helps to make the folded optical system thinner and achieve a wider range of applications.

[0080] In some embodiments, the optical lens satisfies the conditional formula: 24 mm < f < 26 mm, 20° < FOV < 24°, 27.5 mm < TTL < 32 mm, 2.5 < Fno < 2.65, 8.8 mm < IH < 11 mm; where 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 traveled along the first optical axis, the second optical axis, the third optical axis and the fourth optical axis from the object side surface of the first lens to the imaging surface, Fno represents the aperture value of the optical lens, and IH represents the true image height corresponding to the maximum field of view angle of the optical lens. The optical lens provided by the embodiments of the present invention at least has the characteristics of miniaturization, long focal length (super telephoto), large aperture, large image plane, etc.

[0081] In some embodiments, the materials of the lenses and the catadioptric elements in the optical lens provided by the present invention can be glass or plastic. When the materials of the lenses and the catadioptric elements are plastic, the production cost can be effectively reduced. On the other hand, when the materials of the lenses and the catadioptric elements are glass, the geometric chromatic aberration of the optical system can be effectively corrected by the low dispersion characteristics of the glass itself. The first lens, the fourth lens, and the catadioptric elements in the optical lens provided by the present invention can adopt glass or plastic materials; the second lens and the third lens can adopt plastic materials, which not only enable the lens to have excellent imaging performance, but also make the structure of the lens relatively compact, and can better achieve the balance between the miniaturization of the lens and high image quality.

[0082] In some embodiments, the first, second, third, and fourth lenses may be spherical or aspherical lenses. Compared to spherical structures, aspherical structures can effectively reduce the aberrations of the optical system, thereby reducing the number and size of lenses, and further achieving lens miniaturization. More specifically, the first, second, third, and fourth lenses of the present invention may all be aspherical lenses, which can effectively reduce the aberrations of the optical lens, thereby reducing the number and size of lenses, and further achieving lens miniaturization.

[0083] In various embodiments of the present invention, when the lens is an aspheric lens, the surface shape of the aspheric lens satisfies the following equation:

[0084] ;

[0085] Among them, z is the distance vector height from the vertex of the aspheric surface when the aspheric surface is at a height of h along the optical axis, c is the paraxial curvature of the surface, k is the quadratic surface coefficient, and A 2i is the 2i-order aspheric surface coefficient.

[0086] The present invention is further illustrated below with reference to several embodiments. In each embodiment, the thickness, radius of curvature, and material selection of each lens in the optical lens vary; for details, please refer to the parameter tables of each embodiment. The following embodiments are merely preferred embodiments of the present invention, but the present invention is not limited thereto. Any other changes, substitutions, combinations, or simplifications that do not deviate from the novelties of the present invention shall be considered equivalent replacements and are included within the scope of protection of the present invention.

[0087] Example 1

[0088] See also Figure 1 , Figure 1 This is a schematic structural diagram of the optical lens 100 provided in Example 1 of the present invention. The optical lens includes, in order from the object side to the imaging surface along the light transmission direction: an aperture ST, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a folding element Pr and a filter G1.

[0089] The first lens L1 has positive refractive power, its object-side surface S1 is convex, and its image-side surface S2 is convex;

[0090] The second lens L2 has negative refractive power, its object-side surface S3 is convex, and its image-side surface S4 is concave;

[0091] The third lens L3 has negative refractive power, its object-side surface S5 is concave, and its image-side surface S6 is convex;

[0092] The fourth lens L4 has negative refractive power, its object-side surface S7 is convex near the optical axis, and its image-side surface S8 is concave;

[0093] The folding and reflecting element Pr includes a light incident surface S9, a first reflecting surface S10, a second reflecting surface S11, a third reflecting surface S12 and a light emitting surface S13, all of which are planes. The light incident surface S9, the second reflecting surface S11 and the light emitting surface S13 are substantially the same plane.

[0094] The light path follows the first optical axis OA1 through the first lens L1, the second lens L2, the third lens L3, and the fourth lens L4, entering the refractive index element Pr. The light then passes through the incident surface S9 onto the first reflective surface S10, where it is reflected by the second reflective surface S11. It is then totally reflected by the third reflective surface S12, and then reflected by the light exit surface S13. The light then passes through the filter G1 and reaches the imaging plane. The first reflective surface S10 redirects the light path from the first optical axis OA1 to the second optical axis OA2. The second reflective surface S11 redirects the light path from the second optical axis OA2 to the third optical axis OA3. The third reflective surface S12 redirects the light path from the third optical axis OA3 to the fourth optical axis OA4 (the fourth optical axis OA4 is perpendicular to the imaging plane). The light path undergoes three deflections within the refractive index element Pr, with total internal reflection occurring at the second reflective surface S11. Reflection occurs on the first and third reflective surfaces S10 and S12, so these surfaces are either coated or mirrored.

[0095] Specifically, if Figure 1 As shown, the angle θ between the first optical axis OA1 and the second optical axis OA2 is 60°; the angle between the third optical axis OA3 and the fourth optical axis OA4 is the same as the angle between the first optical axis OA1 and the second optical axis OA2, which is also 60°; the angle between the second optical axis OA2 and the third optical axis OA3 is twice the angle between the first optical axis OA1 and the second optical axis OA2, that is, 120°; the first optical axis OA1 and the fourth optical axis OA4 are parallel. LY represents the distance perpendicular to the first optical axis between the intersection of the object side surface of the first lens on the first optical axis and the intersection of the imaging plane on the fourth optical axis, that is, the shortest distance between the first and fourth optical axes, and LY is 10.722mm. LZ represents the maximum displacement of the light path from the object side surface of the first lens to the imaging plane parallel to the first optical axis, and LZ is 13.854mm.

[0096] In this embodiment, the angle θ between the first and second optical axes can be determined based on the spatial configuration and the refractive index of the material of the selected reflective element Pr. Once the angle θ is determined, the angles of the planes in which the various surfaces of the reflective element Pr (such as the light incident surface S9, the first, second, and third reflective surfaces S10, S11, and S12, and the light exit surface S13) are located are also determined. In actual applications, this angle can be set as needed. Specifically, if the angle between the first and second optical axes and the angle θ between the third and fourth optical axes are both 60°, then the angle between the second and third optical axes is 2θ=120°; since the light is reflected on the first reflecting surface S10 and the third reflecting surface S12 and is totally reflected on the second reflecting surface S11, it can be further concluded that the angle between the plane where the first reflecting surface S10 is located and the plane where the second reflecting surface S11 is located is θ / 2=30°, the angle between the plane where the second reflecting surface S11 is located and the plane where the third reflecting surface S12 is located is θ / 2=30°, and the angle between the plane where the first reflecting surface S10 is located and the plane where the third reflecting surface S12 is located is (180°-θ)=120°. It should be noted that, without affecting the reflection of the edge field of view light, the prism corners formed by the first and third reflecting surfaces and the plane where the second reflecting surface is located in the refracting element can be cut, and the prism corners formed by the planes where the first and third reflecting surfaces are located can also be cut. The cut prism corners ( Figure 1 There is no light reflection in the prism corners (shown by the dotted line in the middle), which will not affect the overall light turning effect, but can minimize the size of the reflective element, thereby reducing the overall size of the optical lens.

[0097] The first lens L1 is a glass aspheric lens; the second lens L2, the third lens L3, and the fourth lens L4 are all plastic aspheric lenses; the reflective element Pr can be designed as a polygonal folding prism and can be made of plastic.

[0098] The relevant parameters of each lens in the optical lens 100 in Example 1 are shown in Table 1-1.

[0099] Table 1-1

[0100]

[0101] The surface parameters of the aspheric lens of the optical lens 100 in Example 1 are shown in Table 1-2.

[0102] Table 1-2

[0103]

[0104] In this embodiment, the astigmatism curve, the magnification chromatic aberration curve, and the axial aberration curve of the optical lens 100 are respectively as follows: Figure 2 、 Figure 3 、 Figure 4 shown.

[0105] Figure 2 The astigmatism curve of Example 1 is shown, which shows the astigmatism of light in the meridional and sagittal image planes. The horizontal axis represents the offset (unit: mm), and the vertical axis represents the image height (unit: °). As can be seen from the figure, the astigmatism of the meridional and sagittal image planes is controlled within a range of -0.05mm to 0.1mm, indicating that the optical lens 100 can effectively correct astigmatism.

[0106] Figure 3 The following graph shows the magnification chromatic aberration curve for Example 1, which represents the chromatic aberration of each wavelength relative to the center wavelength (550 nm) at different image heights on the imaging surface. The horizontal axis represents the chromatic aberration value of each wavelength relative to the center wavelength (unit: μm), and the vertical axis represents the normalized field of view angle. As can be seen from the graph, the chromatic aberration between the longest and shortest wavelengths is controlled within ±1 μm, demonstrating that the optical lens 100 is capable of excellent chromatic aberration correction.

[0107] 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 plane, with the horizontal axis representing the axial aberration value (unit: mm) and the vertical axis representing the normalized pupil radius. As can be seen from the figure, the offset of the axial aberration is controlled within ±0.04mm, indicating that the optical lens 100 is able to correct the axial aberration well.

[0108] Example 2

[0109] See also Figure 5 , which is a schematic structural diagram of an optical lens 200 provided in Example 2 of the present invention. This embodiment is substantially the same as Example 1, and the light deflection and transmission path are also substantially the same. The main differences are: the reflective element Pr can be made of glass; the optical parameters such as the curvature radius of each lens surface and the lens thickness are different; in this embodiment, the angle θ between the first optical axis OA1 and the second optical axis OA2 is 60°; the angle between the third optical axis OA3 and the fourth optical axis OA4 is the same as the angle between the first optical axis OA1 and the second optical axis OA2, also 60°; the angle between the second optical axis OA2 and the third optical axis OA3 is twice the angle between the first optical axis OA1 and the second optical axis OA2, that is, 120°; and the first optical axis OA1 and the fourth optical axis OA4 are parallel. Wherein, LY is 11.556 mm, and LZ is 14.135 mm.

[0110] The relevant parameters of each lens in the optical lens 200 in Example 2 are shown in Table 2-1.

[0111] Table 2-1

[0112]

[0113] The surface parameters of the aspheric lens of the optical lens 200 in Example 2 are shown in Table 2-2.

[0114] Table 2-2

[0115]

[0116] In this embodiment, the astigmatism curve, the magnification chromatic aberration curve, and the axial aberration curve of the optical lens 200 are respectively as follows: Figure 6 、 Figure 7 、 Figure 8 shown.

[0117] from Figure 6 It can be seen from the figure that the astigmatism of the meridional image plane and the sagittal image plane is controlled within a range of -0.1 mm to 0, indicating that the optical lens 200 can correct the astigmatism well.

[0118] from Figure 7 As can be seen from the figure, the chromatic aberration between the longest wavelength and the shortest wavelength is controlled within ±1.5 μm, indicating that the optical lens 200 can correct chromatic aberration very well.

[0119] from Figure 8 It can be seen from the figure that the offset of the axial aberration is controlled within ±0.04 mm, indicating that the optical lens 200 can correct the axial aberration well.

[0120] Example 3

[0121] See also Figure 9 , shown is a schematic structural diagram of an optical lens 300 provided in Example 3 of the present invention. This embodiment is substantially the same as Example 1, and the light deflection and transmission path are also substantially the same. The main differences are: the image-side surface S2 of the first lens L1 is concave near the optical axis; the optical parameters such as the radius of curvature and lens thickness of each lens surface are different; in this embodiment, the angle θ between the first optical axis OA1 and the second optical axis OA2 is 60°; the angle between the third optical axis OA3 and the fourth optical axis OA4 is the same as the angle between the first optical axis OA1 and the second optical axis OA2, also 60°; the angle between the second optical axis OA2 and the third optical axis OA3 is twice the angle between the first optical axis OA1 and the second optical axis OA2, that is, 120°; and the first optical axis OA1 and the fourth optical axis OA4 are parallel. Wherein, LY is 10.727 mm, and LZ is 13.992 mm.

[0122] The relevant parameters of each lens in the optical lens 300 in Example 3 are shown in Table 3-1.

[0123] Table 3-1

[0124]

[0125] The surface parameters of the aspheric lens of the optical lens 300 in Example 3 are shown in Table 3-2.

[0126] Table 3-2

[0127]

[0128] In this embodiment, the astigmatism curve, the magnification chromatic aberration curve, and the axial aberration curve of the optical lens 300 are respectively as follows: Figure 10 、 Figure 11 、 Figure 12 shown.

[0129] from Figure 10 It can be seen from the figure that the astigmatism of the meridional image plane and the sagittal image plane is controlled within ±0.05 mm, indicating that the optical lens 300 can correct the astigmatism well.

[0130] from Figure 11 As can be seen from the figure, the chromatic aberration between the longest wavelength and the shortest wavelength is controlled within ±1.5 μm, indicating that the optical lens 300 can correct chromatic aberration very well.

[0131] from Figure 12 It can be seen from the figure that the offset of the axial aberration is controlled within ±0.04 mm, indicating that the optical lens 300 can correct the axial aberration well.

[0132] Example 4

[0133] See also Figure 13 , which is a schematic structural diagram of an optical lens 400 provided in Example 4 of the present invention. This embodiment is substantially the same as Example 1, and the light turning and transmission paths are also substantially the same. The main differences are: the first lens L1 is a plastic aspheric lens; the fourth lens L4 is a glass aspheric lens; the reflective element Pr can be made of glass; the second lens L2 has positive focal power; the fourth lens L4 has positive focal power; the image side surface S2 of the first lens L1 is concave; the object side surface S5 of the third lens L3 is convex; the third lens L3 The image-side surface S6 is concave; the optical parameters such as the radius of curvature and lens thickness of each lens surface vary. In this embodiment, the angle θ between the first optical axis OA1 and the second optical axis OA2 is 60°; the angle between the third optical axis OA3 and the fourth optical axis OA4 is the same as the angle between the first optical axis OA1 and the second optical axis OA2, also 60°; the angle between the second optical axis OA2 and the third optical axis OA3 is twice the angle between the first optical axis OA1 and the second optical axis OA2, that is, 120°; the first optical axis OA1 and the fourth optical axis OA4 are parallel. LY is 11.056 mm, and LZ is 13.820 mm.

[0134] The relevant parameters of each lens in the optical lens 400 in Example 4 are shown in Table 4-1.

[0135] Table 4-1

[0136]

[0137] The surface parameters of the aspheric lens of the optical lens 400 in Example 4 are shown in Table 4-2.

[0138] Table 4-2

[0139]

[0140] In this embodiment, the astigmatism curve, the magnification chromatic aberration curve, and the axial aberration curve of the optical lens 400 are respectively as follows: Figure 14 、 Figure 15 、 Figure 16 shown.

[0141] from Figure 14 It can be seen from the figure that the astigmatism of the meridional image plane and the sagittal image plane is controlled within ±0.05 mm, indicating that the optical lens 400 can correct the astigmatism well.

[0142] from Figure 15 It can be seen that the chromatic aberration between the longest wavelength and the shortest wavelength is controlled within ±1.5 μm, indicating that the optical lens 400 can correct chromatic aberration very well.

[0143] from Figure 16 It can be seen that the offset of the axial aberration is controlled within ±0.04 mm, indicating that the optical lens 400 can correct the axial aberration well.

[0144] Example 5

[0145] See also Figure 17 , shown is a structural schematic diagram of an optical lens 500 provided in Example 5 of the present invention. This embodiment is substantially the same as Example 1, and the turning and transmission paths of the light are also substantially the same. The main differences are: the reflective element Pr can be made of glass; the second lens L2 has positive focal power; the image-side surface S2 of the first lens L1 is concave; the object-side surface S5 of the third lens L3 is convex; the image-side surface S6 of the third lens L3 is concave; the optical parameters such as the curvature radius and lens thickness of each lens surface are different; in this embodiment, the angle θ between the first optical axis OA1 and the second optical axis OA2 is 60°; the angle between the third optical axis OA3 and the fourth optical axis OA4 is the same as the angle between the first optical axis OA1 and the second optical axis OA2, which is also 60°; the angle between the second optical axis OA2 and the third optical axis OA3 is twice the angle between the first optical axis OA1 and the second optical axis OA2, that is, 120°; the first optical axis OA1 and the fourth optical axis OA4 are parallel. Among them, LY is 11.694mm and LZ is 13.832mm.

[0146] The relevant parameters of each lens in the optical lens 500 in Example 5 are shown in Table 5-1.

[0147] Table 5-1

[0148]

[0149] The surface parameters of the aspheric lens of the optical lens 500 in Example 5 are shown in Table 5-2.

[0150] Table 5-2

[0151]

[0152] In this embodiment, the astigmatism curve, the magnification chromatic aberration curve, and the axial aberration curve of the optical lens 500 are respectively as follows: Figure 18 、 Figure 19 、 Figure 20 shown.

[0153] from Figure 18 It can be seen from the figure that the astigmatism of the meridional image plane and the sagittal image plane is controlled within a range of -0.15mm to 0, indicating that the optical lens 500 can correct the astigmatism well.

[0154] from Figure 19 As can be seen from the figure, the chromatic aberration between the longest wavelength and the shortest wavelength is controlled within ±1 μm, indicating that the optical lens 500 can correct chromatic aberration very well.

[0155] from Figure 20 It can be seen that the offset of the axial aberration is controlled within ±0.04 mm, indicating that the optical lens 500 can correct the axial aberration well.

[0156] Example 6

[0157] See also Figure 21, which is a schematic diagram of the structure of an optical lens 600 provided in Example 6 of the present invention. This embodiment is substantially the same as Example 1, and the turning and transmission paths of light are also substantially the same. The main differences are: the reflective element Pr can be made of glass; the second lens L2 has positive focal power; the fourth lens L4 has positive focal power; the image-side surface S2 of the first lens L1 is concave; the object-side surface S5 of the third lens L3 is convex; the image-side surface S6 of the third lens L3 is concave; and the image-side surface S8 of the fourth lens L4 is convex. The lens surfaces have different optical parameters, such as the radius of curvature and lens thickness. In this embodiment, the angle θ between the first optical axis OA1 and the second optical axis OA2 is 62°. The angle between the third optical axis OA3 and the fourth optical axis OA4 is the same as the angle between the first optical axis OA1 and the second optical axis OA2, also 62°. The angle between the second optical axis OA2 and the third optical axis OA3 is twice the angle between the first optical axis OA1 and the second optical axis OA2, that is, 124°. The first optical axis OA1 and the fourth optical axis OA4 are parallel. LY is 12.962 mm, and LZ is 14.339 mm.

[0158] The relevant parameters of each lens in the optical lens 600 in Example 6 are shown in Table 6-1.

[0159] Table 6-1

[0160]

[0161] The surface parameters of the aspheric lens of the optical lens 600 in Example 6 are shown in Table 6-2.

[0162] Table 6-2

[0163]

[0164] In this embodiment, the astigmatism curve, the magnification chromatic aberration curve, and the axial aberration curve of the optical lens 600 are respectively as follows: Figure 22 、 Figure 23 、 Figure 24 shown.

[0165] from Figure 22 It can be seen from the figure that the astigmatism of the meridional image plane and the sagittal image plane is controlled within -0.1mm~0, indicating that the optical lens 600 can correct the astigmatism well.

[0166] from Figure 23 As can be seen from the figure, the chromatic aberration between the longest wavelength and the shortest wavelength is controlled within ±1.5 μm, indicating that the optical lens 600 can correct chromatic aberration very well.

[0167] from Figure 24 It can be seen that the offset of the axial aberration is controlled within ±0.04 mm, indicating that the optical lens 600 can correct the axial aberration well.

[0168] Example 7

[0169] See also Figure 25 , shown is a structural schematic diagram of an optical lens 700 provided in Example 7 of the present invention. This embodiment is substantially the same as Example 1, and the turning and transmission paths of light are also substantially the same. The main differences are: the reflective element Pr can be made of glass; the second lens element L2 has positive focal power; the fourth lens element L4 has positive focal power; the image-side surface S2 of the first lens element L1 is concave; the object-side surface S5 of the third lens element L3 is convex; and the image-side surface S6 of the third lens element L3 is concave; optical parameters such as the curvature radius and lens thickness of each lens surface are different; in this embodiment, the angle θ between the first optical axis OA1 and the second optical axis OA2 is 60°; the angle between the third optical axis OA3 and the fourth optical axis OA4 is the same as the angle between the first optical axis OA1 and the second optical axis OA2, which is also 60°; the angle between the second optical axis OA2 and the third optical axis OA3 is twice the angle between the first optical axis OA1 and the second optical axis OA2, that is, 120°; and the first optical axis OA1 and the fourth optical axis OA4 are parallel. Among them, LY is 11.845mm and LZ is 13.515mm.

[0170] The relevant parameters of each lens in the optical lens 700 in Example 7 are shown in Table 7-1.

[0171] Table 7-1

[0172]

[0173] The surface parameters of the aspheric lens of the optical lens 700 in Example 7 are shown in Table 7-2.

[0174] Table 7-2

[0175]

[0176] In this embodiment, the astigmatism curve, the magnification chromatic aberration curve, and the axial aberration curve of the optical lens 700 are respectively as follows: Figure 26 、 Figure 27 、 Figure 28 shown.

[0177] from Figure 26 It can be seen from the figure that the astigmatism of the meridional image plane and the sagittal image plane is controlled within ±0.05 mm, indicating that the optical lens 700 can correct the astigmatism well.

[0178] from Figure 27 As can be seen from the figure, the chromatic aberration between the longest wavelength and the shortest wavelength is controlled within ±1 μm, indicating that the optical lens 700 can correct chromatic aberration very well.

[0179] from Figure 28It can be seen that the offset of the axial aberration is controlled within ±0.04 mm, indicating that the optical lens 700 can correct the axial aberration well.

[0180] Please refer to Table 8, 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 surface of the first lens to the imaging plane along the first optical axis, the second optical axis, the third optical axis, and the fourth optical axis, the distance TL from the object side surface of the first lens to the light incident surface of the refracting element on the first optical axis, 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 of the optical lens, the entrance pupil diameter of the light lens, the back focal length BFL of the optical lens, the principal ray incident angle CRA at the maximum image height, the angle θ between the first optical axis and the second optical axis, the distance LY perpendicular to the first optical axis between the intersection point of the object side surface of the first lens on the first optical axis and the intersection point of the imaging plane on the fourth optical axis, the maximum displacement LZ of the light path from the object side surface of the first lens to the imaging plane parallel to the first optical axis, the thickness LG of the refracting element equivalent to flat glass, and the numerical value corresponding to each conditional expression in each embodiment.

[0181] Table 8

[0182]

[0183] In summary of the above embodiments, the optical lens provided by the present invention has the following advantages:

[0184] The optical lens provided by the present invention, through the arrangement of four conventional lenses and one catadioptric element, can achieve excellent periscope-style telephoto photography, offering one or more advantages such as a large image surface, a large aperture, and high-quality imaging, significantly enhancing the user experience. Furthermore, because the optical path undergoes three deflections within the catadioptric element, the volume of the folded optical system is greatly compressed. While achieving excellent telephoto photography, the overall length of the optical lens is significantly reduced, effectively achieving miniaturization.

[0185] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0186] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. An optical lens, characterized in that: It consists of four lenses and one catadioptric element, and successively includes from the object side to the imaging surface along the light transmission direction: The first lens with positive optical power, whose object side surface is convex; The second lens with optical power, whose object side surface is convex and whose image side surface is concave; The third lens with negative optical power; The fourth lens with optical power, whose object side surface is convex; The catadioptric element includes a light incident surface, a first reflection surface, a second reflection surface, a third reflection surface and a light exit surface which are all flat surfaces. Among them, the light incident surface, the second reflection surface and the light exit surface are substantially the same plane; The optical axis of the optical lens includes a first optical axis, a second optical axis, a third optical axis and a fourth optical axis. The light path passes through the first lens, the second lens, the third lens, the fourth lens along the first optical axis and enters the catadioptric element, passes through the light incident surface to the first reflection surface, is reflected to the second reflection surface, then is totally reflected to the third reflection surface, and then is reflected to the light exit surface and exits to the imaging surface; the first reflection surface turns the light path from the first optical axis to the second optical axis, the second reflection surface turns the light path from the second optical axis to the third optical axis, and the third reflection surface turns the light path from the third optical axis to the fourth optical axis; the fourth optical axis is perpendicular to the imaging surface; the first optical axis and the fourth optical axis are parallel; Among them, the true image height IH corresponding to the maximum field angle of the optical lens and the effective focal length f of the optical lens satisfy: 4 < ((43.26 / IH) × f) / 23 < 5.

5.

2. The optical lens according to claim 1, wherein: The distance LY perpendicular to the first optical axis between the intersection point of the object side surface of the first lens on the first optical axis and the intersection point of the imaging surface on the fourth optical axis and the maximum displacement amount LZ parallel to the first optical axis of the light path from the object side surface of the first lens to the imaging surface satisfy: 0.7 < LY / LZ < 0.

95.

3. The optical lens according to claim 1, wherein: The distance LY perpendicular to the first optical axis between the intersection point of the object side surface of the first lens on the first optical axis and the intersection point of the imaging surface on the fourth optical axis and the distance TTL passed along the first optical axis, the second optical axis, the third optical axis and the fourth optical axis from the object side surface of the first lens to the imaging surface satisfy: 0.33 < LY / TTL < 0.45; the maximum displacement amount LZ parallel to the first optical axis of the light path from the object side surface of the first lens to the imaging surface and the distance TTL passed along the first optical axis, the second optical axis, the third optical axis and the fourth optical axis from the object side surface of the first lens to the imaging surface satisfy: 0.42 < LZ / TTL < 0.

52.

4. The optical lens according to claim 1, wherein: The included angle θ between the first optical axis and the second optical axis satisfies: 56° < θ < 66°.

5. The optical lens according to claim 1, wherein: The effective aperture DM11 of the first lens and the true image height IH corresponding to the maximum field angle of the optical lens satisfy: 0.9 < DM11 / IH < 1.

1.

6. The optical lens according to claim 1, wherein: The focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: 0.35 < f1 / f < 3.3; the edge thickness ET1 of the first lens and the center thickness CT1 of the first lens satisfy: 0.32 < ET1 / CT1 < 0.

55.

7. The optical lens according to claim 1, wherein: The focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: -8.5 < f3 / f < -0.

3.

8. The optical lens according to claim 1, wherein: The focal length f1 of the first lens and the combined focal length f234 of the second lens, the third lens and the fourth lens satisfy: -1 < f1 / f234 < -0.

1.

9. The optical lens according to claim 1, wherein: The focal length f1 of the first lens and the focal length f3 of the third lens satisfy: -2 < f1 / f3 < -0.

1.

10. The optical lens according to claim 1, wherein: The true image height IH corresponding to the maximum field angle of the optical lens and the aperture value Fno of the optical lens satisfy: 3.2 mm < IH / Fno < 4.2 mm.

11. The optical lens according to claim 1, wherein: The thickness LG of the refractive-reflective element equivalent to a flat glass and the distance TTL passed along the first optical axis, the second optical axis, the third optical axis and the fourth optical axis from the object side of the first lens to the imaging surface satisfy: 0.6 < LG / TTL < 0.7.

Images